Atomic Systems

Hello,

I downloaded the Dorset route and it run perfect after installation. I am not from England, so I just want to ask if these route is really not electrified with gantries etc.? I see gantries not so often in english routes, so is it realistic?
Thanks for answers.

Marc

The Dorset Coast route is electrified using a 750V DC current (third rail). So it is realistic.

Originally seen by the Southern Railway as a cheap means of electrifying the whole Southern network. Unfortunately the maximum speed possible with 3rd rail is something between 100 and 110 mph - therefore there is little scope for improving services through faster train speeds.

Dan

Hi,

I am intrigued as to the technical reasons for the speed restriction on third rail power pickup. Is it because of mechanical limitations of the shoes used?

cheers,

Larry

BR7MT wrote:Originally seen by the Southern Railway as a cheap means of electrifying the whole Southern network. Unfortunately the maximum speed possible with 3rd rail is something between 100 and 110 mph - therefore there is little scope for improving services through faster train speeds.

Dan

It was the LSWR that took the decision to use third rail and yes it was costs when compared with the LBSC overhead system. At that time high voltage ac systems were at a very early stage of development. The LSWR only considered electrification of London suburban routes due to competition from electric trams.

Certainly the Southern continued with the existing system when extending electrification to Portsmouth, but it was good old BR who made the decisions with regard to the electrification of the mainline from Woking to Southampton and Bournemouth.

John

1nternet wrote:Hi,

I am intrigued as to the technical reasons for the speed restriction on third rail power pickup. Is it because of mechanical limitations of the shoes used?

cheers,

Larry

Hi,

It might be because 750 volts is quite low. Trains using overhead wires pick up 25,000 volts. (I'm not sure)

Have a look at: http://www.southernelectric.org.uk/

Callum

Shoes break off pretty easily. Electrical potential energy isn't overly high for 750v DC anyway.

I think the main reason is that the shoes would break off on the ramps that you see at the end of each conductor rail section. These could be modified to a much shallower angle to enable higher speeds, but it's not economical to do so.

The power supply capacity of a 750V system is another constraint, as the energy required to accelerate a train to 125mph (for example) would necesitate higher currents than the system installed currently can provide. A Eurostar draws 6800A on the 3rd rail, and that can only do 100mph. It has something like 5000hp available on 750V, but when it's on the 25kV it has 16000hp.

And of course, there's no real benefit to running much faster than 100mph in the southern region. The Brighton line has some short sections of 100mph, but is mainly 90, and fast trains take an hour or so. The Bournemouth line has a few sections of 100mph, but fast trains get from London to Bomo in 2 hours, and this wouldn't be reduced much by increasing the speed to 125. And of course, the Southern 3rd rail lines are amongst the most congested in the country, and if you increase the speed, you increase the stopping distance, and therefore you have to increase the signal spacing and reduce the capacity.

Thanks a lot for your detailed answers. Has anybody a overview about the lines that used gantries, 3rd lines or are not electrified in the UK??

rooseum wrote:Thanks a lot for your detailed answers. Has anybody a overview about the lines that used gantries, 3rd lines or are not electrified in the UK??

Hi
The main route that was elecrified in the UK was the WCML (late 50s and early 60s).
This is captured very well in msts by the Thames-Mersey route....and coincidentally by the same author as the Dorset Coast.


http://members.uktrainsim.com/filelib-s ... thor=ccsdc




Cheers
Jon

And following on Jon's coments, the East Coast main line and a number of lesser routes such as that to King's Lynn are also now electric with 25,000 volt overhead lines.
Whilst the overhead system has big advantages in its ability to deliver lots more power at high speeds it is very vulnerable to damage. A defective pantograph can close down a lot of the system when it brings down the overheads and they take more time to repair than third rail.

Tony

and its ugly !

Tonysmedley wrote:And following on Jon's coments, the East Coast main line and a number of lesser routes such as that to King's Lynn are also now electric with 25,000 volt overhead lines.

Tony

Hi
I'd assumed he was asking from a msts perspective...I could be mistaken though.
I would agree that OHE can look very ugly indeed.
Cheers
Jon

jbilton wrote: I would agree that OHE can look very ugly indeed.
Cheers
Jon

I don't find OHLE ugly though. It seems to be part of the scenery to me, especially when it's found over 4 tracks so you'll see one whole gantry stretching across 4 tracks, holidng the wires..

Hi Everybody,
Here's some useful information i've found in my BR Handbook regarding overhead electrification periods. The book is dated sometime in the Eighties so it only go's as far as that.


Colchester-Clacton-Walton (Pilot Scheme) 1959
Manchester-Crewe 1960
Liverpool Street-Chelmsford and Southend Victoria* 1960
Liverpool Street-Hertford East-Enfield Town-Chingford-Bishops Stortford 1960
Glasgow suburban (north of Clyde) 1960
Liverpool-Crewe 1961
Fenchurch Street-Shoeburyness (LT&S line) 1961-62
Chelmsford-Colchester 1962
Glasgow suburban (south of Clyde) 1962
Crewe Euston (via Trent Valley) 1962-65
Stafford-Rugby via Birmingham, and Colwich-Stockport via Stoke-on-Trent 1966-67
Glasgow-Gourock-Wemyss Bay 1967
Lea Valley line (Clapton-Cheshunt) 1969
Manchester-Altrincham 1971**
Weaver Junction-Glasgow 1973-74
Moorgate-Hertford North-Welwyn Garden City 1976
KingsX-Hitchin-Royston 1977
Rutherglen-Kelvinhaugh (Argyle Line) 1979

*Conversion to ac. Electrified to Shenfield at 1,500 dc in 1949 and extended to Chelmsford and Southend Victoria on same system in 1956

**Conversion to ac. Electrified at 1,500 dc 1n 1931.