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[Roger in France]

I think you are missing the point I was originally making about insurance.

Regardless of the application of the law I would expect most insurance cover to be invalidated by the use of any form of projectile. Even if you are hard pressed to find a specific clause denying cover I would anticipate some catch all clause would be used by an insurance company presented with a claim.

The position of a self propelled torpedo is fascinating as it is not a projectile and could be argued to be no different from the self propelled submarine whence it emanates (note the very precise language I use here).

When I posted my original warning about the invalidation of insurance I was not intending to be a killjoy but hoping to make any experimenter aware of their probable position. I would say "Go ahead" but make absolutely sure nobody and nothing could be damaged by your experimentation. Also, keep an eye open for the Club Grouse or some member of the public who decides to complain, there is always one or more of these about.

I can think of several model boating activities far more likely to present danger; high speed boating including refuelling; untested boilers, for example.

I have witnessed a very, very, very fast tethered hydro break its tether, demolish the safety net surrounding the pool and embed itself in the exhibition hall wall. This happened last Easter at the Paris Model Show. How anyone could be so foolish as to run such a demonstration indoors I do not know! Fortunately no one was injured but a display stand and other models were damaged and then a fight took place between those sailing and those who sustained damage. If this had not been an above ground pool from which the boat (missile) took off, upwards, I dread to think what would have happened to the legs of those standing around a pool at ankle level.

Roger in France.

[Capricorn]

Ahoy Roger,

I see your point.  I'm not familiar with insurance for model boats or clubs but I'm sure it tends to be restrictive.  Cap 

[das boot]

Beware with playing about with working torpedoes...Bernie Wood and myself did just that a few years back. Bernie set my jumper alight, I killed one of the [then] wife's goldfish and a certain Ron Perrot had to explain to his good woman why there was a rather large hole in the end of their bath. Another one of Bernie's mates did some damage to his hand and his lawn as well, so think hard about using high powered torpedoes...they hurt!

Mine that ended up in U-117 were over a foot long, and were made from ultra lightweight aluminium tubing and were driven by rubber bands...they didn't go roaring off across the lake and they floated once the rubber band had unwound itself, so they could be easily retrieved. They did look good which was the main thing without being dangerous.

[Martin (Admin)]

"Bernie Wood"  a certain "Ron Perrot" Good to hear those name again after such a long time.
Bernie was a regular feature in the Marine Modelling magazine with his cap and jacket covered in badges
and Ron used to make hull and all sort of 'gubbins' for subs, I had one of his "Salcon" units, pendulum based
sub leveler. Does Ron still do submarines?

[das boot]

I haven't heard from Ron in years, his SALCON units were the bees knees back then. The Patrick Henry had one of the first I believe, amazing things they were.
Poor old Bernie...I have a video clip of him falling out of the bar at the AMS show we did at HMS Alliance, the word 'wrecked' springs to mind! We spent a happy evening over a bottle of scotch talking submarines, such a shame he was taken from us so early. The infamous jacket was his trademark, try as I might I could never quite get mine to look quite the same. There will never be another like himself and that's for sure.

[tigertiger]

I think the 12 ft lbs may relate to the value/rating/strength/power of the spring fitted in the air-rifle.

Above that figure and you need a firearms certificate to own the rifle.

I don't think it can be related to muzzle velocity. So many other factors including wear, friction, worn out bore etc. But one thing the armourer can easily establish is the rating of the spring, so this is perhaps why this measure was chosen for legal purposes.

[barryfoote]

I think the 12 ft lbs may relate to the value/rating/strength/power of the spring fitted in the air-rifle.

Above that figure and you need a firearms certificate to own the rifle.

I don't think it can be related to muzzle velocity. So many other factors including wear, friction, worn out bore etc. But one thing the armourer can easily establish is the rating of the spring, so this is perhaps why this measure was chosen for legal purposes.

tigertiger,

It certainly is related to muzzle velocity. The way we used to test the foot poundage was by firing the weapon through a little machine that records the muzzle velocity and from that gives the foot pounds for the weapon. Don't ask me for the equation as  cannot remember...You could find an air weapon would vary in muzzle velociy from shot to shot, depending on temperature, type of pellet fired and even any oily residue left over from cleaning. In law all it takes is one shot to be over and the weapon requires a licence.

Hope this clears things up a little.

Barry

[Subculture]

Does Ron still do submarines?

No.

He sold-up. Some of his moulds went to Matt Thor in the States, and some to Dave Keogh who runs Pandan Model Boats (or at least did). The SALCON has long been surpassed by modern units using solid state accelerometers.

Andy

[tigertiger]

I think the 12 ft lbs may relate to the value/rating/strength/power of the spring fitted in the air-rifle.

Above that figure and you need a firearms certificate to own the rifle.

I don't think it can be related to muzzle velocity. So many other factors including wear, friction, worn out bore etc. But one thing the armourer can easily establish is the rating of the spring, so this is perhaps why this measure was chosen for legal purposes.

tigertiger,

It certainly is related to muzzle velocity. The way we used to test the foot poundage was by firing the weapon through a little machine that records the muzzle velocity and from that gives the foot pounds for the weapon. Don't ask me for the equation as  cannot remember...You could find an air weapon would vary in muzzle velociy from shot to shot, depending on temperature, type of pellet fired and even any oily residue left over from cleaning. In law all it takes is one shot to be over and the weapon requires a licence.

Hope this clears things up a little.

Barry

Hi Footski

I stand corrected, so where did the ft lbs rating come into it. Or was it that Ft lbs is a metric that was superceeded by muzzle velocity? and there is a conversion equation.

[barryfoote]

tigertiger,

The ft/lbs rating was introduced many years ago and actually represents the enegy dispelled in firing the weapon, wheras muzzle velocity measures the speed of an individual projectile. The muzzle velocity measures the speed of the pellet as it leaves the barrel in feet per second (770 being good for those near the 12 ft/lb limit).
This muzzle velocity is flawed in so much as the important speed is generally that uopn reaching the target, which varies considerably on may factors, including wind and distance.
One foot pound is equivalent to dropping a 1ilb hammer weight from 1 foot, hence 12 ft/lbs is like dropping a 12 lb weight from 12 feet. It would bloody hurt if landing on your head.

I have managed to dig up some conversion factors for you..

To convert from foot-pounds to:

Btu, multiply by .001286.
ergs, multiply by 1.356E+07.
gram-calories, multiply by .3238.
hp-hrs, multiply by 5.05E-07.
joules, multiply by 1.356.

I believe ft/lbs was introduced as a much more simple way of putting in place legislation.......

Boy thats nough seriousness for one day 

[Capricorn]

Footski, 12ft x 12 lbs is 144 ft lbs. The rubber band powered torpedo is a great idea, I hadn't heard of that before. 

[barryfoote]

Footski, 12ft x 12 lbs is 144 ft lbs. The rubber band powered torpedo is a great idea, I hadn't heard of that before. 

 ??? ???

[Capricorn]

hence 12 ft/lbs is like dropping a 12 lb weight from 12 feet. It would bloody hurt if landing on your head.

Footski, I was pointing out your math error  .  I believe in this instance you might say 12 ft lbs is like dropping a 12 lb wt 1 foot, or a 1 lb weight 12 feet, (a 12 lb wt dropping 12 feet would be 144 ft lbs).  In any case it would still likely cause a lump.  Out of curiousity, which (of the 12 ft lbs) do you think would hurt worse?  Cap

[barryfoote]

Cap,

Thanks for pointing that out...You are right of course....

As to which would hurt the most.....I reckon that at about 2 feet you would be unconcious so it does not really matter!!

[dougal99]

  Out of curiousity, which (of the 12 ft lbs) do you think would hurt worse?  Cap

Isn't that like asking what weighs more a pound of feathers or a pound of lead? 

[Capricorn]

Dougal99,

Not exactly, one lb dropped 12 ft, might hurt worse than 12 lbs dropped one ft, I guess the point is the kinetic energy is about the same.  The momentum is different though.

[cbr900]

We over here do not seem to have much control over what we can fire, unless it is a
designated firearm, so at our Sub Regatta on the Easter weekend here we had some
fun during our Regatta, I will attach a video clip of one of the Subs firing it's Torpedos
at a model of a Corvette, we think it is quite spectacular, I have several clips to put up,
and will add these as we go...............

http://ca.youtube.com/watch?v=1WvZypihdZ4



Roy

[Capricorn]

Roy, that's quite a show, thanks for putting it on.  Looks like the torpedos had a fair sized charge in them, were they reusabe?  Cap

[cbr900]

Cap,

Yes they are reusable, they are gas powered, with a small  (or not so small) charge in the nose cone...........



Roy

[barryfoote]

Roy,

Very impressive film. Shame about the Corvette though.....

[Martin (Admin)]

Excellent Roy! Are the diagrams of the construction anywhere?

[cbr900]

Martin,

I will check up on that info for you, as the chap that has the torpedo setup lives on the mainland,
so it will take a few days............


Roy

[cbr900]

This is the answer clip from the Destroyer against the subs,
I think it is brilliant, if nothing else it is good viewing.........


http://ca.youtube.com/watch?v=1fuBFAZ90sQ



Roy

[TCC]

We over here do not seem to have much control over what we can fire, unless it is a
designated firearm, so at our Sub Regatta on the Easter weekend here we had some
fun during our Regatta, I will attach a video clip of one of the Subs firing it's Torpedos
at a model of a Corvette, we think it is quite spectacular, I have several clips to put up,
and will add these as we go...............

http://ca.youtube.com/watch?v=1WvZypihdZ4



Roy

Roy, did the overshoots damage tiles?

I have to say, that looks a blast! How do the depth charges work?

[cbr900]

No damage to the tiles, and the same gent has the destroyer
and I will not catch up with him for a while as he is overseas...........


Roy