MILEPOST 40 Glorious Years – The HSTs 40 RPS railway performance society railperf.org.uk ay performance society 40 Glorious Years – The HSTs -1- October 2016 www.railperf.org.uk RPS railway RPS Photos Front cover: HST along sea wall - Chris Taylor This page: HST at Cardiff - Bruce Nathan Centre pages: HST leaving York - Chris Taylor Back page: HST arriving Doncaster David Ashley 40 Glorious Years – The HSTs -2- October 2016 Contents Tables Page Page 4 Introduction 5 Traction power history David Stannard 7 HST Prototype - the early days Michael Bruce 10 Day One David Burton 12 GWR 30 15 GWR in 2016 17 Berks and Hants John Heaton 40 18 Taunton-Tiverton Parkway John Heaton 42 19 Plymouth-Penzance 44 20 The Cotswolds Line 45 20 Cross Country: Birmingham-Derby 46 21 Cheltenham-Birmingham 59 22 Midland Main Line 22 Kings Cross-York - fasts 48 24 York-Darlington 52 24 Kings Cross-York - stopping trains 54 26 Highland Line 58 26 The Future 40 Glorious Years – The HSTs -3- October 2016 . 40 Glorious Years – The HSTs So what do you remember about 1976? To remind you of our way of life back then, we summarise below some of the highlights: Harold Wilson handed prime-ministership to James Callaghan Jeremy Thorpe resigns as leader of the Liberal Party and is replaced by David Steel James Hunt becomes Formula One champion John Curry – Gold medallist in Winter Olympics NEC opens in Birmingham Selby coalfield opens Production of Hillman Imp finishes after 13 years, and Ford introduce the Fiesta. Mark IV Cortina launched The first commercial flight of Concorde takes off Brotherhood of Man win the Eurovision Song Contest with “Save your kisses for me” (since then, only Bucks Fizz and Katrina and the Waves have won the competition for UK – twice in 40 years) Inflation was 16.5%pa Heatwave from 22nd June to 16th July, with the peaks of 35.6C on 28th June and 35.9C in Cheltenham on 3rd July. Parts of South west England go for 45 days without rain. The worst drought since the 1720s The first High Speed Trains start running at 125mph It is a sobering thought that, of those individuals identified, only one is still with us – David Steel. It is equally surprising that the Selby Coalfield, which was to be the saviour of UK energy following the 1973 oil crisis, had all but disappeared by 2004 Who can forget the complex and intensive rail timetable needed to take thousands of visitors from London to Birmingham International for the British International Motor Show at the NEC. Similarly, it only stayed there until 2004, when it moved back to London Excel and was abandoned after 2008. We can only be sad that Concorde that didn’t survive in passenger service beyond 2003 It is ironic that, perhaps, the only 1976 “success story” was the High Speed Train, but that it was intended to be a stop-gap until the arrival of the Advanced Passenger Train, and which was ultimately beset with problems. 40 Glorious Years – The HSTs -4- October 2016 And yes, although we are supposed to be suffering from Global Warming, there has not been a hotter summer in the UK since 1976. So, we are going to review the life of the HST throughout the past forty years, perhaps recalling something that you had previously forgotten, plot the changes to the infrastructure during this time and highlight some performances that seem unbelievable today. We will look at the routes geographically, concentrating on the main line initially, but also examining the progression of the fastest times on “interesting” sections. We will also select secondary routes worthy of your attention. We will probably present the highest ratio of 125mph+ speeds ever to have appeared in an RPS booklet. Look after your broom It is easy to believe that the trains we look at today are the same ones that existed forty years ago. But like Trigger in Only Fools and Horses, who maintained that he had his original broom, although it subsequently received 17 heads and 14 handles, the HSTs had different engines, different branding, different furniture (and lots more seats) and probably different suppliers of each during their lifetime. David Stannard reviews the traction power history: HST Class 43 traction power history David Stannard Small but significant differences in the rate of speed build-up have been noted during prolonged accelerations of HST sets following the fitment of modern MTU 4000 series engines despite these nominally being set to the same rating as the original Paxman Valenta 2,250hp power units that they replaced in order to maintain compatibility with the retained alternators and traction motors. To investigate what has been going on, the Class 43 traction power history has been investigated by performance modelling of accelerations in running-log timings recorded in the extensive Railway Performance Society database archive for HST sets operating between Didcot and Swindon on the Great Western route and northbound from York on the East Coast mainline. The analysis performed is a very ‘broad-brush’ statistical exercise in that the modelling, whilst taking into account line gradients and set formation characteristics, fits just a single rail traction power independent of speed above the initial constant tractive effort regime to logs which range in quality from precision timings of most individual mileposts to more commonly recorded passing times of standard RPS line-side location waypoints rounded to the nearest second. Tolerance fitting analysis and variation analysis for uncertainties in passenger loading (not always recorded by timers) suggests expected scatter of between 2 and 3% in the derived traction powers, whilst in-built model assumptions may produce systematic offset bias of up to a somewhat similar amount. The results for three independent samples of HST sets (including commissioning tests on the ECML) are presented below normalised to the nominal Class 43 mean rail traction power output of 1,770hp (1,320kW). 40 Glorious Years – The HSTs -5- October 2016 Class 43 rail traction power history (triangles: commissioning tests, diamonds GW sets, crosses EC sets) Although this sort of approach is a very indirect method for the investigation of traction powers, on the whole the modelling gives consistent results for HST sets operating on the different routes and seems to have coped well with adjustments to set formations with little change evident in the traction power outputs on strengthening of the Great Western sets from 7- to 8-cars in the late 1980s and of the East Coast sets from 8- to 9-cars around 2004. There will always be occasional individual runs with apparent low power but, with the same analysis methodology used throughout, two pronounced changes appear to have occurred. The first is a sharp increase in rail traction power of around 10% to perhaps just slightly over the nominal rating on fitment of the MTU engines from the mid-2000s onwards. The change most likely follows control system recalibration after both engine replacement and full overhaul of all traction equipment and is what accounts for the noticeable improvement in set acceleration in recent years. The second is an apparent quite marked reduction in the traction power output of the Valenta powered sets by around 7% around 1983 or early-1984, with output remaining down at this new lower level thereafter. It is tempting to link this to the well-documented engine coolant problems which came to a head at about this time but folklore has it that, other than it not being uncommon for individual power cars with particular problems to operate with the top notch relay resistor temporarily ’strapped out’ to restrict power by 20% (evident in the data in increased low power scatter both then and when there were problems with exhaust manifold failures a few years later), there was no general de-rating of the Class 43 power cars from their original output. Another possibility could be an earlier coincidental change to engine calibration or set-up procedures following overhauls at BREL Derby, which were by then occurring at intervals of around 12 -15 months, but correct engine setting would almost certainly have been looked into carefully during investigations at this time. All then something of a mystery remaining to be properly explained. Although replacement MTU engines have been fitted to most HST fleets, sets operating on the Midland main line have been re-engined with Paxman’s successor to the Valenta, the VP185. The performance history of HSTs operating on the Midland route has been investigated by modelling accelerations northbound from Leicester, with simple time-period averages (excluding anonymously low values) presented here due to increased uncertainty in the individual traction powers derived from what are relatively short duration accelerations (predominantly on down gradients and to only moderate line speed limits – initially only 90 mph before track upgrade improvement works). 40 Glorious Years – The HSTs -6- October 2016 Midland HST Rail Traction Power (relative to nominal 1770hp/1320kW per power car) Paxman Valenta-engined sets Mean and standard deviation 1982 Service introduction on Midland main line (2+7) 2 measurements only: 0.99 & 1.01 1983-89 Initially 2+7 sets, gradually strengthened to 2+8 N=16 0.92 (0.04) 1990-94 2+8 formation sets N=12 0.91 (0.03) 1995-99 2+8 formation sets N=12 0.93 (0.03) 2000-05 2+8 formation sets N=12 0.91 (0.03) Paxman VP185-engined sets 2006-16 2+8 formation sets N=12 0.99 (0.03) The findings are very similar to those for the power cars of the Great Western and East Coast fleets.