Dischargers, smoke generator, 4 inch

[Chris Suslowicz]

Originally Posted by Jim Burrill

As David Gordon says, we can have a live, fireable discharger here.

I have plans afoot to make an actual smoke canister that meets local reenactment safety guidelines.

Essentially, smoke compound as used for paintball games filling a cardboard cylinder, all made with no metal parts and weighing no more than one pound.

A blank .303 to ignite it and throw it down range a bit. Not an accurate tactical recreation in distance and duration, but usable for reenacting displays.

Intend to mount them on the Humber Mk4 Armoured car.

Hmmm....

Have a word with your local pyrotechnics/firework manufacturer, since the obvious choice is a 4" cylindrical shell, suitably modified (no lifting charge bag/cone and a very short delay fuse - mainly to prevent the launch charge from blowing straight through and dismantling the shell before it leaves the tube) and loaded with your smoke composition and (obviously) no bursting charge - vents needed to let the smoke out, of course! Launch with a blank cartridge loaded with coarse grained black powder - one of the "cannon" grades ought to do it, because you don't want high velocity. (Nor anyone downrange of it!) And BE CAREFUL!

It would be completely illegal to produce these in the UK (unless you hold a manufacturing licence, etc.), so don't even think about it. (See the various bits of legislation (Explosives Act(s), Control Of Explosives Regulations, HSE rules, etc.) The quantity required would be commercially uneconomical, including having them made in China, (without considering the UK testing required (at your expense) before they would be allowed into the country).

Pyrotechnic manufacture being a permitted hobby/small business in parts of the USA means that you could probably get something suitable produced in small batches.

Careful testing is essential: some smoke compositions do not play nicely if firmly initiated (or overly contained - even a heap may suffice) and can explode(1). Especially test what happens if the delay element is omitted and the lifting charge blows straight through into the smoke composition!(2)

Chris. (4)
(1) Umpteen(3) years ago we discovered what would happen if theatrical smoke powder was used in excessive quantities (or added to flash powder) - you get more bang than you bargained for and very little smoke.
(2) I recall a 75mm cylinder maroon that went off in the tube, entirely too close to where I was standing, due to the "lift" blowing through or a faulty delay element. I Do Not Want To Experience That Again!
(3) Back in 1984, I think... or possibly 1982.
(4) BPA Level 2, which means I get to do the risk assessments for our displays.