Major Flaws in the design section

[Tekrat04]

There are major flaws in the internal volume needed to house certain components.

Fuel System: the ideal that the volume that a fuel tank takes up is the same as the quantity of fuel it contains is flawed. The fuel system needs take up a lot more space then the fuel it contains. Just the wall of the full tank adds to the overall volume. To this we need to add the pluming and pumps to take on the fuel and distribute it to where it will get used. When dealing with cryogenic fuels such as hydrogen it becomes even more so due to the need to insulate and refrigerate the fuel. Does a one liter thermos take up 1 liter of space? No, it takes more a lot more space. So why does 1 dton of hydrogen takes up 1 dton of space?

Internal Hanger: Again the volume needed to house any type of vehicle inside of another is a lot more then the volume of the vehicle to stored. Just the wall of the hanger will add to the volume, not mention the space needed to get in and out of the vehicle. No vehicle is a perfect box, that means there will always be wasted space around it when it get stored.

Hull: The walls of the ships also take up space on the inside of the hull. The same principle applies to armor and reinforcement of the structure.

 

[far-trader]

Hehe, preaching to the converted here Tekrat04

I can live with handwaving the first and last away but I am solidly with you on needing more volume for internally carried vehicles and craft. Not only unrealistic to think that your 30T cylindrical Boat hull will fit in any old 30T hanger or cargo deck area but most of the time I see player's thinking they can throw 30T of cargo in there when the Boat is away. Sure, maybe if it's liquid and you can pump it in (generally I'll allow half useful volume)

And then there is the option to carry your craft in an external clamp. THAT requires extra tonnage? Give me a break, if anything it should be the other way around (and I've handwaved it so in a couple past rules sets).

Oh well, I'll learn to live with it again and handwave as needed. Some versions have made attempts at these issues but T20 is back to the roots (CT) for better (I think) or worse.

So, rant paused, just know you're not alone and welcome aboard

 

[TheDS]

The thing is, everything on the ship takes up volume, including the bulkheads, the hull, and anything hanging onto it. To say that grapples take up no space is to misunderstand what's going on.

When we designate a ship as having X number of Dtons of space, THAT'S IT. That's not the internal volume, that's not the cargo space, that's the WHOLE SHIP and everything on it.

External Grapples take up space according to how big the ship is they are intending to grapple to. While I will agree that the space required may be a bit much, the grapple's volume comes out of the ship, just like those sensor dishes. Your 1000 Dton ship's hull may actually be a little smaller than 1000 Dtons if you scrape the sensors and grapples off of it, but those things are taken into account when you jump, for instance.

A 990 Dton ship with 10 Dtons of crap scattered about its hull uses fuel for jump based on its size of 1000 Dtons, not 990. Get rid of all the extraneous stuff, and sure, it's a 990 Dton craft, but you'll be flying blind.

If you guys use FFS to make your ships, you will see that the hull plating and the frame take up space in the ship. Of course, fuel is still the "wonder stuff" it's always been. Most people assume that the amount of material required to make a fuel tank is negligible. It's not. I don't know what you need to store and seperate liquid hydrogen into tanks, but if you will accept a made up number until some one gets a real one for us, how about that it takes up 10% of the tankage space?

We can handwave just a tad and say that the fuel requirements for something are the same, such that fuel that fits into 1 Dton of tank is used whenever you are asked for 1 Dton of fuel. if you think about it a bit, you'll see that no real changes are needed. You MIGHT feel the need to have mass for the fuel tanks, and I would give them a density of 1. This means that while you're calling 10% of your tankage as a tank, that 10% has a mass of 1 tonne per kl.

So of a 10 Dton tank, 14kl (10%) is actual tank material, and it weighs 14 tonnes.

Most of the books go and tell you that a hanger takes up 2-4 times the volume of the housed craft. If you can pull out a 30 Dton ship from its hanger, you've freed up 60-120 Dtons of space, depending on how spacious the hanger. You CAN fit considerably more boxed cargo into that space.

For a real world example, the ship I was on has hanger space for about 30 helicopters. Usually, they are kept on the flight deck, unless they need to be worked on, but they can be stuffed in (an operation code-named "Stuff-Ex"). When the helos are in the hanger, there's very little room for a person to walk around. The hanger is about 20 feet tall (2 stories). A lot of that space is wasted.

Occasionally, there is need to stuff cargo in the hanger, and when doing that, it is possible to stack it all the way to the ceiling, or nearly so. My estimation is that a helo requires about 3 times its true volume as a minimum, but due to the extra height (in case of getting something really tall, like the Ospreys that they might get) they are getting even more. This is wasted space that can be reclaimed if we stack cargo instead of helo.

 

[GypsyComet]

The "major flaws" noted are only flaws if taken in a real-world engineering context. They exist in this system for a couple reasons:

simplicity of the model - this is a system for designing ships to use in an RPG, not for producing blueprints to send to Boeing or NASA.

Compatibility - T20's design system is strongly based on High Guard, a ship design system for an earlier edition of Traveller, in order to make bringing forward older designs possible without great amounts of concept modification and traumatic removal of hair...

Feel free to charge 20% (or more) volume for fuel carried, and feel free to use the hangar rules from (for example) TNE (wherein the 0% volume surcharge is for special "zero-maintenance" situations and most subcraft are in bays either twice or four times their own volume). The system is open enough to do these things for you. Just make sure you note that these house rules are in force for any designs you decide to share with the rest of the Traveller-playing world.

 

[snrdg082102]

Hello all,

Before beginning I will apologize for my rant, since my comments will probably irritate some or all readers. However, this is not my intent but to make one realize that Traveller in all its forms is:

(1) A game.

(2) That game is based on the imagination of those who designed and those who play the game of a possible far future. That future includes technology that might make million displacement ton starships possible, even though the specific engineering principles do not exist in todays real world knowledge.

(3) Even though there is a lot of science based material used to create the framework, some of that material was simplified for game purposes. Several of the basic ideas of the original Traveller rules have been surpassed by real world advances, notably, the size and capacity of computers.

I do not consider the lack of specific requirements for a detailed list of waste space to be any sort of flaw in the design sequence. Now on to my rant:

Have you stopped to consider that this is not a major flaw but is actually a design simplification? Further, in the comments I did not see mentioned the lack of requiring specifications for corridor/hallway/passageway volume to be taken into consideration as wasted space.

IIRC, the design rules, in at least one of Traveller's, probably classic LBBs, various design systems, either state clearly or by implication that all components are modules that already have the waste space subsumed into the design. The rules also indicate that there is a slop factor of 20% to displacement tonnage. In the descriptions of deck construction in more than one Traveller design rules set there is written that a standard component is approximately 3m high, in which some of the space under the deck (floor) and/or in the overhead (ceiling) is dedicated to mundane things like ventilation, plumbing, wiring, and other items or reasons for empty/wasted space.

I can think of only one design sequence that includes consideration for wasted space, which is GURPS Vehicles. The three design sequences I can remember using, besides those related to Traveller, are Star Trek, BattleTech, and Space Master none that I recall take into consideration wasted space.

One final comment, if the design sequence, or any portion of Traveller's supporting documnentation, does not fit the GM's and players TU then modify them to suit that TU. The idea of using some, all, or none of the official Traveller material is stressed as one of the core concepts by the games original designers and has been restated in various gaming magazines, game products, and discussion boards for the last 25+ years.

Originally posted by Tekrat04:
There are major flaws in the internal volume needed to house certain components.

Fuel System: the ideal that the volume that a fuel tank takes up is the same as the quantity of fuel it contains is flawed. The fuel system needs take up a lot more space then the fuel it contains. Just the wall of the full tank adds to the overall volume. To this we need to add the pluming and pumps to take on the fuel and distribute it to where it will get used. When dealing with cryogenic fuels such as hydrogen it becomes even more so due to the need to insulate and refrigerate the fuel. Does a one liter thermos take up 1 liter of space? No, it takes more a lot more space. So why does 1 dton of hydrogen takes up 1 dton of space?

Internal Hanger: Again the volume needed to house any type of vehicle inside of another is a lot more then the volume of the vehicle to stored. Just the wall of the hanger will add to the volume, not mention the space needed to get in and out of the vehicle. No vehicle is a perfect box, that means there will always be wasted space around it when it get stored.

Hull: The walls of the ships also take up space on the inside of the hull. The same principle applies to armor and reinforcement of the structure.

 

[themink]

I have a whole set of handwaving for when players are allowed near the design section. Whilst it is just a ref section, I use the entire thing as a guideline and fudge with gay abandon.

With the specifics of hangers/housings etc

I have no problem with the hanger for a single craft being very close to the external size of the craft (ie a fighter with an external volume of 10dT needs a hanger of just over 10dt). If on the other hand you want a hanger which you can park a variety of different crafts (ie the ship can take in one of six 10dT fighters) then you need a much bigger hanger. So whilst the ship has one custom fitted hanger, everything has close tolerances, but one you plan for upgrades or flexibility, everything smudges out bigger.

Example - I have a 200 dT merchant in my ATU campeign which was origionally a wing carrier for six 10dT fighters - Each of the fighter bays was multi-role and I gave them 15dT on the plans. Now they have been converted to cargo and five of them carry 12 dT each (the remaining one has a 10dT fighter in it). So it's a jump 1, man 1 merchant with less cargo/pax than a a2!! however the campeign is close to TNE so it is hard to find "perfect" vessels.