Traveller Feats

[Uncle Bob]

The sound of a bullet passing is relatively loud. In the Civil War the subsonic musket balls sounded like bees buzzing. With supersonic bullets, troops fired on from over 400m away perceive the "crack" of the bullet as louder than the report of the gun. Modern sniper rifles are often silenced to disguise the direction of fire.

An officer in the Indian Army (according to Bugles and a Tiger) would unexpectedly clap his hands loudly, then punch his chest with a closed fist. This "crack...thump" sounded like the sonic boom and muzzle report of incoming rifle fire, and his troops were expected to deploy, take cover, and prepare to return fire.

It is theoretically possible to build a projectile that can "mask' its sonic boom, by generating multiple shockwaves that overlap and reduce overpressure. This can be done for an exact speed, in air of a particular density, and only for certain distances from the projectile. So either the projectile has an adaptable shape controlled by a very clever processor, or it is only silent (say) between 200 and 225m when the outside temperature is 50-55 celsius at the earth equivilent altitude of 500-700 meters. You need a different projectile on a warm day, or whem its raining, or if your target is in a coastal city.

So it is either real expensive or real limited.

 

[Simon Jester]

<BLOCKQUOTE>quote:</font><HR>Originally posted by DaddyDragon:
It is possible, under the right conditions for an object to exceed the speed of sound, without generating a sonic boom (ie. the bang you are referring to). Somewhere in the books, it is canon that the Guass Pistol/Rifle family are effectively silent. And this was backed up with an article in Challenge Magazine (if memory serves). I have just finished moving and haven't gotten nearly as much unpacking done as I should, but I will see if I can get documented source material for this from the previous rulesets.

Regards,
Larry

<HR></BLOCKQUOTE>

I seem to remember that article, as well. IIRC the "silent" option required setting the speed of the gauss acceleration to the point that the needle left the barrel at a speed below the sonic threshhold. This would still be plenty lethal: the standard .45 ACP bullet fired from a Colt 1911 is subsonic, for example. This would also allow such weapons to use bullettrap-style rifle grenades...a little low-tech, I admit, but still plenty useful.

Simon Jester
-If it's stupid but it works, it sin't stupid.

 

[lucasdigital]

<BLOCKQUOTE>quote:</font><HR>Originally posted by DaddyDragon:
it is canon that the Guass Pistol/Rifle family are effectively silent. And this was backed up with an article in Challenge Magazine (if memory serves).
Regards,
Larry
<HR></BLOCKQUOTE>

I think I remember Frank Chadwick backing this up in one of the Traveller Digests Q&A's.

Someone he spoke to briefly while on a flight somewhere confirmed that there are ways of avoiding the shockwave induced crack of firearms without having to make the projectile subsonic.

I'm ready to believe him

Mark




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Mark Lucas
Lucas-digital.com

 

[lucasdigital]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Blue Ghost:
sound is going to make noise. The size would have to be calculated based on the projectile's size.

[This message has been edited by Blue Ghost (edited 06 July 2001).]<HR></BLOCKQUOTE>


Generally true but in fact it is calculated from weight, size, and shape of the projectile, plus its altitude, attitude and flight path, and weather or atmospheric conditions.

Just about everything makes noise but the shockwave is a pretty special phenomenon that can be manipulated. To be fair that is not to make the projectile silent but to stop it being very damn loud.

 

[Blue Ghost]

Are you sure about that?

It's my understanding the "speed of sound" is dependent on the mediums density/viscosity, and not subject to alteration.

I think what one might be able to manipulate is the projectile itself, shaping it such that its shockwave (assuming supersonic flight) is sufficiently small enough such that it would not be as loud. That is not as a loud as a jet fighter or high powered rifle slug. But it's still going to make a noise. Especially if fired within a medium that is one measured to be atmosphere in pressure.

 

[Uncle Bob]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Uncle Bob:
<snip>
So it(quiet bullets) is either real expensive or real limited.<HR></BLOCKQUOTE>

obviously, I agree

 

[Fulacin Highport]

And silenced shotgun rounds are REALLY expensive!

I ran across an article in an old Soldier of Fortune (Feb., 1983) where they went into a fair amount of detail on the experimental 'Telecartridges'. These were 12ga rounds that were made from a flexible (or telescoping) metal cup, as the interior of the round. The shot is carried in a 'cup' with the powder charge being completely contained.

Field testing confirmed that these did indeed work, and that the noise of the action on the pump shotgun being cycled was louder than the shot itself. Being too expensive to manufacture, they were dropped (there were a few other issues as well... only worked well in pump-actions, cases sometimes expanded too far and caught in the barrel, etc.)

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Joe Brown