The Anonymous Widower

Steventon Listed Railway Bridge Saved From Demolition

The title of this post, is the same as that of this article on the BBC.

On the face of it it looks like victory for the Nimbys, who have saved a rather ordinary and possibly decrepit bridge from demolition.

But I believe there is more to this story than meets the eye.

The Bridge

The bridge at the centre of the argument may be Grade 2 Listed, but there are lots of similar bridges on UK railways in better condition with similar heritage, that don’t have a listing.

Type “steventon bridge electrification” into a search engine and you’ll find lots of images of the bridge.

  • One picture shows, the bridge with the railway flooded, which puts an interesting slant on the debate. What are the foundations like?
  • Notice, that the bridge seemed to suffer a rather botched repair at the hands of British Rail’s finest engineers.
  • Having read a lot about this story, I suspect that the locals’ main reason for objecting, is that they don’t want the disruption, whilst it is rebuilt.
  • Incidentally, I suspect Great Western Railway don’t want the bridge rebuilt either, as closure will be a long disruption to all services.

I have been involved in the refurbishment of several buildings of around the same age or even older than the bridge. This is the sort of construction, that will have to be replaced at some time. If it’s not replaced, some of the novel techniques that are now available to Network Rail will have to be applied.

Network Rail

The article says this about Network Rail’s solution to the problem.

But following what the company described as ‘extensive and breakthrough testing’ using computer simulations it found a speed reduction to 110mph through the village meant wires could pass underneath the existing bridge.

I do think, that 110 mph is rather convenient. if you look at the maximum operating speeds of trains and locomotives that will pass through.

  • Class 801 train with digital signalling -140 mph
  • Class 801 with conventional signalling – 125 mph
  • Class 800/802 train on diesel power – 100 mph
  • Class 80x train on battery power – 100 mph
  • Class 387 train – 110 mph
  • Class 90 locomotive – 110 mph
  • Class 91 locomotive – 125 mph
  • Class 93 locomotive – 110 mph
  • High Speed Train – 125 mph

Very few trains will have to slow down.

Any train that used onboard power, like a High Speed Train or a Class 80x with batteries, could theoretically go through at the maximum speed, track, signalling and train taken together would allow.

Hitachi

In Issue 898 of Rail Magazine, there is an article, which is entitled Sparking A Revolution, which describes Hitachi’s work and plans on battery-powered trains. This is an extract.

Battery power can be used as part of electrification schemes, allowing trains to bridge the gaps in overhead wires where the costs of altering the infrastructure are high – in tunnels or bridges, for example. This would also have the immediate benefit of reducing noise and emissions in stations or built-up areas.

Elsewhere in the article, it is said that Hitachi trains will be able to do 100 mph on battery power for up to 60 miles.

But would they be able to do 125 mph on battery power for perhaps five miles? I can’t see why not!

The Google Map shows the track through Steventon.

Note.

  1. The bridge in question is at the East.
  2. There are also a couple of level crossings in this stretch of track, where the height of wires is also regulated.

Perhaps, the pantograph should be dropped before going through section and raised afterwards, with power in the section taken from a battery.

Avoiding obstacles like this, may be an economic alternative, but it does require that all electric trains using the section are able to use battery power.

I have a feeling, I’ve read somewhere that a Class 88 locomotive can do a similar trick using the onboard diesel engine.

As a Control Engineer, who trained in the 1960s, I would expect that all pantographs can now be raised or lowered with all the precision and repeatability  of an Olympic gold-medal gymnast!

I do wonder, if the Great Western Electrification Project had been designed around discontinuous electrification and battery-electric trains, the project would have gone better.

For instance, the Severn Tunnel is 7,000 metres long and trains take under four minutes to pass through. The Wikipedia entry for the tunnel has a section on Electrification, which details the complicated design and the trouble that there has been with corrosion.

Given that battery-electric trains have other advantages, design by hindsight, says that a tunnel without electrification and battery trains may have been a better solution.

Conclusion

Network Rail and Hitachi will get the speed of trains through Steventon up to 125 or even 140 mph, possibly by using battery power.

But whatever happens, I’m certain that the bridge will have to be rebuilt! It has the air of a derelict house, that will suck up all your money.

 

April 26, 2020 - Posted by | Transport | , , , , , ,

No comments yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.