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how do you weigh a starship?

miklamar

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POSTS: 2164

Report this Nov. 13 2012, 7:41 am

I have a question about determining the mass or weight of a fully loaded—including with crew and passengers—starship.  Some formulae are available (such as http://en.wikipedia.org/wiki/Gross_tonnage).  But, an older source gave several figures for barges, and these calculations seemed to indicate that 1 ton was equivalent to about every 53 cubic feet of space on the vessel.


Starfleet might consider using one or more of the following techniques, if they do not already use them:


1.       Estimating the mass (weight) by the calculations above.


2.       Using some industrial-strength device to actually weigh a starship just before it leaves the dock.


3.       Place each ship in a space- or air-lock of a known volume and use instruments to measure the difference in pressure or volume (for example) between the occupied lock and the vacated lock.


4.       Actually load a ship of each class—in the water (e.g., Pacific Ocean)—with fuel and cargo, then measure its displacement.  You could then either have the passengers board a ship or boat with their luggage and other personal effects and measure their weight.  Or, like modern airports, you could calculate their (luggage) weight as they arrive to board the aircraft.


The precise weight or mass is important when calculating such things as velocity, momentum, angular momentum, etc.


Also, British laws for merchant ships required commercial ships to have a bulkhead at each end of machinery (propulsion and fuel areas), at the bow, at the stern—a minimum of four or five—and one every 65 feet beyond 285 feet in length.


Var Miklama--Zakdorn, engineer. "A sound mind in a FULL body!" "Time, like latinum, is a limited quantity in the galaxy."

PicardNerd

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Report this Nov. 24 2012, 12:51 pm

But it's in space... there's really not much gravity in space...

FleetAdmiral_BamBam

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Report this Nov. 24 2012, 1:22 pm

Considering a ton on earth is different than a ton on Luna or another world, I suspect the calculations are based on a single G.


And remember, the materials used on starships will be different than what we currently use on seaships, so you'd have to calculate the amount each material would weigh.

CO_Fowler

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Report this Nov. 25 2012, 10:39 am

My guess would be take the weight of the matereials used to build the ship and the weight of what is used to outfit the interior of the ship to get it's gross overall weight.  Since crew and their belongings would be pretty much be in a constant state of change you can only really have that be a seperate weight class.  Same with, say, the aux. craft.  i.e. shuttle craft, captain yacht ( if there is one ) and the like.


Interesting question, really.  Made me think about it a bit before I replied

Pooneil

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Report this Nov. 25 2012, 11:10 am

Weight is irrelevant, since starships operate in a vacuum where gravity is negligible. It would also vary from planet to planet.


Mass is a constant, and could be determined by taking the known mass of all the bits and pieces used to build the ship and adding the atmosphere, fuel, and people. All of those figures should be known, right? If the folks building the ship know the properties of titanium -- density, for example -- they ought to be able to calculate the mass of the final product.


I assume Starfleet engineers know more about these calculations that I do.

miklamar

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Report this Nov. 26 2012, 6:27 am

The weight or mass could be critical in calculations for velocity and momentum.  You would know, or be able to calculate, the ship's weight, and the fuel weight might lessen, as you expend it.


The main difference could be the weights of the crew and passengers, plus whatever personal possessions they might choose to bring aboard.


Perhaps you could estimate their weights, assigning an average of 200 pounds (90.72 kg) for each person and 100 pounds (45.36 kg) for their belongings, for a total of 300 pounds (136.08 kg) for each person onboard.


Var Miklama--Zakdorn, engineer. "A sound mind in a FULL body!" "Time, like latinum, is a limited quantity in the galaxy."

Dark_Q

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Report this Nov. 26 2012, 9:16 am

The best meaans I can think of is to measure how much force must be exerted by a propulsion device to propel an object a certain distance. if a standard impulse engine requires, say, 700 tonnes of force to propel itself 10 kilometers, but requires 7,000,000 tonnes to move an object with the impulse engine the same distance a valid and simple formula can be used to measure gross tonnage.


I can't think of the proper formula at this moment, but I'm sure you can get the idea I have in mind.


"Q wants to do something nice for me..." I'll alert the crew.

miklamar

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POSTS: 2164

Report this Nov. 30 2012, 6:33 am

Quote: Dark_Q @ Nov. 26 2012, 9:16 am

>

>The best meaans I can think of is to measure how much force must be exerted by a propulsion device to propel an object a certain distance. if a standard impulse engine requires, say, 700 tonnes of force to propel itself 10 kilometers, but requires 7,000,000 tonnes to move an object with the impulse engine the same distance a valid and simple formula can be used to measure gross tonnage.

>I can't think of the proper formula at this moment, but I'm sure you can get the idea I have in mind.

>


I wasn't ignoring your response, I was just trying to comprehend what you were saying.  Last night, I think it finally came to me.  You are suggesting that once the ship leaves the docking area, it measures its rate of acceleration and uses that to calculate its weight/mass, by comparing it against other known formulae and equations.


That is both a brilliant and elegant suggestion, Dark Q, since the ship would already be underway to wherever its destination, while you're measuring its weight.  And, although my suggestions are logical and "scientific," yours is really more practical.


Great job, Dark Q!


Var Miklama--Zakdorn, engineer. "A sound mind in a FULL body!" "Time, like latinum, is a limited quantity in the galaxy."

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