Anechoic coatings

[BackworldTraveller]

The Stealth options in starship design are all electronic masking type affairs.

How do you guys cope with applying the build rules for submarines anti-sonar measures?

Are there extra costs for installing equipment in a noise-free mount?

 

[mike wightman]

Sound doesn't travel in a vacuum so you don't need it on a spacecraft.

The reason there is no stealth in space is because:
1 - the crewed are of the ship has to be at a temperature significantly higher than the background, this is easily detected by a thermal sensor out to ridiculous ranges.
2 - the power plant of the ship is a multi-gigawatt fusion reactor, the waste heat from which also makes the ship glow in the IR part of the spectrum.
3 - there is no way to dump waste heat in the medium to long term without revealing your position. it is possible to store waste heat in the short term or even dump it.radiate it away in a direction away from your target, but they will eventually be able to detect you from the trail you are leaving.

Now if Traveller has some sort of magic heat sink - which it must in order for the aforementioned gigawatt reactors to not bake the crew, short out the electronics and then melt the ship - then you could postulate some sort of stealth technology.

For the sake of argument lets assume that the artificial gravity plates and acceleration compensation fields can also control the internal temperature of the ship and dump the energy into the maneuver drive or the jump drive capacitors then you have stealth capability.

Note a black globe generator also gives you stealth.

Or are you talking about building submarines?

 

[Condottiere]

In theory, you could transform the heat to plasma, and blast it out of the fusion rockets.

 

[Fovean]

In my MgT2e ‘verse, LHyd is not fuel but rather refrigerant. Thus the crew doesn’t bake, ships don’t require heat sinks and also the amount of energy being expended from the fusion plant acts as a DM on sensor checks. So you can ‘run silent’ to an extent, not stealth but rather a sort of masking.

 

[mike wightman]

In theory, you could transform the heat to plasma, and blast it out of the fusion rockets.

Which is not very stealthy as the plume gives away your position and mass rather nicely.

 

[mike wightman]

In my MgT2e ‘verse, LHyd is not fuel but rather refrigerant. Thus the crew doesn’t bake, ships don’t require heat sinks and also the amount of energy being expended from the fusion plant acts as a DM on sensor checks. So you can ‘run silent’ to an extent, not stealth but rather a sort of masking.

Umm, then the liquid hydrogen coolant is your heat sink.
You can not carry enough liquid hydrogen to cool your ship for more than a few hours at the most.
Not to mention you have to dump the now hot hydrogen outside the ship, which is easily detectable.

 

[BackworldTraveller]

OK - I thought I'd asked about subs!...I've clearly hit a thread about heat though!

 

[mike wightman]

It's my mistake and I apologise, I misunderstood your OP.

Which rules do you use to build submarines? I agree that sound dampened fixtures and fitting should cost more, but it may be easier to just modify the final cost of the sub to account for the level of anechoic protection offered.

 

[Fovean]

Umm, then the liquid hydrogen coolant is your heat sink.
You can not carry enough liquid hydrogen to cool your ship for more than a few hours at the most.
Not to mention you have to dump the now hot hydrogen outside the ship, which is easily detectable.

Fair enough. Handwavium to be sure. It came about through discussions amongst our group, and it’s what we’ve settled on.

To the OP, apologies. Misunderstood as well

 

[Timerover51]

While the heat generated does provide a bearing to a potential target or intruder, it does not give a range unless you to some maneuvering or have a string of multiple detectors trailing behind you to give some form of cross-bearing. Radar is needed to furnish the range information.

In the U.S. Naval Technical Mission to Japan, the reports of which can be found online, there is a discussion of Japanese anti-radar coatings which did reduce the radar signature of Japanese submarines and also some consideration of changing the angles of the superstructure to deflect the radar returns into the water.

The also worked on anti-sonar coatings, again with some success. The Japanese were not nearly as backward in technology as some portray them. They did have their own working centimetric radar units, which the Germans never managed to build. They also had a pretty good Magnetic Airborne Detector. Their problem was getting the more advanced material into production.

 

[Condottiere]

No moving parts, would be ideal.

Though it should be noted, when mentioning heat, quite a number of the bigger submersibles have been blessed with mini fission reactors.

 

[Timerover51]

No moving parts, would be ideal.

Though it should be noted, when mentioning heat, quite a number of the bigger submersibles have been blessed with mini fission reactors.

The nuclear subs get rid of the excess heat by dumping it into the surrounding water, which makes for a terrific heat sink.

 

[Carlobrand]

...The reason there is no stealth in space ...

No long-term stealth. There are solutions that might work very briefly, but pretty quickly the problem raises its ugly head anew. You could for example equip your ship so that it could flood capillaries through the hull with some sort of chemical that undergoes ferocious endothermic reactions, or with that H2 fuel, or use refrigerants on one side of the hull while glowing like a star on the other side. It really doesn't do much good for your ship to be only half-stealthed or to suddenly go dark and then start glowing again a short while later so, for all practical purposes, no stealth unless you're a half-stealthed ship approaching some hapless merchantman with cheap budget sensors in a region of space that is fortunately entirely devoid of other things that could be looking in your direction from other angles.

As to subs - I don't know of rules for that, so it might be easiest to apply MT's stealth design rules and just say they also apply to vibrations in a fluid medium. Say there's something called vibration masking and it's roughly the same cost and volume as EM masking. Those rules after all do include passive and active audio sensors in the miscellaneous sensors, so having something to counter those would be useful.