Is it just me? Ship Deck Plans

[Madmax]

I am disheartened.
Every Deck Plan I have looked at so far (and I am sure there are many I have not looked at), even in official Traveller products, is in gross violation of the Rules as Written.
Just a few minutes ago I was looking at the deck plans provided by someone (not sure who) for the Marava Class 200 ton Far Trader. If one actually counts the squares (and divides by two) it turns out to be a 256 ton ship.
Mongoose does not seem to be as bad. The Free Trader in the Core Rulebook, if one counts the squares (and divides by two) it turns out to be a 230 ton ship. It is rather difficult to count the squares due to large areas being colored in, so that tonnage is probably not accurate, but none the less is very likely to be larger than it should be.
I don't think I've ever seen a Deck Plan that comes anywhere near the 10% error allowed by the CT rules, and I've been playing Traveller since 1980. Don't get me started on the idiocy of the 100 ton Scout ship deck plans.
Mongoose rules don't even mention an error margin at all.
Why even have rules if every one (including FFE) just ignores them?
Well, does anyone agree, or is there something about Deck Plans that I have completely misunderstood for all these decades?

 

[Condottiere]

The assumption is that each square represents a volume of one and half metres by one and a half metres by threeish metres, basically half a tonne.

The ceiling might not be that high.

 

[Grav_Moped]

+/-10-20%

Here's a couple that are close to correct, give or take borrowing from the "bridge" space allocation for hallways and such, and maybe fudging the landing gear out of fuel tankage...
Type S as a Tailsitter Prolate Spheroid (COTI Thread)
Hull is 10% oversized.

Shugushaag (600Td J5 Freighter, LBB2 2nd Ed.) (COTI Thread)
Deck plans start here.
Hull is 4% undersized.

(Yes, they're my designs.)

There are several threads here on making "corrected" versions of canon deckplans. I think the main issue on the classic Type S plans is that the designers get clever by clipping the top and bottom outside corners of the forward staterooms to fit the hull shape, and not bothering to mention that they did so. Well, that and getting the math wrong on the overall dimensions, but that's a separate issue.

 

[AnotherDilbert]

I am disheartened.
Every Deck Plan I have looked at so far (and I am sure there are many I have not looked at), even in official Traveller products, is in gross violation of the Rules as Written.

Agreed, many published deck plans are more freeform than engineering drawings (I'm trying to be polite), but that has never prevented me from using them.

If we expected geometric perfection from every ship illustration or deck plan, there would not be many of those published. Just be happy there are so many deck plans produced for Traveller.

 

[infojunky]

Twenty percent is the figure given in Traders and Gun boats discussion on the topic.

Access space is part of that above 20%.

So with a nebulous number counting turns into a form of OCD, I know because I've been there.

Note Seeker called the Empress Markers 400 dTons.

 

[atpollard]

The actual deck plan grid itself is part of the problem. 1.5 meters (1 square) is about 5 feet, but how many 5 foot corridors do you see in the real world? The oversized grid (to accommodate oversized miniatures) tends to drive up the size of the plans.

 

[infojunky]

The actual deck plan grid itself is part of the problem. 1.5 meters (1 square) is about 5 feet, but how many 5 foot corridors do you see in the real world? The oversized grid (to accommodate oversized miniatures) tends to drive up the size of the plans.

Yep, when I am drawing plans I don't count the walls or corridors. Note I tend to draw walls through the center of a square to give extra room for miniatures.

 

[GypsyComet]

how many 5 foot corridors do you see in the real world?

The central access corridors of the ISS certainly look close. The baseline TL of the Imperium is 12 to 13, at which point the vacc suits are still pretty bulky. Two suited crew going opposite directions in a corridor are going to need the room.

Two Security thugs holding our Hero by the arms and shoulders on the way to the brig are going to need the room.

Mongoose does not seem to be as bad. The Free Trader in the Core Rulebook...

...were originally published at one deck square per ton, or only half-sized. This is the reason there's a corrected PDF of the sample ship section of the 1st Edition core book that is separate from the purchase version of that book. That lesson stuck, however.

Some of the Mongoose ships were also clearly designed to make for interesting gunfights, making very little sense otherwise. There's one "patrol" ship with a boarding ram that, for no discernible reason except Space Opera, put the brig three decks above the ram with only a ladder between them.

Deckplans are an ongoing case of "close enough for a game".

 

[Timerover51]

Looking at the deck plans for the Empress Marava in Supplement 7: Traders and Gunboats gives some interesting results. I remember doing this for my own purposes quite a while ago, but I still find in interesting. The text describing the Far Trader lists the cargo capacity as 61 dTons. The description with the deck plans gives a cargo capacity of 46 dTons. Then actually counting the 1.5 meters squares in the cargo hold gives 88 dTons. As the fuel tank is above the cargo hold, and needs 60 dTons of volume for the fuel, that sort of dictates the size of the cargo hold.

Personally, I simply used the deckplans as given, as I am not sure if I wanted to go through the effort of producing my own, However, I will need to do that for my own sector. I lean more to ships looking like the Subsidized Merchant in Traders and Gunboats than anything else. I like straight-through loading.

 

[Timerover51]

The actual deck plan grid itself is part of the problem. 1.5 meters (1 square) is about 5 feet, but how many 5 foot corridors do you see in the real world? The oversized grid (to accommodate oversized miniatures) tends to drive up the size of the plans.

Cruise ship corridors run about that so that the ship's stewards can get two carts past each other. In schools and office buildings, the corridors are wider than ten feet. Five feet is actually pretty narrow for a corridor.

 

[Grav_Moped]

The assumption is that each square represents a volume of one and half metres by one and a half metres by threeish metres, basically half a tonne.

The ceiling might not be that high.

I did that in a couple of places in the deckplans I linked. Generally, not in a way that made a lot of difference though.

Another place where errors creep in are wings that contain fuel tanks. How thick are they anyhow?

 

[kilemall]

If it bothers you THAT much, go 1x1 square meter, figure the same 3 meter vertical ceiling/floorspace utilities/crawlspace. That nets you 4.5 tiles per dton, plenty for all the extras plus hallways and facilities you want.


Or 4 meter height per level, with .5 meter utility clearance on either end of the scale, giving you 3 tiles and change. Plenty of room for those undocumented cargo spaces and adventuring crawls through the access ducts.

 

[Grav_Moped]

Cruise ship corridors run about that so that the ship's stewards can get two carts past each other. In schools and office buildings, the corridors are wider than ten feet. Five feet is actually pretty narrow for a corridor.

Yes and no. Residential building codes generally have a 3 foot (900cm) minimum. The average width considered adequate in space, accommodation, accessibility is a range between 42 and 48 inches (106.88-121.92 cm) from a quick look at Google.

However, this assumes the facility occupants are wearing ordinary clothing, not vacc suits...


It also assumes they're not hopping around with their feet affixed to a large elliptical plate to keep them from tipping over.

 

[atpollard]

The central access corridors of the ISS certainly look close. The baseline TL of the Imperium is 12 to 13, at which point the vacc suits are still pretty bulky. Two suited crew going opposite directions in a corridor are going to need the room.

Two Security thugs holding our Hero by the arms and shoulders on the way to the brig are going to need the room.

... and the two man crew of a 100 dTon Scout Ship?
... and the hall that connects 4 "bedrooms" to the "common area"

(PS: The "central access corridor" on the ISS is the CREW COMMONS, so that proves my point.)

 

[atpollard]

Cruise ship corridors run about that so that the ship's stewards can get two carts past each other. In schools and office buildings, the corridors are wider than ten feet. Five feet is actually pretty narrow for a corridor.

Comparing the displacement and occupant load of a typical "Adventure Class Ship" with a typical "Cruise Ship" or "School" makes it an Apples to Oranges comparison. Yes, a ship with 2000 people aboard will need 5' and 10' corridors. A ship with 6-10 people aboard will probably not need an 8' corridor for double rows of emergency egress.

 

[AnotherDilbert]

How much space does a firefighter in a vacc suit (or battle dress) need? Related: How wide are corridors in current warships?


A Scout should be dimensioned for eight people, the carrying capacity of four staterooms. Eight people rushing around at breakfast, or action stations, along the central corridor can be crowded... The crew compartment of a Scout is the size of a small apartment (theoretically 16 Dt × 14 m³ / 3 m ≈ ~75 m² ≈ 800 sq.ft.), quite crowded for 4-8 unrelated adults.


Swedish building regulations require at least 1.3 m width inside an apartment, or at least 1.5 m in common areas. I think it is related to the room a wheelchair need to turn around.

 

[MThompson016]

Corridors on a submarine can be pretty narrow. I'd say we had about 3 feet (91 cm) between the switchboard and non-water tight bulkhead next to MCC on a 726, but only about two feet and a half on the deck (76 cm), so one way traffic in firefighting gear, suit and SCBA, had plenty of room, but not much space for two way traffic. Major passage ways were about 2 1/2 to 3 feet wide, though.

Between platforms (no decks, as they were not the full length of the ship and not directly attached to the hull), the concern was some of the scuttles. What gave space for a front worn oxygen breathing apparatus, or firefighting rebreather, did not offer space for a back worn SCBA.

Height between platforms was sufficient for me standing 6'1" in shoes, but there was about 8" of lights, hydraulic mains, and ventilation between them.

Mind you, it's been about a decade since I was on a boat, much less underway, so this is approximate.

 

[Condottiere]

Problem is that volume dictates performance, so everyone is tempted to cut corners in terms of actual space onboard.

 

[coliver988]

How much space does a firefighter in a vacc suit (or battle dress) need? Related: How wide are corridors in current warships?

A Scout should be dimensioned for eight people, the carrying capacity of four staterooms. Eight people rushing around at breakfast, or action stations, along the central corridor can be crowded... The crew compartment of a Scout is the size of a small apartment (theoretically 16 Dt × 14 m³ / 3 m ≈ ~75 m² ≈ 800 sq.ft.), quite crowded for 4-8 unrelated adults.

Swedish building regulations require at least 1.3 m width inside an apartment, or at least 1.5 m in common areas. I think it is related to the room a wheelchair need to turn around.

Going with apples and oranges when comparing a paramilitary style ship versus a home or a passenger liner (and we have ADA rules here governing hall and door widths as well)

A passenger liner probably should have those nice, wide corridors, at least in the public areas. A Scout ship (or any military ship), you want to maximize equipment and performance over comfort in general.

In Traveller volume is money basically for ships. Passenger ships, the volume pays for itself through having better ratings and drawing more high-paying passengers (though not technically in the RAW, until you get to rule sets that have ergonomics/comfort related rules), but conceptually it does at least.

 

[AnotherDilbert]

In Traveller volume is money basically for ships.

Agreed, completely.

A Scout is certainly not a passenger liner, but neither is it a military ship packed with equipment and personnel. It is, among other things, a long-ranged exploration ship, so some basic level of comfort is probably needed if you live aboard for extended periods without shore leave.


Obviously 1.5 m wide corridors is just a convenience adjusted to the 1.5 m square grid. If you want more granular control, use a 1.0 m square or even 0.5 m square. I've never seen 1.5 m wide corridors as especially excessive, so I'm not bothered by it.