The normal arrangement was a Graviner automatic extinguishing system. This had a pyro-cord running around above the engine, and a sensor above the fluid flywheel. Overheating in either would trigger fire bottles to be discharged through a capilliary tube that also ran around above the engine, and set off the fire alarm circuits.
Handheld portable extinguisers were also carried, normally in the cabs, vans, and at least one in each coach without a van.
