Electrification and its implications for Bath's heritage (merged topics)

[whole diary]

[onthecushions]

The problem was addressed on the EC scheme for The Royal Border Bridge at Berwick where slim masts were used. The point is valid if portal (steel gantries) rather than headspan (wires) catenary was proposed. As Bath area will be modest in line speed headspans should be acceptable. Other details like trimming canopies have also be dealt with sympathetically previously.

The Wharncliffe Viaduct and Maidenhead Bridge will need similar care.

The problem with clearance costs of replacement bridges versus track lowering is timing. Given 10 year's notice, the Western end could be mostly track lowering as heavy maintenance must be needed by then.

A good Engineer is also an Artist.

OTC

[Tim]

A good Engineer is also an Artist.

NR^» (Network Rail - home page) also want to errect a fence or wall in Sydney gardens (because it is a bit of a tresspass hotspot)and the current wall is not even waist height).  They showed off some of their plans in Bath library and they were reasonably symapathetic and had obviously been designed with care. 

[devon_metro]

The obvious answer is some sort of glass/perspex wall.

[JayMac]

The obvious answer is some sort of glass/perspex wall.

It'll have to be impervious to spray cans/etching. If the scrotes can't trespass to graffiti then a nice smooth canvas will suit them fine!

[devon_metro]

The obvious answer is some sort of glass/perspex wall.

It'll have to be impervious to spray cans/etching. If the scrotes can't trespass to graffiti then a nice smooth canvas will suit them fine!

I hadn't thought of that!

[Electric train]

My stock answer to these people is "How dare they insult Brunel's memory". Had he had 25Kv technology we'd have had at least 200 mph broad gauge trains sweeping through Bath.

Absolutely agree Brunel was a cutting edge engineer many years ahead of his time he used the best technology he could at the time and would almost certainly used electric trains if he could.

I am sure the designers of the OHLE^▸ (Over-Head Line Equipment (electrification via catenary)) through Bath and a number of other places will pay attention to the heritage, modern OHLE is much lighter in construction and as the line speed through Bath is relatively low that means even lighter weight construction is possible.  Network Rail wants to produce a 21st centenary railway but the same time it holds the heritage they are custodians of in high regard, certainly the current Board do not want to go down in history as the butchers of the country's heritage

[devon_metro]

The OHLE^▸ (Over-Head Line Equipment (electrification via catenary)) is quite discreet at Paddington!

[The Grecian]

Electrification has hardly ruined the Lune Gorge or the Royal Border Bridge. I don't think one letter in a local newspaper really tells you anything though. The one thing I've found constant around the country is that you get some half-baked utter drivel on the readers' letters page in local newspapers. Mind you, that's also been a downside of the internet  .

[Phil]

Sorry if this is a particularly stupid or naive question, but why is there what appears to be a universal assumption that overhead power lines are going to be installed - has that been explicitly stated anywhere?

Just for the sake of argument, what's to stop SouthWest Trains for example bidding for & winning the franchise at some future date and laying a 3rd rail power source to run their trains through Bath?

It's still electrification of the route, but I fail to see how laying a third rail alongside the existing line could have much of an "impact both visually and structurally on the Brunel assets, particularly through Bath" - hence my question: why the assumption?

[inspector_blakey]

With apologies to Driver Potter, the 750 V dc 3rd rail does have its limitations - it ices up like a b*gg*r in winter, introduces significant extra hazards for staff working at ground level and isn't suitable for truly high-speed use (i.e. not above 100 mph); there may well be others.

Further, remember that the IEP^▸ (Intercity Express Program / Project. This will offer more capacity on routes, save money, give a consistent and safe service and meet customer requirements. Intended to replace HSTs.) "Super Express" trains are going to be built with the rest of the 125 mph network in mind, i.e. 25 kV ac overhead electrification as already exists on the WCML^▸ (West Coast Main Line), ECML^▸ (East Coast Main Line) and elsewhere.

Lovely as it would be to see a fleet of class 73s operating trains through Bath, I don't think it's happening...!

[willc]

It's not an assumption, it's Network Rail policy - because,as the inspector observes, 25kv overhead is a sight better power supply system than 750v DC^▸ (Direct Current), which in future will be used only for infill on the remaining diesel islands in the old Southern Railway area, possibly including Reading-Guildford, or perhaps for a few judicious extensions to the Merseyrail system. If Worting junction-Salisbury-Exeter is electrified, the chances are the only bit that might get third rail would be as far as Salisbury, and even then that's not guaranteed if you would be using dual voltage trains anyway.

You certainly wouldn't be fitting IEPs^▸ (Intercity Express Program / Project. This will offer more capacity on routes, save money, give a consistent and safe service and meet customer requirements. Intended to replace HSTs.) with pick-up shoes and transfomer kit to potter through Bath - similar concerns were raised about views of Durham Cathedral and the Royal Border Bridge at Berwick when the ECML^▸ (East Coast Main Line) was wired but no-one seems to worry about those these days.

[onthecushions]

Just for the sake of argument, what's to stop SouthWest Trains for example bidding for & winning the franchise at some future date and laying a 3rd rail power source to run their trains through Bath?

HMRI^▸ (His Majesty's Railway Inspectorate).

Only extensions allowed, not new systems.

(Heritage operations aren't ruled out, for lovers of SUB/EPB/CIG/CEP's).

OTC

[welshman]

Quite so.  Apart from the health & safety issues of having 750v at your toetips so to speak, there's a basic issue of physics.  You need the electricity to supply power (!)

Kiddie physics tells us that Watts (power) = Volts x Amps (current).  It follows that 750v DC^▸ (Direct Current) supply has to run at a huge current to match the overhead 25,000v supply's ability.  The point of high voltage low current is that it can be used to transmit power over long distances.  Third rail requires frequent sub-stations to maintain the supply at sufficient strength to drive a train.

Your plug in the wall is 250v.  The transmission lines across the country run at anything up to 450,000v 'cos you get more power down the line that way.

Have you ever LOOKED at a third rail pick-up system.  A big mechanical shoe with a plank of wood attached to it. How does that compare with the spindly elegance of a catenary?

I agree with what was said above.  If Brunel had been able to use OHL^▸ (Over-Head Line) we'd have had 200mph trains in 1865.

[JayMac]

Just for the sake of argument, what's to stop SouthWest Trains for example bidding for & winning the franchise at some future date and laying a 3rd rail power source to run their trains through Bath?

Um....because TOCs^▸ (Train Operating Company) run passenger services using rolling stock specified by DfT^» (Department for Transport - about). Network Rail deal with infrastructure. SWT^▸ (South West Trains) could lobby for 3rd rail, but it ain't gonna be them laying it.

[Trowres]

One of the problems with e-forums such as this is that the participants form a self-selecting group with similar properties: in this case perhaps a little too unreservedly pro-anything-rail. There is no need to make disparaging remarks about any dissenting voices.

25kV electrification has been applied sensitively before on certain viaducts, and we may hope that Bath is treated with similar care. However there are plenty of situations where it is downright ugly. Sometimes this is due to the sheer quantity of ironmongery and copper; sometimes due to the lack of design finesse - a deficiency also afflicting many recent colour light signals.