Using Barbettes in GURPS Traveller
The GURPS Traveller Starship design rules allow for standard turrets that hold three displacement tons of starship weaponry. The next larger standard size for a weapon mount is a fifty dTon bay. In Classic Traveller there was an intermediate sized mount used on many warships called a Barbette. A Barbette can be considered to be an oversized turret or, what may be conceptually more accurate, a scaled down 1/10th size external bay. Ten Barbettes replace one bay so they may be substituted, one for one, in place of turrets on Traveller warships. Like external bays, the external tonnage of each Barbette is designed to hold a single universally mounted weapon system and the internal displacement entirely consists of the rotation space of the Barbette. All the weapons designed for the Barbettes have a dedicated hardened mainframe targeting computer and a single roomy crew work station designed into the weapon, similar to bay mounted weapons.
In Classic Traveller the Barbette weapon was usually a Particle Accelerator Weapon (PAW), so I have listed the stats for a series of custom designed PAW's and Meson Guns below. However, in GURPS Traveller, Particle Accelerators and Meson Guns of this size have such short range that they have very limited utility in space combat. So to make the Barbette mount more useful and flexible, I have also included a series of X-Ray Laser weapons sized to fit in them. The general stats for the Barbettes are listed in the table below:
|Barbettes||5 dTon||10 dTon|
|Weapon Space (External Displacement)||5||10|
|Rotation Space (Internal Displacement)||1||2|
|Surface Area (Square Feet)||1200||1800|
|Mass (Short Tons)||1.2||1.8|
Notes: The Barbettes, as listed above, are designed as full rotation turrets. Full rotation turrets require 20% of their external tonnage in interior rotation space. Limited rotation turrets require only 10% rotation space. In Classic Traveller, it is suggested that Barbettes may be less flexible and have more limited rotation than standard turrets. If you want the Barbettes to be limited rotation, simply cut the interior displacement in half. Remember the surface area of the Barbette needs to be armored just like a regular turret or external bay and the external displacement adds to the ship's tonnage for calculating jump drive and fuel requirements.
Weapon Design Notes
Each complete Barbette Weapon System includes:
- Base Particle Accelerator, Meson Beam, or X-Ray Laser with extreme range option.
- Full Stabilization for the beam weapon.
- Universal Mount for the beam weapon.
- A rechargeable power cell capable of powering one shot at the weapon's full rated power.
- A fusion power slice capable of recharging the power cell in one minute.
- Long term access for the fusion generator.
- One roomy crew station with a computer terminal, HUDWAC, and pupil scanner.
- A hardened dedicated Macroframe Computer (Complexity is TL-3), Targeting bonus is TL-2.
|Weapon Description||TL||Compact||Volume||Mass||Cost||Power (MW)|
|1.38 GJ Barbette PAW/10||10||No||5||50.786||2.60||46.0|
|2.7 GJ Barbette PAW/10||10||No||10||99.180||5.03||90.0|
|2.26 GJ Barbette PAW/11||11||Yes||5||45.380||5.69||75.3|
|4.62 GJ Barbette PAW/11||11||Yes||10||92.645||11.56||154.0|
|1.38 GJ Barbette Meson Gun/12||12||No||5||50.760||2.37||46.0|
|2.7 GJ Barbette Meson Gun/12||12||No||10||99.129||4.57||90.0|
|2.26 GJ Barbette Meson Gun/13||13||Yes||5||45.353||5.68||75.3|
|4.62 GJ Barbette Meson Gun/13||13||Yes||10||92.59||11.54||154.0|
|1.4 GJ Barbette Laser/10||10||No||5||47.870||4.73||62.1|
|2.75 GJ Barbette Laser/10||10||No||10||93.917||9.22||121.9|
|1.93 GJ Barbette Laser/11||11||Yes||5||37.352||5.68||85.6|
|4.3 GJ Barbette Laser/11||11||Yes||10||83.075||12.55||190.6|
|2.06 GJ Barbette Laser/12||12||Yes||5||39.842||3.50||91.3|
|4.32 GJ Barbette Laser/12||12||Yes||10||83.420||7.27||191.5|
|2.16 GJ Barbette Laser/13||13||Yes||5||41.755||3.66||95.8|
|4.36 GJ Barbette Laser/13||13||Yes||10||84.741||7.38||194.6|
|Weapon Description||TL||ROF||Damage||Half Range||Max. Range||Acc|
|1.38 GJ Barbette PAW/10||10||1/60||4dx700||4,807 / 0||14,422 / 1||30|
|2.7 GJ Barbette PAW/10||10||1/60||5dx700||6,722 / 1||20,166 / 2||31|
|2.26 GJ Barbette PAW/11||11||1/60||6dx650||6,662 / 1||19,987 / 2||31|
|4.62 GJ Barbette PAW/11||11||1/60||5dx990||9,526 / 1||28,577 / 3||32|
|1.38 GJ Barbette Meson Gun/12||12||1/60||4dx700(!)||4,807 / 0||14,422 / 1||30|
|2.7 GJ Barbette Meson Gun/12||12||1/60||5dx700(!)||6,722 / 1||20,166 / 2||31|
|2.26 GJ Barbette Meson Gun/13||13||1/60||6dx650(!)||6,662 / 1||19,987 / 2||31|
|4.62 GJ Barbette Meson Gun/13||13||1/60||5dx990(!)||9,526 / 1||28,577 / 3||32|
|1.4 GJ Barbette Laser/10||10||1/60||4dx140(2)||40,337 / 4||121,011 / 12||34|
|2.75 GJ Barbette Laser/10||10||1/60||5dx140(2)||56,533 / 6||169,600 / 17||34|
|1.93 GJ Barbette Laser/11||11||1/60||4dx200(2)||52,097 / 5||156,290 / 16||34|
|4.3 GJ Barbette Laser/11||11||1/60||5dx210(2)||77,762 / 8||233,285 / 23||35|
|2.06 GJ Barbette Laser/12||12||1/60||5dx200(2)||58,716 / 6||176,147 / 18||35|
|4.32 GJ Barbette Laser/12||12||1/60||4dx320(2)||85,028 / 9||255,084 / 26||35|
|2.16 GJ Barbette Laser/13||13||1/60||4dx300(2)||65,134 / 7||195,402 / 20||35|
|4.36 GJ Barbette Laser/13||13||1/60||4dx380(2)||92,857 / 9||278,571 / 28||36|