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Inside Stories BOLINGBROKE ON FLOATS

Robert S Grant reveals how an example of the Canadian-built Blenheim – the Bolingbroke – was temporarily converted for waterborne trials

t’s strange how a British Type 142, constructed to his In November 1937, what was a Inewspaper proprietor could specifications, drew RAF interest leisurely peacetime workshop affect seaplane operations in and eventually led to the newly began steps that would turn the a faraway country such as . designated Type 149 Blenheim company into one of the largest This is exactly what happened Mk.I’s maiden flight on June aircraft builders in Canada. Hubert when owner Harold 25, 1936, at Filton, near Bristol. M Pasmore, president of Fairchild Sidney Harmsworth, 1st Viscount The light twin-engined bomber Aircraft’s Canadian subsidiary in Rothermere, decided to acquire advanced to the Bolingbroke Longueuil near Montréal, Québec a personal transport in 1934. The variant, which also flew its initial knew the Bristol Aeroplane Company’s trip at Filton. (RCAF) was seeking a

88 FlyPast May 2020 . An astute patrol saltwater coasts, leading to that better results will be obtained businessman and pioneer pilot, proposals to convert Bolingbrokes if the Edo Company or MacDonald !" $% & The RCAF’s Pasmore lobbied on both sides of to seaplane configuration. Brothers is given an opportunity to Flt Lt A O Adams the Atlantic for an agreement to Unfortunately, few knew the do this work,” said Fairchild’s general expressed his belief that the Bolingbroke’s licence-build an initial batch of 18 difference between metal- manager N F Vanderlipp, who added: wing centre Bolingbrokes. Thanks to influence crunching ocean swells and gentle “In our estimation, the Edo float section would need from Canadian Prime Minister rippling brooks. and gear is sturdier than the Short, strengthening, as well William Lyon Mackenzie King, Questions rose as to which and this contractor is in a position as an increased fi n the British-built example became manufacturer would build the to work with the Edo Company to area for directional control. His view a pattern for the first all-metal ‘seaplane alighting gear and produce the best results.” was later justifi ed stressed skin aircraft manufactured its associated supports’. Bristol by installation of a in the country. In return, Fairchild submitted recommendations Structural conundrum ventral fi n below the despatched technical personnel that its British-built aeroplane On September 16, 1938, RCAF horizontal stabiliser. to England to study the machine’s would be satisfactory in strength Flt Lt Al James pointed out that KEY COLLECTION intricacies. Within two years, the and performance, suggesting that no drawings existed for a twin- 01&&12 $% & Fairchild first Canadian unit took flight under structures should be designed before float installation. It could not be general manager N F the command of RCAF honorary stress studies were conducted. determined whether the seaplane Vanderlipp suggested group captain and test pilot James Ireland’s Short Brothers assembled chassis should be attached directly the Bolingbroke 717 Harold Lymburner. A total of 626 its offering, but RCAF engineers did to the underside of the fuselage or have extra buoyancy forward during Bolingbrokes had entered service by not approve the narrow float track beneath the engines. Designers also operations in rough the time production ceased in 1943. and consequent instability. needed to address crew visibility, ocean conditions. None served overseas, although 115 Fairchild became the next to water spray damage and bomb- The factory complied and 8 Squadrons were deployed to analyse structural strength and dropping clearance. Most float and the Edo 37- Alaska’s Aleutian Islands. torsional stiffness, followed by aircraft depended on spreader bars 15750s fl oats appear bulged in the front RCAF Defence Headquarters’ for rigidity but, in this case, such section. LIBRARY AND The right design decision to place orders with arrangements were impractical as ARCHIVES CANADA Somewhere within British and MacDonald Brothers Aircraft released ordnance could explode Canadian military hierarchies, in , via Fairchild. The on contact with the bars. Since the 0%$1: $% & Test pilot the ‘top brass’ remembered that colonial organisation produced Blenheim/Bolingbroke aircraft James Lymburner received his Canada possessed the world’s floats under licence from New commercial pilot’s longest coastline of 136,755 miles York’s Edo Corporation, including licence in (220,080km) with bays, sounds and some for the US Army’s Martin January 1931, sheltered areas. Further inland, YB-12 bomber. Units completed later joining two the country’s vast lakes and rivers to Fairchild’s specifications would Ellsworth Antarctic Expeditions and had already enjoyed the touch of be transported east by rail from enjoying years as seaplanes and skiplanes. It seemed Winnipeg to Longueuil. a bush pilot with natural for a wilderness nation “In view of the present industrial Canadian Airways. to call upon bushplane types to situation in England, it is believed He also test-fl ew the fi rst Canadian- built . He died on August 5, 1990. CANADA AVIATION AND SPACE MUSEUM

01&&12 >%?&"% Photographed in 1941 at Dartmouth, Nova Scotia, Bolingbroke 717 awaits its fate in company with RCAF Stranraer fl ying boats. Reports stated how ocean landings stretched the metal covering and the RCAF was “A total of 626 displeased with the magnesium alloy fl ap Bolingbrokes had trailing edges. LIBRARY entered service by AND ARCHIVES CANADA the time production ceased”

May 2020 FlyPast 89 Inside Stories BOLINGBROKE ON FLOATS

!"#$ A November 6, were in active service, authorities required anti-corrosion protection. and 16 transverse sections of Alclad 1939, letter demanded would provide just enough Watertight compartments, with (metallurgically bonded layers of that it should “be information without divulging nose bumpers and towing bridles corrosion-resistant aluminium possible for a crewman to gain access to military secrets. for mooring, provided buoyancy sheet), fastened to a welded frame either fl oat from On water, explained Flt Lt E H and surface handling. The with dural . Two footsteps the cockpit or cabin Higgins, drag from struts and specifications also stated that, when on each side of the inboard steps and make fast the supports could increase porpoising taxiing, “floats must not submerge provided entry to the cockpit. anchor lines while the and loss of control during take- in 40-knot winds”. The writer With orders confirmed, airscrews are turning.” Clearly, anyone off. Access to underside hatches naively underlined: “Calm water MacDonald Brothers submitted standing forward of created further danger to personnel must be assumed.” preliminary drawings. Critics the propellers would – the standard front entry could On January 20, 1939, Fairchild quickly highlighted that signed be in grave danger not be used with engines running estimated that one pair of Edo provisions for drain plugs had not from wind and wave since clearance between the 37-15750 floats would cost C$20,470. been incorporated and just 5in movement. LIBRARY AND ARCHIVES CANADA propeller and fuselage measured This grandiose figure included (12.7cm) handhole covers were just 12in (30.4cm). Higgins raised bilge pumps, crew steps and water intended instead of the stipulated the possibility of openings beside constructed from weld- versions greater than 7in (7.7cm). props or behind bomb doors. wood (plywood) to save weight. Draughtsmen somehow overlooked “The objection of the first position Anchors and ropes did not come as anti-corrosion treatment and it was is again the danger of falling part of the package, but adequate noted that joining dissimilar metals forward into the airscrew disc,” mooring eyes did. Fairchild’s would hasten corrosion. Fairchild Higgins reported. “This danger, secretary-treasurer R B Irvine engineering staff went back into however, could be minimised quoted an October delivery subject their offices and the floor workers by means of a detachable ladder to orders within 30 days and cut more metal. Everyone looked running from the float to the aft contingent upon no embargoes, forward to the completion of the end of the walkway on the centre accidents, strikes or delays beyond floats as the European war had section wing. It is not very difficult the company’s control. erupted on September 1, 1939. to move from one wing to the other The RCAF questioned the price over the top of the fuselage, by wing and Fairchild re-tabled C$13,507.50 Finished fl oats or ladder from the float to the wing for an initial pair and C$11,483.08 On May 18, 1940, MacDonald on each side.” per set with an order for 23 pairs. Brothers advised that two pairs In January 1939, the RCAF Within days, Air Cdre Ernest of Edo 37-15750s were available Equipment, Development and Stedman approved a construction for acceptance and delivery to Staff Division handed over 52 contract. Each pair weighed 1,636lb Fairchild. Pasmore’s company specifications for what became the (742kg) upping the type's gross was in the process of producing solitary Mk.III version. Naturally, weight to 13,500lb (6,124kg). Track 15 wheels-only Bolingbrokes and specialised would be measured approximately 18ft intended to assign the 16th off the “built entirely within the Dominion (5.49m) and skin coverings of each line for seaplane experiments. of Canada” and all alloys and steel unit cmprised five longitudinal In the interim, ’s National

90 FlyPast May 2020 lying prone in his position in the vastitudes’ contained more than very nose of the airplane gets his 80,000 separate pieces and 900 sights on the target and presses bolts,” boasted Canadian Aviation the bomb triggers, spring-loaded in the December 1941 edition. doors open.” Curiously, the aircraft designed for war carried only one Eclipse Added strength generator and a single Pesco When 717 made its public debut hydraulic pump. as the world’s only Bolingbroke Both starters turned the three- seaplane, spectators could not bladed de Havilland propellers have been aware of modifications easily and 18 cylinders nourished incorporated into the airframe. by 87 octane fuel came to life. Life in ‘heavy’ waters was not In 12mph (19km/h) surface gentle. In this case, the 56ft 4in winds, Lymburner selected the (17.17m) wing required special box ribs integral with the centreline where the fuselage was joined. Strengthened joints received extra tube bracing, and front and rear struts were cross braced with wire. Covered wells where wheels were previously stowed remained unsealed – not for streamlining or aesthetic reasons, but those of practicality. The rounded nacelle Research Council (NRC) carried fairing panels afforded cut-outs out wind tunnel testing on model for float struts and reduced water aircraft. Results tabulated positive exposure to electric lines and and cost Fairchild C$1,443.11. various tubing. “It is therefore concluded that As test pilot Lymburner slipped the longitudinal stability of the and slid down the grassy banks Bolingbroke seaplane normally of the Ottawa River towards 717 loaded will be perfectly satisfactory, on August 28, 1940, the only noise and it is further concluded that came from the thump of his the rearmost permissible centre of boots on the floats, while fitters gravity position for the seaplane primed bilge pumps and secured should be taken as 15 inches behind inspection panels. He knew the the centre line of the front spar,” reported NRC acting president Chalmers ‘Jack’ Mackenzie. “The so-called Numbered Bolingbroke 717, the subject aircraft had flown on answer to Canada’s July 25, 1940, fitted with wheels before transfer to RCAF Station maritime patrol Rockcliffe’s Test and Development requirements four-panel flaps to 15°. Highly !"#$ The cockpit Establishment on the Ottawa River. experienced in pre-war bush flying, of a land-based Locals already recognised the he knew how to ‘feel’ his way off did not ‘cut it’ Mk.IV restoration at flying machine from newspaper militarily” the water and began the first of Quebec’s Montreal publicity. Slower bush planes had three take-offs. No porpoising Aviation Museum in been operated from the river for occurred. With the Bolingbroke’s Ville de Sainte-Anne- decades, but the new bomber was high wing loading of 31 1/2 lb/sq de-Bellevue shows state-of-the-art. first flight would be anti-climactic ft, runs lasted half-a-mile with what test pilot James Lymburner faced on “The Bolingbroke which streaked without military bands and little cowl gills open for cooling. The August 28, 1940. across Rockcliffe Field at 300 miles more than a few orange-beaked last occurred with +7lb boost. At ROBERT S GRANT an hour is a Canadian version of seagulls surveying the proceedings. 2,500ft and 2,200rpm, airspeed the , which has punchers in wartorn Filton showed 175mph (282km/h) with the top performance of all [twin- could never have predicted that reduced power. Wheeled four-crew engined] types,” Lord Rothermere’s basic design versions with drag-free retractable read the November 22, 1939, issue would lift away from a distant undercarriages averaged 220mph of Ottawa Journal . “Streamlined Canadian river. “Powered by 995hp (354km/h) with the same settings. as a barracuda, the Bolingbroke XV radial engines, Task completed, Lymburner carries all its bombs within the the flying machine intended for rounded out for landing. As the fuselage. When the [bomb aimer] monitoring Canada’s ‘yawning floats contacted the river and

May 2020 FlyPast 91 Inside Stories BOLINGBROKE ON FLOATS

!"#$ De Havilland DHC-3 Otter CF-ODK at Sault Ste. Marie, Ontario, has been pushed from hangar to river side on the same beaching gear used for the 717 ‘Water Bolly’. ROBERT S GRANT

splashed the surface, float bottoms Wg Cdr Herbert Carefoot stated Command to release 717 when the took the load from the wings and on November 22 that his pilots Ottawa River opened to navigation. he lowered the water rudders performed 15-second take-offs and Before departure from Dartmouth before returning dockside. Above landings in 2 1/2ft (76cm) waves to Rockcliffe, service trials should the crinkling of cooling Mercury of “fairly rough chop” and that be continued and, if possible, engines, Lymburner pointed out despite “considerable weaving of crews should participate in actual that the Edo-equipped Bolingbroke the floats” no structural damage patrols, but defective flaps kept was the only aircraft he had flown occurred. However, although the the aircraft grounded. Although “that would take off at near gross outlook seemed positive, in-depth no descriptions of single-engine weight on cruising power.” As investigations revealed intensive capabilities have surfaced, power elated as the ’s metal corrosion and cracked fittings. failures undoubtedly meant open 3,900 employees in Longueuil, 128 Magnesium alloy components ocean emergency landings, with miles (207km) east of Ottawa, he were so badly affected by saltwater predictable results. In February pronounced the project a success. that technicians recommended 1941, 717 went onto wheels again In follow-up reports, Lymburner grounding the aircraft, because with the Mk.III designation suggested introducing a hydraulic flaps and wing trailing edges unchanged. The so-called mechanism for raising and lowering became unserviceable. answer to Canada’s maritime the heavy water rudders in order patrol requirements did not to improve steering. Technicians By the numbers ‘cut it’ militarily. installed a 1,000cu ft (28.3m³) air By the time 717’s smart new floats On June 26, 1941, this bottle to reduce pull-up load and had splashed away from Ottawa memorandum sealed 717’s fate. “It provide a 35° steering range on and toward Nova Scotia’s Halifax will be noted that the bomb load either side of centre. Lymburner’s Bay, performance data had been with full fuel capacity is 500lb notes also mentioned poor posted. According to an undated and as this can only be used under longitudinal stability, so a steel and table, figures showed a 9,370lb the most favourable weather fabric ventral fin was developed. (4,250kg) ‘bare’ weight. With 468 conditions, it is suggested that the Initial proposals specified imp gal short-range fuel tanks, Bolingbroke seaplane will not be seaplane fittings on all production aircrew could expect 200mph a useful type,” concluded Gp Capt Bolingbrokes, but caution (322km/h) or a 990mile (1,593km) Alan Ferrier. narrowed the number to 23, range carrying one 250lb (113kg) A glimmer of hope remained: not including 717. With RCAF bomb. Input from Bristol on AVM Stedman remarked that staff, Fairchild workers and Edo February 6, 1941, claimed evidence perhaps two sets of beaching gear designers working nearly non- of approved 16,000lb (7,258kg) might be exported to the UK. The stop, a morale-breaking edict overload take-offs. Two days possibility of operating a ferry was delivered when Air Cdre later, another communication service in the aircraft’s ancestral Stedman said that “equipping these recommended 15,200lb (6,895kg) country existed, but no further aircraft as seaplanes is not urgent.” take-off with zero bombload. word came. Instead, 717 underwent Nevertheless, during November Confident RCAF upper echelon overhaul in September 1941 until 1940, Bolingbroke 717 was ferried staff stated that “reasonable the dreaded ‘reduced to spares’ to Eastern Air Command 5BR in guesswork, water condition and order arrived on June 21, 1944. Dartmouth, Nova Scotia, for service care exercised by the pilot” would Perhaps a patch of farmland trials in the remaining ice-free do the job. Lymburner’s take-offs or a backwoods shed in the 1940-41 season. occurred at 14,100lb (6,396kg). Dominion of Canada holds the Delivery delays and unsatisfactory On March 11, 1941, chief of staff remains of the world’s only Bristol weather hindered operations, but Francis Heakes ordered Eastern Air Bolingbroke seaplane... FP

92 FlyPast May 2020