Ton

A Ton is a measure of volume and a measure of both mass or weight. It can have three primary meanings:

• A Displacement Ton (abbreviated as dTon or dT) is a unit of volume equal to between 13.5 and 14.0 cubic meters. It is derived from the volume of 1.0 ton (mass) of liquid hydrogen, the typical fuel used by starships, and the fact that a significant percentage of a ship's total volume is taken up by fuel tank volume.
• A Metric Ton (or Tonne) (abbreviated as T) is a unit of mass equal to 1000 kg.
• A Metric Ton-Force (abbreviated as T_f) is a unit of force or thrust equal to the weight of a 1000 kg mass in a 1.0 G gravitational field.

Description: Many Kinds of Tons

Ever wondered why ship entries often have wildly different tonnage measures? Here's why:

1. Deadweight Ton
2. Displacement Ton (dTon)
3. Dry Ton
4. Freight Ton
5. Hydrogen Ton
6. Kiloton (Kton)
7. Measurement Ton
8. Metric Ton (T)

Displacment Ton (Volume)

The foundation of the starship is the hull, into or onto which all other components are placed. Hulls are identified by their mass displacement (...expressed in tons; one ton equals approximately 14 cubic meters) and by their configuration.

Ships may be very large and for convenience have their masses measured in kilotons (abbreviated to Ktons), a unit equal to 1,000 standard tons. Ships of at least a megaton (or Mton), which is 1,000,000 standard tons, are rare enough that "megaton" is not commonly used. Typically when talking about objects in space of a megaton or more (and not talking about moons, planets, stars, or larger objects), one is talking about planetoids instead of ships. These prefixes derive from the pre-spaceflight Terran International System of Units as expressed in Anglic.

Metric Ton (Mass)

• No information currently available.

Metric Ton-Force (Thrust)

• No information currently available.

History & Background (Dossier)

The creation of starship deck plans is based on the assumption that one ton of mass displacement equals fourteen cubic meters. The standard displacement ton used for these calculations is derived from the volume of liquid hydrogen, the fuel source for most standard star faring vessels.

The square grid scale used on most deck plans is 1.5 meters on a side. Clearance between decks is normally 3 meters. This means that two floor squares, extended floor to ceiling, equals four 1.5 meter cubes or nearly 14 cubic meters (four lots of 1.5 m x 1.5 m x 1.5 m = 13.5 cubic meters), or one ton. A 100 dTon starship would thus contain approximately two hundred grid squares within.

Allowances of approximately + or - 10% were made in most areas to allow for better representation of specific parts of the ship and to cover various anomalies. For example, crew quarters call for four tons per sophont: the actual tonnage allocated on many plans is often less than that, but additional area is devoted to communal areas such as galley, mess, wardroom, and recreation areas.

Also, a limited volume of passages has been added to some starships. Passages and access ways which have no other use may be safely added to a ship without affecting volume or displacement for construction purposes. These additional passages should amount to no more than an additional 10% of the ship's total volume.

References & Contributors (Sources)

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This page uses content from Wikipedia. The original article was at Ton. The list of authors can be seen in the page history. The text of Wikipedia is available under the Commons Attribution-ShareAlike 3.0 Unported License.

This list of sources was used by the Traveller Wiki Editorial Team and individual contributors to compose this article. Copyrighted material is used under license from Mongoose Publishing or by permission of the author. The page history lists all of the contributions.

• Marc Miller, Frank Chadwick, John Harshman. High Guard (Game Designers Workshop, 1980), 21-22.
• Marc Miller. Traders and Gunboats (Game Designers Workshop, 1980), 5.
• Jordan Weisman. "Book 2." Adventure Class Ships Volume 1 (1982): 3-4.
• Ken Pick - What is Tonnage? at Freelance Traveller