Deck Plans

vladthemad

Mongoose
Alright, simple question...how does everyone convert tonnage to deck plans? If I have a ship that's 100 tons for example, how many 1.5m squares should it be? Also, as far as equipment is concerned, is it the same ratio? Comparing stats vs. deck plans, some of it looks arbitrary when it comes to the individual items installed into a ship to the deck plans.
 
1 Dton = 13.5 cubic meters.

Assume a 3 meter deck => 1Dton is about 4.5 square meters which is 2 squares of 1.5 meters by 1.5 meters (standard deck plan square).

So 2 squares per Dton.
 
13.5 or 14 that is an OLD debate that we REALLY don't want to have here. Lets call it rounding error.

Still, the 2 squares per ton has been the standard since the 1.5x1.5 meter square became the standard way back in the day. I just wanted to explain where it came from for clarity.
 
Same ratio.

Though remember staterooms are usually drawn out as 3 tons (6 squares) with 1 ton (2 squares) left over for other stuff (such as space to move around in, life support and so on). For barracks space this would be 1.5 tons (3 squares), with .5 tons (1 square) for other stuff.

Then there's an occasional ship with a different deck height, which should be specified. (Usually used for fuel).
 
Rikki Tikki Traveller said:
13.5 or 14 that is an OLD debate that we REALLY don't want to have here. Lets call it rounding error.

It is just what the main rules book states, 14m cubed, to be clear. If someone is ESL, English can be maddeningly vague, 30+ years and I struggle with it, still read sentences that seem like nonsense.
 
vladthemad said:
Alright, simple question...how does everyone convert tonnage to deck plans? If I have a ship that's 100 tons for example, how many 1.5m squares should it be? Also, as far as equipment is concerned, is it the same ratio? Comparing stats vs. deck plans, some of it looks arbitrary when it comes to the individual items installed into a ship to the deck plans.
Two squares = 1 d-Ton (1000 kg of liquid hydrogen)
 
Deck plans usually never add up exactly to displacement. The rule of thumb has been if you are within 20% you are ok. Some like to tighten up that number a bit, but for the most part I never care if the plans show enough fuel squares because that stuff could be stored in lots of places. And unless you do hyper-detailed plans, the 'tween decks stuff is never shown either.
 
phavoc said:
Deck plans usually never add up exactly to displacement.

Some stuff such as armour, reinforced hull, fire control and so on don't show up on deck plans so this can cause the deck plans to be smaller then the displacement calls for.
 
What would the displacement tonnage of this ship be?
Ch10p218.gif

Deck layout of R. H. Goddard. Rotation gives Earth-normal gravity in lowest levels.
Hull volume of the sphere section only is 113,000 cubic meters. 8370 displacement tons, it has 9 decks plus the core. Description states it has a dry mass of 3,000 tons, of which about two-thirds would be their mass driver engines. I'm thinking of doing this ship for orbital, substituting a nuclear thermal rocket for the mass driver, but the sphere would be unchanged. That means about 2000 d-tons would be liquid hydrogen fuel tanks and power plant + NTR Drive.
 
Tom Kalbfus said:
What would the displacement tonnage of this ship be?
Ch10p218.gif

Hull volume of the sphere section only is 113,000 cubic meters. 8370 displacement tons,
You answered your own question.

Anyway, other weight scales mean nothing in Traveller ship design. The unit of 1000 kg of liquid hydrogen is the measuring/building block for Traveller ships.
 
phavoc said:
Deck plans usually never add up exactly to displacement. The rule of thumb has been if you are within 20% you are ok. Some like to tighten up that number a bit, but for the most part I never care if the plans show enough fuel squares because that stuff could be stored in lots of places. And unless you do hyper-detailed plans, the 'tween decks stuff is never shown either.


This is the way I do it also, it seems to work out fine, esp if it isn't a cube.
 
ShawnDriscoll said:
Tom Kalbfus said:
What would the displacement tonnage of this ship be?
Ch10p218.gif

Hull volume of the sphere section only is 113,000 cubic meters. 8370 displacement tons,
You answered your own question.

Anyway, other weight scales mean nothing in Traveller ship design. The unit of 1000 kg of liquid hydrogen is the measuring/building block for Traveller ships.
It approximates the ship's mass for game purposes in determining what a maneuver drive or any other drive will do. the real physics of acceleration is thrust divided by mass.

Here is an example of another starship.
Ch12p271.gif

Interstellar vessel of Island One size, ion-driven. Central arc substitutes for sunlight. Reaction of matter and antimatter gives power (twenty-first and -second centuries).

Island One to refresh your memory is this when not in starship form:
Ch09p166.gif

Cutaway view of Island One. Axial cylinder is air passage and corridor to docks and industries in zero gravity.
If we calculated its displacement tonnage, we'd get a figure way over a million, but most of that is just air, its density is lower than the standard multi-decked Traveller Starship. It is about 500 meters in diameter I believe. This picture gives a scale of the thing:
Ch99p302.gif

Detail of Bernal sphere with size comparisons.

That would be a huge starship, most tables I've seen top out at around 1,000,000 dtons, but I believe the internal volume of this thing is greater than that. 65,400,000 cubic meters or 4,844,444 dtons, it is just a hollow sphere with air in it, it mass would be nowhere near as much as a Traveller Starship of that size, as it assumes a deck every 3 meters of height.
 
Spheres really came into their own when thickness of hull had a direct effect on armour factor, so either you had an unlooked for protection bonus, or you suddenly had more deck space.

In theory, armour factor zero should require a proportion of the hull volume.
 
ShawnDriscoll said:
Traveller is not a simulator. Never was.
Not that I want to start an argument, or even necessisarily disagree .... but what does that actually mean?
... And are you sure that it applies to CT Striker or TNE FF&S?
(which both seemed like they were trying to do/be something other than what the Classic Traveller and Mongoose Traveller Core books strived to be).
 
Just to weigh in on this...

We are currently working on a kind of checklist system that walks even complete deck plan newbies on the processes to go through when creating deck plans from scratch. Included will be a line that says the number of squares you use in a ship can vary by 10% either way to take into account variations in manufacture, living areas and 'gubbins.'
 
Matt,

Will the checklist include guidance or recommendations on things like airlocks sizing, how big you should make a corridor, etc?
 
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