Build:Vessel Size Scale

3.1 Vessel Size Scale

Starships can be categorized by size, based upon their mass. The following table details the Size scale, Length, Beam and Height ranges and Structural Unit (SU) amount, according to the ship’s mass.

Note: Length is generally the deciding dimension, but all four may be considered for the final decision.

Table

Table 3.1: Vessel Size Scale

Mass Range (mt)	Size	Length (m)	Beam (m)	Height (m)	Max SU	Year*
0 - 2	1	1 - 5	1 - 4	0 - 1.9	325
2.1 - 30	2	6 - 50	4 - 10	2 - 5	300 - 625	2064
31 - 60,000	3	51 - 100	11 - 25	6 - 20	600 - 1,000	2162
60,001 - 200,000	4	101 - 150	26 - 50	21 - 30	800 - 1,300	2215
200,001 - 400,000	5	151 - 300	51 - 100	31 - 50	900 - 1,900	2231
400,001 - 1,875,000	6	301 - 400	101 - 200	51 - 80	1,300 - 2,500	2245
1,875,001 - 4,000,000	7	401 - 600	201 - 400	81 - 125	1,500 - 2,750	2284
4,000,001 - 5,000,000	8	601 - 700	401 - 550	126 - 200	2,000 - 3,250	2322
5,000,001 - 6,000,000	9	701 - 800	551 - 700	201 - 300	2,250 - 3,500	2362
6,000,001 - 8,000,000	10	801 - 1,000	701 - 800	301 - 400	2,500 - 3,750	2384
8,000,001 - 10,000,000	11	1,001 - 1,500	801 - 1,000	401 - 600	2,750 - 4,000	n/a
10,000,001 - 12,000,000	12	1,501 - 2,000	1,001 - 1,200	601 - 800	3,000 - 4,500	n/a
12,000,001 - 14,000,000	13	2,001 - 3,000	1,201 - 1,500	801 - 1,000	3,500 - 5,000	n/a
14,000,001 - 17,000,000	14	3,001 - 4,000	1,501 - 2,000	1,001 - 1,200	4,500 - 6,500	n/a
17,000,001 - 20,000,000	15	4,001 - 5,000	2,001 - 2,500	1,201 - 1,500	5,000 - 8,000	n/a
20,000,001 - 23,000,000	16	5,001 - 6,000	2,501 - 3,000	1,501 - 1,800	7,000 - 11,000	n/a

*These years for sizes allowed generally apply only to the UFP, though most Alpha Quadrant species also follow it. The exceptions are for the Breen, Ferengi, Klingons and Romulans (who can build Size 10 starting in the 2370s). Vulcans could build up to Size 6 by 2145.

1) SU amounts are directly proportional to the starship’s mass. For example, a 400,001 mt starship would have 1,300 SUs, while a 1,875,000 mt starship—also a Size 6—would have 2,500 SUs.

2) SU weight varies according to (named) ship class, so that on the lighter Size 6 starship above, a SU would weigh 308 mt, while on the heavier Size 6, a SU would weigh 750 mt. Equipment, systems and spaces for a starship are "purchased" with allotted SUs.

Formulas to determine max SUs (for the class' target mass):

Method 1:

A = mass of lower-end of range (ex: 31 mt)

B = target mass of design (ex: 25,000 mt)

C = mass of upper-end of range (ex: 60,000 mt)

D = SU of lower-end of range (ex: 31 mt is 600 SUs)

E = SU of upper-end of range (ex: 60,000 mt is 1,000 SUs)

F = difference of SUs between E and D (ex: 1,000 - 600 = 400)

X = max SU of design (to be determined)

Y = difference of mass between B and A (ex: 25,000 - 31 = 24,969)

Z = difference of mass between C and A (ex: 60,000 - 31 = 59,969)

- Divide Y by Z, to get percentage amount (ex: 24,969 / 59,969 = 41.64%)

- Multiply F by the percentage amount and round the result (ex: 400 x 41.64% = 166.56, rounded to 167)

- Add the result to D to get X, the design's max SU (ex: 167 + 600 = 767)

Method 2:

X = D + (E - D) x {B - A}/{C - A}

Where:

A = Lower-end mass (e.g., 31 mt)

B = Target mass (e.g., 25,000 mt)

C = Upper-end mass (e.g., 60,000 mt)

D = SU at lower-end mass (e.g., 600)

E = SU at upper-end mass (e.g., 1,000)

X = Max SU for the target mass

Remember: multiplication & division before addition

Divide the design mass by the (determined) max number of SUs to get the mass of each SU (record both rounded and unrounded values).

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