# Ship Mass Recalculated

### General Discussion

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All calculated according to this post.

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SIZE ............. LENGTH ............... WEIGHT
Tiny .............. 20-60 ft. .............. 2.5-65 tons
Small ............ 60-120 ft. ............ 65-530 tons
Medium ........ 120-300 ft. .......... 530-8,300 tons
Large ........... 300-800 ft. .......... 8,300-160,000 tons
Huge ............ 800-2,000 ft. ....... 160,000-2,500,000 tons
Gargantuan . 2,000-15,000 ft. ... 2,500,000-1,000,000,000 tons
Colossal ....... Over 15,000 ft. .... Over 1,000,000,000 tons

Weight is in US tons to two significant digits.

Thank you! I saw the mass table in the book and just about died. We used to make fun of David Weber for starships that had the density of cigar smoke - the idea that a three mile long dreadnought could weigh in at a mere 2,000 tons (for scale, a modern German Braunschweig-class corvette at 293 feet has a full-load displacement around 2,400 tons) was just hilarious.

Pathfinder Starfinder Roleplaying Game Subscriber

Just as another point of reference, the mass of the earth is about 6.5 x 10^21 tons.

Another thing worth pointing out:
The Absalom Station is 5 miles in diameter. It has a population of 2.13 million (which I think is still ridiculously low a population for the significance it has in-lore as a trade hub).
Colossal ships have a minimum length of 3 miles. They have crew sizes ranging from 125 to 500. The one example in the book has a crew of 300.

Noodlemancer wrote:

Another thing worth pointing out:

The Absalom Station is 5 miles in diameter. It has a population of 2.13 million (which I think is still ridiculously low a population for the significance it has in-lore as a trade hub).
Colossal ships have a minimum length of 3 miles. They have crew sizes ranging from 125 to 500. The one example in the book has a crew of 300.

That reminds me of the Deep Space Nine Technical Manual claiming that DS9 was 1400 meters across (which is impossible given the scaling of a Galaxy-class starship) and even though it's MUCH smaller than Starbase 74 (which is actually about the size that Absalom Station is claimed to be in the book), it's also claimed to be "an extremely large freestanding space station regardless of origin."

Sci Fi Writers Have No Sense Of Scale.

Additional note: As mentioned in the previous post, the ranges above are for ships assumed to be 5:1:1 bricks. While this is probably appropriate for Pact World and Veskarium ships, ships with a lot of open volume such as Eoxian ship or narrow, pointed ships like Kasatha ships might be around half the weight listed above.

Wouldn't the mass be roughly a function of a surface area rather than volume, since most of the inside is air (perhaps a bit faster growing accounting for thicker hulls and more internal frames on larger ships)?

E.g. here is an ISS module consisting of two cylinders, a bigger one and a smaller one. They even have identical diameter - but the longer one is only 1.9x heavier, despite being 2.67x longer. So the smaller one is more dense - 131 kg/m3 versus 94 kg/m3 for the larger one. The surface area ratio is 2.1, still higher than the mass ratio - either the smaller module has a thicker hull for some reason, or heavier equipment inside, but presumably on larger scales this would stop mattering as much.

The above math more closely matches up with real world naval vessels. The ISS modules are just hollow cans and probably not too pertinent to interstellar ships packed full of machinery.

Pathfinder Starfinder Roleplaying Game Subscriber

It is doubtful that ISS has even one hull point.

The type of armor that would be needed to give hull points is going to greatly increase the density of the whole. I think it is a good idea using modern naval vessels as a basis.

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Pathfinder Rulebook Subscriber

What, you haven't read up on the latest Janes Guide to Pact World Starships? Govin the Goblin figured out shortly after Golarian vanished that the only reliable material to make starships out of was helium filled marshmallows. You should really do research before besmirching the math on the ships!