Another answer in another forum, posted here for convenient access.
“Looking at the Knight Hawks rules and required drive overhauls, how do fleet actions happen in Star Frontiers? It seems like the logistics of fleet movement would be insane with the way the rules work. All your big ships would be ready to go but waiting on their support ships to get their drives back up. How did the Task Forces stay together to fight the Second Sathar War?”
Looking at the RaW and the implied reality of the setting, this questions requires looking at a couple of aspects of the rules that are not readily apparent in a casual reading of the book.
The first is a misconception about the strategic aspect of the Second Sather War as a boardgame: it is an abstraction of the actual operational requirements of the fleets. In other words, although the strategic game rules specifically say that “each transit box marks one day of acceleration or deceleration” (pp. 56), the actual rules make this statement false.
Why is it false?
Remember the canon mechanic for FTL travel; A ship accelerates to 1% the speed of light, which takes 94.42 hours at 1g (4.72 Standard days = 4 days, 14 hours, 24 minutes). Once this velocity is reached, the ship enters The Void with a thruster push, where it remains for 3-15 seconds (pp. 3) before firing its nose thrusters to slow down enough to exit The Void at the apex of its deceleration curve. The ship then end-overs and decelerates at 1g for another 4.72 Standard days, at the end of which it has a relative velocity of zero in orbit of the target world.
This means that:
1) It will take little under 9.5 Standard days (9 days, 8 hours, 48 minutes... plus 3-15 seconds) to go from any system to any other system, regardless of the distance separating the systems. In other words, it takes as long to go from Dramune to Cassidine (4 LY distance) as it does to go from Prenglar to Gruna Garu (14 LY distance).
2) This transit time does not take into account the time required to plot the jump. Contrary to popular belief, these calculations do not take place while the ship is boosting at 1g to jump velocity; the calculations have to be complete before the ship starts boosting, otherwise they might have to blow 50% or more of their fuel simply in course corrections; once the the ship starts boosting, changing its vector becomes harder and harder the more velocity it has. The time required is 10 hours per light year of distance for 100% safe in addition to the transit time. Yes, this can be reduced (in houseruled theory) by using a second astrogator or sophisticated computers down to 1 day per 2 LY, but anything less than 10 hr/LY is risk-jumping, which is not a good thing. (I will address this a in a little bit.)
3) Transit is technically not “system to system”, but “specific location in one system to specific location in a system (which may or may not be a different one from the point of departure”. This is due to the hard reality of the canon description of FTL space travel: going in a straight line from one world to another. This means that the routes in the Frontier Maps are not so much (for example) “Prenglar to Cassidine”, but “Gran Quivera to Triad”, “Gran Quivera to Rupert's Hole”, “Morgaine's World to Triad”, “Morgaine's World to Rupert's Hole”, their reciprocal routes, and even in-system routes. This means that if the Sathar fleet is seen to boost toward the Prenglar system from Cassidine, the Spacefleet Task Force at Lossend (Timeon) has to choose whether to travel to Gran Quivera or to Morgaine's World; they could have both routes pre-plotted by starting calculations to every world in range from the moment they jumped into Timeon, but they need to pick one before starting to boost, because the two target worlds are in very different positions in the target system.
4) Yes, only one set of calculations needs to be made for the entire task force, provided they are headed for the same target destination; the calculation is performed for the largest (i.e. most complicated) ship and all the other ships simply boost in formation locking their vectors to the lead ship. As mentioned above, while boosting out, the astrogators of the lesser ships can start calculations on outbound vectors from their destination to all other potential target destinations, saving time in the process.
5) The calculations all assume a 1g transit; ships could transit faster by boosting more aggressively at the possible expense of crew health. A crew from New Pale (for example) could boost at 1.4g without any ill effect, since that is the standard gravity of their world. This requires homebrewing rules for high-g health risks and crew performance penalties, but this could cut transit times significantly.
In a nutshell, the “one transit box = 1 day” is an in-game simplification to make for an exiting, quick game, but it does not reflect the actual rules, both explicit and implicit.
Now, regarding overhauling engines, that is a whole different issue.
First things first: atomic drives are not overhauled while the ship is boosting (either accelerating or while decelerating), even if the engine is shut down; it is not only not being performed in freefall, but the radiation from the active engines would be dangerous for the engineers.
Ships that are HS 12 or more might have their nacelles mounted on retractable pylons so that any two opposing engines might be retracted into the engineering section for overhauling while the remaining 2-6 engines continue boosting at 1g, but these ships can make either three or twelve trips between overhauls, so it is not as problematic for them to transit quickly.
Even ships that are HS 5-11 can make three jumps between overhauls, so even frigates (HS 5) can move relatively quickly across the frontier.
Heck, we do not have to worry about support and supply ships, regardless of size, since these generally use ion drives, which do not require overhauls the way atomic rockets do.
The main issue are the assault scouts; their two atomic engines require an overhaul after every jump (I will get to this shortly), and the fact that there are two that are mounted far apart means that the ship cannot be boosting on just one engine (not without “listing” as it is vectoring diagonally to its axis.
There is nothing in the rules that states that a ship must be docked in order to be overhauled, but many players think it is a requirement because they are confusing the atomic drive overhauling rule (pp. 13) with the annual maintenance rules (pp. 10) which does require drydocking. For the record, atomic drive overhauls do not require docking, only time (and the engine must be offline, duh); thus it can be performed on a planetary surface, in the microgravity of a space station hangar, or in freefall.
When all is said and done, it really does not take that long; each engine takes 60 hours minus 1d10 per engineer level, which could be disastrous if it is done after the jump but before deceleration... unless enough time/distance was added in the plotted jump calculations to allow for up to six days of freefall at 1% the speed of light before deceleration thrust begins.
Not a particularly good idea.
The other problem is how we are defining a “jump”; as we have seen, there is no additional energy requirements for jumping. If we go my the as-written definition of atomic fuel expenditure, a ship could theoretically accelerate and decelerate multiple times up to and from jump velocity without actually jumping, and the atomic pellet will remain as good as new. Obviously this makes no sense; it has to be assumed that the fuel pellets provide enough thrust to accelerate at 1g from a relative velocity of zero to 1% the speed of light and back down to zero (with a safety margin to provide enough thrust for one takeoff and one landing in a 1g world).
With proper calculations, we can determine just how many “thrust points” each pellet provides and thus determine when the engine needs to be overhauled based on how many thrust points have been processed through the engine. This will allow us to determine that, for example, a HS 3 ship with a single atomic engine (yes, it is legal and by-the-book) could make two jumps before overhauling, simply because of the lesser strain on the drive.
Yes, I did make these calculations many years ago, but recently discovered an error that made some of the numbers questionable and requiring revision.
So, the question becomes: how does a task force including assault scouts maintain cohesion in fast transit?
You need to understand that a fleet does not have to remain in close formation in transit, even if they are maintaining position relative to each other; the realities of 3d vectored thrust maneuvering, combined to the vastness of space, mean that the sort of naval formations used by 2d wet navies are all but useless.
Generally speaking, the fleet stays together, but when speed is an issue, there are alternatives to waiting for the overhauls if the jump calculations are done.
The first option, particularly viable if the time time difference is not too large, is to have the scouts finish their repairs then boost at high-g to make it to jump velocity in time to jump with the rest of the fleet, then they all decelerate together.
The second option is to detach the scouts and have them jump separately behind the rest of the task force.
A third option is using them as the name implies; part of the scout force jumps ahead of the fleet and... scouts. They scan the system, start calculations for the next jump, and overhaul their engines. When the fleet arrives, they transmit their data and if fleet action is not imminent, they jump ahead to the next system, relieving the scout that is there; itself jumping ahead and so forth.
The most likely is leapfrogging. You must have noticed that militia ships can only jump one system away from their home system (and then only if their home system is not imminently threatened); there is a good use for this; when the fleet jumps in-system, the militia scouts join it while the fleet scouts stay behind overhauling their engines and covering the system while the militia scouts jump with the fleet to the next system. At the next system, the first militia ships stay behind while the second militia ships join the fleet in their place as the fleet jumps again. When the fleet scouts show up, they relieve the first militia ships (so they can jump back home) and stay in their place until they finish their engine overhauls (hopefully the militia astrogators also plotted the jump for the fleet scouts as well as their own).
Through leapfrogging, the fleet always has scouts available to it and the systems are not left undefended.
In conclusion, fleet deployments in the Star Frontiers setting are doable, but they are not as easy to organize as the Second Sathar War mini-game has it appear to be.