måndag 7 maj 2007

Engineering Miracle

Amongst the famous sayings of Dr Johnson is the politically incorrect "A woman's preaching is like a dog's walking on his hind legs. It is not done well, but you are surprised to find it done at all." Much the same might be said about the Pendolino, the fleet of tilting trains ordered by Richard Branson's Virgin company and now running on the West Coast Main line.

This month's Modern Railway has a couple of articles about the Pendolino. What is coming to light in the discussion is astonishing.

The Pendolino fleet consists of 53 trains, each of nine cars, of which 46 or 47 must be in operation each day to run the service. The cost of the trains was such that only this bare minimum was affordable. There have been attempts to procure a further 106 cars to lengthen the train, but this is unlikely to happen, mostly because of the financial and regulatory morass of Britain's botched railway privatisation.

The lengthening scheme has intersected with the first major mishap involving the Pendolino trains - the derailment on 23 February. The initial comments following this focussed on the good performance of the carriages, and it was said that damage was so light that they could all be repaired and put back into service. This seemed optimistic. Each vehicle must be stripped and checked for distortion and it is now thought that several are beyond repair. A further difficulty is that repairing these aluminium bodyshell structures is no easy task - unlike steel, which can be welded with relative ease.

Had the order for the extra 106 vehicles gone ahead, replacements for any that have to be written off could have been built on the production line at around £1.7million each. If not, then replacements will have to be virtually hand-built at almost double the cost

Although Network Rail's insurers will pay, the incident raises other issues. With no spare trains, Virgin has had to use a locomotive-hauled train to fill the gap. And it also appears that each one of the nine cars in a Pendolino train is different from all the others and contains essential items of equipment, so there is no question of taking out odd vehicles, or replacing them with spares, or borrowing from other sets. This known as an "integrated system". One implication is that if the extra vehicles were actually ordered, it would be difficult to add them to the existing trains except as part of the scheduled heavy overhaul programme, as the software will have to be reconfigured and tested. But this level of complexity has also had an impact on daily maintenance and led to what is decribed as a "culture change" in procedures; either the whole train goes, or it does not. The whole operation is now on a knife-edge, with no leeway for things to go wrong.

Pendolinos apparently embody some other very peculiar engineering. A software problem resulted in trains running into the bufferstops at Liverpool Lime Street; this was identified and resolved in less than a week, but it sounds as if there has been a misappliance of science.

And then there are the toilets. If you have travelled in one, you can't have missed the smell of drains that pervades some of the vehicles. Like all modern trains, they have storage tanks for the effluent, but instead of being in the usual place under the floor, they are at a higher level and the muck has to be pumped upwards. This, combined with some insufficiently robust plumbing, has led to persistent problems, compounded by the fact that there are not enough places where the sewage tanks can be emptied and the contents disposed of. And the curved sliding doors to the wheelchair-accessible toilets have been endlessly troublesome.

Fortunately for Virgin Trains, the Pendolino trains have been procured and a build-and-maintain contract from Alstom, whose headache it is to keep them on the road. Like the dog walking on its hind legs, it is surprising to see it done at all. Alstom has risen to the challenge, but that such a state of affairs has arisen at all points to a failure in setting and holding to a sound engineering design philosophy. It would be nice to think that the lessons will be learnt and applied to the replacement fleet for the HST now being developed by civil servants at the Department for Transport, and now referred to as the Inter City Express Programme (IEP).

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