High Density PEP stock on Southern Region

Other work included the acceptance testing of the prototype High Density Stock in summer 1971. Known as the PEP stock (Prototype-Electro-Pneumatic brake) the trains were tested on the Southern Region between Farnham and Alton. 

These were the forerunners of the modern EMU and DMU varieties and there were three sets, two four cars in BR Blue (numbered 4001 and 4002) and a 2 car finished in brushed aluminium (numbered 2001).

We were involved with a great deal of testing on these units and were based at Wimbledon Depot for a while and I remember that we used to lunch at the Woodman pub on Durnsford Road each day. In those pre-Drugs and Alcohol days a pie and a pint was the norm.

I remember testing the trains between Alton and Farnham and staying in the Blue Boy Hotel which was near the station at Farnham.

Click on the pictures for a bigger image

PEP stock No 4001

This is one of the 4-car versions No: 4001in the summer of 1972

Author's collection

PEP stock 4001 It was painted in BR blue

Author's collection

4001 Cab

A closer view of the cab

J Bingham

PEP stock No 2001

Here is the two car version 2001 photographed in 1972 at an unknown location - probably Farnham. 

Author's collection

Selhurst yard 4001 is seen here parked up at Selhurst on 8th July 1972

Ian Walmsley

About to depart Sister set 4002 about to depart from Waterloo in summer of 1974

Ian Walmsley


Waterloo buffers Here's the exception that proves the rule - 4001 in brushed aluminium pictured at Waterloo on 27th August 1974. In 1972, a reformation of vehicles took place and one of the unpainted aluminium cars was marshalled into set 4001.

Ian Walmsley

The trains were novel in that they were the first in the UK having power-operated doors. To ensure the public were aware of this departure from previous practice there was an extensive trial period and educational leaflets were issued by Southern Region. The doors were not controlled by pushbuttons as later doors were but the passengers pushed the handle to initiate the powered opening operation. They were closed remotely by the guard.

PEP stock leaflet

The front and rear of the leaflet

Author's collection

PEP stock leaflet

The inside pages

Author's collection


An insert was provided giving more information about the door operation

Author's collection

The Southern Electric E-Group have a couple of pages here with a number of photographs of the PEP stock and there is a short BR promotional film on YouTube here

I also recommend www.BloodandCustard.com for more information about PEP stock  and what happened to the vehicles



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