Looking into Starship Construction systems

[DaltonSpence]

The main reason I became interested in GURPS Traveller was its starship construction system. I'm not really a player you see; my hobby is designing starships according to a set of rules then drawing up deckplans based on them. (Oh, and I preferred its ATU since I found the idea of an empire falling apart unattractive.) The module based system of GT was sufficiently "crunchy" to allow me to do this but the only software I've found to help me is over 20 years old and has no support. This has got me wondering if any other Traveller version has a better ship design system with easy to use (and more modern) software to help.

Dalton “I won't abandon GT but I want to compare” Spence​

 

[Spinward Flow]

Well ... there's Orbital Yards as an iOS app for LBB5.80 if you like Classic Traveller ...

 

[DaltonSpence]

Sorry, I'm a Windows guy. I noticed there are a lot of Apple or Unix apps out there but at my age changing paradigms would be too hard.

 

[whartung]

Doesn't look (at a glance) any much different from FF&S.

The singular issue with FF&S isn't so much the ship building, its the weapons. Designing weapons is a pain.

A basic spreadsheet will do 90% of the math necessary for, pretty much, any of these.

In HG, the corner cases are notably power and jump fuel, since they're both based on hull size. But those are not that hard to just code out with a simple spreadsheet formula.

After that, they're all pretty modular. Bolt in systems that take space (mass), money, and power. Keep track of those and you're good.

Crew calculations can be fiddly.

The key point is that dedicated software isn't really necessary.

 

[Spinward Flow]

The key point is that dedicated software isn't really necessary.

This is definitely true.

I do all of my starship designs for posting in The Fleet forum using a word processor program (in my case, TextEdit) and PDFs of the CT LBBs. I just use a calculator program on the computer to assist with the math and try to make sure I've got everything written up correctly before posting (always finding little mistakes more than 30 minutes after posting that I can't edit to correct anymore).

 

[daryen]

Mods: If this is inappropriate, please delete this.

In a different thread, DaltonSpence mentioned Tom Bont's Starship creation program. I am not sure if he is using the same one as I was, so, since it is pretty small, I am just attaching the one I have here. I do not know if it still works on current Windows, but I don't see why not. Also attached separately is an updated repository module I created that has a bunch more GTL10 modules for the construction program. These programs were freely available when I originally downloaded and got them. (And, since I am a digital packrat, if I downloaded it at some point, I probably still have it somewhere.)

 

[DaltonSpence]

I think this might be the successor program. I'll take a look and get back to you.

Dalton “who is grateful you took the time for this” Spence​

 

[tjoneslo]

There are three programs built for the GURPS Vehicles (GURPS 3rd edition) to build vehicles.

GURPS Traveller Starships (GTS) - This is focused on the GURPS Traveller Starships build
GURPS Modular Vehicles (GMV) - This is the second version of a program used build vehicles using the modular system from GT: Ground Forces. It can be used to build Starships as well.

GURPS Vehicle Builder (GVB) - This is the full GURPS Vehicles builder. There are settings for building either the GT:Starships, GT:Modular Vehicles, or simply building GURPS Vehicles directly. I am very familiar with this because I helped Tom build it. This is not a free program, it is still for sale on the SJGames site.

 

[DaltonSpence]

GMV it is then. I do have a question about drop tanks and hardpoints though.

There is a folder for Drop Tanks in the "Aux Vehicles/External" repository. I've added a couple of my own custom designs but how am I supposed to use them? According to GT: Starships I'm supposed to mount them on hardpoints but I can't find any of those in the repository. Here is what the book says:

The total weight of all hardpoint loads may not exceed (0.01 × the ship’s hit points) in stons. Each hardpoint weighs 0.05 stons and costs MCr0.0002 per ston of load capacity. Hardpoints are assumed to be “tapped,” allowing the vessel to draw liquid hydrogen from drop tanks and provide power to pods containing electronics.

That's okay, my ship's HP is 135,000 so my 1,200-ston hardpoint would be permitted. I designed this nice VGSL drop tank to go with my Jump Tanker so they could load everything up at the Turley downport. But later it also says:

Ships mounting loaded hardpoints may not enter an atmosphere without destroying the hardpoint and the stores attached.

What about taking off? Will I need a drop tank carrier to take them to the planet to be refilled? Or should the highport refill and reattach them to my Jump Tanker?

Dalton “Why do all my "great ideas" have problems?” Spence​

 

[tjoneslo]

Continue reading on GT:Starships P.34. There are four types of connections for external stores.

• Hard points. These are simple pylons to attach a object. The authors admit they simplified the process of determining streamlining for hard points by simply banning their use in an atmosphere. If you read the original Vehicles, you can use these in an atmosphere, as they're used in aircraft extensively. These are the only external mounts with this limitation.
• Modular couplings. These are more tightly attached and have a single module which fits on them. This is the thing to use for Drop Tanks. They have the same cost/volume/weight limits as Hardpoints. But they can also be explosive.
• Intrinsic couplings. These are more tightly integrated with space allocated in the ship as well as the external limitations. This allows for switching modules for missions.
• External cradles. These the more flexible version version of the Modular Couplings, You can attach (more random) objects to these cradles.

 

[DaltonSpence]

Aside from External Cradles the above are not defined as modules in the GMV repository. In the book only "Hardpoints" mentions drop tanks at all implying that is the preferred method but the only time I've seen hardpoints mentioned in GMV is here:

so the program recognizes them somehow. How should I create one for my drop tank?

Dalton “Where there is a will there's a way … but where's Will?” Spence​

 

[tjoneslo]

What you are looking for in GMV is under "Storage Bays" as "Cutter Module Socket".



The different "Bay Types" are the types I mentioned above. Add this to the ship for different sizes calculations.

 

[DaltonSpence]

The resulting dialog doesn't mention anything about hardpoints either.

I'm trying to create a hardpoint with mass and cost for a 1,200 ston drop tank without actually including the tank's 1,000 dton volume in the jump calculations, and I want it to affect the number of "Hardpoints Available" as listed for my pop turret above. I could just create a no volume User Defined module with the mass and cost but that wouldn't affect the hardpoint total.

Dalton “What we have here is a failure to communicate” Spence​

 

[tjoneslo]

Your sig line is completely appropriate here.

In Traveller ship building terms (generic, not specific) a "hardpoint" is a point where you can mount a turret. By general rules the ship contains one turret hardpoint per 100dTons of size. This is the "hardpoints" you are seeing mention in other places in the program.

In GURPS terms, and general avionics terms, a "Hardpoint" is a specific place on the vehicle where you can mount external pods which may contain weapons, fuel, an EW jammer, or other things.

In terms of the design process, the two of these are not related.

The "Cutter Module Socket" defines the "hardpoint" in the second sense. It specifies the size and weight of the attachment required to attach an external tank. There isn't any limits set by the program these mounting points, it just assumes you will keep things within limits.

 

[DaltonSpence]

Oh! Thank you for clarifying things. The hardpoint UDM (user defined module) I could create would come from this;

The total weight of all hardpoint loads may not exceed (0.01 × the ship’s hit points) in stons. Each hardpoint weighs 0.05 stons and costs MCr0.0002 per ston of load capacity. Hardpoints are assumed to be “tapped,” allowing the vessel to draw liquid hydrogen from drop tanks and provide power to pods containing electronics.

GT: Starships p.34​

That's okay, my ship's HP is 135,000 so my 1,200-ston hardpoint would be permitted. My next UDM will be the drop tank itself. Hmm. I was hoping my loaded VGSL drop tank could be attached to the jump tanker on the planet but even with its low gravity the M-drive can't lift it into space directly. (It might be able to fly into space but I don't want to calculate the stall and top ground speeds for that world by VE3 rules.) Oh well, I guess the drop tanks will have to be filled and attached to the tanker at the highport. (Probably makes more sense anyway.)

Dalton “who is disappointed but will deal” Spence​