Gyrojet Weapons Under Water ?

[rust]

Having had some problems with the native wildlife of my setting's water
world Anuira, the characters have been looking for some weapons that
are more impressive than spear guns firing harpoons with small explosi-
ve "warheads".

They decided to buy a couple of gyrojet rifles and adapt them for under
water use. Since I seem to remember that gyrojet weapons do indeed
work under water, and are even used by some special operations for-
ces, I do not see any problem with the idea - except perhaps the low
range, which I think should be about 15 meters at best.

However, I am really no weapons expert, and so I may well be wrong.
Therefore my question: Are gyrojet underwater weapons really as plau-
sible as I think, or did I miss some problem ?

Thank you.

 

[GypsyComet]

Both the ammo and the gun would need to be adapted, but as long as the propellent works and the bullets don't get completely tossed around underwater, it'll function as a "torpedo gun", though without the seeking ability of a torpedo.

An over-the shoulder torpedo tube that launches super-cavitation 10cm mini torps might be amusing. Those *would* be big enough for guidance...

 

[DCAnsell]

Gyrojets should work out just fine underwater. The projectiles are sealed. There is a project underway now, though I think it is dubious in its likelihood of getting anywhere, to create a fully supercavitating gyrojet projectile for underwater use.

 

[Ishmael]

http://www.freepatentsonline.com/7347146.html

this looks like a modification to gyrojet ammo, if I understand it right.

 

[BP]

How about more high-tech like a magnetohydrodynamics based self-propelled munition (ala Hunt for Red October - but in miniature) - long range and high thrust (can also be seek and destroy). These could be moderately effective against armored targets in a kinetic role - or more so if explosive tips are used.

Also, since its a fluid medium - use of high power, focused ultrasonics - as short range weapons against organics.

For underwater anti-fauna weapons, pulsed lasers may be effective (red) for short to medium range.

Solid chemical propellants could also be used and self-forging penetrators (chemical charge creates shaped high-velocity metal projectile or MHD could also create 'liquid metal' penetrators) - these could be medium range kinetic weapons and effective against armored targets.

I'd have to do a little think'n to make these game balanced - help to know the Tech level of your setting...

 

[rust]

Thank you all very much for your answers.

How about more high-tech ....

Such weapons would be nice for the campaign's future, but right now
the colonist characters have to do with little technology (of about TL
9 / 10) and less money, and the engineers among them will have to
use their skills for research projects to develop more high tech wea-
ponry.

Until then they have to use what is available for civilian divers (e.g.
spear guns) or what can be imported and adapted rather quickly, li-
ke those gyrojet weapons.

To give them more advanced weapons now would make it too easy
for them ... :wink:

 

[DCAnsell]

Rust, you might find some of this interesting reading, on gyrojets in general.

http://www.deathwind.com/project.htm

 

[Emperor Herdan]

Rust;

There was a sequel to the old XCOM game called XCOM2: Terror from the Deep that might be of help to you.

The FAQ on it should have the basic listing of the various weapons. I remember Gas cannons and torpedoe launchers, gauss rifles/pistols (but now the memory is fading) so it might give you a few ideas or leads.

Take care

E. Herdan

 

[atpollard]

I one had a toy frog that you would wind up and it would swim.

You need a swimming Grenade to liesurely pursue its target.

 

[Mithras]

I one had a toy frog that you would wind up and it would swim.

You need a swimming Grenade to liesurely pursue its target.

With a really big spring ....

 

[rust]

Thank you very much for your answers.

I one had a toy frog that you would wind up and it would swim.

A splendid idea - an explosive bait in the form of, and with the typical
movement of, a dangerous predator's preferred prey. A nasty trick,
but a good way to rid a specific region of those predators. :twisted:

I wonder if the player characters will come up with something like this,
but at least I am now prepared for the shock. :lol:

 

[GypsyComet]

Thank you very much for your answers.

I one had a toy frog that you would wind up and it would swim.

A splendid idea - an explosive bait in the form of, and with the typical
movement of, a dangerous predator's preferred prey. A nasty trick,
but a good way to rid a specific region of those predators. :twisted:

You've read Niven's "Legacy of Heorot", right?

 

[rust]

You've read Niven's "Legacy of Heorot", right?

No, not yet, but I obviously really have to do it.

 

[GypsyComet]

You've read Niven's "Legacy of Heorot", right?

No, not yet, but I obviously really have to do it.

Without getting into specifics, the bit I'm thinking of involves something similar to what would happen if you killed off all the adult Hivers on a world.

An ecologist might ask "Were they controlling the numbers of anything else?"

Being PCs, the answer is probably a shrug.

That's when you roll a die to determine how many weeks go by before the answer becomes apparent, and grin at the result...

 

[rust]

An ecologist might ask "Were they controlling the numbers of anything else?"

Ah, I see what you mean. :lol:

Yes, indeed, the characters are quite likely to stumble into exactly that
kind of trap.

Their problem is to remove a group of very dangerous territorial preda-
tors from a site with important natural resources. However, these pre-
dators feed on the young ones of another species of predators, which
is less dangerous, but far more numerous.
If the characters do indeed go one step too far in the wrong direction,
the big predators will all be killed or leave the area, but the number of
small ones will explode - and make it even more difficult to get to that
natural resource unhindered.

What the characters should do is to find a way to live with the big pre-
dators with a minimum of mutual aggression, but - being player charac-
ters - I am almost certain that they will not have the necessary patience,
will go for a violent solution, and in the end will force the colony to forget
about those natural resources for a very long time.

 

[BP]

Ah - low tech solutions...

Well the wind-up toy grenade trick brings to mind a fishing technique I saw once -

Dynamite in a Can - the concussion made floaties of the little aquatic critters in a pond... (large manmade pond - good size fishees)

Not sure the effects in a more open water environ and on bigger species - but I bet it would stun even the hardiest within up to medium range.

<I had to google this now - turns out that it is done in open waters and very harmful to the environment - also called blast fishing - homemade deals include glass bottles with layers of powdered potassium nitrate and pebbles or an ammonium nitrate and kerosene mixture - ouch - can you say unstable?
And just this week 42 blast fishermen were arrested for damaging a World Heritage Site...

Anyway - appears the biggest damage to the fish is the concussion causes gas (ballast) blatters to explode - stunning and or killing them.
>

 

[Dave Chase]

Some real underwater guns

http://world.guns.ru/handguns/hg140-e.htm

http://world.guns.ru/handguns/hg209-e.htm

Its also a good site to start on other real world firearms

EDIT
Missed one

http://www.enemyforces.net/firearms/aps.htm

END EDIT

Dave Chase

 

[rust]

Anyway - appears the biggest damage to the fish is the concussion causes gas (ballast) blatters to explode - stunning and or killing them.

Yep, that was the colonists' first nasty surprise. The local fish do not have
swim bladders (they swim like sharks), and some of the local predators
use natural sonic weapons (with their prey developing a certain immuni-
ty to that kind of attack) - which resulted in both explosives and sonic
weapons used by the colonists to be far less impressive than expected.

 

[rust]

Some real underwater guns

Thank you very much for the links, Dave.

 

[walkir]

How about more high-tech ....

Such weapons would be nice for the campaign's future, but right now
the colonist characters have to do with little technology (of about TL
9 / 10) and less money, and the engineers among them will have to
use their skills for research projects to develop more high tech wea-
ponry.

Well, that's early first Imperium... Even if you want the Vilani and/or Terran Confederation not to have invented underwater weaponry (short of lasers), the engineers can draw from a big list of things usable for this.
I don't think magnetodynamics is to high tech for TL 9.