What is it - any ideas?

[sarabande]

Boats ?

[parsifal]

Well most people have worked out that they were bunks. The question remains under what circumstance and in what special place were they used. I speak with feeling as I have slept on one a few times!

Bunks with retraining straps?

Must be on an aeroplane - trooping flight?

[john_morris_uk]

Bunks with retraining straps?

Must be on an aeroplane - trooping flight?

Not a plane, in fact far from it!

[parsifal]

Not a plane, in fact far from it!

Furthest thing from an aeroplane is a submarine. Is that where they are used?

[Rum_Pirate]

Not a plane, in fact far from it!

On helicopters?

[jimi]

is it a seahorse nursery sandpit

[oldbilbo]

Stackable, fold-away bunks for RMs ( SBS? ) embarked on one or other of HM's untersee boats.

[Wunja]

Is it the transfer sled that takes Virgil from the operations room on Tracey Island to the flight deck of Thunderbird 2 (plus some spares)?

I was going to say that

[Grumpybear]

Bunks to fit on submarine torpedo stowage racks.

[john_morris_uk]

Bunks to fit on submarine torpedo stowage racks.

There speaks someone with inside knowledge..

Its the correct answer; as there are no spare bunk spaces on a submarine, and even when fully bombed up, you leave a space or two on the racks so that you can shuffle the various torpedos and missiles around to load your chosen armament into the tubes, then these spare spaces in the racks are fitted with trays with mattress for 'spare people' to sleep in. My only memory that I will admit to publicly is that, because its an ordnance space, and therefore nor heated, its jolly cold.

I don't think I have broken the official secrets act with any of the above...