Some TNE(BL) design question marks.

[Zembar]

Hello everyone, this is my first post on these forums.

I recently picked up my Traveller books, thinking about starting a new campaign. Call me crazy, but I found that TNE is the easiest system for the players to deal with and for flow etc, so I started digging into the details again. Unfortunately I lent my FF&S to a friend some time ago so I don't have it handy. Hence me using BL rules for now.

What I'm wondering is this:
1) the material volume rules are *very* unclear. For airframe hulls, do I multiply MV for hull shape, hull configuration *and* the 1.3 listed in the text below?
2) for internal structure volume, is it simply unmodified MV*G rating/hull material armor rating?
3) According to the table, a launch tube takes up space equivalent to 25xthe volume of the carried craft. Is this per craft, or per launch tube? If it's per launch tube, how much space does the craft take up, or how many craft fit in each launch tube? There's literally no descriptive text on launch tubes in the rules except where it says each launch tube can deploy 10 craft per turn.

I searched but couldn't find anything on this.. I'm hoping one of you knows.

-- Zembar

 

[MacTrom]

JMHO, but as I recall from that far back, and looking at the box version of Azanti Lightning cruiser, the tube holds one ship, so 25x 1 ship volume. the additional ships are stored in a hanger and rotate into the tube like a revolver's cylinder.

 

[fredofmars]

A launch tube is 25 times the size of the largest vessel that will be launched by it. Then you add hangar space for however many vessels will be carried. I suppose if you wanted to munchkinize it, you could say the launch tube could hold a single vessel normally (one less for the hangar to hold), but then the crew would curse you forever for having made their maintenance, shuffling, etc. much more difficult.

 

[deniable]

I'm looking at a Mk1 Mod 1 FF&S and haven't checked the errata yet, but:

1. Airframes are MV (material volume for this hull size) x MVM (material volume multiplier for the shape; needle, cone...) x 1.3. The airframe mods in the table are for cost only. The 1.3 also modifies surface area.

2. It appears you also multiply by MVM and divide by material toughness. This is the MVM for shape and isn't modified for an airframe hull.
(MV x MVM x Gmax ) / Toughness

3. What the others have said. The launch tubes are bought separately from the hangars. You need a minimal (x2) or spacious (x4) hangar for each craft.

The discussion is giving me some sort of weird metal-storm fighter launch system vibe. If you had low maintenance pilot-less drones, you could spit them out of a tube at a rapid rate.

 

[Zembar]

Thank you, this all makes a bit more sense now.

It does however beg the question why any ship would bother with launch tubes, external grapples are much more efficient space-wise than any launch tube configuration.

If it allowed the ships to be stored at 1xSize, and the 25xSize included a maintenance area when they were "rotated in" for possible launch, it would make sense on ships with many small craft.

Other than that, 2xShip Size+(25xShip Size/Number of Ships) will never be more efficient than 1.5xShip Size(including craft tonnage and assuming worst-case airframe configuration). Is it to protect carried craft from surface hits?

Edit: It occured to me that just having hangars would also be more efficint using that model. The only reason would be surface area, but is that at such a big premium on large ships? Haven't really done the math on that.

I should also add that I'm thinking of some sort of tender-style ship, and military designs usually want to be as cost/space/fuel efficient as possible(doubly so in TNE)

-- Zembar

 

[shield]

The only problems with external grapples are:

1) ships vulnerable to enemy fire (surface hits)
2) messes up your streamlining
3) maintenance is now almost impossible - severe DMs on this and your maint crew will hate you
4) You will need an airlock for each ship (how else is the pilot supposed to get on board
5) Uses up surface area you need for other systems

Hangers get round all these by having a nice warm space where you can do maint / board in peace, are protected by the ships armour and don't use up surface area. Only downside is the volume requirements.

Cheers
Richard

 

[Zembar]

Points 1-4 are adressed with using hangars instead of external grapples. And I thought using a streamlined/airframe grapple would eliminate #2. Looking at the lab ship I assumed that airlocks were part of the grapple. (Not to mention that three cubic meters per grapple is neglible volume)

Using hangars/ports makes it surface area(just one tube instead of all those ports) vs launch speed(if you have 50 hangars and a launch tube you can launch 10 per turn. With ports you can launch them all) and redundancy(surface hit on one launch port=you lose launch capability for one craft, surface hit on launch tube=you lose *all* launch capability).

Redundancy can be addressed by more launch tubes, but that amplifies the problem of volume, and reduces the area advantage.

Side note: How is surface area handled for a launch tube? I'm thinking a simple launch port allocated to the tube using normal variables.

 

[shield]

I think that a carried craft in an external grapple takes up surface area based upon its size - which tends to be bigger than the area taken up by the exit of the launch tube or even hanger doors.

Yes you can upgrade to streamlined grapples to reduce the effects of carried craft on the mothership's streamlining but it costs more and I am not sure if it works if your carried craft are not streamlined.

As for the size of a launch tube exit port - not sure, a normal hanger port of the correct size seems reasonable.

Cheers
Richard

 

[Zembar]

Streamlining of the carried craft might be an issue, but even airframe grapples only take up 0.5xcraft volume, meaning 1.5xvolume total, less than a minimal hangar. Also, if you're looking at tender-size craft, you usually don't spend money and space on airframe, relying on skimmers and landing craft for atmospheric performance.

Area-wise, a launch port takes up area equal to carried craft length squared, which would be about the same as an external craft.

-- Zembar

 

[GypsyComet]

Another difference is that the grapple tender is effectively changing size every time a subcraft arrives or departs. This was sort of the point of the external grapple in the first place, to provide a mechanism that made sense to cover designs like the Fat Trader.

In battle, a grapple carrier risks losing real carrying capacity to "mere" surface hits, while an internal carrier can, with a little luck, keep taking surface hits all day and only impact its land/launch rate.

It's a design choice, and one I appreciate being able to make instead of the writers having made it for me.

 

[Drakon]

It does however beg the question why any ship would bother with launch tubes, external grapples are much more efficient space-wise than any launch tube configuration.

So obviously, the reason for using launch tubes is more important than space considerations. What do launch tubes buy you that hangers don't?

It allows you to rapidly launch a squadron of small craft, and quickly get them away from the ship. Remember that the tubes are used to accelerate the small craft away from the mother ship. This can be very important during combat or abandoning the ship in case of a catastrophy

 

[Zembar]

Now that's a justification I can go along with.

The volume requirements did seem impractical for what is essentially saving some surface area.

Thank you,
-- Zembar