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Beyond Book 2: Expanding the Basic Classic Traveller Starship Design System


When Traveller premiered in 1977, it was printed in the usual three-book format of the period. The starship design system (filling most of Book 2) was a simple building-block system for ships of 100-5000 tons, with the "standard" designs provided for player-characters ranging from 200-800 tons. All in all, a "small-ship" universe, probably in a "cozy" campaign setting of a subsector or two.

But this was 1977, only months after the premiere of Star Wars, with its Galaxy-wide Empire and huge starships. The only other widespread universe paradigm was Star Trek, another big-ship universe with ultra-high "Trek Tech". Both of these paradigms emphasized big ships, maxed-out technology, and a wide-ranging campaign area.

Accordingly, early Trav campaigns tried to push the limit, attempting large ships (up to tens of thousands of tons), a ruling Tech Level of 13-15, and empires about equivalent in size to the later Spinward Marches (a full sector of 16 subsectors).

With the publishing of High Guard in 1980, Travellers got their big ships, with a slightly-more-complex design system (primarily geared towards warships) for ships of up to a million tons. Traveller's official universe, the Third Imperium, spanning dozens of full sectors, provided a big universe for these big ships.

Traveller campaigns of this period emphasized big ships, big campaigns, and Tech Level 15, either in the Third Imperium itself or freelance imitations of it. Travellers had their galaxy and large starships -- but paid a price.

Typical player-characters were still limited by price and numbers to the smaller ships from Book 2 -- the Type A Free Traders, Type R & M subsidized merchants, and Type T & C paramilitary craft. These ships which player-characters could reasonably expect to own and/or control had shrunk to insignificance beside the megaton monsters coming out of High Guard's shipyards. In such a big pond, to become a big fish meant starting at or rising to the level of a high-ranking VIP in a strategic-level campaign. Such Imperiums had lost their scale for the free-traders and adventurers that made up the typical player-characters -- except for vermin and pawns skulking around the edges.

Gedankenexperiment: Low-tech Traveller

Sometime in the 1990s, I tried a thought-experiment. Instead of a TL 15 big-ship, big-universe campaign, why not go as far as practical in the other direction? One subsector (maybe two), TL 11 (with TL12 being gee-whiz cutting edge), exclusively using Book 2-designed starships. A "cozy" campaign universe -- with 15+ years of hindsight, probably what Original Traveller did best. See how much you could do using only Book 2 starships.

Turned out you could do a lot. A lot of the starships from this experiment are now published in The Shipyard -- stretched versions of the Type As & Rs, large liners and bulk freighters of up to 6000 tons, heavy scouts, stretched and tweaked small craft, and multi-role refits for the ubiquitous Type T patrol craft.

However, for the Navy, pure Book 2 became a bit limited; there was little difference between a dedicated warship and a well-armed civilian one, much like wooden ships during the Age of Sail. To bring our interstellar navies up to the "modern era", a little High Guard retrofitting was in order.

The following additions to the Book 2 design system retrofit a little of that High Guard flavor without unduly stretching the basic design system:

HG2 Retrofit: Armored Hulls

Size -- varies by Tech Level
TL 7-9 4 x (ArmorFactor + 1)% of ship tonnage
TL 10-11 3 x (ArmorFactor + 1)%
TL 12-13 2 x (ArmorFactor + 1)%
TL 14-15 ArmorFactor + 1 %

Cost -- MCr (.3 + .1 x ArmorFactor) per ton

Effects -- cuts down the number of hits that do damage:
Armor-1 count 2/3 of hits
Armor-2 count 1/2 of hits
Armor-3 count 1/3 of hits
Armor-n count 1/n of hits

HG2-inspired Enhancment: Laser Bays

A giant laser turret, mounting 30 lasers firing as one. (Added to the original CT starship design system from the Foible Federation campaign of 1977-78, where they were known as "bank lasers".)

10-ton Pulse Laser Bay
Size -- 10 tons
Cost -- MCr 16
Crew -- 2

10-ton Beam Laser Bay
Size -- 10 tons
Cost -- MCr 31
Crew -- 2

Essentially, a laser bay is 10 triple laser turrets ganged together into a single mount for savings in cost and personnel. A laser bay fires as a laser turret with only one "to hit" throw for the entire bay; a hit does 30 hits to the target ship.

Laser bays are found only on military ships as "big guns".

HG2 Retrofit: Missile Bays

A giant missile turret, firing enlarged heavy missiles or "torpedoes". Before the introduction of nuclear dampers and meson guns at TL12, the primary ship-killing weapon. (Retrofitted to the original CT starship design system from High Guard 2.)

50-ton Missile Bay
Size -- 50 tons
Cost -- MCr 12.5
Crew -- 2
Capacity -- 50 heavy missiles, can fire 5/turn

100-ton Missile Bay
Size -- 100 tons
Cost -- MCr 21
Crew -- 2
Capacity -- 100 heavy missiles, can fire 10/turn

Heavy Missile
An enlarged missile fired from Missile Bays. Commonly called a "torpedo" or "bay missile" to distinguish it from the smaller "turret missiles".

Size --1 ton/round
Cost/round -- 5 x standard turret missile
Damage --1D x 1D hits


Mines in Traveller are basically encapsulated light (turret) or heavy (bay) missiles with a special "mine" fire-control/IFF package attached. Instead of being fired directly, they are "laid" in orbital or drift minefields and float in space until activated by coded signal. Once activated, they launch themselves at a target, usually an intruding ship. When a mine fires, it attacks with the EW rating of its Tech Level.

There are four levels of activation:

Activation Level Description
Weapons Hold Fire only on direct command signal to fire, only at target specified in command.
Weapons Tight Fire only on targets positively identified as enemy.
Weapons Free Fire only on targets not positively identified as friendly.
Berserk Fire on anything and everything within range.

In addition, the fire-control package is "smart" enough to obey simple commands like "fire on the first target in range", "let the first X targets pass, then fire at the next", "deactivate at a specified time and reactivate later", "deactivate until receiving new activation signal", etc.

Enhancement: Multiple Engines

In the original Book 2 starship design system, M-drives, J-drives, and Powerplants were fixed sizes (rated by letters in the usual A-Z sans I & O progression) that cross-indexed into hull size to give the drive and powerplant ratings for the ship.

This resulted in a "topping out" effect at larger hull sizes; the largest (Z) engine could only give a rating of 4 (Jump or Gs) in a 3000-ton hull, 3 in a 4000-ton hull, and 2 in a 5000 to 6000-ton hull. (And presumably, 1 in a 10000 to 12000-tonner.)

Also, since engine damage was counted by derating the engines to the next (letter) size with each hit, ships above 2000 tons were progressively more vulnerable to engine hits, until a 5000+ tonner was as prone to "one-hit cripples" as a 200-ton Free Trader.

These limitations can be mitigated by allowing a "cluster" of multiple engines in a single hull. Multi-engined large ships can increase performance over single-engined ships, while absorbing more engine damage.

Design Limitations:

  1. All M-drives, J-drives, and powerplants in a multi-engine ship must be of the same (letter) size.
  2. Each engine of the cluster must have a rating of at least 1 for the size of hull. (This effectively limits Book 2 engines to a maximum hull size of 12000 tons, reasonable for a "small-ship" campaign.)
  3. Each jump drive or powerplant has the same fuel requirements as it would if installed alone. (This has no effect on jump fuel, but brings the Book 2 "ten tons per powerplant number" a little more in line with reality for large ships.)
  4. The drive/powerplant rating for the ship is the sum of all the engine ratings.

In-use Effects:

  1. Large ships are now capable of high performance.
  2. Multiple-engined ships are now more resistant to battle damage. When a multi-engined ship takes an engine hit, roll a die to see which engine is hit, and derate the engine in the normal Book 2 manner. As a hit can go to an already-damaged (or destroyed) engine without further effect, it is possible to survive multiple "free" engine hits, thus making larger ships more survivable.

HG2 Retrofit: Nukes

Before the introduction of nuclear dampers at TL12, nuclear missiles were the heavy-duty ship-killing weapon.

Nuclear missiles are available at TL8+ (while nukes are TL6, getting a small and efficient enough warhead requires a tech level or two more), do 1D x the damage of a normal (HE/fragmentation) missile; for simplicity, radiation effects are assumed to be part of the normal damage.

Nuclear turret missile: 1D x 1D (same as a normal bay missile).

Nuclear bay missile: 1D x 1D x 1D.

Cost (when available): 10 x a normal missile of the size, more for "Thunderballs".

Nukes are a mass-destruction weapon, and are tightly-controlled by the military. Nukes would be found only on actual military ships as a "special round". (At least officially; such a firepower-multiplier is in-demand on the black market under the name of "Thunderballs".)

HG2 Retrofit: Nuclear Dampers

Nuclear dampers are "shields" that neutralize nuclear warheads by futzing with the strong and weak nuclear forces. First described in Book 4: Mercenary, dampers project an interference pattern of strong- and weak-force nodes from two widely-separated antennae which interfere with nuclear fission and fusion reactions, causing the warhead to "fizzle" in a meltdown or much-reduced explosion. The pattern must be focused to hold a node on the incoming missile; for this reason, nuclear dampers require active sensors and precise fire-control.

In CT, nuclear dampers "fire" defensively on incoming missiles, with the base "to hit" throw (as a laser) with an additional DM of the relative Tech Levels of the missile and the damper. If the damper "hits", the nuclear missile will not explode. Note that nuclear dampers have no effect on normal missile warheads.

Nuclear dampers are available starting at TL12:

TL12 -- 50 tons, MCr 50.
TL13 -- 20 tons, MCr45.
TL14+ -- 10 tons, MCr 30.

All nuclear dampers require a crew of 4.

HG2 Retrofit: Rapid Launch/Recovery Facilities

Though small craft can be launched rapidly (ask anyone who's seen a full abandon-ship), they are difficult to recover using standard shuttlebay fittings. Rapid Launch/Recovery Facilities (such as on carriers) allow a ship to launch and recover small craft or ship's vehicles quickly. (Retrofitted to the original CT starship design system from High Guard 2, where they were called "launch tubes".)

Rapid Launch/Recovery Bay:
Size -- 25 x the largest craft that can use the facility.

Uses 10 hardpoints, the same as a missile or laser bay.

ROF -- 40 small craft launched/recovered per turn.
Crew -- 10
Cost -- Cr 2000/ton

Attached Hangarage:
Size -- 1.3 x the capacity in small craft tonnage. (The extra room is required for marshalling the small craft to and from the launch/recovery bay.)
Cost -- Cr 2000/ton

Miscellaneous Note: Adapting "Wet-navy" Ships

A lot of the warship designs done under this system (such as the Kanin, Krupny, Venetian, Worcester, and Mogami) were "Travellerizations" of actual wet-navy ships.

These were mostly scaled from the armament, using the following rules-of-thumb: