This post chronicles some of the history of Dave Merrimans efforts to produce a working torpedo and launch system.
Working up Masters, Tools and Parts for a 1/72 Revell GATO Open Shutter-Door Arrangement, Part-2
A Report to the Cabal:
While delivering all that wonderful information on world-war two era American submarine shutter doors to you I neglected to give any insight on the weapons system such a mechanism supports. I'm putting that right here.
Here's a close look at the configuration and function of the Caswell-Merriman 1/72 weapons system. For the sake of clarity I divide the discussion between the two sub-systems (the launcher and the weapon); dealing with each in detail. Near the end of this chapter I'll give you a quick look at some weapon systems I came up with along the way.
THE WEAPON The 1/72 scale weapon is a classic 'steam torpedo' shape and paint-job. The major departures from scale is the substitution of a propulsion nozzle tube for propellers and the canting of the stabilizers to induce a roll to the weapon as it travels through the water. The weapon is self-propelled and employs the rocket principle for locomotion: A charge of liquefied gas is introduced into the hollow weapon through plumbing while its in the launcher, the liquid introduced through the nozzle. The charge of liquefied gas stays within the weapon (and the launcher breech-block) as long as the weapon is secured within the launcher. In fact, through careful design, the weapon can not be charged off-launcher -- a safety measure: in the event of a catastrophic weapon failure (explosion), the debris is contained within the metal tube of the launcher. A charged weapon is only released through intentional launcher activation. I did not invent the gas propelled torpedo. Credit for that belongs to Mike Dorey.
The weapon is a cast resin structure, the only metal being the hollow nozzle tube that runs with its forward end terminating in the middle of the weapons hollow reservoir. Within the after end of the nozzle tube a convergent nozzle, with a throat diameter of .008", works to eject the gas at a reasonable velocity, producing the thrust needed to keep the weapon in motion once launched from the model submarine.
THE LAUNCHER The launcher comprises the torpedo tube and the attached mechanisms needed to charge and release the weapon when so commanded. Decades of part-time effort has gone into the design of the current launcher configuration. The major innovations has been the incorporation of a stop-bolt to insure the weapon can not leave the tube until the launcher is cycled from 'battery' to 'launch'; a means of easily introducing a charge of liquefied gas into the weapon; and using a fraction of that gas charge to squirt the weapon out of the launcher the moment it cycles to the launch condition.
Below we're looking at three standard hollow cast resin 1/72 torpedoes. A cheat is to paint them green if you want to represent modern 'homing' type torpedoes, or to paint them silver if you wish to represent an old steam powered type torpedo.
The lower weapon is cut-away to show how these things go together. Note that it's hollow and that the pick-up for the boiled off gas is the nozzle tube, to the extreme right this gas is ejected through the nozzle to thrust the weapon forward. The design of my torpedo has changed little in the past twenty years. They are easy to mass produce requiring only the inclusion of a resin plug forward and insertion of the nozzle tube aft during assembly.
There are OLD pilots and there are BOLD pilots but there are very few OLD BOLD pilots. MAG