Wyton

[canberra]

No, Duxford didnt have nuclear weapons.

[j4cko]

I remember looking in those buildings once, when we were looking for the photo lab and in the completely wrong place! The strip lights on the ceiling looked brand new, like that had just been fitted, was quite strange

[PETERTHEEATER]

SSA actually stands (or stood) for Special Stores Area. And the blue note as it was called when the air went through the cannons on the Hunter is a lovely sound.

I was in the RAF at GAydon in the late 50s early 60s and the SSA was 'Supplementary'. Probably this term was superceded by 'Special' at a later date post V-Bomber ops.

[PETERTHEEATER]

I remember looking in those buildings once, when we were looking for the photo lab and in the completely wrong place! The strip lights on the ceiling looked brand new, like that had just been fitted, was quite strange

As I said previously, the Duxford buildings (on the northside of the communal site) were upgraded post war to accommodate 30mm ammunition. A lightning protection system was added and, presumably, the internal electrical lighting fittings upgraded.

[canberra]

A little bit off topic slightly, but is there any real risk from lightning setting off small arms ammunition? And by small arms I include aircraft cannon shells.

[Arcade Al]

A little bit off topic slightly, but is there any real risk from lightning setting off small arms ammunition? And by small arms I include aircraft cannon shells.

I wouldn't think the risk was significant, although an ensuing fire would do the trick!

[Carnaby]

Re the above I agree. Again OT but lightning was responsible for the loss of a very large number of barrage balloons during WWII. It was thus a very serious risk for the ground crew manning the winches. Some interesting documents in TNA on the subject - 174 were lost in July 1940 alone, and calibration equipment was then added to some balloons proving that currents of between 1,000 and 50,000 amps were measured in the balloon cable when struck. Scary stuff.

Graham

[canberra]

Of course the balloons had a very nice earth lead in the cable!!!

[Arcade Al]

That's a very good point re barrage balloons. Presumably at this time they were still filled with highly flammable gas too?

[PETERTHEEATER]

A little bit off topic slightly, but is there any real risk from lightning setting off small arms ammunition? And by small arms I include aircraft cannon shells.

30mm ADEN gun ammunition has electrically initiated primers; they are not struck by a firing pin as percussion caps are.

The post war electrical standards for explosive storage buildings generally require it to be 'Intrinsically safe' that is all cabling and lighting enclosed within steel conduits to prevent any spark or flame from intruding into the storage or work space.

The most important change was the introduction of 'bonding' whereby a copper strap would be run around the interior of the building and connected to the external earth. This allowed workbenches with tops covered in conducting material to be connected to the bonding thus permitting the discharge of static electricity during handling. It the case of 30mm this might included inspection of unboxed ammo (normally supplied in 30 round belts) to ensure that individual rounds were correctly positioned or 'tipped' for target practice.

Adopting a standard electrical installation also permitted a change of use of the building subject to safety distance regulations and other conditions.