## HG 2e Medical Bay and Central Supply Catalog (CSC) Autodoc

Discuss the Traveller RPG and its many settings
AnotherDilbert
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### Re: HG 2e Medical Bay and Central Supply Catalog (CSC) Autodoc

snrdg121408 wrote: Not according to the definition

Volume displacement is the displacement of a fluid expressed in terms of volume as distinguished from displacement expressed in terms of mass. https://www.merriam-webster.com/diction ... splacement
Now I don't understand what you mean. This is exactly what I wrote?
AnotherDilbert wrote: Mass displacement expresses that in mass: A ship displaces 1 tonne of liquid hydrogen (hence a volume of ~14 m³).

Volume displacement expresses that in volume: A ship displaces 14 m³ (hence a mass of 1 tonne of liquid hydrogen).

snrdg121408 wrote: The volume of about 14 m^3 is determined by using a grid of 1.5 m squares of which two squares. One square is 1.5 x 1.5 by approximately 3 m. Two squares is 1.5 x 3 x approximately 3 m = approximately 13.5 or about 14 m^3.

I lay out 100 squares which equates to about 1,400 m^3 of displaced L-Hyd which is equal to 100 ton volume displacement of L-Hyd. That does say that 1 ton of L-Hyd = 1 tonne = 1,000 kg.
Still don't understand what you mean.

Yes, trivially 1 tonne of liquid hydrogen has a mass of 1 tonne.

Yes, trivially ~14 m³ of ship will displace 1 tonne of hydrogen.

Neither statement says anything about the mass of the ship. Ships are not made of liquid hydrogen, nor are they generally immersed in liquid hydrogen.

If LBB2'77 intended ships to be designed by mass, it would have been much easier to leave out the displacement nomenclature and simply talk about mass in tonnes?
snrdg121408
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### Re: HG 2e Medical Bay and Central Supply Catalog (CSC) Autodoc

Hello AnotherDilbert,

The deck plan scale of 1.5 m x 3 m x 3 m is the amount of internal hull space that is occupied by 13. 5 or about 14 m^3.

A hull with a the dimensions of 9 meters from the hull's dorsal to ventral surface, is 12 meters wide and a length of 140 meters encloses a space or volume of 15,120 m^3. Using the deck plan scale of about 14 m^3 the internal volume is about 1,080 tons.

A hull with a mass displacement of 400 tonnes with the dimensions of 9 meters from the hull's dorsal to ventral surface, is 12 meters wide and a length of 140 meters encloses a space or volume of 15,120 m^3. Using the deck plan scale of about 14 m^3 the internal volume is about 1,080 tons.

A spherical hull with an internal volume displacement of 400 tons is capable of holding about 400 x about 14 = 5,600 m^3 of L-Hyd. If my math is correct the hull has a diameter of a rounding to two decimal places about 22.04 meters. A 22.04 m spherical hull has a mass displacement of 200,000 kg or 200 tonnes has an internal volume of about 5,605.75 m^3 or about 400.41 tons of L-Hyd.
snrdg121408 (aka Tom R)
AnotherDilbert
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### Re: HG 2e Medical Bay and Central Supply Catalog (CSC) Autodoc

snrdg121408 wrote: The deck plan scale of 1.5 m x 3 m x 3 m is the amount of internal hull space that is occupied by 13. 5 or about 14 m^3.
Yes, one Dton is ~14 m³.

snrdg121408 wrote: A hull with a the dimensions of 9 meters from the hull's dorsal to ventral surface, is 12 meters wide and a length of 140 meters encloses a space or volume of 15,120 m^3. Using the deck plan scale of about 14 m^3 the internal volume is about 1,080 tons.
Yes, one Dton is ~14 m³.

snrdg121408 wrote: A hull with a mass displacement of 400 tonnes with the dimensions of 9 meters from the hull's dorsal to ventral surface, is 12 meters wide and a length of 140 meters encloses a space or volume of 15,120 m^3. Using the deck plan scale of about 14 m^3 the internal volume is about 1,080 tons.
No, that is not a 400 Dton ship.
Yes, one Dton is ~14 m³.

snrdg121408 wrote: A spherical hull with an internal volume displacement of 400 tons is capable of holding about 400 x about 14 = 5,600 m^3 of L-Hyd. If my math is correct the hull has a diameter of a rounding to two decimal places about 22.04 meters. A 22.04 m spherical hull has a mass displacement of 200,000 kg or 200 tonnes has an internal volume of about 5,605.75 m^3 or about 400.41 tons of L-Hyd.
Yes, one Dton is ~14 m³.
No, a 400 Dton ship does not displace 200 Dton.

I still do not get your point?
snrdg121408
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### Re: HG 2e Medical Bay and Central Supply Catalog (CSC) Autodoc

Hello again AnotherDilbert,

The ispace or volume enclosed by spherical hull with the diameter of 22 meters is approximately 5,575.28 m^3. The space or volume enclosed is where the deck plans use a scale of 1.5 meter squares are used to place the components. Per the deck plan instructions space or volume enclosed 2 squares equal about 14 m^3 which is about 1 ton of L-Hyd. The ispace or volume enclosed of about 5,575.28 m^3 can hold about 398.23 tons of L-Hyd.

The density of L-Hyd is 70.8 kg/m^3 which I think means that the mass is 5,75.28 / 70.8 kg/m^3 = approximately 78.75 kg of mass. The spherical hull enclosing a ispace or volume enclosed of about 5,575.28 m^3 can hold about 398.23 tons of L-Hyd. This amount of L-Hyd has a mass displacement of about 78.75 kg or about 0.07875 tonnes.
snrdg121408 (aka Tom R)
AnotherDilbert
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### Re: HG 2e Medical Bay and Central Supply Catalog (CSC) Autodoc

snrdg121408 wrote: The ispace or volume enclosed by spherical hull with the diameter of 22 meters is approximately 5,575.28 m^3.
Yes, one Dton is 14 m³ and 5575 m³ is about 400 Dt.

snrdg121408 wrote: The density of L-Hyd is 70.8 kg/m^3 which I think means that the mass is 5,75.28 / 70.8 kg/m^3 = approximately 78.75 kg of mass. The spherical hull enclosing a ispace or volume enclosed of about 5,575.28 m^3 can hold about 398.23 tons of L-Hyd. This amount of L-Hyd has a mass displacement of about 78.75 kg or about 0.07875 tonnes.
No, not 78.75 kg.

5575 m³ × 70.8 kg/m³ = 394710 kg ≈ 400 tonnes as expected. Note that the units multiply just as the numbers do.

A 400 Dton ship displaces 400 tonnes of liquid hydrogen whether you express it as mass displacement (400 tonnes) or volume displacement (5600 m³), since 400 tonnes × 14 m³/tonne = 5600 m³.

The density of 70.8 kg/m³ is just the inverse of 14 m³/tonne: 1 / ( 14 m³/tonne ) ≈ 0.071 tonne/m³ = 71 kg/m³.
snrdg121408
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### Re: HG 2e Medical Bay and Central Supply Catalog (CSC) Autodoc

Hello AnotherDilbert,

Thank you for catching my math error between cough my head off and trying to entertain a 4 year show how lousy I am at multi-tasking.

This definition: "Volume displacement is the displacement of a fluid expressed in terms of volume as distinguished from displacement expressed in terms of mass. https://www.merriam-webster.com/diction ... splacement " clearly indicates that there is a distinction between volume displacement and mass displacement which I have clearly not been able to figure out.

I'm going to drop the discussion since we once again have reached an impasse.

My simple if not accurate method of converting the CSC equipment with only weight is to divide by 1,000 to determine the volume required.

Thank you all for the help.
snrdg121408 (aka Tom R)

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