Published 30th July 2012
MANCHESTER - Pendolino No. 390148 became the 14th set to undergoing a H3 overhaul and be lengthened to 11-cars when it was released to traffic on July 22.
All 52 original sets still in service (No. 390033 was written off after 2007’s Grayrigg accident) will be given a H3 overhaul, but only 31 will be lengthened from 9-cars to join the four all-new 11 car-sets already in traffic.
H3 is the third major overhaul for the Pendolino fleet since their introduction to the West Coast main line in 2002. H1 was done after 750,000 miles in 2005-2006, H2 after a further 850,000 in 2009-2010 and now H3 after another 950,000. It is the most comprehensive overhaul to date, but the sets are now covering more miles between major attention.
Each set spends two weeks out of traffic at Alstom’s Longsight depot in Manchester. Two sets are worked on in parallel, with one arriving and one departing each week.
During week one the toilets are stripped out and water tanks removed, then the set is split between standard and first class. Each half-set has its air and brake equipment replaced along with the inter-car couplers and roof-top HVAC (heating, ventilation and air conditioning) units.
Next the two new carriages (standard class trailer and motor cars in the 653xx and 659xx number series) are shunted between the two half-sets and the train is mechanically reformed into 11-cars.
In week two the entire train is lifted on hydraulic jacks and the 18 bogies from the former nine-car set (two bogies per vehicle) are removed and replaced with overhauled bogies. New carden shafts are fitted and connected, then various electrical components are replaced - including the two pantograph tilt units - and the inter-vehicle jumpers reconnected.
The final three days are set aside for static testing followed by a dynamic test run to London and back. If all goes well the overhauled set leaves Longsight on a Sunday to run via Crewe to the Liverpool Traincare Centre at Edge Hill for more dynamic testing and mileage accumulation.
The 18 removed bogies are moved to a different building at Longsight for a major C4 overhaul that takes about a week. Alstom has 24 bogies at the depot any one time to ensure a smooth work flow to keep up with the main Pendolino overhaul schedule.
In the first stage the bogie and its bolster are separated and thoroughly machine washed. The wheelsets are then removed and the frame stripped down. After overhauling each part, the frame, bolster and wheelsets are reassembled and it goes for testing and height-calibration.
The 11-car extension programme has also required changes at the Oxley and Manchester depots used by Pendolinos, where the longer trains have required extra tanking facilities, electrification of more roads, plus extensions pits and and sheds.
The lengthening programme began back in September 2008 when the order was placed for 106 new carriages, equating to four new 11-car trains and 62 standard class carriages for lengthening 31 existing Pendolinos from nine to eleven cars. These extra vehicles were built at Alstom’s plant in Savigliano, Italy and imported by rail through the Channel Tunnel.
The 11-car Pendolinos include an extra motor car so are more powerful than the nine-car version, but the added weight means they have roughly the same acceleration. The longer trains are rated at 5.95MW / 7,980hp (against 5.1MW / 6840hp for the nine-car version) with 14 traction motors (instead of 12) and a total weight of 567 tonnes (versus 466 tonnes). Both versions have 145 first class seats, but the 11-cars have 444 standard and the nine-cars 294.