On 23Sep2021 1838, Cian Witherspoon - amber.narilka at gmail.com (via
tml list) wrote:
> On Wed, Sep 22, 2021, 21:56 Evyn MacDude - evyn.macdude at gmail.com (via
> tml list) <xxxxxx@simplelists.com> wrote:
>
>> Note CT77 is pretty clear on the volume but they use the term mass
>> displacement in tons. But they don't describe what that volume is.
>>
> So Mass Displacment is how ships measure their mass - and its complicated
> since you need to know the volume of the submerged part and the density of
> the displaced liquid to even start doing the math. In high school science
> (secondary school in the UK and related school systems I guess? Late
> teens), displacement is used just to find volume.
> My personal opinion/guess is that MWM and the other developers forward
> ported the ship displacement method into the games future instead of just
> measuring in mass, and people misunderstood that; not surprising, we're
> talking about wargame developers writing for the early rpg audience at a
> time when non-wargamers (a lot of whom were teens going through high school
> science classes) were really getting into the scene. GDW wrote for their
> typical war gaming audience and got picked up by a different crowd, this
> sort of misunderstood crosstalk was inevitable.
> For the best source I've found on measuring ship displacement:
> https://www.gjenvick.com/OceanTravel/ShipTonnage/DisplacementTonnage.html
Displacement was used as a way of measuring a ship's mass because it's
relatively easy. Put in dry-dock. Fill dry dock, measuring how much
water that takes. Compare with the normal requirement, the difference
being the submerged volume of the ship, which given that you know the
density of water, gives you the ship's mass.

As far as I can tell, you're saying that either spaceshipwrights in
Traveller measure a ship's mass by dropping it into liquid hydrogen
lakes, or that Marc Miller, & co. used a technical term without knowing
what it meant. Odd for wargamers from a company that tended to do its
research. Very odd considering how quickly they made it official that
they were talking about the volume of a ton of liquid hydrogen.

--
Rupert Boleyn <xxxxxx@gmail.com>