[GZG] [FT] Fuel, Starship endurance

["John Brewer" <jbrewer@xxxxxxxxx>]

With the production of miniatures & publication of SSDs for the Wichita class Refueling ships, it confirms that the Tuffleyverse starships do indeed use fuel.  But it does ask questions that have never needed to be answered before, execpt by those interested in FT campaign games...

1 - How long can a starship go without refueling? 

& 2 - How much "mass" of fuel does a starship use? 

I looked up Jane's Fighting Ships for information on real-world warships and their cruising ranges.  I found that it varies from "4500 miles at 20 kt" for modern American frigates to "15,000 miles at 17kt" for Iowa class battleships.  I converted the speed & distance to hours of travel time and it came out to 225 hrs & 882 hrs respectively. 

From this, I surmised that starship endurance can be calculated by two possible conventions. 

BY HULL/SIZE/TYPE -

The simplest way is to dig out the old ship groupings from the second edition game and assign endurance by general ship type...

Escort - 240 hrs 
Cruiser - 480 hrs 
Capital - 960 hrs 
Merchant - 1920 hrs 

The number of hours chosen is for ease in calculation since 240 hours is 10 standard days.  Escorts are small and can't carry as much fuel as the capital ships, and the design of merchant ship engines emphasizes fuel economy rather than performance. 

If you want to differentiate between classes of ships, the other convention is...

ENDURANCE DIVIDED BY THRUST RATING 

1920 hrs divided by ship MD thrust 

MD 1 - 1920 hrs 
MD 2 - 960 hrs 
MD 4 - 480 hrs 
MD 6 - 320 hrs 
MD 8 - 240 hrs 

As for how much fuel a starship can carry in tankage, I figure it's 5% of TMF, since MD is 5% times thrust factor (It's a "free" 5% as tankage is part of the hull boxes on the damage track). 

On a SSD, there is a tankage box for as many crew factor boxes on a ship.  On the damage track, the hull box BEFORE a crew factor box is a tankage box.  The effects of damaged tankage boxes is only calculated after a battle, when determining how far a damaged ship can limp its way to a repair station. 

Having tankage as 5% of TMF does imply that a single Wichita class can fully fuel 4 240TMF capital ships, and a Blackpool class could service a good sized battle group.  I could make a point that, except for gravity & inertia, space is a frictionless enviroment, so there could conceivably be some fuel economy. 

As always, I invite your comments (especially about that last thing) 

JBrewer@xxxxxxxxx  

"Always strive to be a good person.  If you can't do that, at least strive to be someone other than an asshole."  

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