T20 Only: Definitions of Terms Used

[Timerover51]

I purchased the T20 CD from FFE, and have started looking through it. As I have a fondness for nautical vessels, I have been looking at the Watercraft book first.

For design, the term "vls" is used. It appears to represent a mass of 1 kilogram, and a volume equal to one-fifth of a liter. Is my understanding of that correct?

Second, this would represent a specific gravity of 5, i.e. five times the weight of an equivalent volume of water. This would be considerably heavier than wood, but also lighter than iron or steel, which have a specific gravity of close to 8. Is this also correct?

I am more used to thinking in terms of displacement tons of 35 cubic feet, gross register tons of 100 cubic feet, and measurement tons of 40 cubic feet. I am looking at verifying the correct equivalence of one sets of terms to the other.

 

[aramis]

Vol (vl) is defined on page 223: 10 L or 0.01 m³

It has no mass association; it is not a dual unit.

The use in the design sequence assumes an SG of 0.1, as 1 vl (10 L) is presumed to mass 1 kg. (page 253.)

 

[Timerover51]

Vol (vl) is defined on page 223: 10 L or 0.01 m³

It has no mass association; it is not a dual unit.

The use in the design sequence assumes an SG of 0.1, as 1 vl (10 L) is presumed to mass 1 kg. (page 253.)

Well then, we have a problem. The following quote comes from Through the Waves, page 4.

The volumes (vls) used by the T20 vehicle design system represent both weight and volume. This is an abstraction to make the vehicle design process easier and faster. You can calculate the real world sizes for vehicles by doing the following. Calculate a vehicle’s volume by multiplying the vls by 5 to get the size in liters, then divide by 1000 to get cubic meters, and again by 14 to get starship tons. A vehicle’s loaded weight in kg is equal to its size in vls. To get an empty weight, subtract 100kg for each passenger and 1kg for each 1vl of cargo.

 

[aramis]

It's one that cannot be resolved. Sorry. I've never read the supplements, and they weren't playtested the same way, either.

 

[Timerover51]

It's one that cannot be resolved. Sorry. I've never read the supplements, and they weren't playtested the same way, either.

Hopefully, tjoneslo will see this and shed some light on the subject.

 

[tjoneslo]

For design, the term "vls" is used. It appears to represent a mass of 1 kilogram, and a volume equal to one-fifth of a liter. Is my understanding of that correct?

Aramis is correct. The Vl is supposed to be a volume of 10 liters. The vehicle TAs have that as 5 liters. In both 1 vls is 1 kg.

volume by multiplying the vls by 5 to get the size in liters,

I do not remember why I changed that. I would have to go back through my notes to figure out why. I have a vague memory of being unable to reconcile the size as generated by the design system vs the size of real world vehicles I was using as examples.