Could someone please explain drop tanks to me.
Who: Is there a specific skilled person needed to transfer fuel from the tanks?
Who and What: Is there a specific skilled person needed to mount the tanks to the ship? Is there a specific type of ship that delivers and mounts them, or is it done in a shipyard?
What: What is the cost of jump tanks?
What: Do drop tanks typically include the fuel or are they provided empty and you have to go fill them up? Are they interconnected with ships systems so that you can fill them in a similar way that you would a ships normal fuel storage (skimming, or landing in water) or do they need to be filled via an outside receptacle at a fueling depot or by a tanker or refueling vessel?
Where: What path does the fuel take when transferred; the complete path from tanks to final utilization? For example, can unprocessed fuel be sent through on ship processors? Is it somehow scanned to determine what type of fuel, perhaps to ensure it is not contaminated (tampered with to cause malfunction of drives)?
When: At what point in time when heading out to the jump limit and prior to jumping is fuel transferred?
How: How long is the transfer? A certain amount per min or hour? Does it vary based on size assuming larger ships and tanks have more connections for transferring fuel? Or better yet, how long from the start of transfer till tanks are dropped and ship is ready to jump?
If possible, give a reference to what Mongoose book and page it's on. On second thought, give any references. I'm sure I'm not the only one interested.
Mongoose, I know zip to zilch about. I'm a CT player. Drop tanks emerge from CT Book 5 (High Guard):
"Disposable fuel tanks may be added to the ship to increase its [the ship's] range. These L-Hyd Tanks are fitted to the outside of the ship, and drop away before jump. The result is more interior space available for cargo and passengers. Such tanks must be replaced each time they are used, so they are practical only on runs to civilized areas, or to increase fuel capacity to allow several jumps. L-Hyd tanks are installed outside the hull, and increase the total tonnage of the ship; drives are reduced in their efficiency based on the total tonnage of the ship. With tanks retained, efficiency is decreased, and jump capability is reduced; when the tanks drop away, tonnage is reduced, and the drive efficiency is increased. L-Hyd Tanks cost Cr10,000, plus Cr1,000 per ton of fuel carried."
Ships jump by consuming a vary large quantity of hydrogen fuel in a very short time. How they do that varies: in CT, the power plant is still required for power, and there's no clear explanation of what the jump-consumed hydrogen is doing (I always envisioned it being collapsed into a little singularity); in MT, the jump drive requires no external power and is instead some sort of uber-powerplant quickly delivering massive amounts of power to the jump grid on the hull.
The drop tanks deliver that fuel, but they increase your ship's size, therefore reducing jump range if you decide to keep them through the jump (bigger ship + same size drives = reduced jump range). In that guise they're just the same as your inboard fuel tank, except they're destroyed more easily in combat. You buy the fuel to fill them same as your regular fuel. The more common technique is to draw the fuel from them immediately prior to jump, jettison them, and then jump - which leaves you able to do your normal jump range and with your inboard fuel tanks still full and ready to use after you emerge from that first jump.
Tricky part there is that your jump drive needs to be designed to give you that little bit of time needed to jettison the drop tanks. Jump drives ordinarly throw you into jump space immediately; any little delay and the drives go boom and obliterate your ship, unless they've got the kind of capacitors that will tolerate the brief delay. Thus we have the occasional discussion of who has drop tanks and where they're available. In canon, General Shipyards had a devil of a time getting the things to work right - possibly complicated by sabotage from agents employed by competitors. So, you can't just mount drop tanks on your free trader or subsidized merchant and then go hopping about - not without some retrofitting to allow the plant to handle it, I think. (Depends on how you interpret Adventure 5.) However, any ship specifically designed to use drop tanks is assumed to have the necessary type of drive to use them.
CT has no special rule about
who does the work of mounting the tanks to the ship, just that it's done at the shipyard: "they are practical only on runs to civilized areas." (I don't pay much attention to who loads my cargo either, so long as it gets loaded.) One presumes the Navy has the necessary skills and tools to carry the things out to their warships in the "field", in the cargo hold of a handy freighter, and then mount them in the field, but that isn't specifically stated. The things aren't reusable, one of the odd bits of canon.
CT has no special rule about needing a specific skill to use them - or by extension a specific person with the skill. Barring such, one presumes any competent ship's engineer knows what buttons to push.
CT has no special rule about filling the drop tanks. In fact, they do not affect streamlining, so you could scoop if you wish.
CT does not describe the fuel purification process. It's not clear whether the fuel is being purified as it's loaded into the fuel tanks or en route from the fuel tank to the power plant/drive. Ergo, it's not relevant to the game mechanic and can be ignored - however its done, the only relevant fact is that purified fuel is arriving at the plant/drive.
CT does not describe the fuel consumption process involved in use of the jump drives beyond some hints that imply it's a quick process occurring immediately before jump and that any delays or interruptions can be very, very bad for your health. CT does say it takes a bit of time to
power the jump drives: under High Guard, two turns (40 minutes) power from a power plant whose rating is at least equal to the jump range being attempted, or one turn if your power plant rating is twice the jump range being attempted - and if your plant can't generate the needed power in two turns, you don't go anywhere. However, since the jump drive draws on that power AND consumes fuel, it's not clear when in that process the jump drive is sucking up fuel or how long that takes. One thing is that if some damage makes it impossible for your plant to deliver that second turn's power, you don't go boom, so it's likely that the fuel consumption process takes less than 20 minutes.
MegaTraveller handles things similarly but not quite the same. In MegaTrav, the drop tanks are only added when needed and drop away prior to jump, so have no effect on jump range. There's no carrying them around. (If you want something you can carry around, you mount exterior demountable tanks.) And in MegaTraveller, the jump drive consumes the fuel to generate power; it doesn't draw power from the power plant. I don't know MegaTrav well enough and don't own enough of the books to know if there's a boom-boom problem; I think it's just a case of the jump being aborted unless something happens at the same instant you're activating the jump field, so if something happened to prevent the tanks from being jettisoned, the jump would just be aborted.
