What's new
British Ordnance Collectors Network

This is a sample guest message. Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Switch No.10 Delay Mk11.

R

ron3350

Well-Known Member
I checked the old posts on the No.10 Mk11 switches and have some questions for the forum.
This white No.10 has a white plastic cap on the screw end . This has not been mentioned before so maybe it is a late post-war addition.
The body is steel plated and is inerted. It has the white safety strip and came with a tight fitting plastic protection bag.
What is the time delay for this white switch? I read 2 hours, 1.5 hours and 1 hour 19 minutes. Which time is correct?

Switch No.10 Delay Mk11.jpg
 
There is a range of delays depending on the temperature. It can be as much as 20 hours at -18 C to as little as 37 minutes at 47 C. A more normal temperature of 16 C gives a delay of 1 hour 45 minute, 21 C gives 1 hour 20 minutes and 27 C gives 1 hour. Note these are nominal times, individual switches will have variations on these times.
 
Those white rubber boots replaced a clear rubber ring around the end.

I believe its to cover the cut wire end to prevent it piercing the vinyl bag. If you notice when the wire protrudes out of the lead washer is normally sharp.
 
Hello,
I only know N°10 MkI so what is the difference between Mk1 and Mk2 ?
Regards
 
From memory the only real change was the addition of an extra inspection hole above the safety strip.

Post war the copper amouple end they started to add a hex to the base either to aid in assembly or disassembly?

View attachment 166558
 
Last edited:
You must log in or register to reply here.
Top