TD, the area shown on 227 was the ground air start panel, a facility to connect a ground air starter trolley for engine starting if the aircraft's own auxilliary power unit (APU) has failed for any reason. it utilises the same ducting that the tailpack conditioning unit uses (used, now not in use!) to feed air forward. 7 tank starboard is effectively just above this panel, sandwiched in the wing-root between the fuselage and the number 3 engine jet-pipe. There is a full metal rib between the jet pipe and tank though, with a suitable airspace either side of it, and fire detection "firewire" on the jet-pipe side of the rib, indicated as No.3 Zone 2. This area has 2 shots of fire extinguishant available to it if required.
DV, MRA2 - Maritime Reconnaisance and Attack, indeed. It is (was!) a submarine hunter-killer!
Thunderbird7, it's not farcical that there was never a bomb-bay fire extinguishant system, at the time the aircraft was designed there was no system available that could deliver a sufficient volume without causing an unacceptable weight/space penalty in the eyes of the designers. There are various types of system available today, I don't deny that, but at what price? The MOD won't spend that ammount on something that's about to go out of service, but that doesn't excuse the lack of such a system on the MR4, in my opinion.
The "Range extension tanks" referred to previously have never, to the best of my knowledge, ever been fitted to an in-service aircraft. In fact, I can guarantee they have never physically existed at ISK from 1985 to the present day. I did hear that they existed (2 sets only) at Warton in the late 80's.
As for tonnes of fuel in the bomb-doors, it has happened before and will no doubt happen again. I have personal experience.