On 12 Jun 2020, at 04:33, xxxxxx@gmail.com wrote:

Great Wiseman's Ghost! NO MANEUVER DRIVE?

I must have blocked the encounter with this nonsensical reality from my mind.

snip

How big of a vessel do you need to get Jump-4, system range commo (w backup), power from batteries or a plant with which to run an appropriate computer, some sort of emergency survival options, and if it fit, a main drive 1-G (I'd settle for a G-fractional drive, but that would require interpolation or extrapolation of existing tables)? What's the minimum size that works in? 110 tons? 120 tons? 130 tons?

Even as written, the X-boat has a 20T bridge and a 1T model 1bis and the comms system is somewhere in those two numbers.

The book 2 problem is entirely the power plant fuel requirements, which are 10Pn = 40T for a B drive in a 100T hull. In a 200T hull the B drive needs 20T fuel and in a 400T hull it needs 10T. In fact a 5000T ship with a Z drive only needs 20T fuel to allow 2G.

Every other Traveller ruleset would have no problem building a 100T J4 design.

Beyond J4 it is not possible because of the minimum 20T bridge, the model 5 or 6 computer and the extra power plant for the 3 or 5 EP that those need.

Phil Kitching