Machine Type
I've created some broader specialisations which cover many specialisations from supplements, which make plausible optional specialisations.
- Micromachines
- Nanomachines
- Robotics
- Optical systems (Optical Instruments, lamps, etc).
- Acoustic systems (Musical Instruments, soundproofing, etc.)
- Solids processing (Mining, Conveyors, Power Tools, etc.)
- Fluids processing (Life-support, pumping, chemical plant, refineries, etc.)
- Electrical systems - this is Electrician.
- Electronics - this is Electronics Repair.
- Weapons - this is Armoury.
- Tools - this is Machinist.
Propulsion system- Wheeled
- Tracked
- Legged
- Rocket {solid, liquid, composite}
- Reactionless Thrusters
- Winged {propeller, jet} {wooden, metal, composite} {ekranoplan}
- Helicopter
- Air-cushion
Power Plant
Note that this includes some types that are invariably static. Also, some power plants require several specialisations: someone who was an expert mechanic for everything at a TL7 nuclear power plant would have (Fission Reactor), (Boiler, with familiarity with nuclear), and (Electric generator). Long-distance electric power transmission would presumably be a familiarity of Electrician.
- Piston IC engine {gasoline, diesel}
- Piston non-IC {steam}
- Turbine engine {gas, steam, water -- hydroelectric}
- Boiler {coal, oil, gas, nuclear-heated}
- Clockwork
- Muscle Engine
- Fission Reactor
- Fusion Reactor
- Antimatter Reactor
- Electric generator
- Thermoelectric generator
- Storage Battery {several types}
- Fuel Cell {types}
- Electric motor
Vehicle type
As per driving, piloting, etc.
All mechanic specialisations default to each other at -4 (but remember TL penalties). Vehicle type specialisations provide defaults to the propulsion system and power plant types used by the vehicle, and to the machine types of any systems that are part of the vehicle at -2. When applying these to a different type of vehicle, or an unfamiliar vehicle, you get+1 to work on the power plant if the power plant of the new vehicle is actually the same model as one in a vehicle you're familiar with, or +1 to work on the propulsion system if it uses exactly the same technology as a vehicle you're familiar with, or +1 to work on a system if it's the same model as one in a vehicle you're familiar with.
OK, let's try a few examples. Take Alf, a hurriedly trained British aircraft mechanic of the WWII period. He has Mechanic (Heavy aircraft)/TL6-12, and familiarity with the Avro Lancaster, which is what the base he works at flies and the Handley Page Hampden, which has been retired from service and gets used for ground training (which tends to use up aircraft). I've picked these examples because I know aircraft of the period moderately well.
Alf is confronted with a Vickers Wellington, EDT: which he's never worked on. For the engines, his default Mechanic (Piston IC Engine) is 10, and he gets +1 because it's actually the same engine as the Hampden he trained on, a Bristol Pegasus. He's at an effective -1, because the engines are installed differently, and their cockpit controls aren't quite the same. For the airframe, the technology is definitely different: fabric-covered
geodetic construction, vs. metal
stressed-skin. His effective Mechanic (Winged, Propeller) is 10, so he's at an effective -2 for work on the airframe, plus -2 for unfamiliarity for the first 8 hours. For work on the radios, his effective Electronics Repair (Communications) is 10, and he gets +1 if the radio is actually the same model as one he knows, or -2 for unfamiliarity.
Next, he's faced with a Spitfire. The engine is the same as in the Lancaster, so he's 11 with that, and the airframe technology is much the same, so he's probably 11 with that. But the radio is a short-distance VHF radio-telephone, quite different from the long-distance HF Morse-code sets in the bombers, so he's 10 with that, less -2 for unfamiliarity.
Now point him at a Gloucester Meteor, and he's in trouble. It's kind of TL7, not the TL6 he's used to. The airframe technology is metal stressed-skin, so he has 11 with that, -5 for TL7; a helpful GM could rule that the airframe is transitional and reduce the penalty. The engines are not a type he knows, though, so he's on the basic -4 default for a different specialisation of Mechanic, and he does get the full TL penalty on them. With an effective skill of 3, less unfamiliarity, he'll hopefully realise he should stay clear.
OK, this version of the skill is a bit complicated, but gives semi-plausible results for historical machines. It may be rather demanding of the GM for fictional machines, but they can always decide that the +1 for the same, or very close, don't apply.