donald haarmann said the following on 16/02/07 22:38:

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On this side of da pond RR fog signals are called RR torpedoes. Oh - by da there
were also explosive lighthouse fog signals.

[great stories snipped]

[Railway torpedoes contained a mixture of potassium chlorate, sulphur, sand,
binder and a neutralizer. (Ellern #155). They were placed on the track behind
parked trains and such. The weight of a following train crossing over a torpedo
would cause it to detonate warning the engineer to stop. /djh/]

There must have been a couple of different types as the early ones I met
were tin plate with a mercury fulminate bulb or so a documentary on
explosives explained, well we never did find much after, but the ones I
saw a few years back felt a bit heavier.

[I can say from personal experience during my misspent youth with both the
real thing and one home-made device, they function well. Just remember one
thing if you are planning on replicating one of these devices; I have replaced
the luck of my youth with knowledge and experience plus not a few gray hairs.
Fireworks should be fun. Loss of your vision or sundry body parts from
using compositions/devices such as these is not fun with fireworks - n'est-ce
pas? [djh]

It seems all the fun things were dangerous. After seeing a schools
documentary about dyes which showed a small segment about the Red Arrows
aerobatic display team once using Aniline dye before changing over to
oils for making their smoke I thought my brother might like to try it
for his radio controlled model aircraft. The stuff wasn't readily
available so it never happened but I've just read up on the effects it has.


Richard.




--
"This week I have mostly been listening to -
RVW's "A Sea Symphony" and lots of William Alwyn stuff.