We used to have platinum lined barrels for when using the machine guns in sustained fire role. Apparently it had some property that was needed in dissipating heat, or something of the sort. Apparently they were astronomically expensive.
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We used to have platinum lined barrels for when using the machine guns in sustained fire role. Apparently it had some property that was needed in dissipating heat, or something of the sort. Apparently they were astronomically expensive.
[QUOTE=Huw Eastwood;28319]It could well be Gary, it's soft and malleable so its conductivity would have to be ridiculously good to make the slightest bit of sense for its use over cheap alternatives like copper though.
Samuel used platinum as I believe that it is impervious to the effect of such as sulphuric acid being applied into the lever pack. Probably in the top range only.
The Danish Testing Authority at one time, maybe till today, were most concerned about this which resulted in Tann putting a brass ferrule in the bottom of the Kromer lock cases which was attached by wire to a relocker.
The Clydesdale Bank in Glasgow, the most far sighted security wise, asked me to conduct an acid attack on the Kromer Novum about 40 years ago. I was much more apprehensive in this test than I would have been with my Gelignite. The lock was attached to a post under which was a covering of soda ash to neutralist the spillage which was considerable as the lock had to be flooded and constantly refilled with fuming sulphuric acid before the levers disintigrated sufficiently for a torque key to withdraw the bolt.
I'm a bit out of touch now but I seem to recall that Aqua Regia, a combination of sulphuric and hydrochloric acid would act similarly on platinum.
Ooh. It's quite heavy.
[QUOTE=safeman;28324][QUOTE=
I'm a bit out of touch now but I seem to recall that Aqua Regia, a combination of sulphuric and hydrochloric acid would act similarly on platinum.[/QUOTE]
In saying that I was a bit out of touch is an understatement as I now realise that where I referred to Sulphuric Acid I should have said Nitric Acid.
Perhaps I'm up a gum tree again with my theory that when Tann sometimes placed a couple of steel levers among the brass ones in the likes of the Tann 4S Reliance Lock it was to lessen the effects of acid upon the lock.
Tom, you will doubtless have this information already but here goes:
Chatwood's Patent 1865 No.778. Keyholes lined with platinum alloy as a protection against acid and heat.
List 6 Sextiple Patent price list 'if fitted with Chatwood's Patent Platinum Key-hole Plug Lock £10 extra.' (date approx.1879). This extra not mentioned in List 5 or below.
I havent taken it apart but it turns out to be a No3 size, List 5 which infact is the same as a List 4A with that lovely dovetail, sliding boltwork added. Locks are 1867 and 1880
The small horizontal key moves the keyhole shutter away.
The larger key then moves the levers on a lock similar to a fanlock (but without the fans).
Then the knob moves the lock bolt into the levers.
Then the drop handle moves the boltwork of the safe,
so that you can pull it open with the pull handle.
Not only is it a nice Xmas present to myself but when I looked at the white paint which obliterated the original paintwork and detailing, I found that it was only whitewash and completely rubbed off with just a dry bit of kitchen paper - easiest job ever!
Slightly OT, but does anybody remember an old Ratner with a top combination lock and a bottom key lock? The combination lock not only locked the boltwork, but also slid a cover down to block the keyway for the keylock.