• Welcome to the new COTI server. We've moved the Citizens to a new server. Please let us know in the COTI Website issue forum if you find any problems.

ships weapons and dTons

i recently noticed that in ships built with weapons already added on, they're weight is added to the ships total tonnage. is this right?:confused: if i bought a stock free trader, then added weapons, i couldn't go anywhere, as my jump and maneuver drives are not for 200+ dtons, just 200 dtons. would i have to get upgraded power plant, m-drives and j-drives for the extra weight?:eek: or does the extra weight/dtons come out of existing space, like cargo probably?:( thanks for any contributions to this question. i did look at the errata to make sure this is correct, so maybe i need advice for a solution to the problem.:o
 
Hi, Bookwyrm67. You are confusing mass and volume, which is easy to do with the way things are stated in some versions of Traveller.

Yes, adding more stuff to your ship would increase the ship's mass, but that doesn't matter to the jump drive - otherwise you'd also be unable to ever carry any cargo, which would make the ship pretty useless as a trader.

Traveller jump drives move a given volume, which is rated in displacement tons (dtons), a unit of volume, not mass. If you have a 200 ton ship, that is its volume, not mass. So when you load it up with cargo, or add weapons, that doesn't change the volume, and doesn't change the result you can get from your installed jump drives.

(Why this also makes no difference to the maneuver drives takes a lot more handwaving and is usually just ignored.)
 
(Why this also makes no difference to the maneuver drives takes a lot more handwaving and is usually just ignored.)

Not in TNE nor T4; 10 metric tons per displacement ton is the rule there. warships can exceed that, and need M-Drives for their rated mass, and will be negatively affected by cargo mass. Most TNE cargo craft come in with about 10 metric tons per dTon available within the rated drive. T4 are somewhat dicy on that score... as T4 has less fuel needed due to allowing gravitic drives.

MT allows 1 metric ton per cargo cubic meter, but actually ignores mass for the gravitic maneuver drives.

One can presume that that is also the mass limit per dTon for other editions as well without doing much violence to the setting. (and that it's subsumed into other rules in CT.)
 
The OP isn't asking about TNE or T4, he's wanting to know how to add weapons to a T20 ship design.

So to answer the question asked, when you design a ship you allocate tonnage to turrets but you don't need to install them until later.

So the 200t free trader may have 2t set aside for the later installation of turrets.

A 1t turret can either be a single, double or triple weapon mount, that is it may contain 1, 2, or 3 of the basic weapons - beam laser, pulse laser, missile, sand caster.

You effectively ignore the mass of the turret weapons.

There are heavier types of weapon mount - there is the 2t turret required to mount energy weapons, the 3t turret for high TL PAWs, the 5t barbette for lower TL PAWs.
 
expanding the post

well, in the t20, when u look at , say the seeker, the dton for the mining laser is taken out of the volume of the seeker. i looked at the sdb and same thing, the weapons tonnage is taken out of the dtonnage for these ships. for comparison, i have seen deck plans for the scout/courier, and they show the space/volume taken up by the hardpoint, or at least the access to it, which could be part of the 20 dton allocated for the bridge space. the hardpoint and turret don't take up space/volume, looks like they are considered part of the hull. i had thought the weight listed for the ships weapons was for cargo purposses in the speculative cargo list. but when you look at the seeker and sdb, the weight of the weapons is taken out of the total tonnage of the ships in question. now i had usually thought that the weight of the weapons was negligle to the ship, considered it part of the turret/hardpoint mechanism, and thus ignored it. the 2 ships i mentioned are built with the weapons as part of the original ship just out of the shipyards. the free trader has 2 hardpoints, and i think turrets (don't have book right at hand) but no weapons, so the weapons have to be added, and going by the other ships with weapons built in from the beginning, they take up volume. so i would 'assume' that if i want weapons in my free trader, i'm going to lose space somewhere, or upgrade the jump, maneuver, and power plant systems to compensate for the extra weight the added weapons will put on the ship. i'll probabley just ignore the weight in my MTU, but i was wondering about the official/cannon view on this, as this could be an interesting twist for the players when getting weapons for their ship, especially since they'll need more credits than just for the weapons, but for any upgrades or changes in the interior of the ships. part of my thinking was that the weapon systems took up more space than the hardpoint gives, power couplings, connections to the computer/sensors, cooling systems, etc... i hope this explains my original post better.
 
One can presume that that is also the mass limit per dTon for other editions as well without doing much violence to the setting. (and that it's subsumed into other rules in CT.)

As a MAJOR house rule. Otherwise, no.
 
thx for help

well, thanks for the help guys. i did read the errata, and that wasn't fixed, unless the ship TAS Form 3.1 wasn't changed and the weight/dton was fixed/mentioned elsewhere. i'll read it a little better later, and just ignore the weapon weight except for spec cargo.
 
As a MAJOR house rule. Otherwise, no.

It's explicit in 2 editions (TNE, T4) that a ship massing below 10 metric tons per Td uses figured acceleration.

It's noted in the rating system for MT that 1 ton metric per kiloliter is normal for cargo space.... which makes a Td of cargo 13.5 metric - so no violence there.

that leaves CT, T20, and MGT - and using 10 Metric Tons per cargo ton puts the striker version of the GCarrier overmass by a factor of about 2... it takes 8Td of volume, masses 160 metric tons.

GURPS doesn't mechanically count.
 
It's explicit in 2 editions (TNE, T4) that a ship massing below 10 metric tons per Td uses figured acceleration.

Outside of those 2 editions it would be a major house rule because it isn't part of the rules. (MT, if I remember has weight considerations for agility but no max weight per volume) That's all I'm saying. Not whether it is a good or bad idea. It's just not RAW outside of TNE, T4.
 
Last edited:
Back
Top