It is an uncatalgoued and unidentified object in a store room at an aviation museum.

I’ve approached Kidde Graviner and had an initial response and am hopeful they may be able to help. In the meantime, I thought I’d attach a photo of the automatic, and also a handheld we have as well, hence my confusion earlier.

The automatic is a Mk 21A and if anyone does recognise it, I would certainly be interested to learn more. It does seem to be dated 2-55, so it’s definitely post-war.

The handheld I can’t quite make out a mark number: it seems to be either a Mk 1A or a Mk 7A. Either way, I assume this is pretty generic and not specific to any aircraft type.

I think I may have led this thread down to wrong path. Does anyone have any APs or other references which indicate to which type(s) of aircraft a Graviner Mk 21A automatic methyl bromide extinguisher would have been fitted? I’m not really interested in speculation of whether they may have been fitted to this or that type. I’ve tried searching online and found nothing but if anyone has a documentary reference referring to this type it would be tremendously helpful. This would avoid any concerns over what it does or doesn’t look like but would give a definitive answer. I clearly made a mistake posting an image of an extinguisher that is not what we have and I’m sorry for any confusion I cause, but what we have in a Mk 21A automatic and that is the only type I’m interested in and the aircraft it would have been fitted to. I would be very grateful for anyone who can help answer this specific query.

Ian,

Thanks, but I’m only interested in the Mk 21A, as per my original post. I need to try and find out what types this mark of extinguisher was fitted to, not simply what types had any kind of Graviner extinguisher installed.

To get back to my original query, if anyone can identify what types had the Graviner Mk 21A automatic extinguisher fitted, I would be most grateful for the information.

Not at present, but I can take one on Friday. I found the pic below by a Google search and although not great, the Mk 21A we have looks exactly the same as this.

Thanks for the suggestion Tony, but it doesn’t seem to be Sunderland. The ladder seen here is definitely different from whatever we have.

Thanks for all the comments. I hadn’t measured the spacings between the steps but can certainly do this – although it will be a few days until I can do it.

What is slightly puzzling – apart from the very large spacing between ‘steps’, is that there is a ‘step’ at the very bottom and top of the ‘ladder’ which you certainly wouldn’t need in order to climb the ‘ladder’. I hadn’t thought about Resmoroh’s suggestion before, but perhaps this is a possibility. Is it some kind of support (although there don’t seem to be any fixing to hold a plank or something similar in place and stop it sliding off)?

Is it possible that it could be an internal ladder in an aircraft – is there anything where there would have been two decks that were at very different heights? Probably not, but just trying to think of slightly less obvious possibilities. If this is a ladder, it doesn’t seem to match any general aircraft access ladders – unless anyone knows different.

Don’t tell me I’ve stumped the forum! Does no-one have even an educated guess? Any suggestions or comments would be welcome (within reason :)).