Bogies have featured a few times in the rail engineer recently. There were two articles on bogie production at the Siemens factory in Graz (issues 90 and 91, April and May 2012), and bogies and wheelsets featured in a two part article by Stuart Marsh (issues 93 and 94, July and August 2012). However, until now, there has been little coverage of bogie rebuilds.
Virgin Trains’ Pendolino fleet is maintained by Alstom at its five traincare centres. At the company’s Longsight depot, as well as ongoing routine maintenance, a major bogie overhaul programme is in full swing. Your favourite railway engineering magazine went to have a look.
A history lesson
The class 390 Pendolino trains first went into service in 2002. The full series of 53 9-car trains was delivered before Alstom closed its Washwood Heath factory in 2005. Many of that factory’s employees were redeployed to traincare centres in Oxley (Wolverhampton) and Manchester to maintain the trains they had just finished building.
The Pendolino fleet virtually runs the West Coast Main Line. Each train covers 1,000 miles a day, meaning that the fleet travels 17 million miles each year. 48 of the 52 train fleet (the train involved in the Grayrigg accident was retired) have to be available for service every day, 364 days a year.
Ten years and 2.5 million miles after the first service, the fleet is now in the middle of its third heavy overhaul (H3). The first was carried out after 750,000 miles, the second after another 850,000, and this third overhaul after 950,000. The trains will probably have to cover over a million more miles before they get overhauled again.
Preparing for H3
H3 is a particularly heavy overhaul, with 27,764 components being changed on each train. The normal service requirement hasn’t changed either, with 11 trains in the traincare centre every night. In order to cope, an extra 120 people were taken on and trained up for H3, creating a new pool of highly skilled workers.
Alstom invested in the depot infrastructure as well. £3.7 million was spent on new lifting equipment from Mechan, improved staff facilities and enhanced in-house workshops which were built by Cairns Cross Civil Engineering. In addition, as the trains are now being lengthened to 11 cars, £20 million was spent on extending the depot buildings.
H3 project manager Lee Kinsey explained that planning started early in 2011, with the first train due to be worked on from 11 March 2012. Because of the scope of the work, it takes two weeks to complete an overhaul. So, with one train coming into the shop and one being returned for duty every week, two trains would be out for service at any one time.
At the same time, Virgin Trains is proceeding with a programme to introduce four new 11-car train sets, and to buy 62 new carriages so as to convert 31 9-car sets to 11-car. This conversion would coincide with H3 so the updates could be done at the same time. The additional four sets would also allow for the two trains being overhauled to be out of service without affecting the passenger timetable.
The four new 11-car trains arrived from Alstom’s factory in Savigliano, Italy on schedule – in fact the fourth set was five months early, much to the satisfaction of new cars project manager Jason Rowbottom.
To start with, the new sets were downgraded to 9-car so they could be entered into the existing timetable. However, earlier this year they were restored to 11-car. The extra new cars started to arrive from Savilgliano as well, so H3 could get underway as planned.
The first 31 trains to go through would have a number of engineering changes incorporated into the work, as these would be the trains receiving two extra carriages to make them up to 11-car sets.
Frames and wheelsets
But back to the bogies. As part of the H3 overhaul, the bogies would have a C4 overhaul. Don’t you just love all these terms? A C4 overhaul is part of the agreement with the train leasing company and is the “periodic (usually based on mileage run) replacement of wheels, bogies, brake gear, etc with new or overhauled components.”
One nine-car train has 18 bogies. These are removed from the train and replaced with a set that, in good Blue Peter fashion, was prepared earlier. The first train through got 18 from the spares stock – after the last train is finished its refurbished bogies will replace those 18 in the stores. This is to allow for a quick turnaround. The programme is still to refurbish a set of 18 bogies every week.
Once removed, they are taken to the bogie workshop, roads 17 and 18 in the Longsight facility. The bolsters are separated and the major components are washed to remove excess dirt and oil.
The wheelsets are removed and sent back to the manufacturer, Lucchini, which is conveniently situated nearby in Trafford Park. The wheelsets are stripped down, overhauled and rebuilt. This involves the replacement of all wheel pans, the overhaul of gearboxes and the replacement on condition of other components such as brake discs and axles. Meanwhile, at Longsight, other bogie components such as brake callipers, yaw dampers, axle guides and other associated components are stripped down and replaced or refurbished.
At this stage the tilting mechanism is accessible, and can receive attention. Pendolinos use a mechanical system in the bogie to achieve tilt. An electric actuator mounted under the bogie moves a tie-rod backwards and forwards which causes the bolster to tilt with respect to the bogie frame. Small wheels run in a curved rail to control the axis of the tilt, and there is a deflection in the rail which serves as a ‘lock’ in the vertical position. It is a reliable system, but like all mechanical devices needs servicing from time to time.
Once rebuilt, with a fresh wheelset installed, the bogie and its bolster are reunited and the completed assembly set up for height and balance. It is important that the four “corner weights” – the weight on each wheel – are near enough identical. It is all quite precise and complicated, and with 18 being turned around every week the team is rebuilding over three bogies a day.
The team on roads 11 and 12 are busy as well. Each train spends a week on each road as the two week process is split into two halves.
To start with, a 9-car set arrives at Longsight on Saturday night. On Sunday the toilets are stripped out and the water tanks removed before the train is moved into road 11 on Monday morning. The First and Standard Class sections are split and the First Class section is removed.
The Standard Class air and brake equipment is replaced and returned to manufacturer Knorr-Bremse for overhaul.
On Tuesday, the inter-car couplers on the Standard Class half-rake are removed using a special tool and a process that looks vaguely reminiscent of a dentist extracting a tooth. Replacement couplers are fitted and the half-rake reformed.
The First Class section replaces Standard Class on Wednesday. HVACs are removed and are overhauled in Manchester in the new workshops, and replaced by fresh ones. The air and brake systems are replaced.
The couplers are replaced on Thursday and the half-rake reassembled. The next day, the
two new carriages are coupled up to First Class, and the Standard Class brought back in to form the new 11-car set.
On Sunday, the whole set is moved to road 12 and the bogies and cardan shafts are disconnected. The bogies are exchanged on Monday, the whole train being jacked up high enough that the old bogies can be run out below the ones on the two new cars, which, of course, remain in situ. The wiper motors are also replaced – they will be rebuilt at the Oxley Traincare Centre.
Tuesday is an electrical day. The pantograph tilt mechanism is replaced and the inter-vehicle jumpers reconnected. The Lucifer solenoid valves that control the tilt mechanism are replaced, along with other electrical components.
Interestingly, the flexible jumper cables have never been replaced. Manufactured by LPA, the original cables are still in use, three major rebuilds and 2.5 million miles later! This speaks volumes for the quality of the original cables. New additional jumpers have been added since, for Wi-Fi and the like, but the original power jumpers just keep soldiering on.
By Wednesday on the second week the train is ready for static testing. This continues for another two days before a dynamic test run on Sunday, after which the whole train goes off to the traincare centre in Liverpool. And, by this time, the next train has already arrived for its H3 service.
Until 28 April 2013, it will be a never ending process.