Swedish train accident on Sunday evening

This accident, with one fatality, appears to have involved a train and a heavy construction vehicle. The exact cause remains to be discovered. According to one report, the train was going too fast past a site where repairs were in progress. However, a union commentator has been critical of the practice whereby work is successively sub-contracted to the point that those actually doing the work are unaware of the correct safe working practices. Does that sound familiar?

In the UK, track maintenance these days is usually done with a complete line possession, the trains being diverted or replaced by buses. Despite all the complaints this leads to, perhaps there is more to be said for the practice.

Trams are good value for money? Or are they?

"Trams are very expensive to install, especially on UK streets. Where ever the track goes, the road has to be dug up and all the services (water, gas, elec, phone) have to be moved 50ft to one one side. For miles."

You are talking about on-street trams. Outside the city centres, most of the mileage of tramways in many European cities is off-street anyway, the same goes for Manchester and Croydon.

The expense of renewing services for on-street tramways must be compared with the alternative of underground railways. Buses can only carry a limited volume of traffic before they become inefficient and cause environmental problems of their own. Cities need tracked electric transport if they are go grow beyond a certain point and still flourish. Stockholm, with a metro, has also supplemented it with a new tramway, the first section of which opened last month.

Many British cities have had, or will soon have, their underground services renewed anyway. If a decision is made to relocate them on the assumption that there might be trams in the future, the additional cost is minimal. Had this decision been made ten years ago in Brighton, for instance, the streets would now have been tram-ready. It is a matter of planning ahead.

It is also the case that many British cities had extensive tramway systems until the 1950s and the services may still be mostly in the right place. Until the information is obtained and collated, nothing can be said with certainty.

In the Edinburgh case, it has been remarked that the utility companies have taken everyone for a ride and got their old pipes and cables renewed at the taxpayers' expense. I don't know how true this is, but it does not sound entirely slanderous.

Station dwell times

Station dwell time is the time a train stands at a station while the passengers get on and off. In the days of slam door trains (above), with ten doors on each side of the carriage, this could be less than 20 seconds. This was possible because passengers were well disciplined and closed the doors after them. Circumstances change and some time in the 1960s, the decision was made to replace slam door trains by trains with power-operated doors, a changeover that was finally completed about five years ago. One effect is that station dwell times have become a matter of concern, due to, amongst other things, the operating time of safety devices; for instance, plug doors do not open until 15 seconds after a train has come to a stand. When there are many stops on the route, the extra time builds up.

Commuter trains normally have doors at the 1:3/2:3 positions, which is intended to give better access than the alternative end-door location, but this layout has disadvantages. When bodyshells are designed on the monocoque principle, substantial reinforcement must be provided around door openings part-way along the vehicles. The vehicle itself is divided into three compartments, which restricts the options for seating layouts. It is difficult to provide intermediate doors between the entrance lobbies and the seating areas, which makes extra work for the heating and ventilation system; in the winter, seated passengers are blasted with cold air every time the doors open. Unless station platforms are fairly straight, there can be large gaps between the platform and the train. In some of the earlier designs of train such as the class 313 and 455, loading and unloading was glacially slow until the vehicle layouts were redesigned a few years ago.

Is there scope for improvement? There is a need to study precisely what happens at stations when the trains are in actual service. First, the passengers alight, and then the waiting passengers get on. The delaying factor for alighting passengers seems to be the need to take care stepping down off the train. For boarding passengers, the delay seems to be the time for those already on the train to move down inside the car, so that the queue backs-up on the platform.

If this is the case, the most useful improvements that could be made would appear to be the provision of a larger step-board to close the gap between the platform and the train, and the elimination of pinch-points inside the vehicle. These changes could mean that there are many routes where end-door vehicles could be used instead of the present 1:3/2:3 stock. There are many commuter routes where the original sliding-door fleet is approaching the end of its service life, and could therefore be replaced by newer cascaded stock presently running on longer-distance commuter services where end-door vehicles would be more suitable, provided that attention was paid to the detailed design of the doorways and the space around the entrance areas.

Short life expectancy of X2000 trains

An article in Göteborgs Posten recently referred to the growing list of defects occurring on the Swedish X2000 tilting trains (picture in blog title) and predicted that they would be replaced after a relatively short service life.

New trains such as the Regina have better acceleration and bogies which are easier on the track, giving similar journey times without the need for the same top speed and the associated complications of tilting.

There is probably a more effective alternative to premature scrapping. The X2000 trains could be provided with new bogies and the power cars rebuilt or converted to driving trailers. An off-the-peg type of locomotive such as the Bombardier TRAXX would provide the traction. This ought to offer very much better value for money.

Seat comfort and design

Despite decades of collecting ergonomic data, seat design on public transport is as erratic as ever. The most comfortable train seat I have ever sat in was in a second class compartment in a carriage built for the North London Railway in the mid-1860s. This was a bizarre shape - the back of the seat had a cross section like half a pear. Which meant that it provided good lumbar support. I have sat in uncomfortable seats in first class inter-city trains, and comfortable seats, like the one illustrated, on commuter trains.

The key things to get right are lumbar support ie of the lower back, and the angle of the cushion, which should slope slightly from front to rear. If lumbar support is absent, a rolled-up sweater will provide it. Once these two things are correct, the spine will adopt the correct position.

Seats in British Railways mark 1 stock were mostly on the sloppy side, exept for the last of the type, introduced in the 1970s. Much research went into the seats on mark 2 stock, and these felt odd at first but one noticed the benefit at the end of a long journey. Unfortunately, the designers went and spoilt the things with headrest wings which were hideously uncomfortable for people with long torsos.

More recently, seats are something of a lottery. Southern's class 377 stock has excellent seats in some of the vehicles whilst others in the same 4-car unit are exactly wrong, with a horizontal cushion.

Most train seats these days are curved in both directions, like car seats, to provide lateral support when cornering, but this makes them difficult to upholster. Trains do not go round corners so fast that lateral support is needed, and bench seats with a correct cross section are all that is required.

The need to provide lumbar support coincides conveniently with the need to provide room for luggage between seat backs, as the curvature needed for the former creates space for the latter. An excellent example is the class 180 Adelante (below).



The fashion for unidirectional (airline style) seating in trains ought to be questioned. A few more seats can be fitted in, but at the cost of luggage space. A further drawback is that the upper edge of the seat back is unsupported, which means that the seats need a much heavier frame than if they were designed to be back-to-back or fixed to a bulkhead, and even then are liable to uncomfortable resonant vibration. With seventy or eighty seats in the average rail vehicle, this must add a substantial weight penalty.

The subject needs to be looked into.

Never mind the gap

Never mind the gap, originally uploaded by seadipper.

Retractable steps are standard on modern Swedish trains. This one slides out from under the floor. This probably pays for itself because people get on and off quicker and it presumably prevents accidents.

Important Inter City Express documents

Although the Inter City Express programme has been cancelled, these two documents contain much useful information relevant to future rolling stock design in general. They address, amongst other things, many of the shortcomings of trains such as the Pendolino, generally considered to be Britain's most unpopular train.

On the other hand, they reveal the extent of the mission creep which seems to be a feature of so many UK government projects. There seems to be a failure to appreciate the difference between what is important and what is merely nice to have. Is it really necessary to have passenger counters, or power points at every seat. There has also been a tendency to specify in details matters that might be better left to the designers resolve. Is it necessary to have a toilet in every vehicle, provided that there are enough of them overall and that they are reliable? Modern train toilets are complicated and have ancillary equipment which is needed regardless of the number in a vehicle. It might be more cost-effective to provide some vehicles with two or more toilets, whilst others have none.

These specifications need to be gone through carefully to ensure that design solutions are not unduly constrained, possibly leading to better alternatives being blocked.

Technical Specification for Inter City Express programme
Inter City Express Programme - invitation to tender