What about Tractor Beams?!?

By Maxim C. Gatling, in Rogue Trader Gamemasters

Does RT mention them? If so could someone tell me what page so I can look it up when I get home?

The Original RT and other Archeo-Canon and fluff references mention them in passing, but as they weren't ship-combat rules they weren't really detailed out, just sort of mentioned as a standard ship component like Teleporters (used to be).

The reason I mention Tractor Beams is...

Ships take decades or even centuries to build...

Warp-capable ships are near priceless....

Many ships have served for centuries or even millenia and have been retrofitted scores of times...

So and so defeated whatsisname and hauled the Forbidden Fantasy back to Holy Terra as his prize...

Sound familiar?!?

Ok, so apart from some short games to test game mechanics (ship battles and soforth) with my kid, we haven't actually started our Campaign yet. I KNOW my players aren't going to want to scrap components off the Emperor's Bounty, they're going to want to HAUL IT HOME. In Dark Frontier there's a perfectly good Space Hulk just dying to be brought back and refitted. In the adventure at the back of the RT book, there's a couple good ships if the PC's can figure out how to bust them loose from the ice....

From obscure references to ancient 40k text it can be done. If I remember correctly the Gellar Field could cover more than one vessel and that was how they towed crippled ships through the warp. But even so, could you tow a larger ship with a smaller ship?

So there's a couple questions I'm sure at least one of you has already encountered.

How? Is there a giant winch on the back of the ship with gargantuan tow chains? Here, put on your Space Suit and hook this to the bumper...

Tractor Beams? What was your home-brew rules for them? Should they be Archeotech? Does RT mention this and if so, what page?

What about Profit Factor?

Certainly a functioning ship is worth more in the long run than simply scrapping components off a ship and selling them. I KNOW my players, given the difficulty of Acquirring Ship Components won't want to sell them, they'll hoard them in a warehouse until they have enough to outfit a Hulk they've salvaged. My players will think "It may take a decade or two, but it'll be worth it."

Can or should Tractor Beams have a combat function? I've lost many Star Fleet Battles games by underestimating the power of being able to stop or change another ship's direction... Maybe they're just so short-ranged they don't have a feasible combat application?

That was an awful lot of questions...

No Tractor-Beams are not in the Rogue Trader.

it probably should be an Archeo-tech component.

Tractor-Beams can be used in combat but it is an unorthodox tactic, mostly employed by Orks.

.you asked more questions but I am tire now.....

I seem to remember that from back in the Space Fleet days when Orks had those ridiculous-looking ships with the stupid giant pincers on them....

Base Size? That's a really lame explanation of Tractor Fields, but considering the source...heh heh.

The point is they DO exist.

Although this "on all the time" and "draws Torpedos and Nova Cannon shells straight to you" thing just ain't making the final cut...nosirreee....

Maxim C. Gatling said:

I seem to remember that from back in the Space Fleet days when Orks had those ridiculous-looking ships with the stupid giant pincers on them....

Those were Imperial ships, not Orks. No Orks in Space Fleet at all.

Dalnor Surloc said:

Battle Fleet Gothic had tractor fields. Mostly this was to explain why certain ships had larger than normal bases.

http://www.warseer.com/forums/showthread.php?t=18962

All because they mispacked a bunch of Ork kroozer blisters with the wrong bases. OTOH, the BFG cruisers of all kinds should have been on large bases from word one. Much more stable that way, and it would have nicely differentiated capital ships from escorts.

Maxim C. Gatling said:

Base Size? That's a really lame explanation of Tractor Fields, but considering the source...heh heh.

The point is they DO exist.

Although this "on all the time" and "draws Torpedos and Nova Cannon shells straight to you" thing just ain't making the final cut...nosirreee....

Well, it is Ork technology, so you can't expect it to function in a practical, let alone logical, manner...

i've always seen ship salvage (when one recovers the whole ship) as fixing the ship up enough to power warp engine and gellar field, installing new ones if necessary, sticking a skeleton crew onboard then having the ship limp home on short warp hops (coming out of the warp to check integrity of fields/drives.

That should require the presence of the main (working) ship to ensure repairs, provide defense, etc. While the wrecked ship limps slowly back to port, with a tiny complement of brave folks aboard.

If i remember the only race that have Tractor Beams are the Orks, they use them for hauling in asteroids and converting them into ships. Also yes a smaller ship could tow a larger ship, you're in space remember there's no gravity so the mass of the ships doesn't really matter. All it would be would be a matter of inertia.

Also people tend to leave Space Hulks alone becasue they tend to be made of amalgamations of random crap, and there's lots of unpleasent junk out there. Also they tend to behave on their own whims and will re-enter the warp at random, so they're not really something you'd want to try and recover. Salvage equipment from yes, recover no.

My assumption on claiming prizes was something much cruder than Tractor beams. Namely, using the same sort of mag-cables and macro-grapnels you would use in a boarding action to lash your ships together, and re-wiring the Gellar field to cover the other ship.

Considering the fact that artificial gravity is commonplace tractor beams are almost certainly existant within the Imperium. Based on the fluff however, they aren't standard equipment. Most ships probably don't have them. I also would imagine that they are very energy hungry, and only really effective in rather large ships.

RocketPropelledGrenade said:

My assumption on claiming prizes was something much cruder than Tractor beams. Namely, using the same sort of mag-cables and macro-grapnels you would use in a boarding action to lash your ships together, and re-wiring the Gellar field to cover the other ship.

This is what I'd assume as well. Considering that the pictures I've seen of an imperial void mine field consists of several asteroids and mines having been lashed together with giant chains, hauling huge vessels with similar chains would be the 40K thing to do. happy.gif

Varnias Tybalt said:

RocketPropelledGrenade said:

My assumption on claiming prizes was something much cruder than Tractor beams. Namely, using the same sort of mag-cables and macro-grapnels you would use in a boarding action to lash your ships together, and re-wiring the Gellar field to cover the other ship.

This is what I'd assume as well. Considering that the pictures I've seen of an imperial void mine field consists of several asteroids and mines having been lashed together with giant chains, hauling huge vessels with similar chains would be the 40K thing to do. happy.gif

Very much so by canon. Look at Footfall, which is basically a bunch of lashed-up ("tethered") planetoids. Tractor beams are certainly possible, but they're likely to be xeno- or archeotech rather than a commonplace thing.

Orks had a Traktor beam weapon in 2nd Ed as a troop artillery weapon. I could see a tractor beam weapon as a Xeno tech or Archeotech weapon (like a Graviton gun). The damage would be weak (probably high morale damage but low Hull/Crew damage). However, it would allow the attacker to move a ship or slow its movement. The mechanics should be simple and focus on debilitating the ship for boarding. In that respect, it's much better for Orks.

In BFG under the fluff for the Ramilies Class Star Fort it talks about tugs and towing stuff through the warp. They do not mention if tractor beams are used but given the Ramilies gigantic size (it is so big it has all sorts of special rules for it including the ability to have orbital defenses (other space stations) assigned to it like a planet)) it just does not seem that chains are going to cut it.

I would guess that the imperium does indeed have tractor beam tech, just not in such a way that it is useful in combat. This would also fit with the orks tendancy to "sup up" other stuff they find and put it to military use.

If I remember correctly from the book Warriors of Ultramar, the Imperial Navy actually pulled large orbital refineries with chains, not tractor beams, in order to hurl them at the Kraken splinter hive fleet. As such, I'm with the consensus that the Imperium uses large chains to haul everything around and that Orks are the only ones with actual tractor beam technology. Somebody else will have to double-check this for me, though, as I currently do not have the book at hand.

I'd like to agree with the above poster that since artificial gravity is so common in 40k (every ship and orbital station, graviton guns etc) there really is no reason why tractor beams would not be in use. From a science veiwpoint (irrelevant, but useful for inspiration) a tractor beam that only pulls, pushes and holds an object on a set distance is a much simpler application of artificial gravitons than creating a stable effect of gravity. I can however see that big chains would be cheaper, more available, easier to maintain, requiring less skilled operators or even more good looking and better fitting with the grimdark world. So I'd use both methods and choose depending on how hightech I wanted the towing ship to feel.

As for travel times: Acceleration increases with the force applied and decreases with the mass pushed. So a small ship would loose very much of its acceleration when towing a larger ship. Then the travel times (if, once again we listen to insufficient real world science) will increase with the square of the decrease of acceleration. So if a swordclass frigate, weight 6 Megatonnes, tries to tow a Lunar class Cruiser, weight 28 megatonnes, this ekipage will now weigh in at 34 MT. The weight increase factor is 34/6 =~ 5.7. So acceleration will take 5.7 times as long as it usually does. So travel times will be increased by a factor 5.7^2 =~32. The usually weeklong normalspace trip that takes a ship from a safe jump point to a planet in the system would now take more than half a year.I will not guess how engine power vs ship mass affects the speed of warptravel though. I would think extending the geller field is the most important part, unless you see this haul through the warp as an excellent way to clean out any stowaways or remaining crew from the previous owner ;-)

But most of all ask yourself: Would it be cool and make for a good story if the players worked as highway-mechanics, towing home wrecks left and right? I think not, so I would rather equip them with a supporting salvage crew, eventually. A small fleet of tugboats with powerful motors and geller fields that can be called in after the hulk is cleared of genestealers and warpentities, the ghost of her former captain is put down and the orc warparty trapped at deck 45 have been recruited as your bodyguards. 3 years of boooooring work later the salvage crew will have brought the remains of the ship in to dock and can start stripping it. In the meantime the RT and his friends can do much more dashing storyfriendly things!

I only just noticed that the maximum sustainable acceleration of a ship is indeed noted in the ship stats. So lets say a swordclass frigate would want to tow (through normalspace) a Lunar calss cruiser from holy Terra to Mars. Lets say this is done at such a time that the planets are as close as possible to eachother, that means roughly 0.52 AU = ~80 billion meters. Worst case it is about 5 times as long. Acceleration of a Swordclass Frigate that is not towing anything is 4.5 gravities. So roughly 45m/(s^2). As calculated above the acceleration of the towing ekipage will be roughly 45/5.7 =~7.9 m/(s^2) so about 0.8g. Since it is not a good idea to crash into Mars at full speed, and as we really don't have any friction that will slow us down we will accelerate for the first half of the trip, and then turn the ekipage around and slow down for the second half fo the trip. That way we will be at zero speed at our destination. So we calculate the travel time for 40 B meters (the half way point), and then double that time.

Distance (d) travelled with a steady acceleration can be calculated as d=(a*t^2)/2 if we solve this for time ( since that is what we are looking for) we will get:
t = sqr(2*d/a)
That means time taken is the square root of (twice the distance, divided by the acceleration). Lets our numbers:
t= sqr(2*40 000 000 000/7.9) = ~100 000 seconds =~ 27 hours. So the entire trip will take just over two days. Not too bad.

A similar towing trip from holy Terra to Neptune would take about two weeks.

****, I just realised I was wrong in my previous post... the travel time does not increase with the square of the decrease in acceleration, it does of course increase with the square root of the decrease in acceleration. So a much smaller increase of travel time. Oh well, it's just science after all.

Mellon said:

I'd like to agree with the above poster that since artificial gravity is so common in 40k (every ship and orbital station, graviton guns etc) there really is no reason why tractor beams would not be in use.

Wait, what?

From what I've read, graviton guns are considered to be extremely rare pieces of technology. The same goes for artificial gravity in space ships and orbit stations (they create it by using "grav plates" which are installed in the decks of ships and stations in order to provide artifical gravity for the crew and passengers).

These are not very common either. In fact, the grav plates are one of the primary reasons why space hulks and other kinds of wrecks often attract salvagers and scavengers, because the knowledge of how to create grav plates is nearly a lost art of the Mechanicus (sort of like with plasma rifles and plasma pistols) and not something that is considered "readily available".

Also, grav plates and graviton guns are still just examples of pretty small scale and very local gravity manipulation (no where near the scale of energy use and sophistication of a tractor beam), and the fact that only Orks are mentioned of using more large scale gravity manipulation in their "traktor beamz", it seems to imply that it is a volatile and dangerous technology to tamper with (i.e something only an Ork would consider).

All of these reasons would reasonably explain why artificial gravity is a rare thing in the Imperium, and why they seem to favor using gigantic chains for towing things through space in all the illustrations rather than using something more high-tech.

Oh, cool. I was under the impression that the fake gravity inside ships and stations were rather common tech, in the way that oxygenproducers/carbondioxidereducers are. I believe it is because the only gravity lacking spaceships or stations I've ever heard about was so due to a power outage or similar system failure, never by design. If the grav-plates really are that rare and expensive, I would expect most areas of a ship to be un-graved. For example, it would be enough for the crew that actually are supposed to spend time planetwards to live in grav conditions. Similarily there would be several un-graved areas in orbital stations that would have entertainent for sailors that needed them. Lifting and carrying jobs and shuttle docking would be so much easier in areas without grav plates. Ships could be built with less "upp-down"-symmetry. Not only would this be reasonable it would also be awesome and cool, so very appropriate for the setting. And since I hadn't really heard about similar things, I just assumed that there was a sort of gravity field generator controlled by a cognigator that compensated for inertia and ship acceleration in a pretty uniform way all over the ship.

And then I thought, If I can create a fake gravity that can pull with the force of around 5 times normal earth surface pull (say the 5g needed to compensate for the acceleration of a Havoc class raider), it really wouldn't be that hard to apply that force on any other item nearby, at least to pull it towards me. However, I found the small note about grav plates in the RT book, so my mind is somewhat at ease.

Now I got all curious as to how the gravplates work when the ship they are mounted on accelerates. Do they remove sideways inertia from the crew on top of them? Do they apply a similar acceleratory force on the crew? And how do the crew then feel? a few g can be pretty unhealthy if suffered for a while. Do they just create their own little bubble of space where no other points of reference are valid? Would that even be enough to counteract innertia? Can I mount every second gravplates in the "roof" to create strange local gravity phenomenons? :-)

Mellon said:

Now I got all curious as to how the gravplates work when the ship they are mounted on accelerates. Do they remove sideways inertia from the crew on top of them? Do they apply a similar acceleratory force on the crew? And how do the crew then feel? a few g can be pretty unhealthy if suffered for a while. Do they just create their own little bubble of space where no other points of reference are valid? Would that even be enough to counteract innertia? Can I mount every second gravplates in the "roof" to create strange local gravity phenomenons? :-)

Crap, I wish I could remember where I read about the methods of artificial gravity in starships in the 40K setting. It's one of those obscure things where you just know you read it somewhere, but it's hard to recall the specific text.

A good bet would be that I read it either in one of the Battlefleet Gothic books, or the Space Hulk books, but I can't be sure at the moment. Im just positive that I read something about grav plates and what they are used for and that they are rare and one of the main things that hulk scavengers go for first. Im gonna have to get back to you on this one in case I find my source.

Don't worry too much about it. It's merely my curiosity that wants feeding :-) I'll look at the old Spacehulk books, they could contain some other inspirational ideas.

Ork Tech only works because enough orks believe it does. The warp drive on the sample Ork Raider is a load of boyz chanting "'Ere we go, 'Ere we go, 'Ere we go!" after all. There is nothing logical about it, and I imagine several tech-priests have aneurysms trying to figure out why red ones go faster.

They have had several tractor/magna-beam weapons though. My favourites were the Lifta-Droppa tanks from Epic 40k. Does exactly what it sez on da tin.

As for Imperial vessels, I'm pretty sure it consists of taking everything that isn't nailed down onto a working ship, repairing the wreck if possible and cutting out the useful bits if it isn't. A hull is a lot of metal, but it's the tech that is worth picking up.

That said, it may be possible to tow a ship through the warp. It would be hard to steer, and would need a supercharged Gellar Field (Or enough power in the wreck to run it's own one). I'm planning on waving a similar carrot in front of my players, requiring a replacement Gellar Field Generator to be brought along.

St. Jimmy said:

Ork Tech only works because enough orks believe it does.

Subject to debate - it could also be considered that the device works in the same fundamental way (because Ork technology is, whether the Meks making it know it or not due to having the knowledge built into their genetics and more an instinct than a matter of understanding, built upon the same scientific principles as that of everyone else), but is simply constructed in a manner too haphazard and imprecise to function under normal circumstances. The psychic field Orks produce allows the device to function effectively when its construction should not allow it to do so...

Simply taking a cardboard cut-out of a gun does not make a gun, no matter how much you convince an Ork that it should be firing bullets.

Red ones going faster... a mixture of unconscious bolstering (in the manner described above) and unconscious construction methods (Mekboys making two identical vehicles, with the red-painted vehicle built in such a way that it actually is faster, but not realising what he did to make it so, meaning the only difference he can see is that the faster vehicle is red)