The new GW electrification is noteworthy for the chunkiness of the overhead structures, which are heavier than the notably solid gantries installed for the 1500kV Great Eastern electrification which was installed in 1949. One of the reasons for the adoption of 25kV electrification was that the smaller current flows made it possible to use thinner and lighter contact wires, and consequently lighter and cheaper structures. The Great Western's tunnel of steel must come at a commensurately heavy price, which has helped to push further electrification schemes into the realm of the unaffordable.
The overhead structures for the 15kV system used in Switzerland, Germany and Sweden are like gossamer in comparison. What has happened to let loose this orgy of over engineering?
onsdag 16 augusti 2017
UK electrification schemes cancelled #1
I have tried without success to discover the underlying reason why major UK electrification schemes have been cancelled.
As I understand it, electrification costs have increased due to new regulations which require more generous clearances in relation to 25kV overhead wires and on-train equipment. What I have not been able to find out is where these new regulations have come from. As far as I can mak out, their immediate source is the Office of Rail Regulation (ORR), which has adopted Electricity at Work Regulations. But when and where have these come from? Has there been an input from the EU's regulatory bodies?
If they are an EU requirement, was there an application for derogation having regard to the special circumstances in the UK? If not, why not?
To whom, if anyone, is the ORR answerable?
As I understand it, electrification costs have increased due to new regulations which require more generous clearances in relation to 25kV overhead wires and on-train equipment. What I have not been able to find out is where these new regulations have come from. As far as I can mak out, their immediate source is the Office of Rail Regulation (ORR), which has adopted Electricity at Work Regulations. But when and where have these come from? Has there been an input from the EU's regulatory bodies?
If they are an EU requirement, was there an application for derogation having regard to the special circumstances in the UK? If not, why not?
To whom, if anyone, is the ORR answerable?
tisdag 10 januari 2017
Support pulled from D-train
The D-train is a project to recycle the London Underground's District Line D78 stock, introduced in 1978. It was heavily refurbished between 2000 and 2003 with new bogies and other equipment. It is basically in sound condition and good until at least 2025, but it was decided to replace it with the S-stock to provide London Underground surface lines with, for the first time, a uniform fleet.
This will in due course almost certainly prove to have been a bad strategy for London. Railway rolling stock tends to suffer from some weaknesses which show up almost immediately, and others which show up after a decade or two, in both cases affecting the entire fleet. The thirty Bulleid-designed Merchant Navy class all had to be taken out of service and eventually rebuilt, following an incident in 1953 which revealed a fundamental failure with the design. A similar thing happened with the thirty GWR King class locomotives after it had been in service for almost thirty years. It would be good luck if the entire fleet of S-stock is not eventually affected by some defect which means that it will all have to be taken out of service for remedial action.
But to return to the D78 stock. Adrian Shooter saw the opportunity to recycle this stock for secondary services on the national system. In principle that was a shrewd move, though easier said than done, because the trains are electrically powered and the intention is to operate them on lines which are not electrified. The chosen approach was to install underfloor engines to power generators to drive the trains' existing electric motors.
This might have sounded like an economical solution, but fitting generators under the floor of a train can be tricky; the weight of the equipment is one difficulty and the lack of space another.
And so it has proved. The initial use of the trains, now designated class 230, was intended to be between Nuneaton and Coventry. However, an engine caught fire on the trial run and the backers have pulled out of the project. That seems like a precipitate decision, but the project, it is claimed, has now been delayed to the point that it could not meet the timetable set for development.
One has to wonder about the thinking that lay behind the notion. Putting the generator in a separate and reasonably spacious compartment would have been easier and less likely to run into trouble. Using the carriages as locomotive-powered push-pull sets would have been even less risky, and more flexible too, especially if the locomotives used in the trial had been of a well-established type such as the class 20 or 37, of which a number are still serviceable.
Then there is this, specifically designed for secondary routes, within the constraints of the contemporary railway environment. It is nearly eight years since the developer, DLM-AG of Winterthur, came up with the proposal. The firm has so far failed to find sufficient interest for the minimum build of twenty units, costing around £30 million in total, which would be necessary to achieve a favourable price, around 30% of that of a comparable diesel locomotive.
This will in due course almost certainly prove to have been a bad strategy for London. Railway rolling stock tends to suffer from some weaknesses which show up almost immediately, and others which show up after a decade or two, in both cases affecting the entire fleet. The thirty Bulleid-designed Merchant Navy class all had to be taken out of service and eventually rebuilt, following an incident in 1953 which revealed a fundamental failure with the design. A similar thing happened with the thirty GWR King class locomotives after it had been in service for almost thirty years. It would be good luck if the entire fleet of S-stock is not eventually affected by some defect which means that it will all have to be taken out of service for remedial action.
But to return to the D78 stock. Adrian Shooter saw the opportunity to recycle this stock for secondary services on the national system. In principle that was a shrewd move, though easier said than done, because the trains are electrically powered and the intention is to operate them on lines which are not electrified. The chosen approach was to install underfloor engines to power generators to drive the trains' existing electric motors.
This might have sounded like an economical solution, but fitting generators under the floor of a train can be tricky; the weight of the equipment is one difficulty and the lack of space another.
And so it has proved. The initial use of the trains, now designated class 230, was intended to be between Nuneaton and Coventry. However, an engine caught fire on the trial run and the backers have pulled out of the project. That seems like a precipitate decision, but the project, it is claimed, has now been delayed to the point that it could not meet the timetable set for development.
One has to wonder about the thinking that lay behind the notion. Putting the generator in a separate and reasonably spacious compartment would have been easier and less likely to run into trouble. Using the carriages as locomotive-powered push-pull sets would have been even less risky, and more flexible too, especially if the locomotives used in the trial had been of a well-established type such as the class 20 or 37, of which a number are still serviceable.
Then there is this, specifically designed for secondary routes, within the constraints of the contemporary railway environment. It is nearly eight years since the developer, DLM-AG of Winterthur, came up with the proposal. The firm has so far failed to find sufficient interest for the minimum build of twenty units, costing around £30 million in total, which would be necessary to achieve a favourable price, around 30% of that of a comparable diesel locomotive.
tisdag 7 juni 2016
Navy's new destroyers will fail in the Gulf
It seems that it is not just transport projects that get messed up by civil servants. Defence procurement is another field of failure. Defence chiefs have told a House of Commons committee that the new £1bn class 45 destroyers are likely to suffer engine failure in warm waters.
fredag 11 mars 2016
Crossrail 2
Crossrail2 is a project for a new cross-London railway running roughly from the south-west to the north-east. It is not a vanity scheme in itself - on the contrary, it is a long-overdue construction of a project first put forward in 1904 and from time to time ever since. It links together existing routes which at present running to Waterloo, by diverting them into an underground route northwards to Seven Sisters and Tottenham. Amongst other benefits, this will reduce pressure on congested Waterloo.
There are questions, nevertheless. From the south-west, four separate routes converge into one, which is always a potential source of operating difficulties. At the northern end, the line splits into two, which means that some of the trains arriving from the south will have to turn back before they get to the end of the route, probably at Tottenham or Seven Sisters.
More seriously, should it be built as a full-scale railway with overhead electrification, or as a tube? The former, with 6 metre diameter tunnels, involves excavating three times as much material as a 3.5 metre diameter tube.
A related issue is the choice of electrification. The routes from the south-west are already electrified with a 750V DC conductor rail supply. If this were continued throughout the length of the tunnels, the latter could be constructed to a 5 metre diameter instead of 6 metres, ie only 70% of the excavation volume. A conductor rail DC system would also avoid having to fit the trains with heavy transformers, as well as providing greater reliability and reduced maintenance costs, since conductor rail electrification is almost a fit-and-forget arrangement.
The argument usually given for 25KV electrification is that it is more energy-efficient, which is true over long distances where transmission loss becomes an issue at low voltages due to the much higher currents. However, Crossrail 2 is a short-distance railway and transmission losses are not going to be so significant.
There are questions, nevertheless. From the south-west, four separate routes converge into one, which is always a potential source of operating difficulties. At the northern end, the line splits into two, which means that some of the trains arriving from the south will have to turn back before they get to the end of the route, probably at Tottenham or Seven Sisters.
More seriously, should it be built as a full-scale railway with overhead electrification, or as a tube? The former, with 6 metre diameter tunnels, involves excavating three times as much material as a 3.5 metre diameter tube.
A related issue is the choice of electrification. The routes from the south-west are already electrified with a 750V DC conductor rail supply. If this were continued throughout the length of the tunnels, the latter could be constructed to a 5 metre diameter instead of 6 metres, ie only 70% of the excavation volume. A conductor rail DC system would also avoid having to fit the trains with heavy transformers, as well as providing greater reliability and reduced maintenance costs, since conductor rail electrification is almost a fit-and-forget arrangement.
The argument usually given for 25KV electrification is that it is more energy-efficient, which is true over long distances where transmission loss becomes an issue at low voltages due to the much higher currents. However, Crossrail 2 is a short-distance railway and transmission losses are not going to be so significant.
onsdag 26 augusti 2015
Corbyn calls for "Ladies Only" carriages
A curious side issue in the Labour Party's leadership campaign is his call for carriages for women only. "Ladies Only" compartments were usual on trains in Britain at least until the late 1950.
But why the fresh call for them? Could the real problem be that too many seats are being crammed into too small a space? And could that be due to the fact that a railway carriage in 1955 cost around £6000, compared to £2.6 million today - a real increase by a factor of nine, so every square inch of floor space costs that amount more?
Now there is a question that really does call for an answer, because the 1955 carriage wins hands down in terms of spaciousness, comfort and general ambience.
But why the fresh call for them? Could the real problem be that too many seats are being crammed into too small a space? And could that be due to the fact that a railway carriage in 1955 cost around £6000, compared to £2.6 million today - a real increase by a factor of nine, so every square inch of floor space costs that amount more?
Now there is a question that really does call for an answer, because the 1955 carriage wins hands down in terms of spaciousness, comfort and general ambience.
måndag 22 juni 2015
Gothenburgs "first" electric bus
It might be unfair to call this a vanity project, but the new route 55 which started last week is being promoted as Gothenburg's first electric bus. It is not, because there were a few trolleybus routes running until the early 1960s. It is a hybrid, with charging points at each end of the route, using an overhead supply and a pantograph on the roof of the bus. Charging takes about five minutes.
It runs on electricity on the flat sections of the route in the centre of the city, which makes it quiet and emission-free when running on its batteries, but the engine starts up as soon as it hits a slope.
This probably takes battery power as far is it will go. The underlying problem with batteries is the poor energy density, both in terms of mass and volume - they are bulky and heavy and can not store enough energy. They are also expensive due to the use of materials which are relatively scarce. The technology will ultimately be seen as a dead-end.
Road transport fuels must have a high energy density. Hydrogen fails because it does not liquify at ambient temperatures and can only be stored under great pressure. The same applies to methane. Hydrogen also needs to be used in fuel cells which require costly platinum as a catalyst. This is why short-chain hydrocarbon fuels such as petrol and diesel have persisted.
One possibility which has been proposed is ammonia. It has a good energy density, though not as good as a hydrocarbon. Its great advantages are that it can be liquified no great pressure - less than 10 atmospheres, if I recall, at ambient temperatures and that the waste products are harmless nitrogen and water. It can be used in fuel cells, and has been experimentally, but for some reason the technology seems to have been neglected.
This probably takes battery power as far is it will go. The underlying problem with batteries is the poor energy density, both in terms of mass and volume - they are bulky and heavy and can not store enough energy. They are also expensive due to the use of materials which are relatively scarce. The technology will ultimately be seen as a dead-end.
Road transport fuels must have a high energy density. Hydrogen fails because it does not liquify at ambient temperatures and can only be stored under great pressure. The same applies to methane. Hydrogen also needs to be used in fuel cells which require costly platinum as a catalyst. This is why short-chain hydrocarbon fuels such as petrol and diesel have persisted.
One possibility which has been proposed is ammonia. It has a good energy density, though not as good as a hydrocarbon. Its great advantages are that it can be liquified no great pressure - less than 10 atmospheres, if I recall, at ambient temperatures and that the waste products are harmless nitrogen and water. It can be used in fuel cells, and has been experimentally, but for some reason the technology seems to have been neglected.
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