:)
I bow to your greater knowledge..however believe me when I say that 12 foot lbs is the unit of measurement beyond which an airgun is considered to be a section one firearm and would need a licence, although it would almost certainly not be granted one.
Hi Footski,
No question of 'greater knowledge' my friend, I was genuinely confused by your use of 'foot lbs' as a measure of pressure.
Your own 'Correct' knowledge of the UK firearms act is the greater.
I now know that you really were referring to 'force' which I have always understood to be referred to as 'foot lbf', in order to distinguish it from torque which is 'foot lbs'
Of course, nowadays, the METRIC bunch seem to have won the day, and the use of Newton metres and/or Joules is the more common.... not that I agree... He He.
Capricorn,
Thanks for correcting my confussion...by the added reference you pointed me to, that immediately sorted my thinking out, and all became clear.
Any way chaps, I did a bit of searching on the net to see if I could glean anything directly from the firearms act..... not a very helpful document...
I give some relevant extracts, which exactly tie in with Footski's figures....(wish I could remember things like this)
The Firearms (Dangerous Air Weapons) Rules 1969 require that certain air weapons can only be held legally on a firearm certificate. It is possible to measure the velocity of pellets, discharged from an air weapon, by the use of an electronic chronograph. From these measurements the kinetic energy of the pellet at the muzzle can be calculated. Air weapons deemed specially dangerous have a muzzle energy in excess of:
In the case of an air pistol: 6 ft/lbs
In the case of an air weapon other than an air pistol: 12 ft/lbs
Such weapons are classified as Section 1 firearms and are required to be held on a firearm certificate. These weapons are subject to all the controls and regulations pertaining to Section 1 firearms, although the "ammunition" (pellets) are not.
These rules do not apply to an air weapon designed for use only when submerged in water, e.g. harpoon gun.
The last line of the above may hold a key to model torpedoes...!!
I note also the same confusing use of foot lbs rather than foot lbf, but this is clarified somewhat by the 'Muzzle Energy' statement.
New legislation
(3) Prohibition of certain Air Weapons
The Anti-Social Behaviour Act 2003 Sec 39 creates an additional category of prohibited firearm, to be added to Sec 5 of The Firearms Act 1968.
The new subsection is Sec 5 (1) (af) and reads as follows…
Any air rifle, airgun or air pistol which uses, or is designed or adapted for use with, a self-contained gas cartridge system.
From 20 th January 2004 it will be an offence to manufacture, sell, purchase, transfer or acquire any air weapon using a self-contained gas cartridge system.
Anyone who already owns one of these weapons on that date will be able to keep it legally, only if they obtain a firearm certificate from the police. Applications for firearm certificates must be made before 1 st May 2004.
Alternatively, existing owners can hand their weapons into police for disposal. Again, this must be done before 1 st May 2004.
From 1 st May 2004 it will be an offence, punishable by a minimum of 5 years and a maximum of 10 years imprisonment, to possess a self-contained gas cartridge weapon without the necessary firearm certificate.
"References to the date of 1st May 2004 in the passage above were copied from publicity issued by central government. Unfortunately the date is incorrect by one day, i.e. certificate applications were required to be submitted to police on or before 29th April 2004 and holders who failed to do so would have committed the offence of unlawful possession with effect from 30th April 2004. The MPS administered applications in accordance with the correct dates, but regrets the oversight which appeared in this web page."
What is being banned:
The ban applies to any air rifle, air gun or air pistol that uses, or is designed or adapted for use with, a self-contained gas cartridge system.
From 20 th January 2004 it will be an offence to manufacture, sell, purchase, transfer or acquire such a weapon.
From 1 st May 2004 it will be an offence to possess one, unless it is held on a firearm certificate.
What is NOT being banned:
The ban does NOT apply to weapons that use CO2 bulb systems because CO2 bulbs do not contain a projectile and are not therefore completely self-contained.
I could find no meaningful reference to 'Torpedoes' other than in direct connection with arms trading.
So what about model torpedoes....
Just for fun, I did some rough calculations to see how close they came to the figures under the firearms act....... I think the results could be of some interest.
Model torpedoes
A typical full size torpedo would be of the order of 20ft – 24ft in length and with a speed of 50kts.(25m/s or 84.48ft/s)
Consider a model torpedo @ 1/8th scale…. This would be approx 2.5ft – 3 ft long.
If this was travelling at SCALE speed (velocity (v)) of 6.25kts (3.2187m/s or 10.56ft/s)
If the model weight (mass (m)) was kept down to say e.g. 16oz (1lb or 0.45359kg)
Then kinetic energy (KE) would be: -
KE = 0.5 x m x v^2 = 0.5 x 0.45359 x 3.2187^2 = 2.352Nm (Joules)
Which is = 0.52875ft/lbf
Well within the 6ft/lbf limits for an air pistol let alone the 12ft/lbf for an air rifle.
Even at twice scale speed i.e. 12.5kts (6.4008m/s or 21ft/s)
This would only increase to 9.292Nm or 2.08892ft/lbf
Which is still well inside the limits.
Given the above, it would be interesting to see (find out) just how this stood up under the terms of the latest UK firearms act amendments.
And remember, we are not necessarily talking about an air driven torpedo, although I assume the velocity factor would remain the same, even for an electrically driven one.
By the way, according to the UK act, air weapons with a muzzle velocity force of less than 1ft/lbf are exempt from the firearms laws so in the first case (Scale Speed) no possible problem can exist. :-\
Even the Twice Scale speed scenario is well under the 6ft/lbf limit so it is arguable if this would be acceptable or not….. common sense, and the firearm act, say’s it should be exempt… however… even though the firearms act itself may not provide a means of prevention, there are probably several other NEW PC nanny state laws that can be called upon…..solution…..!!!! ASK THE LAW.
So much for a free country !!!
Hope you find this of some interest.
Best regards to all.
AlexC
Author
Topic: Working torpedoes anyone? (Read 31668 times)