Unless its in G1... "if there is a need to adopt an alternative rule or arrangement to the ones set out in the rule book..." and various considerations thereafter.
This linked thread, whilst nominally about the locos in class 74 form, has relevance: some of its posts touch on booster / flywheel arrangement (is similar to both 71 and 74). I can't recall the post #s but I hope it helps.
www.railforums.co.uk
Yes.
Presumably because in this country there has never been the need for such a rule.
There's definitely one of those right next to Westenhanger station, I noticed looking back at my footage from there, a 373 panning back up
Yeah that's what I was thinking of, it's still called a Voltage Change by Eurostar even though the actual voltage on both sides is still 25kv
See post 37, we have one at Westenhanger to change from the HS1 catenary setting to the Eurotunnel one.
Yes, and I think it does something to the fire doors too, and also sets the clocks to Continental time. The process for a driver though is exactly the same as if going from a 25kv section to a 1500v one so they're all just treated as "voltage changes".
My recollection is that all trains entering Swiss frontier station elecrified on something other than 15kV was that trains were routed only platforms wired on the system they would depart on. There were four current shunting locos to recover the stranded loco after it had coasted in with pantograph down. Then the Departure loco could come in under its own steam.
I seem to recall it's also something to do with the 50Hz frequency, where the pulses are a national standard but are thus fractionally different between UK and France at a boundary between the two. For the same reason the major power transmission cable between UK and France under the Channel converts to DC on one side, and is reconverted back to AC of the recipient country on the other side. For some reason it needs to be more complex than a normal neutral section.
I'm a bit sceptical of this, because normal neutral sections insulate between 25kV supplies that are very much out of phase with one another, and that's the same thing between different powergrids that aren't synchronised.
There are 2 neutral sections inside the tunnel and one just outside on the French side.I'm a bit sceptical of this, because normal neutral sections insulate between 25kV supplies that are very much out of phase with one another, and that's the same thing between different powergrids that aren't synchronised.
The explanation about different mechanical settings for the pantograph makes more sense because when you look at a class 373 power system selector switch, it has a different mode for LGV as well. (Image is from this twitter post)
From left to right the options are:
- BR AC for North of London working,
- HS1 AC,
- BR DC which now does nothing of course
- EuroTunnel AC
- LGV AC
- French classic lines AC
- Belgian DC (3kV)
I guess this one doens't have a French Classic Lines DC (1.5kV) for whatever reason, or maybe it's around the corner and we can't see it.
But the noteworthy point is that it has 5 different modes for 25kV AC which will be for what the maximum height can be or whether the height is fixed as well as probably other stuff too
Out of interest, is there a neutral section within the Channel Tunnel or is it fed only by one side at a time?
Oh how interesting, are those near to the "English" and "French" crossovers?
One is just inside at the UK end and one is midway through!
Might it have been a 4TC (4 coaches, Trailer Control)?
I saw a programme last year (can't remember if it was TV or an old TV programme on youtube) on the channel tunnel and if I remember correctly the tunnel is supplied by both countries but i think normally it's configured to be supplied by 1 country with the other countries supply only to be used as a backup. The same applies with the signalling (there are duplicate signal boxes with 1 normally in use and the other (in the opposite country) is a backup incase the power supply or fire alarm, evacuation of signalling centre etc means the normal 1 is knocked out of action).
Certainly could have been - at the time I wouldn’t know the difference. But were 4TCs often seen that far east? As you put, they were usually used on the line to Weymouth.
They did see some use on special workings at times, but yes certainly out of their normal way.
This also used to happen at Chiasso when an Italian loco and coaches on a service further north eft the DC overheads south of the platforms and coasted into the station. It was then removed by a SBB shunter to allow a Swiss loco to take the train on to Zurich. The Italian loco was then returned to the DC overheads.It's been used on the GEML, when work is taking place on one pair of tracks, trains have run on the other with the power switched off between Shenfield to nearly Stratford. There was a thread about it here a while ago with some technical detail, and indeed some members had driven it. With initial impetus of descending Brentwood bank, it's then gently downhill all the way. Special signs are erected for it:
Trivia: Longest stretch of coasting on a train in regular passenger service.
There’s no need for me to take anything up with anybody. It’s immediately obvious to me, as a seasoned railwayman, who signs both AC and DC traction, why the suggestion of trains coasting off the juice, via engineering sections, is profoundly nonsensical. The more interesting question is why...
At the Italian/Swiss border station, with incompatible overhead electrification (3kV DC/15kV AC), I recall the wires ended on approach, and restarted on the new system at the departure end. Incoming trains lowered their pantographs on approach before their wires ended, and braked to a stop in the platform. A diesel shunter then coupled up to the loco, pulled it forward, and then uncoupled and gave it a mighty shunt at speed, the electric loco then rolling back through the station and coming under its own wires again.
I saw some years ago that the normal situation is for the entire Eurotunnel system to be fed from France with the UK feed as a backup because French power is cheaper.
I understand the selector also determined power consumption limits. For example the GV(Grande Vitesse / high speed) position allows the train to draw full power from the 25kV AC supply, whereas the BR setting limits the amount of power drawn by the train and affects acceleration. Similarly the F (France) 25kv setting allows a greater power draw than BR 25kV settings, but not as much as in the GV setting.I'm a bit sceptical of this, because normal neutral sections insulate between 25kV supplies that are very much out of phase with one another, and that's the same thing between different powergrids that aren't synchronised.
The explanation about different mechanical settings for the pantograph makes more sense because when you look at a class 373 power system selector switch, it has a different mode for LGV as well. (Image is from this twitter post)
From left to right the options are:
- BR AC for North of London working,
- HS1 AC,
- BR DC which now does nothing of course
- EuroTunnel AC
- LGV AC
- French classic lines AC
- Belgian DC (3kV)
I guess this one doens't have a French Classic Lines DC (1.5kV) for whatever reason, or maybe it's around the corner and we can't see it.
But the noteworthy point is that it has 5 different modes for 25kV AC which will be for what the maximum height can be or whether the height is fixed as well as probably other stuff too
Out of interest, is there a neutral section within the Channel Tunnel or is it fed only by one side at a time?
