Do not forget that this is explicitly addressed in CT's TCS; on page 35, under "Jump Failure" it explains that power plants are required in order to Jump, but a Jump may be undertaken without a working computer onboard so long as a nearby friendly has one that can be linked to. ...
I found that rule difficult with respect to the linking computer and bridge, inasmuch as it had the potential to violate bridge-size or computer-size rules.
"...(T)he linking ship must have a computer and bridge as least as large as that of the damaged ship ... Both move at the jump rate of the slowest ship ..."
So, a 200,000 dT recovery tender pulls up on the 200,000 dT dreadnought, links, and the two jump out of the system together - with a grand total of 4000 dT of functioning bridge between them since the dreadnought's bridge is currently scrap metal exposed to vacuum. But, a 400,000 dT dispersed structure docking tender taking out a dreadnought with a scrapped power plant would need an 8000 dT bridge. Similarly, the 75,000 dT recovery tender with its model-6 computer can pull out a battlecruiser with a dead computer, but you can't build a 150,000 dT docking tender with a model-6 computer.
It also created other headaches. Apparently there's this bit in canon where one ship can prevent another ship from entering jump space. So, either these two jump fields are being coordinated to make the ships behave as if they were one ship, or these two ships are jumping far enough apart from each other to avoid triggering misjump - while connected to each other with a cable that is either equipped with a jump mesh or about to be subjected to naked jump space.
And, again, what happens if the cable fails in mid-jump? Okay, rules only put a roll on after every jump, but rules are not role-play, and all it needs is one fanatic marine hiding in some crawlspace for this week's episode to turn into a disaster movie. Does the cripple precipitate out of jump space somewhere in interstellar space between origin and destination, or does it disintegrate entirely as its jump mesh suddenly turns off while in jump space, exposing the entirety of the crippled ship to the physics of jump space? Or, does it precipitate out in the middle of Tholian space in the Terran Empire universe?
(Mental note: working on a recovery crew can be hazardous to one's health.)
That does seem to make it pretty clear that the post-81 CT jump drive requires continuing power from the power plant throughout the jump - which leads us in turn to the question in the immediate previous paragraph. (I'm not sure how much of TCS remains canon, but I don't see any reason that specific element would be decanonized given that it supports existing canon rather than creating problems.)
...As for running power through cables to get the J-drive going, this is one of my hypotheticals for how Type XT Xboat Tenders support power-plantless Type X Xboats. But there is absolutely nothing in canon to support the idea -- if there was, we would see other examples of it: you could fit a "starship" with nothing but a J-drive and a cargo bay, slap Drop Tanks on it and power it up externally to get it into Jump, and you have just perfected the over-100-dton J-torp. ...:
I made the "J-torp" several years ago, though it did carry its own power plant and other essentials. I made a module for a modular cutter that contained a 10 dT bridge extension, a Model-1 computer, some fuel, and the "special field cables" found on the jump ship in
Supplement-9, Fighting Ships, with a bit of space left over for a half-stateroom and maybe a couple of emergency-low-berths, depending on whether you aimed for a 100 dT finished volume or a 110 dT finished volume.
Idea was that a crippled ship in need of summoning rescuers would deploy the cutter with a jump module, the cutter crew would go EVA to deploy the field cables around either a rigging of spars or another cutter (or two cutter modules if the module was set up for a 110 dT volume, depended on how big the original ship was and how much it could carry), and the jump cutter would then do a jump-1 to the next destination. The crew would have to EVA and stow the field cables before the cutter could move on maneuver drives at the destination to do something like refuel or land; a second cutter could maneuver independently once undocked but, if two extra modules were being transported, they'd have to be left to drift while the cutter went to get fuel or whatever, then it would return to them and re-dock them before redeploying the net and making another jump. It would make for an interesting adventure while the crew of, say, a
Broadsword made their way back to a friendly port to get help for their ship and crewmates.
