Västlänken - the chaos begins

Next week come the first major disruptions due to Västlänken. Major alterations to Gothenburg’s tram services are always a feature of the summer as the holiday season is set aside for renewal of track. That is a story in itself, because the fleet of Italian trams that came into service in 2010 are inflexible and cause additional wear on curves. However, on top of this, there are closures in preparation for Västlänken, and to crown it all, the road tunnel along the Göta Älv will be closed for six months in one direction for the same reason. That will cause horrendous and widespread delays and congestion.

It is already proving to be a project too far, and that is just a month into the construction period.

In addition, trenches are appearing all over the place, blocking the entrances to shops and restaurants, which cannot be doing their business any good at all. I wonder how many bankruptcies there will be before the wretched scheme is complete?

Microsoft’s underwater data centre

Microsoft’s underwater data centre idea plumbs the depths in several ways. The idea is to use cold surrounding seawater to dissipate the heat generated. This is of course low-grade heat, but it is perfectly suitable for the heating of buildings, hot water systems, etc, which adds up to a huge amount of energy use worldwide, especially in the colder parts of the world.

A data centre in Helsinki uses the waste heat in this way, heating a group of adjacent buildings. I would be happy to have a data centre in our basement if it meant no more heating bills. There is a fibre optic cable in the street outside, so there is no need for an underwater cable.

What are Microsoft engineers thinking of?

Minding the gap

Gaps between platforms and trains are another problem caused when there is a mis-match between the infrastructure and the trains. When the system was built in the early days of Queen Victoria, passenger carriages were short four-wheeled vehicles, typically less than 10 metres long. Over the next century, the standard length of a British passenger vehicle had risen to 20 metres. With bogies close to the ends, and about 14 metres apart, there would be a large gap on sharply curved concave platforms. This was not usually a problem with slam-door trains as passengers would lower the window inside the door and use the top of the window frame for support when getting on and off. The trains were also fitted with external handrails. This was not an ideal arrangement but it worked.

The first large scale use of sliding door trains on the national system adopted the 1/3:2/3 configuration, as in these class 313 trains seen here at Brighton. The size of the gap is obvious. From the mid-1980s, this 1:3:2/3 configuration became standard for all trains in Britain apart from the inter-city fleet, where end doors became the standard. The final BR designs, however, adopted a 1/4:3/4 configuration, with two seating bays between the vehicle ends and the doorway vestibule.  This was a feature of the Networker and derivatives of the design including the 20 metre Electrostar classes. This reduced the size of the gap because the doorway was only just inside the bogie wheelbase. The 23 metre Turbostars were similar, but with five bays instead of four between the doorways.

The new CAF Civity trains for Northern seem to have reintroduced the problem, as these are 23 metre vehicles with the doorways three bays in from the ends, and four bays between the doorways. As the photograph shows, the doorways are well inside the bogie wheelbase, which could give rise to large gaps at concave platform faces. We shall see.

The problem could of course be solved entirely if the trains were fitted with retractable steps, but that is a step too far, it appears.

The UK loading gauge question

One would have thought that a priority for rolling stock designers would have been to make the best use of the limited UK loading gauge. Seemingly not. The illustration of the interior of the new locomotive-hauled Nova 3 coaches for Transpennine Express is taken from an article in International Railway Journal; I hope this is acceptable under the fair use of copyright rules.

Take a look at the skirting area. This shows the problem caused by the very sharp lower bodyside curvature apparent in exterior views of the stock. This example is almost the rule. The same thing affects much of the rolling stock built since 1990, including the BR-designed Networkers and the BREL Electrostars and Turbostars. The bodyside profile makes no sense within the parameters of the UK loading gauge.

As is well known, the British loading gauge is little bigger than that permitted for narrow gauge railways such as those of Japan and South Africa. This is mostly due to the closeness of adjacent tracks and the low bridges and tunnels, but the problem is aggravated by the British practice of having high platforms, approximately 90 cm high. The issue was carefully examined when British Railways was formed in 1948, and the result was the C1 loading gauge (diagram above), which applied to passenger vehicles of a nominal width of 20 metres with bogie centres 14.17 metres apart - as close as practical to the vehicle ends. The mark 1 stock was built to comply with this standard, and more recent stock such as the Bombardier class 377 Electrostars are constructed to the same main dimensions.

Eventually, longer vehicles came into use. These were made narrower, in accordance with a geometrical formula to take account of overthrow on curves. Another important change was the use of air springing which is softer, which meant that carriages had to be narrower at the cantrail, where the sides meet the roof.

As far as the passenger space is concerned, the salient point is that the maximum width of the loading gauge is available from 1.225 metres above rail level and upwards for about 1.2 metres, when the vehicle body has to become narrower. The C1 loading gauge for 20 metre vehicles allows a full 2.82 metres, tapering to 2.62 metres at the cantrail. Logically, it generates a profile similar to that in these vehicles below.

The important factor here is the floor height. The standard height used to be 1.3 metres, which resulted in no loss in width, leaving space for skirting level ducts without cutting into legroom; this is a feature of, for instance, all the BR mark 1 stock. The Hitachi 800 series are also unaffected due to the high floor level enforced due to the size of the underfloor engines. Suburban stock, on the other hand, with a lower standard floor height, can suffer badly from reduced floor width, although it does not affect the Siemens Desiro class 450 and similar types. That said, one wonders why lower bodyside curvature is needed on suburban stock at all as the footsteps project beyond the bodysides.

The problem can be seen clearly in the top photograph; passengers sitting next to the windows will only be able to put one foot on the floor unless they twist themselves at an angle. Why, then, do these vehicles have such pronounced lower bodyside curvature, since there is no necessity for it through loading gauge constraints?

Britain’s new inter city trains

I am planning to discuss the new Hitachi inter-city trains in several pieces on this blog. I put it under the heading of  “vanity schemes” because they were clearly not the best value-for-money replacement for the HST fleet and came about due to the political influence of the civil servants within the Department for Transport who developed the project and then protected it at all costs.

These trains have many good points, in particular the quality of the finish and detailing inside and out, the smooth ride and surprisingly low noise levels when on diesel power. However, they also have many shortcomings, which are due to the specification produced as a result of the work of the DfT.  Hitachi has made the best of a concept that could have been better conceived.

There is a lot of poorly utilised space due to the length of the vehicles.This is noticeable in the uncomfortable seats misaligned with windows, inadequate space for luggage in a location where passengers can keep it supervised, and the need to “mind the gap”, which should not be necessary given that various forms of retractable step have been around on continental railways for about 20 years.

The Great Western 2 x 5-car formations are inefficient in terms of space, cost and staffing requirements. There is an unusually large gap between vehicles, which means the gangways are long and again, space is wasted. Acceleration is sluggish when starting on diesel power.

If the trains had been built as 23 metre, 72 seat loco-powered push-pull sets, close-coupled like mark 3 stock, the passenger experience would have been very much better and the cost very much less. Of course that means the electrification would have had to be completed as planned for the trains to run.

Phasing out diesel

British politicians are now saying that the future for the railways is hydrogen or battery power and that diesel traction should be phased out by 2040.

Batteries have made vast improvements over the past couple of decades. Lithium supply is a problem but several of the elements on the top left hand side of the Periodic Table are candidates and we can expect substitutes to be adopted. However, the underlying problem of energy density is unlikely to be solved since there is no Moore’s Law in operation. The likely use of battery power will be for use on routes which are electrified for most of their length; one could envisage a train running from Paddington to Maidenhead on electric power and continuing to Bourne End and Marlow under battery power, where it could receive a top-up before returning; similar trains could also provide the all-day shuttle service on the branch. Apart from the provision of batteries, they would be similar in almost all respects to the regular fleet of electric trains running only on electrified routes.

Hydrogen power dead end?
Hydrogen powered trains, on the other hand, look like a specialised niche. The hydrogen has to be made somehow, probably by electrolysis of water. This energy is recovered in a fuel cell where it is converted into electricity. Both processes result in losses, on top of the usual losses associated with the drive train and control systems. That is not the end of the energy losses. There are also losses associated with the transport of the hydrogen, which is not a portable fuel. Hydrogen will liquify only at extremely low temperatures, below 33°K. That is cold. At ambient temperatures is has to be compressed and put in tanks capable of withstanding extreme high pressures, which means they are heavy, and both compression and liquefaction consume large amounts of energy. A German experiment aims to use otherwise unusable electricity from wind generation to produce the hydrogen but this seems an inefficient and expensive way of making use of it.

What is the overall thermal efficiency when all of this is taken into account? There is a discussion of the subject here, in relation to automotive applications of hydrogen fuel cells. Then there is platinum to consider. Fuel cells require platinum catalysts. Alternatives are not even on the horizon. It is one of the rarest of elements. Platinum mines are not environmentally friendly. Taking one thing with another, this technology is nothing like as clean as it seems, and not particularly cost effective.

Battery power might have specialised applications such as the branch line off an electrified main line, referred to above. Hydrogen power looks like a dead end. Neither is a candidate for the hoped-for replacement of diesel power. Politicians should get to grips with basic chemistry and physics before going public about their aspirations.

GWML electrification disgrace to British engineering

The Great Western Main Line electrification makes slow progress. Between Swindon and Bristol Temple Meads the project has been abandoned due to the cost, which is a mercy as it avoids disfiguring the Cotswold landscape. The work to Cardiff proceeds, much delayed, as here at Bristol Parkway. The overhead structures look as if they were designed to carry the weight of the trains, not the thin contact wires and supporting catenary.