Philip Phlopp
Established Member
- Joined
- 31 May 2015
- Messages
- 3,003
A question that can be skipped by anyone not interested in the really detailed stuff...
Back in March I asked what they would do with the ATF through Pangbourne, as through the station they were using TTCs alongside the back of the down relief platform to support the main line side OHLE. Effectively there would be a gap the length of the station with nowhere to hang the down main side ATF on. http://www.railforums.co.uk/showpost.php?p=2504849&postcount=2278
I noticed a coupe of days ago (as highlighted in the photo below) that they seem to have fitted a special clamp to the ATF insulator on the last portal east of the station, with the cable coiled up and hanging below. This suggests that there will be a transition here from bare cable to insulated cable, that will presumably be run in trunking at ground level? Does anyone know exactly how they do this connection, as it must be required elsewhere on the various ATF systems around the country, typically through tunnels as discussed earlier in the thread. Does the connection take place on another insulator?
A supplementary question then, as previous posters have said the ATF is positioned where it cannot 'fall into danger' if damaged, so is the ATF always kept well clear of platforms?
This is how ATF wire to cable transition is handled for the Linslade tunnels - the ATF wire is terminated by an insulator, prior to which a pair of wires take the feed into a suitable cable (or pair of cables) which then join into a single twin core cable to run through the tunnel.
https://s-media-cache-ak0.pinimg.com/originals/76/85/41/7685415bf594243d79364a1180fd28fc.png
The bare wires at the end of the two cables are generally held in place by an insulator, much like the cable retainer on a plug, before the fully insulated cables run down the mast.
It's really no different to the way we get 25kV into and out of the wiring.
And yes, ATF wiring always kept in a position of safety for passengers, whether through the use of earthing bars, by using cable runs etc.
EDIT - and as you've probably got GL/RT1210 about - "auto-transformer" is the word to look for, to see the requirements.
Last edited: