'Displacement ton' here is a ton of liquid hydrogen, not a ton of water. Why? Because Ithillid likes to use Traveler for everything. And I do quite seriously mean everything, there's a Traveler sheet for the Apollo out there. Probably one for the Barghest and Kelpie too.
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Okay. I can work with that. Thank you for telling me that. The analysis below is based on the outmoded premise that "displacement ton" means the same thing for spacecraft that it does for seagoing ships, the only other context in which I have heard it used and the context in which the concept of "displacing a ton of water" is most directly meaningful.
Since even in
Traveler, I doubt that ships ever float on liquid hydrogen seas.
A Fletcher class displaces about an olympic swimming pool at full load. 500 displacement tons is a bit under three times that size. 14.3 cubic meters = 1 displacement ton.
CAVEAT: Everything noted below is based on the assumption that 'displacement ton' means to the reader what it means to, for example, the real-life world's navies and merchant marines.
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[blinks]
en.wikipedia.org
en.wikipedia.org
The
Fletcher-class destroyers are listed as having a displacement of 2050 tons. They are 115 meters long, 12 meters high, and... Well,
keel to waterline they are five meters high, but
from the waterline to the top of the superstructure is in the vicinity of another fifty feet or fifteen meters.
If you wanted to fit a
Fletcher in a rectangular box, the box would need to be about 115*12*20 = 27600 cubic meters. This would not really allow room to get around
past the hull at the sides and bottom, so you would actually need a larger box if you wanted to be able to maneuver people and machinery around it.
By contrast, the
Santa Maria is estimated as having a displacement of 150 tons or so. This is broadly in keeping with the
Fletchers being roughly five times as long, twice as wide, and having twice the draft of the
Santa Maria... modulo details of the hullform. The
Santa Maria if you unstepped the masts, would assuredly fit inside an 8000 cubic meter box, though you would definitely need to take it out of the box to put the masts in.
EDIT:
Of course, if you swim seas of liquid hydrogen, your idea of a "displacement ton" does not align with that of the world's seafaring navies. At which point yes, a
Fletcher-class destroyer's displacement drops to something more like around 140-150 tons, and the
Santa Maria's to something more like ten tons.
Liquid hydrogen is very fluffy in addition to being deadly cold.