1939-1945
1939 saw London's firefighters gearing up for war. The National Government instituted the Auxiliary Fire Service (AFS) to augment the resources of the regular fire service and it also saw the cork helmets withdrawn and the issue of steel helmets to firefighters.
The AFS firefighters were attached to the regular Brigades but under the control of the Home Office. They were issued standard Olive Green steel helmets but oddly those in the London area got Battleship Blue helmets. At first these "battle bowlers" had no insignia on them but after a while instructions were sent out for them to have hand-painted AFS badges and unit identifiers painted on them. Later still water-slide transfers were provided but many stuck with the hand-painted version.
1939 Briggs Motor Bodies Ltd MkII Steel "Brodie" Helmet
Meanwhile the LFB issued Carmine Red steel helmets which were later changed for Green with a broad Red stripe around the crown.
1939 Rubery Owen & Co Ltd. MkII Steel "Brodie" Helmet
The story behind this is maybe Urban Legend, but it is said that during the German air raid on Thameshaven (August 1940) British fighter pilots reported being able to identify the firefighters because their bright red helmets stood out so distinctively! That is when the colour was changed.
1940 Rubery Owen & Co Ltd. MkII Steel "Brodie" Helmet
In 1941 the regular Fire Brigades were disbanded and a National Fire Service (NFS) formed. It absorbed both the regular firefighters and the Auxiliary firefighters into one nationally unified body.
1944 Briggs Motor Bodies Ltd MkII Steel "Brodie" Helmet