Midland Main Line Electrification

[Adam]

To me, at any rate, it would seem sensible to retain the 3rd rail between Southampton and Basingstoke, as well as providing that section with OHLE.

 

Although as many have said, it'd be fairly easy to equip all the Cl.444s and 450s with pans etc, this is adding a further complication to these units plus putting additional time in the schedule for having to stop at Basingstoke.

 

Seems to me that if the decision is taken to install OLE then it would be an unforgivable waste of taxpayers money to keep the third rail underneath it! The justification for replacement is very largely to avoid the renewal costs of the third rail and particularly its power supply, where presumably the equipment installed at first electrification is coming up to life expiry.

 

Two points here. In the long term, it probably is sensible to replace the third rail with OHLE along the entire SW mainline (including to Exeter), but I can see little benefit, in the short term - which here probably means 15-20 years - of having to re-equip the entire SWT Desiro fleet with 25KV gear (since the fleet is maintained at Northam and some work on 455s seems to go on at Branksome) for the sake of about 20 miles of track. The power supply issue is a Red Herring I think because most (all?) of the sub-stations were replaced just before the Desiros turned up. The pragmatic traditions of the Southern and BR(S) suggest that until or unless plans are developed to wire Basingstoke - Waterloo keeping the third rail intact would be sensible and flexible. Transferring between the two systems on the go is technically possible: Eurostars did it for years, and I guess that tweaking the software on the Desiros to cope shouldn't be an insurmountable challenge.

 

Adam

[roythebus]

Although the British and French networks are both three-phase systems running at a nominal 50Hz, they are controlled independently so the phases can shift slightly between the two. The DC link across the Channel is a bit like a much larger version of a three-phase traction package on an EMU, with electronics rectifying the AC to DC at one end and at the other producing AC in exact phase with the local network.

 

Separately from this, because a particular section of AC railway only has one conductor it can only be supplied with one of the three phases of the high voltage distribution network. One way of maintaining balance between the phases is to feed nearby sections from different phases, but connecting the phases together would result in a huge short-circuit so they have to be separated by neutral sections.

Thanks Edwin for putting my slightly tongue-in-cheek comment into more technical terms! I speak with Dungeness power station engineers quite a lot, so pick up an awful lot of info about power supply problems and the phase differences. I KNOW what happens when you connect 2 phases together, having done so when trying to get a set of vehicle lifts to work by holding in a contactor. There was a big flash and a bang, and a couple of burnt out circuit breakers, and that was on 440v! I hate to think what it would do to the grid...

 

Re dual-voltage Basing-Soton, this would make sense to retain the operating flexibility the Southern has always had. What would happen beyond Soton to Weymouth?

[Glorious NSE]

What would happen beyond Soton to Weymouth?

 

Not mentioned in the docs, so the governments presumption would be a change back to DC at Southampton - but this is just that, the governments instruction and not a fully developed plan, so more or less could be included in the finished scheme.

 

Interestingly the RSSB study doc on it has Basingstoke-Weymouth as the 25kv changeover test route...

[chrisf]

To save anyone else looking, the new issue of Rail Express went to press too soon to cover the announcement. I expect that Rail was a bit more fortunate: it is due to hit the doormats of subscribers on Saturday.

 

Chris

[melmerby]

I look at that spot practically every day (assuming I'm awake - unlike you lads, I'm on the cushions!). Given the proximity of the adjacent Aston Church Road (that the chord presumably crossed by way of a bridge, dropping at the same time and curving to meet the Castle Brom line), I can't ever quite picture how the chord must've looked in my mind's eye. You can see the shape of the railway boundary on the lower route though, which does suggest a curve once diverged at this point.

If you look on an early OS map (e.g. Godfrey Edition Warwickshire 14.02) You can see the chord which looks as if it was provided so that Metro Cammell could get access to the Aston - Stechford line. Was it was ever used for normal traffic? On some maps it is classified as "siding" or "other" rather than being shown as a 'proper' LNWR or Midland line.

 

There was also a link on the other side of the Birmingham-Derby line which gave access to the Gas works from the Aston - Vauxhall line as well as from the Midland line.

 

Keith

[lapford34102]

Interestingly the RSSB study doc on it has Basingstoke-Weymouth as the 25kv changeover test route...

 

Once past Millbrook and the Freightliner complex it's a fairly simple run all the way through. Just the main line and a few loops and sidings though the Lymington branch would need considering.

 

A couple of questions though. Would the electrification kit put in the Weymouth section have to be thrown out or can it be adapted for 25kv. Also what about structures, are the built with the possibility of OLE kit being put in at some stage ?

 

 

Stu

[Joseph_Pestell]

We all seem to have gone a bit off topic. Since when was Weymouth on the Midland?

[Glorious NSE]

Hi Joseph, true, but it's now the same project!

[lapford34102]

We all seem to have gone a bit off topic. Since when was Weymouth on the Midland?

 

Just so and apologies for that but we do seem to be looking at one of the biggest shake ups in our railways since Victoria was on the throne plus there's an element of joined up thinking here which is somewhat novel for UK transport policy.

 

So to put things back on track is there/has there been a future proofing policy that any new structures etc are built with the possibility of OLE kit being put in at some unspecified time.

 

Stu

[Fat Controller]

Once past Millbrook and the Freightliner complex it's a fairly simple run all the way through. Just the main line and a few loops and sidings though the Lymington branch would need considering.

 

A couple of questions though. Would the electrification kit put in the Weymouth section have to be thrown out or can it be adapted for 25kv. Also what about structures, are the built with the possibility of OLE kit being put in at some stage ?

 

 

Stu

Stuart, all bridge renewals and similar works that have been done over the last 20 years or so have been planned with possible electrification/gauge enhancement in mind (wherever feasible), I believe.

Edited July 18, 2012 by Fat Controller

[Glorious NSE]

The new signalling works in the East Midlands seems to all be done with 25kv in mind - the similar works in Hants don't, and there is a comment in the RSSB doc that implies that 25kv clearances were not specified during the Southampton tunnel work, that doesn't neccesarily mean they aren't there, but it does imply that structures 'tweaked for gauge' may not have been treated the same as all new structures which should be 25kv capable.

 

That shouldn't be an issue on the MML itself I would have thought, I don't believe that has been gauge-enhanced yet anyhow, not being much of an intermodal route South of Derby before now except for the bit where the cross country route between Felixstowe and Nuneaton shares it...

[Peter Kazmierczak]

IF 25kV OHLE were extended westwards beyond Southampton, then some of the structures have tight clearances. Here's cemetery junction in Bournemouth; presumably lowering the trackbed would be a better option in these instances.

[Ohmisterporter]

Whilst lowering the trackbed is an option it can bring with it further problems. How deep can the trackbed be lowered before the bridge abutment foundations are affected? Also, a lowered trackbed under a bridge, or more especially a tunnel, can result in water collecting at the lowest point requiring expensive and ongoing pumping. I have some experience of this with a bridge under a motorway on my way to work. In some cases biting the bullet and rebuilding the bridge is the most practical solution.

[phil-b259]

Basingstoke - Southampton conversion only really makes sense because of the ammount of non 'southern' traffic (frequent intermodals, XC services, etc). Pretty every other 3rd rail route in the south east is dominated by EMUs to and from London (OK, Kent may have Channel tunnel flows which it can factor in) - hence the only advantage for conversion on these routes would be a more efficent electricity distribution system (and better reliability for the 20 or so days of bad weather over the winter.

 

I remain to be convinced that the potental conversion of the Bsingstoke - Southampton section can be replicated elsewhere, the benifits don't justify the costs and we would be better off spending the money on wiring up other bits of the UK network than simply replacing one type of electric system with another.

Edited July 18, 2012 by phil-b259

[Kris]

I remain to be convinced that the potental conversion of the Bsingstoke - Southampton section can be replicated elsewhere, the benifits don't justify the costs and we would be better off spending the money on wiring up other bits of the UK network than simply replacing one type of electric system with another.

 

It makes sense if the conversion is done at the point that replacement of the existing kit is required to start with but after this has been going for a while then a full change over starts to make sense.

[Edwin_m]

IF 25kV OHLE were extended westwards beyond Southampton, then some of the structures have tight clearances. Here's cemetery junction in Bournemouth; presumably lowering the trackbed would be a better option in these instances.

 

Looking at the amount of space above the train, and even allowing for the flat top of the 444 unit, you're probably not far off having 25kV clearance there!

[jamie92208]

There has certainly been some quite detailed preparatory work done on the MML scheme. A friend of mine is associated with a group who use an old railway building not far from Clay Cross. They tried to buy some of the surrounding land a couple of years ago and were told that it would be needed for electrification masts so it wasn't for sale but could be leased with the usual clauses about access when needed.

 

Jamie

[jamie92208]

I think that one of the main justifications for conversion is the transmission losses that are assumed to be in the 3rd rail system. A recent article in Modern Railways aboyut the fitting of electric meters to trains stated that the losses in the 25Kv system are known to be about 5% and that the 3rd rail was nearer 25%. As more trains are fitted with meters there will be a considerable saving in the bill. I laos see an enourmous amount of heavy duty cabling on the Southern as well as all those very frequent track sectioning cabins. All that should provide quite a large sum in salvage money.

 

Jamie

[roythebus]

Regarding future thinking on bridge rebuilding, the bridge on the WLL at West Brompton was rebuilt in about 1970 to 25kv clearances. It still awaits the wires...

[Glorious NSE]

Regarding future thinking on bridge rebuilding, the bridge on the WLL at West Brompton was rebuilt in about 1970 to 25kv clearances. It still awaits the wires...

 

They have gradually got closer since then, just not by much...

[RJS1977]

...but was it rebuilt specifically for OHLE, or was it rebuilt for some other reason (e.g. structural), and given 25kV clearance "just in case"? If youre building a new bridge anyway, most of the time it doesn't make much difference to the cost to give the greater clearance.

[Godders]

I have yet to see in this forum or in the goverment's plans any justification for the electrification of the MML. The enormous capital costs will take take decades to repay at today's rates, if at all, as there are no hard figures on running costs of the vehicles involved. As far as journey times are concerned there is not going to be much of a saving on London-Leicester as this town has virtually the same average speeds on journeys as London-Birmingham, which is already electrified. I will concede that London-Sheffield could gain on speed but this would appear not to be a power issue that electric traction could improve but a track constraint. Electrification is not the answer to this, track alignment probably is. PS current average speeds from London to Leicester are 87mph, Derby 85mph and Sheffield 77mph. Hardly slow, consider the following London to Three Bridges (where I live) 52mph, London to Brighton 56mph.

How about this, if 25kV electrification is so beneficial then why not electrify the whole of the network South of London and make mega savings as the traffic density is magnitudes greater than any of the proposed electrified routes.

[roythebus]

...but was it rebuilt specifically for OHLE, or was it rebuilt for some other reason (e.g. structural), and given 25kV clearance "just in case"? If youre building a new bridge anyway, most of the time it doesn't make much difference to the cost to give the greater clearance.

With a view to it being used by channel tunnel trains I was told at the time.

[roythebus]

To answer Godders, I think the first answer is political, they have to be seen to be doing something! As for operating figures, no doubt some will be along soon.

 

Journey times may not improve much with wires alone, as you rightly say some track improvement will surely be built into the project. At one time, London-Rugby speeds were about 90 mph start to stop.

 

As for SR improvements, nothing will ever improve the journey times there much beyond what the are now due to the layout and sheer volume of traffic, except maybe HS3!

 

The politics is to be seen to be creating "capital projects", "infrastructure investment", "investment in jobs(probably in Japan) and the like. Remember, there's an election in 2 years...

 

Me, a cynic?

[The Stationmaster]

To answer Godders, I think the first answer is political, they have to be seen to be doing something! As for operating figures, no doubt some will be along soon.

 

As soon as they've been written to fit the investrment case.

PS I'm not a cynic (well not much, more a realist) - it's just that I've been around for a while and have seen some of it before