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?

 

[BP]

Hmmm... I actually designed a vessel around the gravitic + reaction drive thrust (7g in your example) idea

It was a 400-ton - so I better check were I got prices from (or maybe I scapped the idea...)

The reaction M-Drive for small ships is simply MCr 2xTonnage (the table is a waste). Don't recall prices specifically for standard or Capital ships...

[The R-Drive can also be usefull in close combat :twisted: ]

The normal gravitic M-Drive is simply MCr 2xTons +2 (except for Code A which is only MCr 2). Oh - and the tonnage is simply code (index) times 2 minus 1 (again, except Code A which is 2 tons - so larger, but less expensive).

The rest of the drive tables generally work the same way - with just a few exceptions.

Tables are really handy for roleplay. But design isn't roleplay. Its a shame that tables are used for design systems - that is generally just wastefull (of page count) and limiting... High guard mixes in formulas for Capital ships - which is good (though inconsistent in content as well as form). People who shy from simple math are not likely to be doing their own designs - by nature they tend to hate that kinda stuff...

 

[AndrewW]

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.

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

These are also covered in Scoundrel:

High-Burn Thruster: This is a powerful chemical rocket that can give a temporary speed boost to a ship. To determine the eeffects of the thrusters, choose an M-Drive that produces the desired speed... The high-burn thruster weighs 20% and costs 20% of that M-Drive.

 

[Zowy]

The problem is your internal gravitic field would need to be upgrade to handle that much thrust or they would overload.

You could shut down your G-Drive and then use a R-Drive, but how long can a crew function at 6Gs before blacking out? Even if everyone was in flightsuits and control couches, to keep blood from pooling in your arms and legs?

 

[BP]

The problem is your internal gravitic field would need to be upgrade to handle that much thrust or they would overload.

You could shut down your G-Drive and then use a R-Drive, but how long can a crew function at 6Gs before blacking out? Even if everyone was in flightsuits and control couches, to keep blood from pooling in your arms and legs?

Certainly to be accounted for - but using the rules, fuel runs out fairly quickly at high G - and 6G is not too much (for the times) assuming the crew isn't trying to move around.

Small craft already support upto 16Gs...

 

[Vargr]

High-Burn Thruster: This is a powerful chemical rocket that can give a temporary speed boost to a ship. To determine the eeffects of the thrusters, choose an M-Drive that produces the desired speed... The high-burn thruster weighs 20% and costs 20% of that M-Drive.

This was more in line with was I thinking in my example. But, why is the fuel so expensive for a HB Thruster? 10,000cr a ton?



Ha-a! I belive 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.

 

[BP]

Ah - that is handy - so Code F would be MCr 12 (actually MCr tons +1 as original formula is 2x tons +2)?

Guess I'll have to get Scoundrel

 

[AndrewW]

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

Been there done that. (Before Scoundrel was even out...).