Notably, a railtour with a 4-SUB around Kent to an Ashford open day in the early 1980s had to have the lighting fuses removed for the Kent Coast section because of the higher voltage. The Mary-Go-Round, see https://sixbellsjunction.co.uk/80s/820814se.htm .
There may have been others, but I was on that one!
I think there was a directive that the fuses had to be removed or replaced by a member of CM&EE staff. I read about a tour where SUB 4732 was hauled by Sarah Siddons and the Underground bloke was startled by the overvoltage trips popping out on the SWD. They just reset them and she was fine.
A few of these substations are still about in my local area. Are they still running or are they obsolete and just too hazardous to demolish?
It was the late 1920s that mercury arc rectifiers started replacing the rotary converters; this assisted the installation of remote control of substations from a central point.
We've had discussions here about this in the past. It was certainly stated in a Modern Railways article on the 1967 electrification as such, and it was likewise denied on here by multiple members who had been engineers on the scheme. Seems it was either a typo, or someone had misunderstood some overvoltage figure as being the nominal one. The article described the special measures needed now SUB units could run themselves to Eastleigh for overhaul, which are those mentioned above.
The line was quadrupled in St Mary Cray area, and new less tightly curved spurs built near Petts Wood. This increased power requirements so new substations. But suburban trains worked as far as Sevenoaks.
Or would that have been primarily for stock compatibility? i.e. allowing the suburban stock (now exclusively EPBs) to multiple with the HAPs and CEPs.
I suspect the SUB trip was done in summer, as I believe the fuses on the heaters had to be taken out when sent to 750V areas.
Lighting as well according to that railtour writeup quoted earlier.
I did hesitate to put that in, as they would presumably have had to run on a route without tunnels, and I couldn't think of a way to do that across Kent.
No. That‘s a myth that has been previously demolished, apparently it was the open circuit output of the rectifiers. One of the rail magazines used it in error, IIRC.
For timing purposes, I think 675 volts was assumed. That 850V thing just won't go away! I saw it demolished by Richard Catlow on the uk.railway Usenet group over 20 years ago, and it was demolished in books over 50 years ago.
I think I saw that, back then Richard Catlow definitely seemed to be a respected name in uk.railway for electrification questions…
Started as an apprentice electrician at Selhurst depot in 1987, now a widely reknowned railway eletrification engineer.
So they could only go as far as Alton?
I believe it was not unknown for SUBs to go to Eastleigh with the heating & lighting circuits isolated (I don't know if the headcode box lights were affected).
Most SUBs had stencils at the front and a red oil tail lamp rather than illuminated headcode blinds like later Southern Region stock.
And to think the APT or PEP stock was about at the same time!
The stencils were mounted on a frame over a white opal glass fronted box, and inside that box were a number of light bulbs. These illuminated the stencil so that the digits were visible at night or in dull weather.
