Port Type	Quality	Shipyards	Repair	Fuel	Min TL
A	Excellant	Starships	Overhaul	Refined	10
B	Good	Spaceships	Overhaul	Refined	9
C	Routine		Major Damage	Refined	7
D	Poor		Minor Damage	Unrefined	5
E	Frontier
F	Routine		Major Damage	Unrefined	7
G	Poor		Minor Damage	Unrefined	5
H	Frontier
X/Y	No Facilities of any type

Excellent- 5 star hotels and Restaurants(Waldorf), Hospitals and facilities for alien races, etc..
Good- 4 star hotels and restaurants(Hilton) , Hospitals and facilities for most major alien races, etc....
Routine- 3 star hotels and restaurants(Holiday Inn), Hospitals for local alien races, etc...
Poor- Duckin motel, The Dew Drop Inn, Clydes Jump Drive repair, Hospitals for local race, etc...
Frontier -Essentially a flat open unprepared field with a port building, maybe a windsock and a fat guy smoking some local weed in a pipe.
"Ayua, g'arts fya. Bwayle. Claintra by 'ere the moonsa, Ayup."  If used for enough years the landing area will be dynamicly compacted by traffic.

Note: Quality refers to the amenities available. A type D starport and a type G spaceport (both Poor) would have similar facilities (Bars, Hotels, Guilds, Warehousing), but the Type G while able to repair some minor damage to starships would not have the parts or equipment to work on Jump Drives.
They are also graded by size as determined by traffic. ie... A-9, B-4, C-2, D-4.
 

Traffic

    A system will have some amount of traffic based on population and TL, Starport and Proximity to other systems. The ports in place will be able in theory to handle the traffic.

Unmodified size = Pop/2 +TL mod
TL modifiers
TL 0-2    TL 3-4        TL 5-6        TL 6-8       TL 9-11       TL 12-13         TL 14-15       TL 16+
  -0.5         0                  0.5              1                 1.5                 2                    2.5                  3

The unmodified size is modified by the port type and neighbor modifier
                                        Starport class
Unmodified size    A         B          C           D          E            X
7+                        0        -1         -1.5       -2          -2.5        -5
6-6.5                    0        -0.5      -1          -1.5       -2          -4.5
5-5.5                   0          0         -0.5       -1         -1.5        -4
4-4.5                    0.5       0         0          -0.5       -1          -3.5
3-3.5                    0.5       0.5       0            0          -0.5      -3
2-2.5                    1          0.5       0.5         0            0        -2.5
1-1.5                    1          1          0.5         0.5         0         0
<1                        1.5       1          1            0.5         0.5      0

Neighbor modifier.
If the nearest system is 1 parsec away add 1.5. If it is 2 parsecs away add 1. If the nearest system is 4 or more parsecs away subtract 1.

    The smallest possible class A port is an A1. All others may be a size 0 port.
    Ports on a X boat route or main trade route have a minimum size of 6. Ports on a feeder route have a minimum size of 5. Ports on jump-1 mains or minor trade routes have a minimum size of 4.

Port Size	Dtons Cargo/yr	Passengers/yr	Dtons Shipping/week	Max size vessel Served/Constructed
0	<10	<1	*100/5yr	100
1	10-100	1-5	*100/5yr-200/yr	200
2	100-1k	5-50	*200/yr-140/month	300
3	1-10k	50-500	*140/month-350/week	500
4	10k-100k	500-5k	350-3500	800
5	100k-1M	5k-50k	3500-35k	5k
6	1M-10M	50k-500k	35k-350k	10k
7	10M-100M	500k-5M	350k-3.5M	100k
8	100M-1G	5M-50M	3.5M-35M	1M
9	1G-10G	50M-500M	35M-350M	1M+

    The average value for a port will be three times the minimum for that port size. Capitals, Hubs and others will be on the high end of the range.
The tonnage of shipping handled will be 1.5 x cargo tonnage plus 5 dtons x the number of passengers.

Berths/100k dtons of shipping/week. 1)     20k dton berth 6)     5k dton berths 40)   800 dton berths 180) 100 dton berths

Various sizes and types of ships make up the traffic using a port. The table below gives the ratios of sizes for the differant ports Port L M S 0 0 0 10 1 0 0 10 2 0 0 10 3 0 0 10 4 0 1 9 5 0 2 8 6 1 2 7 7 1 3 6 8 1 4 5 9 2 4 4

Roll the large ships until the tonnage equals the percentage of large ship traffic, followed by the medium and finally small ships.

Examples:
   Glisten/Spinward Marches [2036] is Population 9, TL 15, it is on a Xboat route and major trade routes and has three class A ports,. It is a subsector capital and major trade Hub with neighboring systems within 1 parsec. Its pop/2 is 4.5 plus 2.5 for TL 15 for a total unmodified size of 7. This gets no modifier for Starport. 1.5 for a neighbor within 1 parsec totals 8.5. Round up to a final port size of 9  It is already larger than required for its location. Its three ports handle 9G dton of cargo as a hub and 500M passengers as a capital. We decide that Glisten city, Kaityl and Porfiru each handle a third. Glisten City handles 3G dtons of cargo and ~167M passsengers for a total of ~5.3G dtons of yearly shipping capacity, divide by 50 to get the average weekly tonnage of ships for ~107M dtons/week. This means Glisten city has (1067) 20k dton berths, (6402) 5 k dton berths, (42680) 800 dton berths and (192060) 100 dton berths.Kaityl and Porfiru have similar ports. Twenty percent of the vessels visiting Glisten are over 5kdtons(~ 3000 vessels/week, 40% are 1kdton to 5 kdtons (~17000 vessels/week) and the rest are under 1kdtons (~86000 vessels/week).

   Saursus/Spinward Marches [1320] is Population 5, TL 7, and has six class D ports. Its nearest neighbor is 2 parsecs away. Its pop/2 is 2.5 plus a TL mod of 1 for a total of 3.5. It receives no modifier for starport type, it is not on a trade route or X boat route. It gets a modifier of 1 for its neighbor for a total size of 4.5 rounded to 5. Its ports handle 300k dtons of cargo and 30k passengers a year split evenly among them. Divide by 50 for 6000 dtons cargo and 600 passenger per week. (6000*1.5)+(600*5) for a total of twelve thousand dtons of shipping per week or two thousand dtons per port, using each ports ten 100 dton pads and two 800 dton pads. Twenty percent of the vessels visiting Saursus are 1kdton to 5kdtons (~2 vessel/week) and the rest are under 1kdtons (~14 vessels/week).

    Grote/Spinward Marches [1731] is population 4, TL 11, and has a single class A port with only the down component. It is on a jump-1 main. Its pop/2 is 2 with a TL modifier of 1.5 for an unmodified size of 3.5. Its starport mod is 0.5 and it gets 1.5 for its neighbor at 1 parsec for a total size of 5.5 rounded up to 6.
    3M dtons of cargo and 150,000 passengers per year move through the port. Divide by 50 for 60k dtons cargo and 3000 passengers per week for a total of 105k dtons of shipping per week giving one 20k dton berth, six 5k dton berths, forty-two 800 dton berths and one hundred eighty-nine 100 dton berths. Ten percent of the vessels visiting Grote are over 5kdtons (~2 vessels/week), 20% are 1kdtons to 5kdtons (~ 15 vessels/week) and the rest under 1kdton (~140 vessels/week)

Construction

    Commercially built starships are available from Class A ports at a minimum TL of A. Class B ports may produce spaceships commercially at a minimum TL of 9.
    Any Government may produce ships at its Space Transport TL at 1/50 the normal rate regardless of and in addition to any commercial yards in system. They may build one size larger than normal for their shipyard size.
Ships may be produced using the formula below.

Yearly dtonnage produced = population/1000

Modifiers: In x 2.5, Ri x 1.2, Ni x 0.5, Po x 0.8
Modifiers are cumulative.

The amount of the workforce allowed to work on each 100kdtons or less of hull is determined by production.

dtons Production/year                    % work force/100k dtons of hull
<1,000  dtons                                               100%
  1,000-10,000                                              50% not less than 1k dtons
  10,000-100,000                                          25% not less than 5 kdtons
 100,000-1,000,000                                        2% not less than 25 k dtons
>1,000,000 dtons                                            1% not less than 25 kdtons

 Whether building ships or habitats there is an initial startup period of two years before any actual construction takes place. Construction times in days may be found by dividing the tonnage of the ship by the capacity devoted to it. This assumes a single 12 hr shift. By working two shifts the time may be cut in half. The construction of orbital habitats uses one hundreth of the normal resources to produce, ships maintenance and repair uses up one tenth of the shipyard resources that construction takes.

Examples:
    Glisten is a TL 15, Hi In system with Starport type A. It has a population of 7e9.
Working one shift it can build 7e9/1000x2.5 = 17.5M dtons of any type vessel per year up to TL 15. If it wished Glistens government could produce an additional 7e9/1000x2.5/50 =350k dtons of any type of ship per year. Glisten is capable of producing 17.85M dtons of shipping per year. Its yards are producing 700M dtons of orbital habitats (700M dtons/100=7M dtons capacity) and is performing maintenance on 20M dtons (20M dtons/10=2M dtons capacity) of shipping. It has 17.85M-7M-2M = 8.85M dtons excess capacity for building new ships. Glisten is building a line of 420 kdton Ducal class Battleships. Because Glisten can produce over 1 M dtons of shipping only 4% or 714kdtons of the systems production capacity could be dedicated to each new vessel. So it will take 420 kdton/714 kdtons/year or 8 months to build each ship. If Glisten were to add a second shift it could maintain its commercial duties while producing  63 Ducal class Battleships per year.

    Forine is a TL 10, Hi In Ic Na system with a Class D starport. It has a population of  6e9.
It has no commercial yards but its government, working one shift, can build 6e9/1000*2.5/50 = 300 kdtons of any type of vessel per year at its Space Transport Tech Level. It must maintain a fleet of 570,800 dtons of Starships using 57.08k dtons capacity. 300k-57.08k=242.92k dtons capacity to devote to new construction. It is building 7000 dton Destroyers. It could devote up to 2% or 6k dtons capacity to each new hull, Minimum capacity allowed is 25k dtons because of size so the port could complete a unit in about four months. Just over thirty-four ships per year could be produced.