Can you ID this air raid shelter?

Hope this is OK, mods. Over on Amateur Photographer someone would like to know what sort of air raid shelter his house had when he was a lad. If anyone knows, it will be here!

The link is:

http://www.amateurphotographer.co.uk/forums/showthread.php?115826-WWII-air-raid-shelters-some-info-please

(I’m happy to pass messages on as I suspect most of us here aren’t on AP)

Thanks,

Adrian