D Stock Westcode Brake Question

[Old Walter]

Hi there, just a question regarding Westcode braking on the D78 stock: On A and C stocks the EP braking system had a set of blowdown magnets which let air out of the brake cylinders in certain conditions, did the D stock seven step relay system have something similar such as a retarder? I can’t find mention to anything like this, the nearest thing being a slip-slide system was fitted to (also Westcode) 1973 stock but was removed. Thanks in advance for any info.

 

[Dstock7080]

7-Step Westcode on D Stock didn’t have retarders.
A wheel slip-slide detection system was fitted and reminded in use while with LT/LU.

 

[100andthirty]

The only "slip-slide" on D stock was in motoring for control motoring current if wheel spin was detected. There was no wheelslide protection (WSP) system. The brake designers very carefully matched brake force to wheel load (known as balanced or matched) which made the train fairly resistant to wheel lock up and flats (famous last words!). 1973 tube stock had WSP in its early days but it was unreliable and was removed. The experience of D stock was such that WSP was thought un-necessary on 1992 tube stock. This was a mistake and WSP was added in the late 1990s.

 

[Old Walter]

Thanks so much to both of you for the replies, certainly fills in a few blanks and the info is greatly appreciated, great stuff : )