Locomotive CAD Drawings by Euan Cameron EXPANDED CAPTIONS

North British Railway Locomotive CAD Drawings by Euan Cameron EXPANDED CAPTIONS

This document contains expanded captions to the NBR locomotive drawings produced by Euan Cameron. Please use the bookmarks to navigate to each caption page.

Revised 23 March 2007

nbr038_1869_rebuild_Drummond_livery_dwg http://euankcameron.fotopic.net/p 38740316.html

Engine wheelbase 7’ 6” + 7’ 10”: wheels 3’ 8” + 6’ 0”

In 1869 Cowlairs works turned out two nominal “rebuilds” of R. & W. Hawthorn singles that comprised a great deal of material from other sources. Little is known about the first, No. 37, although it had the same wheelbase as its more famous sister locomotive No. 38. 38 clearly shared a large number of design features with William Steel Brown’s 2-4-0s of the Edinburgh and Glasgow Railway from 1862, later the N. B. R. 351 class (see below for Nos. 351-6). It had the same double frames with outside cranks, the unusual coupled wheelbase of 7’ 10”, the abnormally long eccentric rods to the valve gear, and the most unusual feature of the reversing lever being squeezed between the driving wheels and the outer splasher plates. However, the outside frames followed a different pattern and were spaced slightly differently from the 351 class. In this case the locomotive was left-hand drive, whereas the E & G engines were right-hand drive.

This drawing is based on the General Arrangement of the rebuild, as below, with the boiler and superstructure inferred from the fine photograph taken by A. E. Lockyer at Cowlairs in the 1890s shortly before the rebuilding and from “working back” from the GA drawing. The tender as shown here derived originally from a Stephenson and Co. 0-6-0 of the early 1860s, much rebuilt by Drummond, and was towed behind No. 38 before its 1893 reconstruction and for some years afterwards. Several older engines had tenders based on the Stephenson goods engine tender frames. Its dimensions have been estimated based on evidence from the N. B. R. diagram book. nbr038_Holmes_rebuild_dwg http://euankcameron.fotopic.net/p25232621.html

Engine wheelbase 7’ 6” + 7’ 10”: wheels 3’ 8” + 6’ 1”

In 1893 Holmes evidently considered 38 to be worth a separate rebuild closely similar to that of the 351 class, sharing the same boiler but with other design details worked out sep- arately. The result was an extremely robust and powerful 2-4-0 which achieved some level of renown on Clyde coast commuter trains. It also worked elsewhere over much of the N. B. R. system.

The drawing here is based closely on the Cowlairs Works General Arrangement prepared for the 1893 rebuild (No. 1216B). However, the Cowlairs drawing gives only limited information about the outside frames, and a degree of conjecture is involved here. Some time after rebuilding 38 was equipped with a standard Wheatley 1,800 gallon six-wheeled tender, despite the mismatch between the running-plate heights of the locomotive and tender, and worked with this appendage for many years. nbr039_rebuild_Holmes_livery_detailed_c_dwg http://euankcameron.fotopic.net/p39482915.html

Engine wheelbase 7’ 0” + 7’ 3”: wheels 5’ 1¾”

Thomas Wheatley’s 0-6-0ST saddletanks form a most complicated and confusing series of locomotives, with at least six distinct classes and variations within several of them as to details. No. 39 was an example of the most numerous class of engines with 5’ 1¾” driving wheels, built between 1871 and 1873. The engines were numbered 39, 51, 62, 113, 136, 149, 221-2, 229-30, 255-6, 261, 405-6 although not built in numerical order. Most took the numbers of earlier engines that had been scrapped: only 405-6 were charged to capital.

In their original form these saddletanks echoed John Ramsbottom’s designs for the LNWR, with plain inside frames, saddle tanks over the boiler barrel stopping short at the rear of the smokebox, and weatherboards fore and aft with no cab roof.

Holmes’s rebuildings gave the engines new tanks and platework, with a softer line than before but the same basic design principles. The new boilers had the dome set further back than the originals but were otherwise of more or less the same dimensions. Some degree of standardization took place at rebuilding: the boiler used on the 39 class was also used, for example, on rebuilds of the Beyer, Peacock 2-2-2s, 2-4-0s and 0-4-2s and on some of Wheatley’s smaller goods 0-6-0s.

The drawing here is based on the Cowlairs General Arrangement for the rebuild of No. 39, drawing No. 1386B. This shows the first rebuildings of two members of the class in 1895. Subsequent rebuildings of other examples exhibited slight variations as to the cab and splasher combination and the cab footsteps.

These engines were long-lived, and one lasted to be class J81 of the L. N. E. R. The inde- fatigable raconteur Norman McKillop (“Toram Beg”) described his early years as a young cleaner-fireman working to an old driver called Andrew Manzie on No. 39 in Haymarket goods yard around 1910 in his book Enginemen Elite. Prior to that 39 had been one of the pilot engines at Haymarket west end before the advent of the Holmes 795 class 0-6-0Ts. nbr055_1867_rebuild_Drummond_livery_2c_dwg http://euankcameron.fotopic.net/p39524974.html

Engine wheelbase 7’ 3” + 7’ 9”: wheels 4’ 6”, 6’ 1½”, 3’ 9”

This unique and surprisingly successful 2-2-2 was constructed under Thomas Wheatley’s superintendency at St Margaret’s Works, Edinburgh and completed in August 1867. It inherited the number of, and employed some parts from, the original N. B. R. No. 55, a Crampton 2-2-2-0 built by E. B. Wilson and Co., makers of the famous ‘Jenny Lind’, some two decades earlier. Notably, the 1867 rebuild included the carrying wheels and the distinctive carrying wheel springs of the Wilson original. It also had Allan straight-link valve gear, which was most unusual on the N. B. R. and may have been derived from the original Crampton. Like many of the earlier N. B. locomotives it was driven from the right-hand side.

The drawing here shows the engine as in the early 1890s and in Drummond livery. The tender is one of Wheatley’s small wooden-framed four-wheelers, which were used exten- sively on older engines and varied considerably in dimensions, wheel diameter and many other details. The locomotive drawing is based on the official drawing of the rebuild, as described below, with the boiler and superstructure reconstructed from photographs. The tender is estimated. nbr055_final_rebuild_as_1009_dwg http://euankcameron.fotopic.net/p25232623.html

Engine wheelbase 7’ 3” + 7’ 9”: wheels 4’ 6”, 6’ 1½”, 3’ 9”

This drawing shows No. 55 after it received a further rebuilding (really a reboilering) in 1897. It received a Drummond boiler probably of 1877 vintage (the date given on the works plate) and a Holmes cab. It retained however the decorative paddlebox driving wheel splasher from the 1867 rebuilding and other details such as the sandboxes as well as the mainframes and valve gear. A new iron-framed tender, as shown here, replaced the ancient wooden-framed four-wheel original. This replacement tender came from a Dübs & Co. 2-4-0 of the 341 class, dating from 1865 and recently scrapped. The engine was renumbered as 1009 on the duplicate list in 1901.

No. 55 was reputed to be very fast, and must have been popular and successful enough to be worth rebuilding at such a great age. It ran until c. 1909 especially in west Fife and to Perth. The drawing here is derived from a Cowlairs official drawing of the 1897 rebuild (No. 183B) and the official works drawing of the Dübs tender, order No. 32T, slightly altered. nbr070_Drummond_livery_dwg http://euankcameron.fotopic.net/p27492798.html

Engine wheelbase 7’ 3” + 7’ 9”: wheels 5’ 1¾”

It is an almost futile exercise to try to discern a “standard” pattern to Thomas Wheatley’s 88 0-6-0 goods engines with 5’ 1¾” driving wheels. Two similar but slightly divergent contract builders’ designs, 12 by Neilsons & Co. and 15 by Dübs & Co. respectively, started off the series in 1868-9; the remainder were built at Cowlairs in stages over the remaining years of Wheatley’s superintendency.

The Cowlairs engines had slotted frames similar but not identical to the contractor-built designs; the early ones had box splashers to the lower part of the cab, and some had leading and driving wheel slotted splashers apparently purloined from William Hurst 0-4-2Ts.

By the 1873-5 period something almost like standardization crept in. The splashers were solid, the boilers were 10’ 1” long in the barrel and 5’ 5” in the firebox, and the cabs had a rounded cutaway and a bent-over short roof as on the 2-4-0s and 4-4-0s built at the same period.

No. 70, one of the 1874 examples, is shown here to demonstrate this later version of the Wheatley goods engine. The frames and splashers are taken from the Cowlairs GA of the Holmes rebuilds, Cowlairs General Arrangement No. 716B for the locomotive (as described below for No. 283 below) and No. 213B for the tender. The superstructure is reconstructed from other evidence.

The livery is the Drummond livery with dark olive green, black bands and red lining as described in Mr. Allan Rodgers’s article on the subject and shown in a contemporary photograph of No. 70. nbr141_164_original_Drummond_cab_livery_dwg http://euankcameron.fotopic.net/p38740307.html

Engine wheelbase 7’ 5” + 7’ 7”: wheels 4’ 0” and 6’ 6”

In 1869 Thomas Wheatley designed his first two entirely conventional 2-4-0s, with inside frames throughout and the then unusually large coupled wheel diameter of 6’ 6”. In their original form the engines had the typical Cowlairs boiler of the 1860s, domeless with a square-based safety-valve trumpet over the firebox, usually with a 10’ 2” barrel and a 5’ 0” long firebox. The minimal concessions to elegance of design lay mostly in the paddlebox splashers over the driving wheelset. These engines showed some resemblance to John Ramsbottom’s Newton class 2-4-0s of 1866 onwards, which also had 6’ 6” coupled wheels and paddlebox splashers.

In their original form these engines had box rear splashers and a plain bent-over weatherboard, as seen on this site on No. 38 and on many other early Wheatley engines. 141 had hinged side-flaps fitted relatively early on. 164, as shown here, was given a hybrid Wheat- ley-cum-Drummond style of cab similar but not identical to that fitted to 4-4-0 No. 224 between 1880 and 1885 and to 264 from the 1880s until 1893. This cab is attested by a photograph in the A. G. Ellis collection showing 164 at Haymarket shed in the 1880s and in Drummond livery. Like many of the earlier engines, it had no brake gear on the locomotive even though the Westinghouse brake system was fitted for tender and train.

The drawing here is based on Cowlairs general arrangement No. 1077B, the official and very detailed General Arrangement for the rebuilding of this class, as described below. The superstructure has been re-created from photographs. nbr141_rebuild_Holmes_livery_dwg http://euankcameron.fotopic.net/p33958193.html

Engine wheelbase 7’ 5” + 7’ 7”: wheels 4’ 1” and 6’ 7”

Holmes rebuilt both 141 and 164 around 1890/1. The rebuilding followed Holmes’s by now standard pattern and created a well-balanced and elegant design, if a little more top-heavy than some of the others.

The drawing here is based on Cowlairs general arrangement No. 1077B, the official and very detailed General Arrangement for the rebuilding of this class. Unfortunately like some others it contains inconsistencies between the lines drawn on the sheet and the dimensions written over them; resolving these internal contradictions is not a precise science. Note also that this drawing shows the smaller Wheatley pattern of tender with a 4’ 8” + 4’ 8” wheelbase rather than the 5’ 2” + 5’ 2” found on the larger examples. These smaller tenders were not nearly as common as the diagram books sometimes suggest, and were often exchanged for the larger variety as passenger engines with longer runs required more water capacity than originally provided for. nbr207_Holmes_rebuild_dwg http://euankcameron.fotopic.net/p38740313.html

Engine wheelbase 7’ 1” + 6’ 8”, wheels 5’ 1¾”

Between 1865 and 1867 the North British Railway took delivery of 36 nearly identical 0-6- 0s from the newly-founded Glasgow Locomotive works of Henry Dübs. Dübs set up in competition to his former masters at Neilson & Co., and to judge from the resemblance between early Dübs engines and Neilson products of a few years earlier, must have taken sheaves of working drawings from the Neilson drawing office when he set up his own con- cern.

The 185 class somewhat resembled two much less numerous classes of 0-6-0s built by Hawthorns of Leith and Robert Stephenson & Co. in the early 1860s. These should not however be called “Hurst engines” after the contemporary N. B. R. locomotive superintend- ent, because this is an anachronism. Before the time of Stroudley and Drummond, contract builders retained considerable latitude to impose their own design styles and details on the commissions they received from railway companies. In any case, Hurst could only order locomotives on the permission of the appropriate committee of the Board.

The original engines had parallel boilers with large bell-mouthed domes in the Beyer, Pea- cock manner and a raised firebox. They had box splashers over the trailing wheels and a bent-over weatherboard. The chimneys had copper caps and parallel sides. (A drawing of this form is in process.)

This drawing shows one of the engines, No. 207, as rebuilt by Matthew Holmes in 1892. Both Drummond and Holmes had taken hands in rebuilding the class. Both kinds of rebuilds had boilers of the same barrel and firebox dimensions as the originals, except that the raised firebox was dispensed with. Round cabs were fitted. Drummond’s rebuilds did not have brake gear, whereas Holmes’s had brake shoes on the engine. Many of the Hol- mes rebuilds had Westinghouse brake to make them suitable for mixed traffic on local and branch lines. No. 207 was used on the Montrose and Bervie railway, a windy branch line in Angus that had originally been worked by the Caledonian before the N. B. took over its running.

This drawing is based on the Dübs original general arrangements for the design as first built, order numbers 38E and 38T, with the rebuilding details derived from the diagram books and photographs. The sharp-eyed may notice that the running plates of engine and tender do not match up exactly. That is how the engines were designed. Different draughtsmen worked on engine and tender, and imposed different frame heights on the two halves of the locomotive. nbr213_original_dwg http://euankcameron.fotopic.net/p26281631.html

Engine wheelbase 7’ 3” + 7’ 3”: wheels 3’ 6”, 6’ 6”, 3’ 6”

This drawing shows one of the most successful, and in some respects innovative, designs to appear on a Scottish railway in the 1850s. The Edinburgh and Glasgow railway made the bold decision to order some 2-2-2 express locomotives from the newly-formed company of Beyer, Peacock and Co. of Gorton works, Manchester in 1855. The first six engines were delivered in 1856.

Charles Beyer, an immigrant engineer from Saxony in Germany, had perceived that the chief problem afflicting the first generation of steam locomotives was the feebleness of the frames, aggravated by the inability of the conventional Stephenson / Hawthorn designs to make appropriate allowance for the fact that the boiler expanded more than the mainframes during normal operation of a steam locomotive. The engines of the 1840s and early 1850s, including those on the Scottish railways, literally pulled themselves to pieces because of this basic design defect. Beyer saw the need to use full-length plate frames running from buffer-beam to drag-box, with the smokebox and cylinders firmly anchored at the front end and allowed to slide on expansion brackets at the rear. He had the advantage that metallurgy had progressed since the first locomotive designs were worked out in the 1830s, allowing more solid and longer iron plates to be produced.

With this basic engineering principle worked out, Beyer was able to produce 2-2-2s, 2-4- 0s, 0-4-2s, and 0-6-0s with a great variety of frame configurations. All his designs for the E&GR, however, had mixed frames, with the carrying wheels on outside axle-boxes and the driving wheels on inside bearings. As can be seen, Beyer believed in a degree of orna- mentation but also in simplicity of line. The Beyer, Peacock singles were elegantly and economically laid out, with inside cylinders and launch-type link motion valve gear. The tenders echoed the design principles of the locomotives.

This drawing is based on the surviving original Beyer, Peacock General Arrangement drawings, order numbers 66 and 67 for engine and tender respectively. The livery is conjectured based on the works photograph of E&GR No. 23 taken at Gorton Works in 1856. nbr213_Wheatley_rbd_dwg http://euankcameron.fotopic.net/p26196371.html

Engine wheelbase 7’ 3” + 7’ 3”: wheels 3’ 6”, 6’ 6”, 3’ 6”

The Beyer, Peacock singles were destined to have very long lives, exceeding 50 years in passenger service. By the time the last example was withdrawn they were almost absurdly small for contemporary traffic.

During their existence several were rebuilt in a variety of interesting ways. The most famous rebuildings were those initiated by Drummond in 1880 and completed by Holmes (a drawing of these is in process). However, this drawing shows an interesting and unique variant, Wheatley’s rebuild of No. 213 from 1875.

Wheatley gave the engine a new boiler, a cut-down version of Wheatley’s standard boiler with large dome and stovepipe chimney. At one stage this engine had a large brass bell- mouthed dome from a Stephenson 0-6-0, but later was fitted with a more typical Wheatley open-topped dome as shown here. Rather oddly the pitch of the boiler was slightly lowered from the original, about an inch lower than the 6’ 7½” of Beyer’s design.

The drawing, based on the same sources as the previous one, shows the locomotive as running in the mid-1890s. As first rebuilt the engine had no brakes on the locomotive; then Drummond fitted Westinghouse for tender and train only; finally around 1893 Holmes fitted brake shoes to the engine linked to the air brake system.

The locomotive remained in this form until Holmes rebuilt it to more or less the 1880 Drum- mond pattern in 1897. By that time it was unusual, certainly among express passenger engines, in still having essentially a Wheatley profile. nbr224_1885_rebuild_Nisbet_Compound_dwg http://euankcameron.fotopic.net/p35560320.html

The notorious Tay Bridge “diver” was first built, along with its twin No. 264, as a modifica- tion of the Wheatley 2-4-0 with a leading Adams bogie, and its original form is shown in the drawing of No. 264 below.

This drawing shows a most interesting and somewhat bizarre experiment in which Mat- thew Holmes indulged relatively early in his superintendency. A relative of his called W. H. Nisbet had patented a system of tandem compounding for steam locomotives, using two sets of Joy valve gear operating from shared bearings on the locomotive connecting rods. The point of the system seems to have been to allow the driver to use high-pressure steam expansively in the small high-pressure cylinders while allowing a relatively late cut-off in the low-pressure, larger cylinders sharing the same piston rod.

The tandem compound experiment was tried uniquely on No. 224 for two years from 1885. The high-pressure cylinders were housed over the leading bogie wheel between 12” long forward extensions of the mainframes. To allow for the upward angular motion of the Joy gear valve rod, the 4’ 0” boiler was pitched high, at 7’ 5½” from rail level, but of the same overall dimensions as the Wheatley original. Unlike most of Holmes’s boilers of this type, this boiler had seven additional longitudinal stays, which reduced the heating surface but increased the rigidity. This suggests that the boiler was intended to run at higher than usual pressure, though no documentary evidence to this effect has been found.

The result must have been a very front-heavy, underboilered engine with too much cylinder capacity to evaporative surface, which was also uncommonly complicated to drive. While the experiment was reported as a success in the engineering press, within two years the engine had been radically simpled / simplified by the elimination of the front cylinders. The engine ran with two cylinders, its high, small boiler and Joy’s valve gear until a further rebuilding in 1897 (below).

The drawing is based on the Cowlairs 1885 General Arrangement, drawing No. 847B, supplemented by information about the design from the contemporary engineering press. nbr224_1897_rebuild_larger_tender_c_dwg http://euankcameron.fotopic.net/p39482913.html

In 1897 Matthew Holmes rebuilt No. 224 for a fourth and final time. On this occasion the engine was restored to the sort of unambitious simplicity already achieved with the 2-4-0s and No. 264. New 17” x 24” cylinders were fitted, and a boiler identical to that already found on 264, 141, 164, and the 418 class 2-4-0s (below). The extended mainframes and rather short, minimal arched cab were retained from the 1885 rebuilding, as was an extra- large “piano cover” in front of the smokebox dating from the “simpling” of the engine in 1887. The original short-wheelbased Wheatley tender was replaced with one of the larger design with a foot longer wheelbase.

In this form 224 served for another 22 years, being eventually withdrawn in 1919. This drawing is derived from the sources listed above, with additional data from diagram books and General Arrangements of other Wheatley rebuilt designs. nbr228_Holmes_rebuild_c_dwg http://euankcameron.fotopic.net/p39482917.html

Engine wheelbase 7’ 3” + 7’ 9”: wheels 5’ 1¾”

Wheatley’s first large 0-6-0ST locomotives were Nos. 226 and 228, built in 1870. The frames and motion of the large Cowlairs goods engine of the period were married to the boiler of the big-wheeled 2-4-0s. A small dome was located over the firebox as on 224 and 264, built the following year. A saddletank covered the whole boiler, and the overall effect was closely akin to the Ramsbottom L&NWR 0-6-0STs except for the larger wheels.

Holmes rebuilt No. 228 in 1901 to the form shown here. The rebuild followed the pattern seen on all the other Wheatley tanks of the same period. As rebuilt No. 228 lasted longer than all the other locomotives of this type. The London and North Eastern Railway classed it as ‘J86’ among the small-wheeled tanks, apparently thinking that it had smaller wheels than it actually did. The same company finally withdrew it in October 1924.

This drawing is based on Holmes’s General Arrangement for the rebuilding, Cowlairs drawing No. 82B. nbr237_Drummond_rebuild_dwg http://euankcameron.fotopic.net/p26196373.html

Engine wheelbase 6’ 8” + 7’ 10”: wheels 3’ 6” and 6’ 0”

Between 1859 and 1862 the Edinburgh and Glasgow Railway took delivery from Beyer, Peacock and Co. of four 2-4-0s with the same boiler design as the last two 2-2-2s and twelve 0-4-2s ordered from the same company. Unlike the six 2-2-2s of 1856, these engines had large bell-mouthed brass domes over the fireboxes with Salter safety valves on top. All the designs were of the mixed-frame type with carrying wheels located in outside bearings on an external subframe assembly.

In 1881 Dugald Drummond began rebuilding the 2-4-0s along similar lines to his rebuilds of the 2-2-2s, begun the previous year. One of the first to be treated was No. 237, which had been named ‘Alexandria’ in the Drummond phase of naming nearly every passenger engine where there was somewhere to paint a name.

The rebuild featured a boiler proportioned differently from the original. The Beyer, Peacock boilers had a barrel 10’ 1” long and a firebox 4’ 7” long. The Drummond replacements lengthened the firebox to 5’ 0” and shortened the barrel to 9’ 7”. Drummond fitted Westing- house brake equipment on the locomotives, but no brakes were fitted on the engines themselves until some years into the Holmes superintendency. The stroke of the cylinders was lengthened from 20” to 22”, the bore of 16” remaining the same.

The platework included the round cab, a design style which Drummond had borrowed from the Stirling brothers on the G&SWR. In the case of the 2-4-0s the cab was wrapped right around the wheels and coupling rods, following the very broad box splashers of the original design. The result was a cab that was almost exactly as broad as it was high, giving the engines an extremely squat, dumpy appearance.

Nevertheless these engines seem to have been quite successful and continued in use for nearly another three decades. 237 was photographed many times at Perth and elsewhere.

The drawing is based on Beyer, Peacock Order No. 379, the original General Arrangement for this class. The rebuilt boiler and platework are deduced from the N. B. R. diagram books and careful scrutiny of photographs. The tender is reconstructed from the diagram books and the General Arrangement drawing of the tender of the 2-2-2s. nbr264_original_Drummond_livery_dwg http://euankcameron.fotopic.net/p38740317.html

Thomas Wheatley’s first 4-4-0s represented a fairly minimal adjustment from his 141 class 2-4-0s, with the same coupled wheelbase, the same size driving wheels, and a very similar boiler. One change was that Wheatley very sensibly turned away from the Salter safety valve at this point. The E. & G. Cowlairs boiler of the 1860s, which Wheatley used on many of his rebuilds of older locomotives and on his earliest 2-4-0s and 0-6-0s, had Salter valves exhausting steam through an elegant brass inverted trumpet. These safety valves were far too easy to tamper with, especially when the springs were actually located in the cab on the boiler backhead as in this case, and Wheatley began to strip them out and replace them with a fully enclosed spring-loaded valve. 224 and 264 received a very small done over the firebox in the original position of the Salter valve cover, with the new spring- loaded valves enclosed in the top.

The drawing is based on the Cowlairs 1885 General Arrangement of 224, Drawing No. 847B, for the frames. The boiler dimensions and pitch are recorded in contemporary re- ports from the 1870s. The platework is inferred from photographs and Wheatley’s normal practice. The small weatherboard above the handrail is shown in an early photograph of 264, although the engine received a slightly larger top section to the cab in the 1880s. The livery follows the Drummond style as seen in the same early photograph. nbr264_rebuild_Holmes_livery_2c_dwg http://euankcameron.fotopic.net/p39482914.html

The rebuildings of the first Wheatley 4-4-0, No. 224, were several and complex (see above). There is much less mystery about 224’s twin, No. 264. This engine remained in and the usual platework. It is probable that the trailing plate springs were replaced with coil springs, but that change is not recorded on any of the drawings of Wheatley rebuilds, so plate springs are shown here throughout.

264 was associated for many years with the Waverley route and in particular with the Bor- der counties line from Riccarton to near Hexham via Reedsmouth. This difficult and de- manding route through beautiful Northumberland countryside attracted a variety of elderly locomotives, including the Beyer, Peacock engines 2-2-2 No. 215 and 0-4-2 No. 325. Bor- der counties trains worked through to Newcastle General station via running powers over the North Eastern. In rebuilt condition 264 was attached to the larger Wheatley tender. In later years it also had front footsteps fitted over the rear bogie wheels.

The drawing is based on the Cowlairs General Arrangement of 224, Drawing No. 847B, for the frames and basic platework, supplemented by photographs and drawings of other Wheatley rebuilds. The tender drawing is based on Cowlairs General Arrangement No. 213B. nbr283_rebuild_dwg http://euankcameron.fotopic.net/p25263187.html

Engine wheelbase 7’ 3” + 7’ 9”: wheels 5’ 1¾”

Matthew Holmes did his best to bring some order into a confused state of affairs when the

10’ 1” barrel and 5’ 5” long firebox, a standard component used for Holmes’s 0-6-0s, 4-4- 0s, 0-4-4Ts and 0-6-0Ts with 17” diameter cylinders, as well as for the larger of the Wheat- ley rebuilds. A new cab was fitted, although in most cases the original leading and driving wheel splashers were retained. Some of the engines were Westinghouse fitted, while most had only steam brakes and the tender handbrake.

The drawing here shows No. 283 as rebuilt in 1889. It is derived from Cowlairs General Arrangement No. 716B for the locomotive, and No. 213B for the tender as described above. Noteworthy are the cast centres to the wheels with T-section spokes, an economy device to which Wheatley resorted for many of his new engines intended for slow traffic. Somewhat surprisingly to modern eyes, no provision was made for balancing the wheels except for the opposing of the inside and outside cranks on each side. These wheel centres were somewhat prone to cracking, and the older wrought-iron wheels in several cases proved more durable.

An archival drawing exists for the final rebuild of this class in Reid’s time, and this will be added to the collection in due course. nbr351_Drummond_rebuild_Holmes_livery_dwg http://euankcameron.fotopic.net/p38740306.html

Engine wheelbase 7’ 7” + 7’ 10”: wheels 4’ 0” and 6’ 0”

William Steel Brown, a trainee of Archibald Sturrock from the G. N. R. at Doncaster, head- ed the Cowlairs works engineering team during a particularly exciting period in the early 1860s. In those years a formidable array of talent worked for the E. & G. R., including Wil- liam Stroudley, Dugald Drummond and Samuel Waite Johnson. Brown was chiefly, though perhaps not exclusively, responsible for the first really successful passenger locomotives to be built at Cowlairs works. These robust double-framed 2-4-0s arrived from 1862 onwards, with 6’ 0” driving wheels and 4’ 0” carrying wheels and domeless boilers. A number of their details echoed Sturrock’s Doncaster practice: they quite closely resembled some of Sturrock’s 2-2-2s and also a class of 2-4-0s, curiously built after the E&GR examples. In N. B. R. days the eight engines in the class were numbered 349-356, although No. 351 was the first to be built.

There is no truth in the often repeated story that these locomotives ran with unlagged boilers in their early careers. It presumably derives from the fact that a works photo was taken in ‘shop grey’ of the first of them, E. & G. R. No. 101 (later N. B. R. 351) before it was complete. This photograph indeed shows the boiler without lagging, but also (for example) shows the engine without a tender or a safety-valve cover. There can be no doubt that the boilers were safely lagged and cleaded when the engines entered service.

This drawing shows the first of the class, No. 351, as rebuilt by Drummond in 1882. This rebuild preserved much of the original, including the frames and pierced splashers, and probably used the original boiler shell at the original pitch. However, Drummond boiler fittings were added and a round cab roof. In the Holmes period the engine received very short brake levers and shoes between the driving wheels.

The source for the locomotive drawing is the Cowlairs official rebuilding General Arrange- ment for No. 356 (No. 982B), heavily interpreted and amended with the aid of a good broadside photograph of the engine. No official general arrangement survives for the Steel Brown tender. In this case the evidence of the diagram books has been eked out with photographs. nbr354_first_rebuilding_dwg http://euankcameron.fotopic.net/p38740305.html

Engine wheelbase 7’ 7” + 7’ 10”: wheels 4’ 0” and 6’ 0”

This drawing shows an interesting rebuild of one of the first batch, N. B. R. No. 354, formerly E. & G. R. No. 104 built in 1863. This engine was one of two rebuilt c. 1882, around the very end of Drummond’s time or the very beginning of Holmes’s. The rebuild involved reorganizing the boiler fittings (probably on the original shell) and fitting a unique cab which combined aspects of Drummond and Stirling practice. This engine worked out of Dundee and was apparently extremely successful. Although fitted with Westinghouse brake, the locomotive had no brake gear on the engine itself until its second rebuilding.

One feature of these early 2-4-0s that cannot easily be rendered on a drawing is that the enginemen in the sheds tended to adjust the springs to as to hoist the engines up on their leading wheels, to increase the load and therefore the grip of the first pair of wheels on the track and lessen the risk of derailment. Many 2-4-0s therefore appear in contemporary photographs in a sort of “sit-up-and beg” posture. It can have done nothing for the factor of adhesion but may have saved a few accidents.

The sources for this drawing are the same as those for the drawings of 351 and of 354’s second rebuilding, amplified by careful scrutiny of photographs. nbr354_second_rebuilding_dwg http://euankcameron.fotopic.net/p25232616.html

Engine wheelbase 7’ 7” + 7’ 10”: wheels 4’ 0” and 6’ 0”

Matthew Holmes laid down a design in 1886 for rebuilding No. 356, one of the second batch of Steel Brown 2-4-0s completed under Samuel Johnson, and the rest of the 2-4-0s were gradually rebuilt to this design. In 1897 No. 354 was rebuilt from its Drummond appearance to resemble the rest of the class.

The boiler on these engines was a ‘standard’ designed by Holmes for a number of his re- long. It was used not only on the 351 class 2-4-0s but also on the final rebuilds of Wheatley’s 4-4-0s 224 and 264, on the Wheatley 2-4-0s of the 141 and 418 class, and on the unique Wheatley double-framed 2-4-0 No. 38 (q.v.). In the case of the double-framed locomotive there were no inside bearings to the trailing drivers, so the firebox could be placed far back, just clearing the trailing axle but no more. Since the cab front spectacle plate was set as a rule no more than c. 5½” in front of the firebox backhead, in this case the result was an unusually short and compact space for the crew. These locomotives were right-hand drive throughout their existence, with the additional peculiarity that the reach-rod for the reversing gear was run down the narrow space between the outside of the wheels and the inside of the coupled wheel splashers.

The source for the locomotive drawing is the Cowlairs official rebuilding General Arrange- ment for No. 356 (No. 982B). This drawing is a prime example of the principle that a works drawing does not solve all puzzles. It is one of the most problematic documents to survive from the Cowlairs drawing office: inconsistencies and internal contradictions abound. The drawing is therefore here offered as a best effort to resolve those contradictions in a way consistent with the photographic as well as the documentary evidence. nbr356_Holmes_rebuild_Johnson_tender_dwg http://euankcameron.fotopic.net/p38740312.html

Engine wheelbase 7’ 7” + 7’ 10”: wheels 4’ 0” and 6’ 0”

This drawing represents No. 356, one of the last of the Steel Brown – Johnson 2-4-0s to be built and the first to receive the full Matthew Holmes rebuilding treatment.

The S. W. Johnson 2-4-0s had some minor differences from the original four, chiefly in details such as the profile of the rear footsteps. The most significant difference, however, was in the tenders. The first four Steel Brown engines had tenders styled after the Beyer, Pea- cock type, but with 4’ 0” wheels matching the front carrying wheels of the locomotive. Since the top of the frame was only at 3’ 10” from rail level, this entailed a complicated construction of the water tank with internal ‘splashers’ to accommodate the wheels. John- son greatly simplified the design: he gave the tenders smaller wheels, a simpler, longer and slightly lower water tank, and mainframes that were deeper and more solid than the original version. These frames rather copied Neilson practice than Beyer, Peacock.

This drawing has been derived from the same sources as the others of this class. The livery shown is the early Holmes style that was applied when 356 was first rebuilt. In later years 356 was paired with a large Wheatley six-wheeled tender, reputedly to work trains around the Fife coast that required a greater water capacity. nbr358_final_rebuild_as_1011_c_dwg http://euankcameron.fotopic.net/p39482916.html

Engine wheelbase 7’ 6”, wheels 4’ 3”

This drawing shows the final rebuilding of two rather bizarrely celebrated locomotives, Tho- mas Wheatley’s 0-4-0 tender engines Nos. 357 and 358. They probably owe their celebrity to the fact that they lasted to a later date in main line service than any other 0-4-0 tender engines in Britain (at least until the resurrection of Sharp, Stewart 0-4-0 Furness Railway No. 20 in the preservation era!) The North British Railway had a range of four-wheelers, mostly inherited from other concerns or sometimes even from private owners. The two Wheatleys were the last to be built to this archaic design and the last to remain in service.

These engines were built in 1868 out of miscellaneous retrieved materials. They had a 7’ 6” wheelbase and deeply slotted mainframes, with wheels of approximately 5’ 1” diameter. As first built they had domeless boilers with raised fireboxes and flared safety-valve trum- pets over the firebox. They had basic vertical weatherboards with no roof of any kind. They had the crude Wheatley wooden-framed tender.

Matthew Holmes carried out a fairly thorough rebuild of 357 and 358 in 1899 and 1902 respectively. The wheel diameter was set at 5’ 1”, and the engines were given a new Holmes boiler at 6’ 8” pitch with the usual fittings, including a small chimney, the usual dome with safety valves, and conventional non-lifting injectors. The box lower section to the cab was retained, but a long bent-over weatherboard, probably taken from a Dübs and Co. 0-6-0, was set on top. Each engine received a new iron-framed tender although these were not of the same pattern. That on 357 came from a Stephensons 0-6-0, while 358’s appears to have been purloined off a Neilson 90 class 2-4-0. In each case a new tank was fitted and the tender frames were rearranged to have the hornblocks and springs outside rather than inside the frames.

In 1911 W. P. Reid somewhat peculiarly decided to extend the life of these oddities still further. However, the final ‘rebuilding’ was actually less drastic than appears. The most dramatic visual change was that the driving wheels were replaced with Wheatley cast-iron wheels of 4’ 3” diameter. (Incidentally, these were not the only four-wheelers to be rebuilt in this way.) This change lowered the frames and boiler by 5” overall, and required the bufferbeam to be re-sited higher up and weighshaft balance weight to be altered. The handbrake formerly fitted on the engine was replaced with a steam brake cylinder under the footplate. The boiler was unchanged. A diminutive cab, styled after the Reid side-window roofed cab but obviously without windows, was fitted in place of the old weatherboards. To match the lowering of the engine, the tender wheels were replaced with new ones of a much smaller diameter.

357 and 358, already on the duplicate list, had meanwhile been renumbered 810/11 in 1895 and 1010/11 in 1901. 1011 lasted to be inherited by the L. N. E. R., in N. B. R. lined black livery with its number in control numerals painted on the tender. In this form it was withdrawn late in 1925.

The drawing is based on Reid’s General Arrangement drawing for the rebuild of these two engines, Cowlairs drawing No. 3709B. The tender is based on Neilsons’ drawing of the 90 class tender, much revised in the light of photographic evidence. nbr382_original_dwg http://euankcameron.fotopic.net/p25232626.html

Engine wheelbase 7’ 3” + 7’ 9”: wheels 3’ 11½” and 6’ 0½”

The Neilson 382 class 2-4-0s were a successful and (by N. B. R. standards) fairly large class of passenger locomotives, comprising twelve examples, and had a long life. They were the third series of a sequence of mixed-frame 2-4-0s with outside bearings to the leading wheels and inside bearings to the drivers, of which the first six had been delivered by Neilson & Co. to the N. B. R. in 1861. Contrary to what is often reported, all three 2-4-0 classes, these and the very similar six Dübs & Co. 2-4-0s of the 341 class had the same engine wheelbase of 7’ 3” + 7’ 9”: this is proven by consultation of the original works drawings for each, all of which have survived. The 1865 Dübs engines were in fact so similar in constructional details to the 1861 Neilsons that it is tempting to assume that Henry Dübs set up his new firm with some of the designers and even some of the patterns and drawings taken over from Neilsons. The 382 class of 1866-7 were rather different in many respects from their predecessors, most obviously in the domeless boiler and a curve to the outside frames that was more elliptical and flowing than on the earlier deliveries. All the main components were redesigned within the overall framework of the same size and specification of locomotive. The boilers were 10’ 0” long in the barrel and 5’ 0” long in the firebox. The driving wheel springs were equalized. There were various minor detail variations between the first four and the last eight of the class. The drawing here is accurate for Nos. 382-5.

One feature that cannot be shown on this drawing is a very large horizontal injector fitted to the first four of the 382 class on the right hand side of the boiler only. The remainder also had a single injector on the right hand side, but set vertically. The reversing gear was also situated on the right hand side of the locomotive. These locomotives suffered a variety of detail changes during the Wheatley and Drummond years but worked well enough to earn a comprehensive rebuilding from Holmes, with individual locomotives being treated at intervals between 1888 and 1892. (There was only one rebuilding process, not two as is sometimes implied.)

The drawing here is based on official Neilsons drawings for both the engine and tender. The livery is somewhat conjectural, but the lining pattern closely follows the works photograph of No. 382. Note that N. B. R. engines ordered new during William Hurst’s superintendency did not carry cast numberplates. In some cases at least the numbers were painted on to the cab sides. nbr382_rebuild_dwg http://euankcameron.fotopic.net/p25232629.html

Engine wheelbase 7’ 3” + 7’ 9”: wheels 3’ 11½” and 6’ 0½”

The Holmes rebuilding of the Neilson 2-4-0s, executed between 1888 and 1892, produced a particularly elegant and well proportioned locomotive. Only the third and last series of engines received this treatment: the 1861 and 1865 locomotives were withdrawn in the 1890s in their original form or as modified by Wheatley. To the 382s Holmes fitted a small boiler, unlike that of any other class, air brakes throughout, and his usual pattern of cab. In this form they worked all over the system on local trains almost until the eve of the First World War.

By a curious accident one of these engines was featured on an early piece of cine film taken in 1898. An early experimenter with film ran a camera across the Tay Bridge on a flat wagon pushed by a Drummond tank engine. The resulting footage showed two south- bound trains passing the camera: the second was hauled by a brand new 729 class 4-4-0, but the first was a Tayport local hauled by a little Neilson rebuild, probably No. 383. (The remainder of the film showed Esplanade Station, then a Holmes 4-4-0, a Wheatley 0-6-0 and an ‘Abbotsford’ in Dundee yard. An edited version of this film, omitting the first part with the 2-4-0, can be seen on http://youtube.com/watch?v=o0n09P969fw.)

This drawing is based on the sources for the drawing of the original design, supplemented with the diagram book sketch of the rebuilds and careful reference to photographs. The livery follows the early Holmes pattern with dark red outside frames, but with the darker body colour that was becoming current c. 1890. This colour scheme has been derived from careful examination of a photograph of 382 taken soon after rebuilding. nbr418_425_early_Wheatley_livery_dwg http://euankcameron.fotopic.net/p35562647.html

Engine wheelbase 7’ 3” + 7’ 9”: wheels 4’ 2” and 6’ 0”

By 1873 Thomas Wheatley had arrived at something like a consistent style, and built a range of locomotives all with inside frames, sharing similar components and design details. These were chiefly goods 0-6-0s with 4’ 3” or 5’ 1¾” wheels, but also included eight 2-4-0s and four 4-4-0s. The eight 2-4-0s of the 418 class had 6’ 0” driving wheels and a boiler common with the smaller goods engines. The large dome enclosing the safety valves and the cab with its minimal top section followed Wheatley’s by now standard pattern. This drawing shows one of the class in Drummond livery with olive body colour and dark red valances, certain Drummond details such as the lamp-irons and tallow cups, and the reservoir for the Westinghouse brake system. After the Westinghouse brake was adopted as standard after the 1876 brake trials, many earlier locomotives were not fitted with brake shoes even though they had air brake equipment for the train and tender.

This drawing shows the Wheatley livery and omits all power brake equipment. This reflects the first appearance of the class as built in 1873. The livery is based on a detailed photograph of No. 418 taken when it was briefly fitted with the Smith non-automatic vacuum brake for comparative tests in the 1870s. As first built the engines had no automatic brake of any kind.

The drawing is based on the sources listed below for the rebuild of 426, supplemented by careful scrutiny of photographs. nbr418_425_original_Drummond_livery_dwg http://euankcameron.fotopic.net/p38740308.html

Engine wheelbase 7’ 3” + 7’ 9”: wheels 4’ 2” and 6’ 0”

This drawing shows one of the class in Drummond livery with olive body colour and dark red valances, certain Drummond details such as the lamp-irons and tallow cups, and the reservoir for the Westinghouse brake system. After the Westinghouse brake was adopted as standard after the 1876 brake trials, many earlier locomotives were not fitted with brake shoes even though they had air brake equipment for the train and tender.

The drawing is based on the sources listed below for the rebuild of 426, supplemented by careful scrutiny of photographs. nbr420_as_built_421_first_livery_dwg.JPG http://euankcameron.fotopic.net/p 35562649.html

In 1873 Wheatley designed his first four ‘production’ 4-4-0s, which shared the same boiler as his large 0-6-0s. These represented a slight enlargement of 224 and 264, though retain- ing the same cylinder proportions. 420 to 423 were probably the very first N. B. R. engines to be fitted with Westinghouse brakes, and the automatic brakes were showing their use- fulness on the Waverley route trains even before the 1876 brake trials. The 420s worked on the Waverley route in the first instance, although they proved unable to cope with the length and weight of the trains over Falahill and Whitrope banks without assistance. 421 served as the model Westinghouse locomotive at the 1876 brake trials on the Edinburgh and Glasgow main line. After being supplanted by the ‘Abbotsford’ 4-4-0s on the Waverley route the Wheatley 420s worked mostly in the Forth and Clyde valleys, and had a long and highly creditable career almost exclusively in express passenger service.

This drawing shows one of the class in the original Wheatley green livery, just after the Westinghouse brake equipment was added early in 1876.

The drawing is based on the sources for the rebuild of No. 420 as below, supplemented by the very rare and sparse photographic evidence for this class. nbr420_original_Drummond_livery_dwg http://euankcameron.fotopic.net/p38740309.html

420 ran from 1873 to 1887 before being rebuilt, and it is fairly certain that like others of the class it was repainted in Drummond livery before being rebuilt. This drawing shows it as it would have appeared just before rebuilding. It is based on the same sources as the others. nbr420_rebuild_Holmes_livery_dwg http://euankcameron.fotopic.net/p25232624.html

Between 1887 and 1890 Holmes rebuilt all four 420s, and as rebuilt they served until the First World War for much of that time on main line passenger service. This drawing shows 420 just after rebuilding. The geometry of the cab and other platework was standard with the rebuildings of the other Wheatley engines built with 6’ 6” wheels. Like the others, the 420s had their nominal wheel diameter increased to 6’ 7” by the use of thicker steel tyres.

The drawing is based on Cowlairs drawing No. 815B, the arrangement produced for the rebuilding of the class, which includes sufficient detail of the mainframes and other aspects of the design carried forward from the original form. Note how the lining pattern of the main body panels is echoed on the coupling rod splashers and the front extensions to the mainframes. nbr426_rebuild_Holmes_livery_dwg http://euankcameron.fotopic.net/p25232603.html

Engine wheelbase 7’ 3” + 7’ 9”: wheels 4’ 2½” and 6’ 1” usual details. This rebuilding once again produced an admirably balanced and well proportioned locomotive with all the power necessary for the small local trains of the period. Al- though not reported as such in the diagram books, all the 418s were normally fitted with the larger size of Wheatley tender.

This drawing is based on Cowlairs General Arrangement Drawings 1193B for the locomotive and 213B for the tender. The livery is believed to be correct for 1890, just after the locomotive was rebuilt. nbr426_Reid_rebuild_as_1247_late_livery_dwg http://euankcameron.fotopic.net/p25232625.html

Engine wheelbase 7’ 3” + 7’ 9”: wheels 4’ 2½” and 6’ 1”

The second rebuilding of six of the 418s to resemble the other Reid rebuilds in 1915, during the First World War, has become something of a legend. The resulting engines were popular favourites, worked all over the local branches in the lowlands, and were widely and often photographed.

Yet in fact what Reid planned for the 418 class 2-4-0s was exactly the same operation as had already been performed for the much more numerous Wheatley 0-6-0 goods engines for some years. It had been discovered that the Wheatley goods engines were extremely solidly built in the frames and valve gear, were fundamentally still sound, and were perfect- ly capable of sustaining a further renewal and of giving another decade or so of useful service. Reid therefore reboilered them with boilers of nearly identical proportions to the first rebuilds, with more modern fittings, and left the rest of the locomotive pretty much alone.

The Cowlairs pipe arrangement of the 418 rebuild (drawing No. 4489B) shows that the same process was actually intended in the case of the 2-4-0s. It shows a modern boiler with combination injectors and dual brake equipment fitted to the 418 design as rebuilt by Holmes c. 1890, with the round cab and other platework quite unchanged. In the event Reid decided, presumably quite late in the process, to have a miniature version of his side- window cab designed for these engines, duly made the subject of a part drawing (No. 4509B) which also survives. This change also entailed fitting new sandboxes and the addi- tion of front footsteps.

These locomotives lasted well into the L. N. E. R. era in a variety of liveries, some lined-out and some not. The locomotive shown was in fact the last in service as L. N. E. R. No. 10247, in lined black. It is here shown in the fully lined N. B. R. livery applied at the point when it was rebuilt.

The sources for this drawing are Cowlairs drawings 4489B and 4509B as described above. nbr430_second_rebuild_Holmes_livery_2c_dwg http://euankcameron.fotopic.net/p39482912.html

Engine wheelbase 6’ 9” + 7’ 9”: wheels 4’ 3”

These Wheatley saddletanks were a curious anomaly, but a numerous and long-lived class of 20 locomotives. As built they constituted a class of small-wheeled 0-6-0s first built in 1873, with boilers and cabs very similar to those of the Wheatley 418 class 2-4-0 (q.v.)

Around 1890 Matthew Holmes decided to convert the entire class into saddletanks. The frames were slightly extended at the rear and provided with brakes, which had been absent from the tender engines. New platework was provided, in the form of a tank similar to that on Holmes’s other rebuilds of Wheatley tanks, and the same roofless cab weatherboards seen on other Wheatley 0-6-0STs.

However, rather strangely Holmes decided to leave the Wheatley boilers, which were less than 20 years old, alone. So in their first rebuilding the 430 saddletanks had stovepipe chimneys, smokeboxes with snaphead rivets, and domes in the middle of the barrel rather than towards the rear as on Holmes boilers. The spring-loaded safety-valves formerly enclosed within the large Wheatley dome were allowed to exhaust through a space in the small dome enclosed with a elongated rounded metal surround where the lock-up safety- valves would normally have been.

Around ten years later the original boilers wore out. Since Holmes did not wish to replace the saddletanks so recently fitted, unique boilers were designed for the class to fit the existing tanks. These boilers had the usual Holmes fittings, but with the dome set on the middle of the boiler as on a Wheatley engine.

The class proved to be quite useful as shunters. Before the construction of Holmes’s 795 class 0-6-0Ts some 430s were used as pilots at Edinburgh Waverley East End (the West End of the station was the preserve of the large-wheeled 0-6-0STs). The engine shown, No. 430, lasted until 1924 and was withdrawn as one of LNER class J84.

The drawing is based on Cowlairs General Arrangement No. 4938B, amplified with information from the diagram books. Drawing 4938B in fact shows a proposed and unexecuted further rebuild proposed by Reid, in which the class would have undergone some updating of the fittings and received a cab similar to those on the Ivatt tank engines of the Great Northern Railway. Some retrofitting of the engine shown in the General Arrangement is therefore required to depict the actual final appearance of the engines. nbr465_Holmes_rebuild_dwg http://euankcameron.fotopic.net/p33958195.html

Engine wheelbase 7’ 6” + 7’ 9” (original) 7’ 6” + 8’ 0” (rebuilt): wheels 5’ 0”

Dugald Drummond’s first large locomotives for the N. B. R. were some goods 0-6-0s, extremely heavy for the period, which rather resembled those of his mentor and teacher Wil- liam Stroudley. Like Stroudley’s goods engines these had a long boiler perched on a relatively short wheelbase, with substantial overhangs front and rear and a spacious cab with a full roof and handrail pillars.

As first built these engines had crosshead pumps and a condensing feed-water heating arrangement by which some of the exhaust steam was fed back from the cylinders through a large-bore pipe down the middle of the frames to the tender to warm the water. In theory this arrangement was supposed to save fuel, but in practice the inconvenience and limita- tions caused by the reliance on crosshead pumps were not worth whatever modest sav- ings were made, and Drummond replaced the pumps with injectors on all his engines after a few years.

Drummond’s dependency on Stroudley’s ideas was not absolute. Drummond did not follow Stroudley’s ideas in the matter of valve-chests or Salter safety valves, and had his own ideas in the matter of chimney and dome profiles and cab roofs. He never adopted the pe- culiar late Stroudley tender with inside bearings to the wheels.

It is noteworthy that large boilers designed for the Big Drummond goods engines were used unaltered for the first four ‘Abbotsford’ 4-4-0s. The latter engines were ordered as the result of amending an existing order for 4-4-0s, and some of the design peculiarities of the first 4-4-0s reflected this dependency on material ordered for the goods engines. The goods engines had a relatively shallow firebox, sloping sharply up to the rear to clear the rear trailing axle. The ashpan was similarly ingeniously shaped to clear the running-gear and the exhaust steam pipe for the feed water heating.

Matthew Holmes rebuilt the class between 1898 and 1903. The boiler designed for the Holmes 18” 0-6-0 replaced the original type with its sharply sloping grate. As a result Hol- mes had to extend the wheelbase by three inches. Since other aspects of the profile of the frames were preserved from the Drummond originals, it really does look as though additional metal was ‘spliced’ between the driving and trailing axles. If entirely new frames had been fitted to the class at rebuilding, they would surely have lasted longer than the early 1920s.

This drawing is based on the Cowlairs official General Arrangement for the rebuild of the class, Cowlairs drawing No. 1372B. nbr474_original_livery_dwg http://euankcameron.fotopic.net/p26196372.html

Engine wheelbase 7’ 9” + 7’ 9”: wheels 4’ 6” + 7’ 0” + 4’ 6”

In 1876 Drummond was busily ordering quite large numbers of big 0-6-0s from Neilson & Co. and from Cowlairs works. He then conceived a desire to accelerate the fastest Edin- burgh to Glasgow expresses, which were still being hauled at the time by Beyer, Peacock singles, capable of a maximum speed in the high 50s of miles per hour.

Accordingly Drummond quickly designed a medium-sized modern 2-2-2. Much has been made of the resemblance to the Stroudley single ‘Grosvenor’, but Drummond also devel- oped a boiler and valve gear set that he would re-use for his 17” tank engines and small goods engines throughout his superintendency.

As first built the two singles, 474 and 475, had the same feed water heating and crosshead pumps as the 0-6-0s. However, these fixtures were very quickly replaced with conventional injectors. Other archaic features in the design remained, notably the wooden brakes on both engine and tender. (The drawing currently displayed imports the tender from other Drummond designs and shows metal brakes, which is not correct and will be amended.)

The two locomotives worked on the Edinburgh and Glasgow main line for over 30 years, looking quite strange when they were hauling Reid bogie carriages, and were never rebuilt. Over time they acquired Holmes safety valves, tallow cups and other detail modifications, and went through several changes of livery. They were both withdrawn in 1910, reputedly without being placed on the duplicate list; however, duplicate numbers are assigned to them in a contemporary diagram book, and it seems likely that they received these for a short while as their capital stock numbers were re-used for Reid 0-4-4Ts before the singles were withdrawn.

The drawing is based on the detailed engraving of the General Arrangement published in the contemporary engineering press. nbr476_Holmes_rebuild_dwg.JPG http://euankcameron.fotopic.net/p25235813.html

Engine wheelbase 6’ 6” + 6’ 7” + 9’ 0”: wheels 3’ 6” and 6’ 6”

This is the first of several drawings of the famous ‘Abbotsford’ class, Dugald Drummond’s first 4-4-0s and one of the first designs that can fairly be called the modern steam passenger locomotive. The class appeared in three batches of four, the first two foursomes from Neilson & Co. and the last quartet from Cowlairs works.

This drawing shows the first of the class as rebuilt by Matthew Holmes in 1902 with the larger boiler introduced four years earlier on his ‘729’ class. Six of the twelve Abbotsfords were rebuilt to this design. The drawing is based on Cowlairs General Arrangement No. 1660B, a particularly clear and fine piece of draughtsmanship. nbr479_rebuild_as_1324_late_livery_dwg http://euankcameron.fotopic.net/p31496511.html

Engine wheelbase 6’ 6” + 6’ 7” + 9’ 0”: wheels 3’ 6” and 6’ 6”

This drawing, based on a published photograph, shows a particularly pronounced example of a phenomenon described in the introduction: the replacement of nearly all the major components of a locomotive which nevertheless inherits the number and the theoretical ‘identity’ of its predecessor.

The reason for the replacement of the mainframes of the locomotive has not been officially stated, but may be conjectured to be as follows. The mainframes of the Drummond 4-4-0s had a ‘splice’ just ahead of the cylinder block, which thinned the width of the frames by two inches overall. This device was used to facilitate the turning of the front bogie wheels on curves. Unfortunately N. B. R. engines were often lifted by the front buffers to service the bogies, and even in the case of the Holmes engines the extreme shearing pressure on the front section of the frames often caused the mainframes to buckle upwards. This syndrome can be seen in multiple photographs of Holmes 4-4-0s late in their careers.

Presumably something similar but worse must have happened to 479, the former ‘Abbotsford’, because it was rebuilt in Reid’s time with a whole new set of frames based on the Holmes pattern, but shortened by 3” at the rear end to match the Drummond design. The result was an interesting composite of different styles, though almost nothing except the tender was pure Drummond. Note that the front bogie wheels have ten spokes while the rear set has twelve – this is quite authentic.

This drawing is based in information from a variety of archive drawings, including the Gen- eral Arrangements for the rebuilt Abbotsfords and the Holmes 729 class, besides photographs. nbr490_original_Drummond_livery_2c_dwg http://euankcameron.fotopic.net/p39524969.html

Engine wheelbase 6’ 6” + 6’ 7” + 9’ 0”: wheels 3’ 6” and 6’ 6”

The lovely and celebrated ‘Abbotsfords’ are in some respects rather elusive subjects for a drawing. The archive drawings for the first Neilson batches have not been located, and the published General Arrangement for the class dating from 1878, while lavishly dimen- sioned, shows aspects of the design that never reached production, such as the feed water heating and crosshead pumps. It also shows a pattern of brake shoes that was not used on this class.

This drawing therefore shows the first of the Cowlairs-built final quartet, which employed a number of standard Cowlairs components not used by Neilsons (e.g. the steam keys and injectors). The other main difference from the first eight lies in the brake gear, which was directly operated Westinghouse air brake gear right from the start. It required something of a ‘stretch’ to fit the vertical air brake cylinder with cams and levers to driving wheels spaced so far apart.

This drawing is based primarily on the published drawing for the class and on the Cowlairs arrangement of the rebuild (for the framing) but includes details from the part drawings of the Drummond model in the Royal Museum of Scotland. nbr491_rebuild_as_1387_dwg http://euankcameron.fotopic.net/p25411750.html

Engine wheelbase 6’ 6” + 6’ 7” + 9’ 0”: wheels 3’ 6” and 6’ 6”

The remaining six Abbotsfords were rebuilt in 1904 almost identically with the first six except for the cab. The side-window cab had been introduced the previous year on the large 317 class 4-4-0s (not yet shown in this gallery). It was not exactly the same as that used on Reid’s designs: the roof lacked an angle iron, and the curve to the trailing edge of the sidesheets had a different geometry. The cabs of the Abbotsford rebuilds followed the 317 rather than the Reid pattern, though an inch shorter in height than the 317s. 1387, formerly 491, was the last of the Abbotsfords to survive in service and worked on local trains from Edinburgh into Fife in the mid-1920s. It and 1361 lasted long enough to receive full L. N. E. R. green livery and lining out, though attached to Holmes tenders by that point. The ‘patch’ over the cylinders shows where the original cylinder castings had been replaced with the later Holmes pattern, which did not have the fully cast channel for the outward section of the exhaust duct.

The cab is derived from the General Arrangement of the Holmes 317 Class 4-4-0, Cowlairs No. 1742B, slightly modified. nbr566_081_original_Drummond_livery_dwg http://euankcameron.fotopic.net/p38740314.html

Engine wheelbase 7’ 6” + 8’ 0”: wheels 5’ 0”

This drawing shows one of Matthew Holmes’s earliest products. His first designs followed Drummond’s general principles closely, but with numerous variations as to detail. Most im- portantly, Holmes insisted right from the start on flat grates rather than sloping ones. This meant in general that for any given design Holmes allowed 3” longer in the wheelbase to accommodate the firebox with its flat grate. So the first 17” 0-6-0s looked very like Drum- mond engines, but had a 3” longer coupled wheelbase compensated by a rear overhang reduced by the same amount. Holmes also resorted to slotted mainframes, not used at Cowlairs since Wheatley’s superintendency. He followed his own choices in details such as clack valves, whistle settings, and in due course also tallow cups.

There were several variants of the 566 class 17” 0-6-0 (later LNER ‘J33’ class). The first twelve had Drummond-style cabs and tenders very similar to Drummond’s design. The next dozen, the variant shown here, had Drummond cabs but the early Holmes tender without footplate valances. The next six in turn had round Stirling-type cabs and the same kind of tender. Finally, six engines were produced with round cabs and the final design of Holmes tender with valances. As a general rule the earlier engines tended to have steam brakes only as first built, while the later ones had Westinghouse and were used for mixed duties.

The drawing here is based on Cowlairs General Arrangement No. 386B, showing the first version of the 17” 0-6-0. The tender is derived from the sources for the standard Holmes tender, somewhat adapted. The livery is standard Drummond, since it has been proved that Holmes did not adopt his first distinctive style, with cream-black-red lining, until around 1886. nbr566_140_rebuild_late_livery_dwg http://euankcameron.fotopic.net/p25235817.html

Engine wheelbase 7’ 6” + 8’ 0”: wheels 5’ 0”

Two of the 566 class 0-6-0s were rebuilt or rather reboilered in 1908; the remainder were all treated between 1911 and 1913. The rebuilding process added yet further diversity to the class already distinguished by two different cabs and three different tenders, since irre- spective of age some engines received new boilers with safety valves on the dome, others boilers with a small Reid-pattern dome and safety valves on the firebox crown. In all cases the boilers had faceplate combination injectors, and therefore dispensed with the clack valves on the boiler side above the leading wheel. This drawing shows 140, one of the Westinghouse fitted engines, as rebuilt in 1912.

The drawing here varies the information contained in the Cowlairs GA No. 386B, and bor- rows details from other sources, e.g. for the rebuilt boiler. The cab is based on Cowlairs detail drawing No. 1277B, prepared for Drummond 0-6-0 No. 524 and therefore slightly adapted to take account of the different framing of the Holmes engines. nbr574_original_Drummond_livery_dwg http://euankcameron.fotopic.net/p38740315.html

Engine wheelbase 6’ 6” + 6’ 7” + 8’ 3”: wheels 3’ 6” and 6’ 6”

Matthew Holmes’s first essay in designing a 4-4-0 followed extremely closely on a design for a light 17” 4-4-0 drawn up by Drummond and built only in the form of the model in the Royal Museum of Scotland (which confusingly is named and numbered for ‘Abbotsford’, although it is nothing of the kind). Drummond had prepared two designs for light 4-4-0s, one with a 7’ 9” and one with a 8’ 0” coupled wheelbase, employing the same boiler as used on the 494 class 4-4-0Ts. Holmes took the latter design and stripped out the Drum- mond boiler with its sloped grate, replacing it with the boiler already used on the 17” goods engines of the ‘566’ class. This required the coupled wheelbase to be lengthened by 3” as on the 566s. He then applied his own design of cab and rearranged the brakes, again to conform to his 17” goods engines. Otherwise aspects of Drummond’s design, such as the bogie frame profile, spring arrangements and livery, were perpetuated on this class though on no subsequent engine built by Holmes. (Holmes would later exchange the coil and spring arrangements on the 574s to conform to his preferred practice.)

The resulting six engines were useful enough, though Holmes did not extend the class be- yond six examples. They were used as pilots and for all kinds of ‘special’ work including, for example, a ceremonial train on the occasion of one of W. E. Gladstone’s Midlothian election campaigns.

Possibly because of the unusual genesis of this class, no General Arrangement has been located specific to the 574s despite careful research. This drawing has therefore been compiled from the diagram books assisted by the copious information available for the Drummond light 4-4-0 design. However, one detail has eluded me so far, the precise shape of the tiebar that linked the rear coupled wheel brakes and must have looped around the reverser reach arm. More evidence is needed before this detail can be added. nbr574_rebuild_1911_livery_dwg http://euankcameron.fotopic.net/p25411064.html

Engine wheelbase 6’ 6” + 6’ 7” + 9’ 0”: wheels 3’ 6” and 6’ 6”

In 1911 W. P. Reid gave the 574s an extremely drastic ‘rebuild’ which essentially involved removing all of the locomotive except the bogie, wheels and tender and renewing the rest. Simply put, Reid constructed a variant of the ‘729’ class 4-4-0 but with his own design of cab and boiler fittings, and with a brake arrangement closer to that of the original 574s. This design in due course became the L. N. E. R. ‘D31’ class, an extremely useful general purpose passenger design that lasted into the early 1950s.

In one respect, however, the 574 rebuilds differed from the rest of the Holmes 4-4-0s as rebuilt by Reid. As first built in 1911 they had a weighshaft for the reverser, with a large balance weight, underneath the plane of the driving axle, linked by a long sweeping curved reach-rod to the lever reverse in the cab. This arrangement is clearly shown on the Gener- al Arrangement and is visible on a photograph of 579 at Inverkeithing before the First World War. In this photograph the usual reach-rod and lever arm normally seen in front of the left coupled wheel splasher are conspicuously absent. The 574s had had their reversing gear altered to the standard ‘D31’ pattern by the early 1920s at the latest. This drawing shows the 1911 arrangement.

This drawing closely follows the Cowlairs General Arrangement No. 3559B. nbr587_original_livery_dwg http://euankcameron.fotopic.net/p31693485.html

Engine wheelbase 7’ 6” + 8’ 3” + 6’ 6”: wheels 5’ 9” and 3’ 6”

Matthew Holmes’s 0-4-4T was an enlargement of a Drummond design, the ‘157’ class first built as 0-4-2Ts and converted to run with trailing bogies and a lengthened rear end c. 1881. The Drummond tanks had been successful in their rebuilt form and Holmes chose to produce his own version.

The coupled wheelbase was the same as in the Drummond 0-4-4Ts, and also the same as the front section to the wheelbase of the Drummond and Holmes 0-6-0s. This allowed the re-use of the valve gear layout from the Drummond and Holmes 17” 0-6-0s and a number of standard components. Holmes lengthened (by 3”!) the distance between the rear driving wheels and the bogie wheels to accommodate the flat grate of the boiler from the ‘566’ class 0-6-0s and the ‘574’ class 4-4-0s. The cylinders were 17” x 24”. Overall Holmes stretched the rear end of the Drummond 0-4-4T design by a few inches here and there, allowing the side tanks to be made slightly lower and the whole design less top-heavy.

After this design Holmes evidently decided that, with the Drummond small 0-6-0 and 4-4-0 tanks for local work, and the large 4-4-0Ts and two classes of 0-4-4T for heavier trains, all the needs for passenger tank engines on the N. B. R. had been met. No further passenger tank engines were built until Reid’s time, and those were enlargements of the 586 class with bigger boilers at higher pitch.

This drawing has been prepared using Cowlairs General Arrangement No. 890B, the original works drawing for the class. nbr589_rebuild_late_livery_dwg http://euankcameron.fotopic.net/p25267783.html

Engine wheelbase 7’ 6” + 8’ 3” + 6’ 6”: wheels 5’ 9” and 3’ 6”

The Holmes 0-4-4Ts were rebuilt around the same time as the 17” 0-6-0s, with the same boilers as the latter, and with the same resulting diversity between examples. Some locomotives received new boilers with safety-valves on a Holmes-pattern dome like the originals; others, like the one shown here, were fitted with the small closed Reid dome and safety-valves over the firebox crown. Injectors and a variety of details were brought up to date. As L. N. E. R. class G7 the class continued to work into the grouping on a variety of branch and local services.

This drawing has been prepared with the assistance of Cowlairs General Arrangement No. 4133B, prepared for the rebuild. nbr600_original_Holmes_livery_dwg http://euankcameron.fotopic.net/p25232614.html

Engine wheelbase 6’ 6” + 6’ 7” + 9’ 3”: wheels 3’ 6” and 7’ 0”

The twelve majestic Holmes ‘seven-footers’ appeared between 1886 and 1887 and are personal favourites of mine. Technically speaking, Holmes designed a boiler with the of an ‘Abbotsford’ type, with a 10’ 3½” barrel and 6’ 6” firebox, and of course with a flat grate. He then inserted this boiler in an Abbotsford-style mainframe, adjusted for the 7’ 0” wheels, and lengthened the coupled wheelbase by the necessary three inches. One curious anomaly was that although the cylinders were 18” x 26” as on the Abbotsfords, Holm- es fitted a slightly narrower chimney of dimensions more usually associated with 17” cylinder engines. The slightly greater degree of ‘choke’ was a good idea and was taken up on many engines when rebuilt.

The result was satisfying visually and extremely successful mechanically. These engines were used on the principal express trains of the N. B. R. for many years even after they had been superseded by later and more powerful designs.

This drawing follows the Cowlairs General Arrangement No. 941B for the class as first built, with the frame details cross-checked with the drawing of the rebuild. nbr600_rebuild_first_livery_dwg http://euankcameron.fotopic.net/p31496513.html

Engine wheelbase 6’ 6” + 6’ 7” + 9’ 3”: wheels 3’ 6” and 7’ 0”

W. P. Reid gave the seven-footers a much more modest rebuild than the 574s in the same year as the latter, 1911. The frames, cylinders and valve gear arrangements were basically untouched apart from renewal of worn parts, although the cylinder blocks were renewed with the later Holmes 633 pattern, which was mechanically identical though different in casting details. The brakes were altered to a clasp arrangement like that used on Holmes’s West Highland Bogies and 317s and the Reid 4-4-0s. The boiler was similar to the original though slightly different in construction, and of course more modern injectors and safety valves were fitted. The main visual changes were the more pronounced taper on the chimney, a distinctive and attractive feature, and of course the side-window cab. Even in their altered appearance the engines remained very elegant.

As rebuilt the seven-footers continued to work Edinburgh to Glasgow expresses into the 1920s as well as local trains all over the system. No. 603 worked on the West Highland line for some years, most implausibly for an engine with such large wheels but with appar- ent success.

This drawing follows Cowlairs General Arrangement No. 3564B. Note that although this drawing shows the engine with Westinghouse brake only, most of the class were ultimately dual braked. nbr602_original_Holmes_pow_livery_dwg http://euankcameron.fotopic.net/p33056110.html

This drawing shows the special decoration devised for Seven-footer No. 602 when it drew the ceremonial train at the opening of the Forth Bridge in 1890. It also shows some of the extra detail, including the highlighting of wheel centres and spokes, that Holmes used for his higher-status passenger engines before 1893.

The sources for this drawing are the same as those for the other Seven-footers. nbr634_original_Holmes_livery_dwg http://euankcameron.fotopic.net/p25373229.html

Engine wheelbase 6’ 6” + 6’ 7” + 9’ 0”: wheels 3’ 6” and 6’ 6”

Holmes waited until 1890 before adding to the number of 6’ 6” express engines with a 9’ 0” coupled wheelbase. The 633 class began to appear in that year and production continued into the middle of the decade. These were entirely straightforward engines in what was now Holmes’s mature style, and they were both reliable and on occasions very fast indeed. No. 293 reputedly held for many years – perhaps still does – the record for the fastest run from Edinburgh to Dundee, at an almost unbelievable and terrifying 59 minutes.

The locomotive shown here was the subject of quite a celebrated photograph taken at Perth around the middle to late 1890s. It shows the locomotive as built but in the later Hol- mes livery. Note that this particular example had bogie wheelsets with twelve rather than the more normal ten spokes. These anomalous bogies circulated around the Holmes 4-4- 0s even after rebuilding.

The drawing is based principally on Cowlairs General Arrangement No. 1197B, supplemented by a number of other drawings and additional evidence. nbr641_Reid_rebuild_late_livery_dwg http://euankcameron.fotopic.net/p25411065.html

Engine wheelbase 6’ 6” + 6’ 7” + 9’ 0”: wheels 3’ 6” and 6’ 6”

This drawing represents the more typical ‘D31’ type rebuild, in this case of a 633 class 4-4- 0 carried out in 1918. The Reid / Chalmers rebuilds of the later Holmes 4-4-0s were much less radical than those that produced the first six, Nos. 574-9. In these later rebuilds the frames were mostly untouched, except that the weighshaft for the reversing gear was moved from below the plane of the cylinders to some 16¾” above it, and the now redun- dant lower frame extension was cut off. This gave a more direct and natural link to the lever reverse that replaced the Drummond-style screw reverser on the rebuilds.

This drawing shows the Reid pattern rebuild with Adams equalized bogie springing and the taller, more tapered chimney. Walter Chalmers designed a slightly different pattern of rebuild with independent helical springs on the bogie axles and a parallel chimney one inch shorter than on the Reid versions.

This drawing follows the Cowlairs General Arrangement No. 3559B with modifications. The example illustrated, No. 641, worked from Dunfermline Upper shed on the eve of grouping. nbr660_original_Holmes_livery_dwg http://euankcameron.fotopic.net/p25232610.html

Engine wheelbase 7’ 6” + 8’ 0”: wheels 5’ 0”

Drummond’s 18” goods engines had shared boiler designs with the ‘Abbotsford’ 4-4-0s – indeed the reverse is more true, since the first Abbotsfords were built with materials for some 0-6-0s ordered but then cancelled in favour of 4-4-0s at the last minute. However, Holmes abhorred the steeply sloping grates of the ‘big Drummonds’ and took until 1888 before producing an equivalent 18” goods with a 4’ 6¼” diameter boiler. In the end he struck a compromise between the large and small Drummond goods. He gave his 18” 0-6- 0s a boiler barrel 10’ 2¼” long and a firebox 5’ 5” long, the latter being the same length as fitted to the 17” goods. The cylinders and valve gear of the big Drummonds were incorpo- rated without significant alteration (indeed Holmes used Drummond’s two standard valve gear layouts for new locomotives for most of his career). The result was the most numerous class of engines on the N. B. R., built almost identically both by Cowlairs, Neilsons and Sharp Stewart. (Neilsons showed a touch of individuality by varying the cutouts on the tender mainframes from Holmes’s standard – take a close look at Maude’s tender for compar- ison.)

The drawing here shows No. 660, one of the Cowlairs-built engines. It is based on Cow- lairs General Arrangement No. 1109B and also on the Sharp Stewart General Arrange- ment. The sources for the Holmes tender are multiple, including Cowlairs drawings Nos. 1403B and 5020B. nbr660_rebuild_late_livery_dwg http://euankcameron.fotopic.net/p25232606.html

Engine wheelbase 7’ 6” + 8’ 0”: wheels 5’ 0”

W. P. Reid’s rebuilding of Holmes’s 18” goods engines preserved the lengthwise dimensions of the boiler but enlarged the diameter considerably (to the same as seen on the ‘729’ class 4-4-0s) and also raised the pitch slightly. At the same time the chimneys were fitted to 4½” less than the full height allowed by the loading gauge, yielding a maximum height of 12’ 7½” and making the design look even more compact. Apart from the reboilering and the new side-window cabs, little was changed in this very successful goods locomotive design.

No. 660 was rebuilt in 1913, before the black goods livery and control numbers came in, and can therefore be depicted accurately in the full N. B. livery of the Reid period.

The locomotive drawing is based on Cowlairs General Arrangement Drawing No. 4314, prepared for the Reid rebuild, and the tender on drawing 5020B. nbr700_original_dwg http://euankcameron.fotopic.net/p25235815.html

Engine wheelbase 6’ 6” + 6’ 7” + 8’ 2”: wheels 3’ 6” and 5’ 7”

The Holmes ‘West Highland Bogie’ or 693 class was an interesting venture. Holmes inserted the boiler from his very successful 18” goods, complete with its shorter than normal smokebox, into a shortened passenger locomotive frame, adapted for much smaller driving wheels. He then fitted 18” x 24” cylinders, with their stroke an inch shorter than was standard for the Drummond and Holmes 4-4-0s.

Produced from 1893 onwards ostensibly as a small-wheeled version of the Holmes 4-4-0 for the West Highland Railway, more of the class were built than the rather sparse sched- ules of the West Highland line could possibly require, and they worked on secondary, local and mixed traffic in all sorts of areas of the N. B. R. system. They are reported to have been slippery customers, but one wonders whether this was in the somewhat special con- ditions of the West Highland (where the same criticism was more recently made of the ‘Glens’).

The West Highland Bogies were not rebuilt with the exception of No. 695, which underwent a complicated and expensive rebuild, involving two successive sets of new frames, to accommodate the boiler design from the Reid superheated 4-4-2Ts and cylinders with piston valves above. The fact that the remainder were not rebuilt has contributed to the impres- sion that they were relative failures. It is a mystery to me why the class was not more simply and much more cheaply rebuilt with the boiler from the rebuilt 18” 0-6-0s (the ‘J36’ design) which would have fitted in the locomotive without the need for any drastic mainframe reconstruction. The perception may well have been that, given the relentless increase in the size and weight of carriages, the age of smaller 4-4-0s was past.

The drawing is based on the published General Arrangement of the class for both locomotive and tender. nbr765_original_dwg http://euankcameron.fotopic.net/p25235814.html

Engine wheelbase 6’ 6” + 6’ 7” + 9’ 0”: wheels 3’ 6” and 6’ 6”

In 1898 Holmes copied the initiative taken two years earlier by J. F. McIntosh of the Cale- donian and fitted a substantially enlarged boiler into his standard 4-4-0. In reality virtually nothing was changed from the frames and motion of the 633 class: the nominal increase in cylinder diameter to 18¼” was no more than a slight boring out of the standard casting, and many locomotives theoretically with 18” cylinders had cylinder bores as wide as that and more. The principal change was the enlarged boiler; important additional details were the new combination injectors on the backhead and the pressure sanding gear under the running plate. The cab was extended backwards somewhat, and additional handrails and footsteps were provided for the convenience of crews.

The 729 class took over from the earlier 4-4-0s on the major expresses. They ran for some twenty years before being rebuilt to the ‘D31’ pattern, which entailed purely cosmetic changes, the essential size and mechanical workings of the locomotives remaining unchanged. It was some of the 729 class that lasted the longest of all, working on the Silloth branch trains into the early 1950s.

This drawing is based on Cowlairs General Arrangement No. 1508B.