A most interesting group portrait from the IWM archives. Listed as "Group portrait of the ARP Rescue and Demolition Teams from Brigham, Middlesbrough and Bridlington. Tom Alderson GC is in civilian clothes sitting on the Mayor's right."
Rare to see the Repair Party/Road helmets (marked RP/R). A few appear to have specific armbands and the standard Civil Defence blue with gold lettering is being worn. There is a chap with a white helmet and three diamonds with a specific role I cannot quite make out. Given that everyone is in bluette overalls I would safely say the photo in pre-Summer 1941.
News about interesting insignia, ARP related info and period photos that turn up.