Reaction Drives

[Vargr]

Boy! Seems like every day I find something new about this game that raises questions marks over my head.

Today's theme: Reaction Drives.

So I was checking High Guard and found about these babies. The specific information in the book regarding these deals only with small craft and capital ships.

On page 42 it is stated that they take the same space as a normal M-Drive; so we just need to use the table on pages 107-108 of the Rulebook to know how big a R-Drive must be for the usual kinds of ships players use.

It is also said on HG pg.42 that R-Drives are cheaper than M-Drives, but I cannot find any formula or table to determine what the cost would be for ships in the 100-2000 ton range. Can someone point me in the right direction?

My second doubt is about the effects of adding a reaction drive to a ship that already has gravitic prupulsion.

For example: Let's assume someone fits your typical 1g-Thrust Free Trader with a type F reaction drive (6g of thrust) for those moments when you need to run away from something really, really, REALLY fast.

When the crew fires up the thing I assume the total thrust will be over the 6g granted by R-Drive because the spaceship already has a 1g thrust of it own due to the M-Drive.

So would the total thrust be for both drives working togheter? 7g? Too negligible to count? Or something in between?

 

[aramis]

I'd stack them... but I'd also point out that the M-drive includes the needed G-Comp... so you go splat if you're in the hallway when it goes off...

 

[sabredog]

Or at least some warning bell to go off before you light them up so everyone can get in the crash couches. And not to mention the vector changes and what that might do to the crew.

So the possibility opens of having to include acceleration compensating equipment to counter the effect of hitting the "afterburners" but more importantly, to enable the crew to survive or even just accomplish any kind of maneuvering off a straight line because that's were the real problem lies. Blackout, redout, torn aortas and other jellied innards ...it gets ugly.

So either the rule would need to be that the thing only allows for straight line acceleration, or you can introduce the sort of things found in all sorts of science fiction: oil baths (Mote in God's Eye), flourocarbon fluids filling all body cavities in special suits (Forever War), or at least some sort of G-suit to help some.

An example from MTU:

Pilot Armor TL-9 25,000CR
Because of the cramped conditions and the lack of full power inertial compensators in craft less than 40 tons without small craft bridges ordinary vaccsuits and combat armor are too cumbersome to wear. Pilots and crews of such craft in the military wear specially designed suits designed not only for protection against spalling and other physical impact damage, but to protect the wearer from injury due to high G maneuvering.
The vacc-tight suit is woven from ballistic cloth with mesh reinforcement in the joints and seals. Overlapping ballistic ceramics further cover the joints and shoulders, with shin, forearms, and thigh protective plates that are inserted in pockets. A clamshell cuirass protects the upper torso (lighter in composition than regular combat armor) and has sockets for plugging in the acceleration reduction systems onboard the craft the wearer is crewed on. The helmet had datalink jacks for connecting to the craft avionics and targeting systems, 100 PWR radio, and contains a combination filter / compressor mask for use when a vacc-tight seal isn’t required.
A manually-variable camo film is standard on the hard surfaces.
The suit provides armor at the level of Combat-1.

 

[Vargr]

I'd stack them... but I'd also point out that the M-drive includes the needed G-Comp... so you go splat if you're in the hallway when it goes off...

Or at least some warning bell to go off before you light them up so everyone can get in the crash couches. And not to mention the vector changes and what that might do to the crew.

So the possibility opens of having to include acceleration compensating equipment to counter the effect of hitting the "afterburners" but more importantly, to enable the crew to survive or even just accomplish any kind of maneuvering off a straight line because that's were the real problem lies. Blackout, redout, torn aortas and other jellied innards ...it gets ugly.

Oh absolutely!

I like the idea of poor crewmembers strapped down going "AAAaaaaaauuuuuggghh!!!" when the ship's captain decides to have some emergency acceleration. :rofl:


I belive, in the meanwhile, I may have found the answer to both my original questions.

Check the data for Blockade Runner, Buccaneer–class on Scoundrel pg. 91.

The text blurb says the ship is equiped with a High-Trust Burner; but the stats actualy list a Type F Reaction Manouvre Drive for a total thrust of 6 (3+3).

The R-Drive appears to follow what is said on High Guard, it takes the samer number of tons as Type F M-Drive and the listed fuel for 3 hours of operation checks out according to High Guard's formula.

The price listed for the R-Drive on the ship data is 50% of that of an equivalent M-Drive.

 

[sabredog]

Oh absolutely!

I like the idea of poor crewmembers strapped down going "AAAaaaaaauuuuuggghh!!!" when the ship's captain decides to have some emergency acceleration. :rofl:
[/U].

I wonder how long it'll take the players to figure out how effect an anti-hijack device that might be.

You know - these might be useful to build lift boosters for big ships to help them get off the ground (if you have the sort of limits I do on how big a ship can land), or at least to lift cargoes to the big ships in orbit.

Also as something that can be strapped onto high priority x-boats to get them out to the jump points ASAP, then drop the boosters for recovery right before jump.

A way to try to make it past a blockade....all sorts of little add-ons to some adventure.

OH - I just thought of something - if the players lit these things off to escape, then hit the jump button, they'll still be at that level of G while in jump space - and when they drop out! They'll need a chiropractor-bot when they finally slow down.

 

[Marchand]

As thruster plates are a pure handwave anyway; and if no-one IYTU has ever tried strapping R-drive onto an M-drive-equipped ship before (at least that the PCs know about); how about hitting them with this - the resulting acceleration with both drives working is 5g.

Why? The thrust-plates are trying to accelerate the ship forwards at 1g using space-warping gravitics. With a 6g reaction thruster burning, the thrust-plates are still trying to accelerate the ship forwards 1g. But they only have power to offset 1g of the forwards acceleration being produced by the R-drive.

And/or - fire up R-drive, thrust-plates go kaboom. New thrust-plates please.

 

[aramis]

OH - I just thought of something - if the players lit these things off to escape, then hit the jump button, they'll still be at that level of G while in jump space - and when they drop out! They'll need a chiropractor-bot when they finally slow down.

Accelleration DURING jump has no effect; yu exit jump the the same vector as you entered.

 

[sabredog]

OK, that's what I thought..but wasn't sure. Since nobody in any of my games ever thought of strapping giant hi-tech RATO bottles on their ship to go beyond the 6G limit I never thought much about it. Normal ops in my game mean that unless you are reasonably sure there isn't going to be anything in the way when you drop out of jump you stop before hitting the jump button.

But thinking about that potentially enormous vector when coming out on the other side leads to amusing possibilities. Speeding tickets for one.

 

[far-trader]

Many potentially amusing possibilities...

But thinking about that potentially enormous vector when coming out on the other side leads to amusing possibilities. Speeding tickets for one.

Light Speed Limit Strictly Enforced