I had an interesting epiphany, but since i have no access to my books atm, i wanted to propose this to the community and discuss this.

Is it possible to create a ship that operates similar to a submarine? What weapons would be a good use? Can it be done with cruiser-sized ships? Does shooting torpedos break Silent Running? Why is there a monkey on the bridge?

A raider with torps, Empyrean Mantle (ItS) and Passive Detection Arrays (from HA) is something I've seen in both of my campaigns.

Empyrean Mantle gives a bonus to staying undetected during Silent Running (though the language is curious) and Passive Detection Arrays allow you to do Active (and Focused) Scans while remaing Silent.
There is no obvious reason it can't be done with cruisers as all above-mentioned components come in cruiser sizes.
They're just slow as molasses.

There's even a Cypra Drive in BFK, but it only works for Escorts (transports, raiders and frigattes).
Or you can make friends with some of the nastier type of Eldars, and pick up mimic engines and a shadowfield. (both HA).

Does shooting torpedos break Silent Running?

Not sure, but I have ruled for that in my campaigns it does, which I think is RAW. Not sure though - and even less sure about launching small crafts, ie. bombers.

Yes, stealth carrier is plausibly an option.

As for the monkey, you might want a look at the Psychic Familiar rules, NP p. 108ff

You're pretty much already conducting your ship like a submarine in RT. But, what Tenebrae said adds more style to it. As for the monkey, are you referring to the one an NPC RT has? I seen the stats for it somewhere too, but don't have my books with me at the moment. But yep, it could also be a psych fam. Didn't know the NP had them. Maybe I might buy that book after all.......... Nah.

A raider with torps, Empyrean Mantle (ItS) and Passive Detection Arrays (from HA) is something I've seen in both of my campaigns.

Empyrean Mantle gives a bonus to staying undetected during Silent Running (though the language is curious) and Passive Detection Arrays allow you to do Active (and Focused) Scans while remaing Silent.

Does shooting torpedos break Silent Running?

Not sure, but I have ruled for that in my campaigns it does, which I think is RAW. Not sure though - and even less sure about launching small crafts, ie. bombers.

Yes, stealth carrier is plausibly an option.

"Needless to say, if the ship fires any weapons, it is immediately detected as well.", page 218 of the rulebook. Torpedoes are unquestionably weapons. Hit & Run is not a weapon, however, so a GM may well judge that using small craft doesn't count (however, if he is anything like me, he makes small craft automatically show up on the battle map anyway). Not that it really matters, and I'm going to explain why.

First off, the language in the Empyrean Mantle description is clear as crystal. The Active Augury test to automatically detect any silent ships within range (yes, silent running is that easy to break) is normally +0 (challenging, I believe), like every other test where no difficulty is specified. When using it against ships with an Empyrean Mantle, the test is at -20 (very hard, I think). Of course, any enemy ship that actually matters at all is going to have someone with decent perception, a couple of plusses to Scrutiny and a boost from the ship's own detection, so you're boned either way.

Silent Running seems to be meant more for blockade running and escaping combat than sneak attacking.

I statted up exactly this kind of vessel as a sample vessel for my group recently - using the Orion transport hull. It had insane bonuses to Silent Running, penalties to be detected while Silent Running, ability to use Detection actions while on Silent Running, Torpedoes AND still managed to maintain excellent Maneuverability and a top speed of 11.

Its also an incredibly mono-focussed vessel and outside of being stealthy and firing torpedoes at unknowing victims, it can't do much else.

Just like a real submarine!

I seriously consider doing such a thing with a carrier, or maybe we can houserule some kind of torpedo-bay that can be fired without being autodetected. Would be interesting to discuss the physics around this.

Also, the monkey was a joke. But alas...

First off, the language in the Empyrean Mantle description is clear as crystal. The Active Augury test to automatically detect any silent ships within range (yes, silent running is that easy to break) is normally +0 (challenging, I believe), like every other test where no difficulty is specified. When using it against ships with an Empyrean Mantle, the test is at -20 (very hard, I think). Of course, any enemy ship that actually matters at all is going to have someone with decent perception, a couple of plusses to Scrutiny and a boost from the ship's own detection, so you're boned either way.

I agree that's what it means, but that's certainly not how I would've phrased it.

Oh well, a matter of personal taste I guess.

Just like a real submarine!

I seriously consider doing such a thing with a carrier, or maybe we can houserule some kind of torpedo-bay that can be fired without being autodetected. Would be interesting to discuss the physics around this.

Also, the monkey was a joke. But alas...

Call it "Soft Launch", When torps are soft launched, the launching ship has time to quietly move away from the spot of launching. Torpedoes are launched with compressed gas, and their engines do not activate until commanded to, either by a timer or low powered signal ( raises detection possibility by +5 ). Torps only move at 1 VU/turn, until their engines power up, and then they run normally.

Might be used to extend the range of torpedoes by the number of VU's the delay is active, but if used in such a way, there should be a penalty to hit.

Might also be used to use torpedoes like mines - deployed out a hatch rather than through launch tubes, they have zero velocity, and stay in the area they were left in unless activated.

I can think of a couple of other possibilities that would work with this launch method.

Thats actually not a bad idea. There's shenanigans to be done with it.

My group has a heavily modified Cobra Class with Archeotech Cypra drive, Empyrean Mantle and Passive Augers, Plasma Accelerated Torpedo tubes and a dorsal Jovian Class missile battery... they christened her "Red October"

How is a ship going to move away from the site of a torpedo launch without using its main drives? Using the main drives means powering up. Using just thrusters it wouldn't move far enough away to change a single VU in position and surely the target can figure out the most likely spot for the launching ship.

I wouldn't allow for it myself, just because players would then attempt the same tactic every time. Be careful what you let your players get away with.

How is a ship going to move away from the site of a torpedo launch without using its main drives? Using the main drives means powering up. Using just thrusters it wouldn't move far enough away to change a single VU in position and surely the target can figure out the most likely spot for the launching ship.

I wouldn't allow for it myself, just because players would then attempt the same tactic every time. Be careful what you let your players get away with.

Silent running doesn't mean that you come to a dead stop or can't maneuver, it just means that you move at half speed and all related Skill Tests increase in difficulty by one level ( Rogue Trader pg 218 ).

Let them try it every time, it doesn't mean that they will pass every time, and a penalty to hit with the torps, means that they are not always going to be successful, heck you could even increase the shooting skill test by one level to see if it remains undetected. If you really want to continue stacking the deck against them, rule that it takes a full round for the torps to come to full speed, and until they are at full speed, the opposing ship get's a +5 to shooting the torps.

The thing is, you don't want to just say that players can't do any specific thing - you let them have a chance, and then set modifiers so it reduces the likelihood of success, if continued success causes a problem. If they start doing it to often, the word can start getting passed around, that in that in a particular area of space surprise tactics are being used, and the other ships start making greater use of the opposing Active Augury Extended Action, which used to detect ships on Silent Running. Or worse, opposing ships start using the same tactic against them.

In short, there are so many ways to deal with the situation with fairness, that there is really no need to out right rule against your players using the tactic.

My players would quickly figure out where that torpedo came from and I don't play their opponents one lick dumber than they are. You're right, don't outright disallow it, and I wouldn't, but it still wouldn't work well without many other factors in place, afctors hard to duplicate consistently. And no, I'm not going to house rule a way for them to make it work. My players wouldn't appreciate it if I house-ruled a way for their opponents to get over on them and I try to run a fair game.

Ships can't detect each other until they are within 20 VUs + 5 VUs per success or their Augurer. That's already surprise range. That's already within torpedo range. My players get surprise often enough as it is.

Ships can't detect each other until they are within 20 VUs + 5 VUs per success or their Augurer. That's already surprise range. That's already within torpedo range. My players get surprise often enough as it is.

Ah, common mistake.

Ships can't detect other ships on silent running beyond that range.(this is the range of Active Augury, RT, p.216)

Ships not on Silent Running can be seen from rather further away (never defined, in a mellow system, a hot engine could conceivably be detected while light minutes away.

I don't believe I made a mistake.

"If the scan is successful, the GM should reveal basic (and important) information about celestial bodies, phenomena, and ships (note the plural) within 20 VUs of the vessel. If there is a vessel on Silent Running within scan range, it is immediately detected."

"For every degree of success, the character can extend the range of his scan by 5 VUs."

It's rather explicit. Any and all ships within 20 VUs are detected, even if they are on Silent Running. The difference between this and Focused Augury is that the latter can only be performed at 20 VUs or less ("within extreme range of his vessel"), and it can only be applied to a single enemy vessel. In this latter example it goes further to imply that the 20 VU range is THE extreme range of augurs.

And yes, I understand that this defies science. I wasn't going to go there at all, so let's not.

Well, arguing that Ships can only be detected via Active Augury means that Silent Running is meaningless, because all ships (in your understanding) are automatically on silent running.

Also, what happens when a detected ship moves beyond range?
And do you perhaps require active augury used every round to retain knowledge of surrounding ships?
If not, how do you reconcile this with your stated opinion?
Which, after all, as far as I can tell, is that you can only sense ships with an active, rolled action.

"If the scan is successful, the GM should reveal basic (and important) information about celestial bodies, phenomena, and ships (note the plural) within 20 VUs of the vessel.

I fail to see the importance of pointing out the plural?

I don't believe anyone was arguing that it affected only a single ship?

As far as I can tell, the "basic (and important) information" to be revealed about ships isn't existence but rather things like classification ("Cobra-class Destroyer", "Ork attack ship!") and plausibly identity ("It's the Mary-Beth sir"). Even things like status ("Looks like she's taken a beating sir" or "Mother of ¤#"¤#"¤! She's launching bombers sir!")

That's a fair point and I'll have to talk with the group about it. We've always ruled that the target must be detected to be fired upon, and only stayed that way if within 20 VUs, but yes, it does seem to negate the advantages of Silent Running altogether (something which my current group has never attempted, heh, bloody warmongers that they are).

I would have already agreed with the rest of your points, and I read the plural as implying the difference between Active Augury and Focused Augury and thus reinforcing the notion that ships must be kept "on the screens" each turn.

A few notes on how I see things, and you're welcome to disagree, I'm mostly trying to explain how I run things.

Ships (not on Silent Running), planets and the like are trivially detectable, atleast if they are on the same side of the star as you. You don't get a lot of information, just stuff like "Ship, probably a big one" or "Gas Giant".

These are detected without roll at some distance.

Object can "hide". The moons of a gas giant are much easier to count when you're close, and a ship can be lost easily enough if there's interference, ie it's stationary over the pole of a planet.

In general, ships aren't detected until you're "reasonably close" - which might still mean a day away.

Most imperial ships will indentify themselves by vox at significant distance, but not always.

Active Augury will tell you about ships on Silent Running in the affected volume.

It also tells you what class of ship it is, assuming you have the ability to identify it.

Loki Q-ships will usually identify as another type of transport, for example.

Active Augury also tells you about "non-emitting objects" ie small astroids.

Focused Augury tells you about this one specific ship you're scanning. types and locations of components. Are shields active (yes they are!), are weapons powered etc. The scanned ship will know it is being scanned, some may consider this a hostile action.

Focused Augury can still be fooled via eg. Wolf in Sheep's Clothing.

Well, that's certainly how I'd run detection in a Traveller game, but I've tried to run things RAW except where the group consensus is that it's broken, which is relatively rare (we use Mathhammer and some home-grown navigation rules). I'll present your view to them and I'm sure it will generate discussion, seeing as we haven't run into Silent Running yet (they are only on their 4th Endeavor, though...I should be fair to them, they aren't complete warmongers; they've negotiated their way out of a couple major encounters and shown mercy to their opponents on a couple others...for profit, of course).

Another question then, you say that most Imperial ships will ID themselves at a distance. What do you suppose is the speed of STL communication? Is this mostly via astropaths? Keep in mind that personal vox only have a range of 1 km, so commo tech is in the gutter.

Via Vox transponders (so, radio) be default.

Range is a lot better in space (less stuff to interfer), but range is still limited, especially when a ship is near a Gas Giant or other source of radiation.

Some ships/captains will announce themselves via astropath ASAP - the navy are especially prone to this.

Mind you, orks are just as likely to broadcast "WAAAAAAAAARGH!" with enough power to interfere with non-ork communications.

I've been using radio as the default, too. It's slow...30 minutes to Jupiter from Earth. There is no conversation, just declarations.

I've been using radio as the default, too. It's slow...30 minutes to Jupiter from Earth. There is no conversation, just declarations.

Absolutely.

If you want conversations, use an astropath.

But to ID yourself (especially to announce yourself as the Imperial Navy Cruiser His Might ), all you need is a declaration.

We just use STL as instantaneous. Even though tech is garbage, we like being able to have those kinds of conversations so we suspend disbelief. We pretty much treat our bridge as having a "Viewscreen" from star trek when it comes to in system, short range communication. I know it probably doesn't match with the fluff, but it allows for more roleplaying so we use it.

We just use STL as instantaneous. Even though tech is garbage, we like being able to have those kinds of conversations so we suspend disbelief. We pretty much treat our bridge as having a "Viewscreen" from star trek when it comes to in system, short range communication. I know it probably doesn't match with the fluff, but it allows for more roleplaying so we use it.

I do this as well. I don't need facts and science getting in the way of my game.

I don't.

My main group has no-one without a degree in physics or astronomy.

Running semi-realistic physics is easier than winging it, sometimes.