More Walk-thrus of...

[robject]

Dalthor: for all drive values, simply total up the percentage of the hull they will take, resulting in a number from 0.0 to 0.9. Subtract 1.0 from that number. Then divide the payload by that number. The result is your hull size.

 

[pendragonman]

Dalthor: for all drive values, simply total up the percentage of the hull they will take, resulting in a number from 0.0 to 0.9. Subtract 1.0 from that number. Then divide the payload by that number. The result is your hull size.

That formula gives a negative number. Is that deliberate?

 

[Hemdian]

Just to paraphrase robject, if I may, the formula is:

M=F/(1-V)

where F = total tonnage of fixed size items,
V = total percentage of variable size items,
and M = minimum total tonnage of all items (ie. the whole ship).

So, if F = 123 dtons and V = 52% ... M = 123/(1-0.52) = 256.25 dtons

 

[FreeTrav]

...all of the above?

 

[JFGarber]

I would dearly love to see an example of starship combat. I do not own and have never played HG--there seem to be some fundamental assumptions that have carried over that I'm not tracking.

 

[whulorigan]

I would dearly love to see an example of starship combat. I do not own and have never played HG--there seem to be some fundamental assumptions that have carried over that I'm not tracking.

I'll second that. I am rather intrigued by T5's Starship Combat and the way it handles targeting and armor, but I would like to see how it works in actual play, and if there are any "conceptual issues" that arise that are not immediately apparent from a read-thru.

I'd also like to see some of the classic Traveller Aliens (i.e. Aslan, Droyne, etc.) worked up with the Genetics/Sophont Creation system, and see how the new elements of T5 (genetic profile, senses, et al) are detailed for those species.

 

[robject]

Just to paraphrase robject, if I may, the formula is:

M=F/(1-V)

where F = total tonnage of fixed size items,
V = total percentage of variable size items,
and M = minimum total tonnage of all items (ie. the whole ship).

So, if F = 123 dtons and V = 52% ... M = 123/(1-0.52) = 256.25 dtons

Thanks Peter, a formula says it so much better than my text!

One more thing for all: note that if your percentage-based components total 100% or higher, the ship design is invalid*.

Invalid Example: a TL12 starship design with 10 jumps of fuel. Fuel requires 100% hull volume, leaving no space for anything else.


* Unless something offloads those components. Like drop tanks offloading fuel, for example.

 

[robject]

ThingMaker walk-thru: Ultimate Tape Player (TL11 item) (http://www.travellerrpg.com/CotI/Discuss/showthread.php?t=32234)

 

[dalthor]

Just to paraphrase robject, if I may, the formula is:

M=F/(1-V)

where F = total tonnage of fixed size items,
V = total percentage of variable size items,
and M = minimum total tonnage of all items (ie. the whole ship).

So, if F = 123 dtons and V = 52% ... M = 123/(1-0.52) = 256.25 dtons

The issue I ran into is that those percentages can vary by total hull size. For example, J-4 in 200 ton hull is 12.5%, in 400 ton hull is 11.25%, and in 800 ton hull is 10.6% -- the bigger the hull, the less space the drive uses as a percentage.

This can lead to inaccuracies in the final calculation, especially if more than one item has a variable percentage based on hull size. While it will get you in the ballpark, the exact hull size may be off if you applied the wrong percentage(s).

It is much more noticeable with anti-matter plants, which add +30 to the tonnage, compared to the +5 added to Jump drive tonnage.

Maybe I'm just missing something simple. After all, If I had brains, I'd be dangerous.

 

[robject]

So I think we need a walkthru dedicated to building drives from the tables -and- building starships "backwards" (sum up the payload first, then sum up all the percentage-based elements, turn the math grinder one crank, and out pops a ship).

The issue I ran into is that those percentages can vary by total hull size. For example, J-4 in 200 ton hull is 12.5%, in 400 ton hull is 11.25%, and in 800 ton hull is 10.6% -- the bigger the hull, the less space the drive uses as a percentage.

A bit of handling should fix this problem. The formulas on page 337 show you how:

J - Jump Drive
Jump Volume = ( Hv x Jn / 200 ) x 5 + 5; round up the result in parenthesis before multiplying by 5.
Hv = hull volume.
Jn = jump number.


Examples

Jump-4, from the table:

200t hull = D drive = 20t + 5t
400t hull = H drive = 40t + 5t
800t hull = R drive = 80t + 5t

Jump-4, from formula:

200t hull: J-drive vol = (H x Jn / 200) x 5 + 5 = (200 x 4 / 200) x 5 + 5 = 25t
400t hull: J-drive vol = (400 x 4 / 200) x 5 + 5 = 45t
800t hull: J-drive vol = (800 x 4 / 200) x 5 + 5 = 85t


Shift the 5 tons of overhead out of 'drives' and into 'payload', and you're good.

(Note that this means that if you have a jump drive, maneuver drive, and power plant, then your payload increases by 5 tons. Why? Because that's the total overhead of all three: Jump drives are +5, Maneuver drive is -1, and Power plant is +1. Except of course when you're using Maneuver Drive A, in which case your total drive overhead is 6 tons).

Now the Antimatter plant has errata logged against it (the formula on page 337 is assumed to be correct, and the table is assumed to be incorrect), and M-drive A hits that minimum volume requirement. But the other drives all play nice.

 

[dalthor]

A walkthru is on my to-do list, and has been for a while. Some of us may remember a side remark I made in the past about Q-ships.

http://www.travellerrpg.com/CotI/Discuss/showpost.php?p=468134&postcount=382

Here is the reason for that comment.

I'll probably do the Beowulf to help keep it simple. I was thinking about an initial build, and then applying tech level stage effects to "upgrade" it to TL-15 or 16.

I was facetiously going to call it the "Baddo-wolf" and then realized that it would make a pretty good example.

More to come, one of these days, in a separate post.