[RichHI1]

NTarrant I do not inderstand why e are not communicating. So I will try to express myself better. Southern Railway lines london to Brighton are currently electrified using DC 3rd rail. For the speeds that can be run on this track, 3rd rail has worked satisfactorily for many years. Bucksnet suggests upping to 25kv to modernize. One major reason to mobe to 25kv overhead is to allow for larger power to enable high speeds such as shinkansen or TGV or to allow for heavier freight trains such as some US lines. The Brighton line was not built to support 180-200 mph speeds and there are no very heavy long ore trains to justify changing to 25kv. If it was electrified from scratch it might be done with 25kv overhead for standardization but not due to current drawn requirements.

[Bucksnet]

I think the current Brighton line trains top out at 108mph, but the line could handle higher speeds, plus new trains would accelerate faster.

[RichHI1]

I believe the line speed maxes at 100 mph. Going for substantially higher speeds would require relaying sections of permanent way both to smooth out some curves and alao remodel a number of junctions in South London, higher speeds would also require upgraded signalling and would cause problems in the peak periods of mixed speed paths as upgrading all the routes out of Victoria or London bridge would be a mjor task. Furher there are some line features such as viaduct and tunnels which may well require hardening and would certainly add cost to electrify. It is possible to achieve a moderate speed invrease without 25 Kv and connections to other lines can be done with mixed mode stock such FCC use, the Eurostars and the twin poee electrostars that Souhern bought. Going back to the old non stop running avoiding east vroydon would probably give you more time saving than upgrading where possible to 125 or 140 mph line speed.

[NTarrant]

Yes Rich, I know what Bucksnet is suggesting, but it won’t happen in the forseeable future. There is no need to remodel junctions in South London, there are sections of the Brighton line that can accomodate 110mph, although as Bucksnet says it max out at 108.

The whole purpose of the RUS (Route Utilistion Strategy) was to iron out inefficent workings and identify where frequencies could be increased. An example is the Victoria to Bognor/Portsmouth/Southampton which now has a good frequency and fast service with the splitting and joining at Horsham.

There is always a lot that could be done but there is little that can be done which is revolutionary in these times!

[RichHI1]

Agreed. I still miss the Bognor service. Ia Sutton and Dorking that bit the bullet when all trains had to stop at gatwick. Ah well… Don’t get me started on Steam to Bournemouth or the Hastings Diesel…

On related point I see class 442 is rated at 100 mph. I further understans the running gear of the 442 is based on the 4rep units used to push pull 2 4tc units prior to electrofication past Poole. Yet I remember a school outing in 1969 when we travelled back from Southampton on a non stop service. As a train mad schoolboy i spent most of the journey looking into the back cab of the 4 rep which showed 110 for brief periods between winchester and Basingstoke. Is the bournemouth line rated higher or was it 1960’s when health and safety was not so strong? We had had hither green on the Southern then but not clapham.

[NTarrant]

I think you are right about the 442’s, I think it was more capacity for the same power using lighter units, allegedly.

The line between Winchester and Basingstoke has always been fast, although a bit slower through Popham and Micheldever tunnels, as far as I am aware it is still the same. Don’t forget Clapham was nothing to do wuth speed.

[RichHI1]

No but from memory safety in the 1960’s was not a preoccupation on road or rail or air. The only train crashes that were about speed i can remember were all buffer crashes not high speed, such as Moorgate, canon street, glasgow. The only Southern one iremember reading about was many many years previously at Salisbury when the LSWR and GWR were racing.

[BusinessTraveller]

Just to say we’re looking into the issues with links within forum posts, which users seem to be experiencing at the moment, particularly in this thread.

We will let you know once these have been fixed.

[BusinessTraveller]

The issue with hyperlinks within forum posts has now been sorted (hopefully!).

[Author]

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