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The Advanced Passenger Train or APT is the name of a series of experimental and production trainsets designed to speed up rail journeys through their novel use of a tilting system to reduce the centrifugal forces felt by passengers inside the train. The original concept came about through research undertaken by the British Railways Research Division at Derby Railway Technical Centre in the 1960's. At the time, work on enhancing journey times on main line services in the UK had mainly come about through improving acceleration/braking on rolling stock, easing specific infrastructure restrictions, and better signalling. However on routes such as the West Coast main line, the gains possible through improving super elevation or more powerful rolling stock were reaching a point of diminishing returns. The route itself, made up of some of the World's oldest intercity railway was sinewy for much of its length. Although rolling stock and track was capable of sustaining higher top and average speed, the degradation in passenger comfort would be intense as the effect of the numerous curves made themselves felt. One answer was to build a new, straighter route capable of higher average speeds, as was being looked into at the time in France and Japan. However, the very serious costs involved in such a venture ruled this out at an early stage. Thus the way was set for the tilting train to make its presence felt.

APT-EEdit

Studies throughout the late 1960's led to the decision to push ahead with the construction of a test set made up of a gas turbine powered proof of concept set. The train, named "Advanced Passenger Train - Experimental" featured a number of high tech innovations, many introduced by the specially created design team deliberately brought in from outside the industry. The body of the train itself borrowed from fuselage technology then being utilised in the growing airliner industry. This led to a train that was strong, and yet 45% lighter than a comparable piece of roiling stock then being constructed by British Railways. Another link to the aerospace sector was the use of the aforementioned gas turbines to power the train. As well as their high power to weight ratio and high economies at high speed, they also allowed the "E-train" to operate across the network to allow demonstration to a number of potential customers. The APT-E was designed to operate at speeds up to 155mph/250kph, but within a braking envelope similar to trains then only operating at 100-110mph. To achieve these high levels of deceleration, a novel "hydrokinetic" system was implemented which used the power of water to act against turbine blades on each axle to slow the train. This allowed high rates of retardation to be applied without creating exceptional amounts of heat and requiring frequent replacement of costly brake pads.

The APT first made a run out from Derby during July 1972, but immediately fell victim to the strained Union relations existing at the time and was blacklisted for only having one seat in the driving cab (Midland Railway services at that time requiring both a driver and second man due to agreements with ASLEF and the RMT). Attempts to move the set elsewhere for testing nearly led to an all out strike, so the APT-E sat at Derby for nearly 12 months whilst a second seat was fitted and issues smoothed over with the union. Upon it's return to service in August 1973, the train was moved to the GWR where it was trialled between Reading and Bristol, achieving a new British speed record of 152.3mph. Further trials saw the E-train visit Scotland and the North East, although much of it's test career was spent on the Midland main line south of Derby, It was here during 1976 that the train reached 143mph on the curved route, simultaneously setting a St Pancras- Derby time record that (as of 2010) is yet to be beaten. The APT-E completed it's testing program in late 1976, and after a short spell on display in London moved to the National Railway Museum in York where it remains to this day.

APT-PEdit

DevelopmentEdit

Whilst the testing program was ongoing, the marketing team of British Railways Engineering Limited was courting railway companies with the concept. As with Concorde, a project that the APT shared so much in common with, initial interest in a production version of the train was high. Several operators, both at home and abroad could see the potential for speeding up their own services without recourse to expensive and disruptive construction of new lines. At the time however, much of BREL's attention was focussed on delivery of the later tranches of the HST fleet to the Great Western and Midland, as well as other more conventional projects. By 1974, only the LNWR (operators of the electrified WCML) were prepared to commit themselves financially to a share in the construction of a prototype fleet of tilting passenger trains. Around this time, electrification work on the WCML was approaching completion. LNWR management hoped that the introduction of tilting electrified trains on the route by 1983 would head off competition from the car and plane, whilst not requiring any great further investment in infrastructure.

DescriptionEdit

  • Pantograph
  • Two power car set up
  • Tilt system
  • Articulated setup
  • Signalling system

Construction and testingEdit

The agreement for the construction of two "APT-P" trains was agreed, and the responsibility for further commercial development of the project switched from the Research department to the main BREL business. The first full trainset appeared from Derby in 1979, with testing commencing later that year. December saw the initial prototype reach 161mph in tests, a record that was not beaten for well over a decade. The remaining two sets began testing in 1980, with the trains becoming a familiar sight out and about on the West coast main line.

Commercial and political pressure on the development team during 1981 led to one set being pressed into use for a series of PR specials (achieving London-Glasgow in 4hr 15m), but bad press management and a series of technical failures meant that the train was soon seen as an embarrassment. However an outside assessment of the project during 1981 reported that the train and the technology used were effectively sound, and political pressure from the train builders of Derby and the progressive management of LNWR kept the project on track. Testing on the trains continued during 1982 and 1983 with occasional "relief" workings in public service.

APT-SEdit

Cancellation and rescueEdit

By 1983, a worsening economy threw the whole project into doubt. Management at LNWR cut their initial pre-order of 23 APT-S (squadron) trainsets to 15, then 8. Such an order in isolation would not have been commercially viable for BREL to undertake, and only crisis talks between the two parties and the Secretary of state Tony Benn prevented the project and all further research from being cancelled there and then. The new agreement saw a commitment to the first APT-S trains entering service by 1985 at the latest. Total fleet size was amended at x sets (including parts of the two adapted "P" trains), but with a shorter rake (8 trailers instead of 10 or more). This allowed for a single power car to be situated at one end of the train instead of two at the centre (removing the need for expensive "double crewing") whilst retaining near design performance over Shap and Beattock. In addition, increased provision was made on the trains for First Class passengers, the intention being to market the services primarily as premium services.

Production of squadron power cars began in earnest, with the first "hybrid" set (formed of new build Squadron and former -P trains) entering service as a relief train during the Winter 1985 timetable change.

Into serviceEdit

From Summer 1986 the APT-S fleet operated several "crack" services on the London-Glasgow route in around 4 hours and 20 minutes (with one stop at Preston). The route was chosen as it provided the greatest demonstrable time saving on the WCML, and was also able to actively compete with air travel on the city centre to city centre business market. Late 1986 saw further services introduced on the London-Manchester and Liverpool routes. The full APT-S fleet had entered service on the West Coast by late Spring 1987. As a precaution against cancellations through failure and for reasons of timetabling, most APT services operated in front of a "shadow" conventional service formed of locomotive and stock. This decision created some bad press for the project, as whilst the APT fleet was able to provide significant "headline" reductions in journey times on routes it was introduced on, the majority of travellers were still travelling on trains taking considerably longer (in some cases longer than pre-APT). There were also complaints from destinations not served by the new trains, such as Birmingham and much of the North West. Furthermore, the APT operated as a premium service with a surcharge of a few pounds for travel in addition to the normal fare. This caused some observers to accuse LNWR of profiteering.

The train itself was also still problematic. At some points during 1986 and 1987, barely half a dozen trainsets were operational. This was especially true during the winter of 1986 where issues with the hydrokinetic braking system reemerged. Concerns with the sophisticated ATC signalling system saw train speeds reduced to conventional levels throughout much of the Summer of 1986. In addition. an APT-S derailed during November of 1987 which again led to the APT service being suspended for over a fortnight whilst checks were made on the rest of the fleet. Even through to 1990, there were still concerns over the ride quality and reliability of the tilt packs and hydrokinetic brakes on the fleet.

The introduction of the APT did however prove a considerable financial success. Takings grew by up to 30% on some flows. Even where an APT operated service only ran a few times per day, there was an overall significant positive impact on passenger numbers. Very importantly, First class ticket sales grew significantly throughout the network. The relatively low operating cost of the train (no significant additional track wear, marginal energy consumption, more efficient use of rolling stock per passenger mile) also provided a boost for the LNWR, and eventually allowed for the phasing out of considerable amounts of ageing rolling stock.

During the late 1980's, the program also provided the effective basis for the IC225 program. Mirroring the APT-S format, minus articulated trailers and the problematic braking and tilt systems, the 140mph trains went on to provide highly reliable and sterling service along the East Coast.

The fleet todayEdit

By the mid 1990's, much of the fleet was beginning to show signs of wear and tear. In addition, chronic failures were occuring with certain elements of the train's design. The most pressing issue however was the fleet's limited capacity. Increasing passenger growth through the middle of the 1990's, combined with a desire to expand and improve the high speed service on the West Coast line led LNWR to look at procuring a new fleet of trains to operate front line WCML services. Therefore in 1997 an order was placed with Alstom for 53 new Class 390 Pendolino tilting trains to replace the APT and remaining loco hauled trains on "front line" services out of London Euston.

With the commencement into service of the first Pendolino sets in mid 2002, the APT-S fleet began to enter the works for a full overhaul. One First class trailer was removed from each set. An upgraded tilt package was installed, whilst the entire internal layout of the train was gutted and reconfigured. The first "refreshed" APT entered service on the Birmingham/Manchester/Liverpool-Edinburgh/Glasgow network of routes in May 2004. The introduction of these trains allowed the replacement of many of the remaining loco hauled services on northern half of the WCML, allowing an improvement in the number of paths available to other services. However the use of this type of trains on these services has led to some issues, as the single plug door per carriage and less spacious interiors have been criticised.

Several APT vehicles have been written off in accidents during 1988 and 1995. During the fleets midlife upgrade, several vehicles that had been in store were reactivated to create a "hybrid" set, 370 0xx. All units are currently based at Glasgow Shields depot, with day to day servicing taking place at Oxley, Edge Hill and Longsight