l0rDn0o8sKiLlZ
05/14/18 10:07 PM
73.251.251.247
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Title says it all; so here's my questions:
EDIT: 30-ton corrected to 35-ton.
EDIT-Mk.2: Posting the Work in Progress designs from MegaMekLab to the Designs thread for the curious.
A: Is 6-tons of fuel adequate for a 35-ton* Aerospace Fighter?
B: What kind of range would 6-tons of fuel give an Aerospace Fighter w/ a 210 rated Engine and 8/12 movement?
C: What kind of range would 15-tons of fuel give an Aerospace Fighter with a 12 rated Engine and 4/6 movement?
D: What are your thoughts on how much (or little) an Aerospace Fighter should have and why?
E: What does your design process look like?
Off-Topic:
A: How does the RL10(Bomb) weapon work? Is it an internal bomb bay? Can it be mounted externally?
B: Can you utilize a Command Console Cockpit with an Aerospace Fighter? If so, what does it do? And can you mount a C3 Master Unit on it? I'm looking to make an AWACS / Satellite style hybrid for a Command and Control Aerospace Unit at 60-tons w/ 15-tons of Fuel.
"Woad Raider, kill things today."
Edited by l0rDn0o8sKiLlZ (05/14/18 11:17 PM)
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Cray
05/15/18 07:51 PM
97.101.136.19
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A: Is 6-tons of fuel adequate for a 35-ton* Aerospace Fighter?
The typical fuel load for any BT fighter is 5 tons. More than that is an advantage.
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B: What kind of range would 6-tons of fuel give an Aerospace Fighter w/ a 210 rated Engine and 8/12 movement?
In space: unlimited. Once you're in orbit or achieve escape velocity, you can drift forever (compared to typical game time scales, anyway).
In air: In the atmosphere, you need to expend 1 fuel point per thrust point spent per turn. However, the length of turn, size of the hexes, and thrust points spent per turn depend on your altitude (low altitude map, high altitude map.)
Low altitude
Per Total Warfare p.81-85, The low altitude map uses hexes that are 1 BT ground map board across (i.e., 500 meters) and turns that are 10 seconds long. Per p. 85, winged units do NOT travel like ground units. Instead of spending thrust points to cross hexes, you spend thrust points to change velocity.
A 'Mech or VTOL on the ground map will spend 9 MP to travel across 9 flat, simple ground hexes. A fixed wing vehicle on the low altitude map expends thrust to change velocity, so a fighter that spends 9 thrust (and thus 9 fuel) reaches a velocity of 9 and covers 9 hexes that turn.
"But wait, didn't you just say it doesn't move like ground units...?"
Hold on a second, I'm getting to it.
On turn number 2, that fighter traveling at 9 hexes per turn doesn't have to spend 9 thrust points to maintain its velocity. Instead, per p. 84 TW, they have to pay half their velocity in thrust points (round down) to maintain their current speed (if they want to). That fighter traveling at 9 hexes per turn only needs to spend 4 thrust points (and thus 4 fuel points) to continue traveling at 9 hexes per turn.
Fuel consumption on the low altitude map is thus half your velocity (round down) per 10-second turn.
6 tons of fuel is 80 points x 6 = 480pts of fuel.
Figuring you waste a ton launching and landing, that leaves 400 points of fuel to move at low altitude. From the above discussion, you can see you'll cover about 800 hexes on 400 points of fuel. The time required will vary depending on your velocity (max of 2x safe thrust at low altitude), but it works out to (roughly) 2 hexes per fuel point.
800 hexes at 0.5km each equals 400km range, or about 240 miles. Sucks, right?
But low altitude flight represents afterburning, dodging, jinking, combat flight. Try moving onto the high altitude map, which overlaps the low altitude map and is suitable for peacetime flight at reasonable altitudes.
High altitude fuel
High altitude movement (in rule terms) is more like moving in space, but with annoying atmosphere effects, and is covered from p. 79 to 80 in Total Warfare.
High altitude movement turns are the same as space turns (60 seconds long) and the hexes are 18,000m across. You're going to go a lot further on a tank of gas in high altitude movement mode.
Also, you do not lose half your velocity per turn on the high altitude map. Instead, you lose 1 velocity point per turn, period (unless you pop your air brakes). It takes 2 thrust points to accelerate.
Finally, there are safe velocity limits depending on altitude. (Altitude 0, ground row/low altitude: 2 hexes per turn. Row 1 [18-35km altitude]: 3 per turn. Row 2 [36-54km]: 6. Row 3: 9. Row 4: 12. Space interface: 15.)
Since you're only losing 1 velocity per turn and spending 2 thrust points (2 fuel points) to offset that drag, it quickly becomes apparent that "faster is more fuel efficient, and faster means higher altitude."
However, conventional fighters (and support vehicles) are limited to rows 0 and 1. The only thing traveling higher and faster are aerospace fighters and other spacecraft, who don't need to fart around in the atmosphere. For about 1 ton of fuel, they can pop into orbit (above the interface, and about 30 hexes/turn) and reach anywhere on an Earth-like planet in 45-50 minutes.
Therefore, I'll only calculate range for high altitude movement in row 1 (~60,000ft altitude, 18km). The safe limit there is 3 hexes per turn. At high altitude, 1 hex per turn (18km / 1 minute) is about mach 1. So, this scenario is looking at traveling at about mach 3 at about the cruising altitude of an SR-71.
You're covering 3 hexes per turn using 2 thrust points to maintain velocity. That 2 fuel points per turn. Figuring you set aside 1 ton for takeoff and landing, that's 400 fuel points again. 400 fuel points will last 200 turns.
During each of those 200 turns, you cover 3 hexes. Total range: 600 hexes. Size of a hex: 18km. 600 x 18km = 10,800km (~6500 miles.)
Much better than low altitude flight, right?
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C: What kind of range would 15-tons of fuel give an Aerospace Fighter with a 12 rated Engine and 4/6 movement?
In space: unlimited.
Low altitude: 14 tons (setting aside 1 for takeoff and landing) x 80pts / ton = 1120pts.
1120pts x 2 hexes/pt = 2240 hexes.
2240 hexes x 0.5km/hex = 1120km (~700 miles).
High altitude: again, assuming row 1 movement at 3 hexes per turn and 2 fuel points per turn, 1120pts of fuel yields 560 turns of movement.
560 turns x 3 hexes / turn = 1,680 hexes.
1680 hexes x 18km / hex = 30,240km (18,900 miles)
Note that thrust and engine rating were irrelevant for range, for the most part.
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D: What are your thoughts on how much (or little) an Aerospace Fighter should have and why?
I like 6 to 10 tons. It gives more endurance than the 5-ton standard. In space, you'll be able to reach higher velocities and cut travel times better than standard fighters. 10 tons is enough to start talking about chasing DropShips, which can shift to strategic fuel mode and outrun most fighters. (For any military DropShip, that 1.84 tons of fuel per day at 1G, i.e., 2 thrust points.)
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E: What does your design process look like?
I start with the fighter's concept/role, faction, and tech level, and go from there.
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A: How does the RL10(Bomb) weapon work? Is it an internal bomb bay? Can it be mounted externally?
As a matter of fluff, on aerospace fighters, all bombs are considered to be inside the vehicle even if they don't count as cargo per se. Bombs and rocket pods dangling outside the fighter would be burned off in reentry otherwise.
RL/10s are used as a "strike" weapon (p. 245 TW) of their normal range and effect.
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B: Can you utilize a Command Console Cockpit with an Aerospace Fighter?
Yes. It's available to BattleMechs, Industrial Mechs, Conventional Vehicles, Support Vehicles, Aerospace Fighters, and conventional fighters, per p. 301 Tactical Operations.
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If so, what does it do?
Many things, depending on the rules you're using. It matters a lot for more advanced play, counting as a satellite communication system, gives initiative bonuses, and other matters scattered throughout Tactical Operation. For conventional BattleTech:
The second MechWarrior ignores hits from ammo explosions
The second MechWarrior can spot for indirect fire without the usual +1 to-hit penalty
The second MechWarrior, if acting as a force commander and not a MechWarrior, gives a +2 initiative to their side
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And can you mount a C3 Master Unit on it?
No. Per p. 209 Tech Manual, Protomechs, fighters, small craft, and DropShips may not mount C3 masters. The C3 system operates on the ground map and isn't suited to aerospace.
Mike Miller, Materials Engineer
Disclaimer: Anything stated in this post is unofficial and non-canon unless directly quoted from a published book. Random internet musings of a BattleTech writer are not canon.
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GunslingerPatch
07/26/18 03:29 AM
216.134.254.194
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I've never liked fighter fuel. For a simple one-off fight it works. But in campaign terms, that fighter was on patrol in space and spent fuel getting to the fight and going back home again. And 5 tons don't cut it for that, not in space and absolutely not on the planet. And lot of dropships and ships have the same problem.
Just look at the 6 tons of fuel or 480 fuel points down in the atmosphere. Let's say you are burning 5 points of fuel a turn... a 10 second turn. You have less than 17 minutes between takeoff and landing. Including getting there, getting back, and combat. So, how far away from the fight is the airfield?
And of course, looking at the canon ships, the fighters don't have a way to refuel and fly more than once do they? Maybe they run on magic brownies. On most dropships, if you use the ship fuel to refuel the fighters... well, the dropship's tank are going to run dry fast.
On a Leopard CV that's 30 tons of fuel per sortie on a ship that carries only 137 tons of fuel and an 87 ton cargo bay. That ship needs it fuel, it is not there to keep the fighters fed. Some fuel is there in the cargo bay I suppose, but just one or two sorties worth, 3 total assuming the fighters already had full tanks, and then that fighter squadron is just 6 paperweights. You can't really say the fuel is in the fighter bay, though the canon does say that, since the bay can hold up to 100 tons of fighter, so there is no room for a fuel tank, spare parts,spare ammo, and the pilot's quarters unless you make the fighter bay a good bit bigger.
To put this in perspective. During the Battle of Britain, the German fighters, once they were over England, had 15 minutes to fight with, any more and they would run out of gas on the way back to France. While a thousand years and more later and a space capable fighter flying down low can stay in the air less than 17 minutes?
When I make fighters, dropships, and jumpships I always give them lots of fuel. It makes me feel better. But even so, mostly you just have to ignore fuel, if you try to keep track of fuel usage by the canon rules, it mostly just won't work. And those new dropships that don't even carry a lousy 100 tons? Ignoring the fuel often works better. It's that or watch them drift off into space after they run out of gas, yelling for the tow truck.
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Retry
07/26/18 01:11 PM
174.70.184.145
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I've never liked fighter fuel. For a simple one-off fight it works. But in campaign terms, that fighter was on patrol in space and spent fuel getting to the fight and going back home again. And 5 tons don't cut it for that, not in space and absolutely not on the planet. And lot of dropships and ships have the same problem.
Just look at the 6 tons of fuel or 480 fuel points down in the atmosphere. Let's say you are burning 5 points of fuel a turn... a 10 second turn. You have less than 17 minutes between takeoff and landing. Including getting there, getting back, and combat. So, how far away from the fight is the airfield?
And of course, looking at the canon ships, the fighters don't have a way to refuel and fly more than once do they? Maybe they run on magic brownies. On most dropships, if you use the ship fuel to refuel the fighters... well, the dropship's tank are going to run dry fast.
On a Leopard CV that's 30 tons of fuel per sortie on a ship that carries only 137 tons of fuel and an 87 ton cargo bay. That ship needs it fuel, it is not there to keep the fighters fed. Some fuel is there in the cargo bay I suppose, but just one or two sorties worth, 3 total assuming the fighters already had full tanks, and then that fighter squadron is just 6 paperweights. You can't really say the fuel is in the fighter bay, though the canon does say that, since the bay can hold up to 100 tons of fighter, so there is no room for a fuel tank, spare parts,spare ammo, and the pilot's quarters unless you make the fighter bay a good bit bigger.
To put this in perspective. During the Battle of Britain, the German fighters, once they were over England, had 15 minutes to fight with, any more and they would run out of gas on the way back to France. While a thousand years and more later and a space capable fighter flying down low can stay in the air less than 17 minutes?
When I make fighters, dropships, and jumpships I always give them lots of fuel. It makes me feel better. But even so, mostly you just have to ignore fuel, if you try to keep track of fuel usage by the canon rules, it mostly just won't work. And those new dropships that don't even carry a lousy 100 tons? Ignoring the fuel often works better. It's that or watch them drift off into space after they run out of gas, yelling for the tow truck.
Well, for starters in an atmosphere you cruise around on the high-altitude map thing if you actually want to get around (which iirc have 60 second turns), and fuel goes a lot further up high too. You only go low if you want to strafe something, really. Cray can give you more specific info with hard numbers.
A carrier dropship would carry spare fuel among its allocated cargo space, presumably not from its own fuel capacity which may not even be compatible with fighter fuel.
The Leopard CV, it's a fairly short-ranged, low-endurance vessel. That's understandable though; at under 2,000 tons it's far lighter than your typical sea-based escort carrier, and they're not jump-worthy on their own, so they'll either be 1.Operating planetside or stationside with friendly facilities capable of restocking the dropship or 2.Being dragged by via Jumpship or Warship which will also be carrying other Dropships stocked with consumables & have sizeable consumable cargo space allocated themselves.
WWII fighters are piston-engined air breathers, while BT Aerospace Fighters obviously cannot be air-breathing engines as there's no air in space. BT ASF are more rocket-y like the Me-163 or the various space rockets & shuttles, less efficient and much lower endurance. Even then BT rockets are actually notoriously efficient, being able to sustain multiple G's (sometimes even 10s of Gs) of acceleration for quite a decent chunk of time (modern jets can manage a little over 1G on a good day). BT Conventional Fighters are basically air-breathing jets though. It's also worth noting that among the improvements that Jets gave to air combat, endurance is not on the list. Modern fighters simply cannot stay in the air as long as a vintage P-47, P-51, or F-82, although they don't need to.
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Cray
07/26/18 06:03 PM
67.8.230.40
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Just look at the 6 tons of fuel or 480 fuel points down in the atmosphere. Let's say you are burning 5 points of fuel a turn... a 10 second turn. You have less than 17 minutes between takeoff and landing. Including getting there, getting back, and combat. So, how far away from the fight is the airfield?
Why not try high altitude movement? 6 tons of fuel will get you over 10,000 kilometers. See the calculations and rules citations I provided earlier.
Mike Miller, Materials Engineer
Disclaimer: Anything stated in this post is unofficial and non-canon unless directly quoted from a published book. Random internet musings of a BattleTech writer are not canon.
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GunslingerPatch
07/27/18 01:33 PM
216.134.254.194
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It doesn't work. I don't need math to know it. High altitude, low altitude, the engine has to produce thrust to keep it flying and that burns fuel. In this case, water, heated and turned into thrust. To take the same 6 tons of fuel that can keep a fighter in the air less than 17 minutes at low elevations and then say up high that's a 10,000 mile range doesn't work.
Have you ever read about how many thousands of pounds of fuel a jet fighter goes through in just one outing? An F-18 is a dwarf next to a 50 ton aerotech fighter.
There are many things in Battletech that have such huge problems, which is why so many huge problems just get ignored in the canon. But unlike others, this particular problem had a simple and easy fix all along... that was never used to fix it.
Just change the fuel usage. It still wouldn't be realism, but it could fix it. Make fuel usage all the same in atmosphere, low high, don't matter, combat and non-combat usage would matter, like ships in space. Make a ton of fuel a lot more fuel points as well. And then a fighter with 5 tons of fuel, in space or cutting air, would have a big enough fuel tank for the job. A fighter's range is its endurance, how long can it fly, how long can it fight, before it has to leave? It probably still wouldn't be very realistic, but it would beat the hell out of what we have now.
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Cray
07/27/18 03:21 PM
67.8.230.40
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It doesn't work. I don't need math to know it. High altitude, low altitude, the engine has to produce thrust to keep it flying and that burns fuel.
That's what the rules say: if you stop producing thrust, your speed falls and then you fall.
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To take the same 6 tons of fuel that can keep a fighter in the air less than 17 minutes at low elevations and then say up high that's a 10,000 mile range doesn't work.
The low altitude performance is a bit nerfed, but it represents after burning combat maneuvers. You can use the "high" altitude map in the ground row - the same altitudes as the low altitude map - and get most of 10,000km range, too.
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Have you ever read about how many thousands of pounds of fuel a jet fighter goes through in just one outing? An F-18 is a dwarf next to a 50 ton aerotech fighter.
An F/A-18E/F is 30 tons (29,937kg, if you're nitpicking). The F-18's low-bypass turbofans are also much less fuel efficient than fusion torches, so the fact that an aircraft technologically 1,000 years behind a BT aerospace fighter needs up to 13,000kg of fuel to get less range isn't surprising.
Mike Miller, Materials Engineer
Disclaimer: Anything stated in this post is unofficial and non-canon unless directly quoted from a published book. Random internet musings of a BattleTech writer are not canon.
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Retry
07/27/18 04:10 PM
174.70.184.145
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It doesn't work. I don't need math to know it. High altitude, low altitude, the engine has to produce thrust to keep it flying and that burns fuel. In this case, water, heated and turned into thrust. To take the same 6 tons of fuel that can keep a fighter in the air less than 17 minutes at low elevations and then say up high that's a 10,000 mile range doesn't work.
Have you ever read about how many thousands of pounds of fuel a jet fighter goes through in just one outing? An F-18 is a dwarf next to a 50 ton aerotech fighter.
There are many things in Battletech that have such huge problems, which is why so many huge problems just get ignored in the canon. But unlike others, this particular problem had a simple and easy fix all along... that was never used to fix it.
Just change the fuel usage. It still wouldn't be realism, but it could fix it. Make fuel usage all the same in atmosphere, low high, don't matter, combat and non-combat usage would matter, like ships in space. Make a ton of fuel a lot more fuel points as well. And then a fighter with 5 tons of fuel, in space or cutting air, would have a big enough fuel tank for the job. A fighter's range is its endurance, how long can it fly, how long can it fight, before it has to leave? It probably still wouldn't be very realistic, but it would beat the hell out of what we have now.
No, that's not how that works at all.
A prime reason a fighter needs to constantly expend thrust is to counteract the effects of atmospheric friction, or drag, which constantly works to slow the fighter down. Drag is directly proportional to atmospheric density, twice as much "stuff" in the way means you're getting slown down twice as much, and you'll have to pump in twice as much thrust (and roughly twice as much fuel) to counteract that force and stay flying at a constant velocity.
The atmospheric density at sea level is about 1.2 kg per cubic meter. At 60k feet that drops to about .1 kg per cubic meter, so around 10% of the drag, requiring ~10% of the thrust to counteract the drag. You might need a higher angle of attack and a bit more thrust than that to make up for the corresponding loss in lift, but BT's aerospace fighters produce insignificant lift in the first place and are basically bricks with huge engines so that won't change much, net result is a massively increased combat radius by flying at higher altitudes. The largest radius can be achieved by going to orbit where there's no drag because there's no atmosphere, so an Aerospace fighter pilot can go from one side of Jupiter (or a ~130,000 mile range) to the other simply by using its gravity to orbit the planet using marginal amounts of fuel to correct as necessary.
This holds for real-life atmospheric fighters as well: Combat missions for aircraft (As detailed by their Standard Aircraft Characteristics sheets, or SACs) start by climbing up to a high altitude and cruising to their location, as they wouldn't manage to get nearly the range they do by flying nap-of-earth. This also holds for commercial airliners, of course.
Ex:Below is a SAC for the FJ-4 fury, an official govt document detailing the performance specifications of a fighter from ages past. Observe pg.5 with the Radius vs Altitude graph, and note the how the fighter's combat radius increases with altitude. Also note pg.6 where the general "combat missions" sections all include a segment where the fighter climbs high to cruising altitude shortly after takeoff.
http://alternatewars.com/SAC/FJ-4_SAC_-_30_August_1958.pdf
Battletech's Aerospace Fighters is fluffed as a "fast-pumping, dual-chambered fusion engine", so it's not necessarily spewing out heated water. And the Conventional Fighters certainly don't use heated water, of course.
A lot of what you're saying are "problems" aren't. For instance,
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Just look at the 6 tons of fuel or 480 fuel points down in the atmosphere. Let's say you are burning 5 points of fuel a turn... a 10 second turn. You have less than 17 minutes between takeoff and landing. Including getting there, getting back, and combat. So, how far away from the fight is the airfield?
If you're expending 5 points of fuel a turn, you're creating 5Gs of acceleration from your engine. Firstly, you're not cruising to the fight if you're at that level of acceleration, you're making wild maneuvers close to the ground evading Rifleman & Partisan fire and jousting Angels & Corsairs pretending you're in Top Gun. 17 minutes at 5Gs acceleration with only 6 tons of fuel is insanely efficient.
Secondly, if you're a 100 ton Aerospace fighter, that means you're producing almost 5 meganewtons of thrust. And for 99% of Aerospace Fighters (including most 100-ton designs), that's still in its Safe Thrust envelope. A F-18 can't even manage a tenth of a Meganewton of thrust with its two engines unless it's got its afterburners on, and then it still only makes just over .15 meganewtons.
I'm not 100% sure the maximum amount of energy Aeros can extract from the fuel, but if you give 'em too many thrust points you might have them extracting more energy per ton of fuel than there is in a ton of matter. BT engines are that good.
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Just change the fuel usage. It still wouldn't be realism, but it could fix it. Make fuel usage all the same in atmosphere, low high, don't matter, combat and non-combat usage would matter, like ships in space. Make a ton of fuel a lot more fuel points as well. And then a fighter with 5 tons of fuel, in space or cutting air, would have a big enough fuel tank for the job. A fighter's range is its endurance, how long can it fly, how long can it fight, before it has to leave? It probably still wouldn't be very realistic, but it would beat the hell out of what we have now.
If fuel usage was the "same" in all atmospheric ranges for a unit of range, then the fighter fusion rocket engines would magically lose massive amounts of efficiency just by climbing high as opposed to hugging the ground. That's much less realistic, not more.
If I were to change anything, I'd make fuel points inversely proportional to weight, so a 5 ton fighter engine isn't 20x less efficient than a 100 ton fighter with 20 times less newton-seconds of impulse. So a 50 ton design might have 80 points per ton, a 100 ton may have 40 points, and a 25 ton design has 160 tons. At least, for fighter craft, I'd rather not mess too much with dropships & warships if I don't have to.
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GunslingerPatch
07/28/18 12:09 AM
216.134.254.194
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Fuel points by weight of the fighter I could go with, though many larger fighters would need redesign since almost everything of every weight has a 5 ton fuel tank. Either way, I think fighters need lots more points per ton for the distances at which they operate to make sense.
I'd like most any change that would mean you could expect a fighter to go out and patrol or run an attack and not be concerned overmuch about how much time the pilot has to get stuff done and get back to base. The Germans had 15 minutes. 1000 years later, an aerotech fighter should be able to go a lot farther than that, have an hour or more to hang around and fight and not run out of gas. Or come down from orbit and go back and not run out of gas. And it should be something you can do and it be within the rules instead of largely just ignoring the fuel entirely.
Dropships and jumpships. Well, when I make one it has more fuel in the tanks than anything canon does. Since fuel for these units is expressed as not just points, but how many days or normal and combat ops will it have, I have an easier time ignoring fuel points when there is an actual space battle. Except that there are canon dropships out there that if they make a one week run in from the jump point and back out again, at normal speed, their tanks are dry.
One thing never done, is a statement on how much fuel a dropship expends when landing on a planet, or taking off from a planet. This would be important, esp. with a dropship that only have 50 tons of fuel on it, much less 100. A Leapard with 137 tons of fuel uses 2 weeks of fuel and normal speed to go in and out from the jump point, we can do that math and see how many tons that is. But how many tons of fuel did it cost to land and take off? No combat maneuvers in atmosphere, just land and take off. We have no number for that.
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ghostrider
07/28/18 01:39 AM
66.74.61.223
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The problem with space is you can coast at current speeds. Only turns and changing that speed is needed. So the burn days doesn't say it all about round trips to the jump point and back. So that saves fuel.
The ton of fuel for launch/landing sounds a bit high. I could see more fuel being used for a VTOL set, but less for normal aerodyne sets.
Most forces invading a system has dropships with fuel for the combat forces in them. The books suggest there are mammoths that are fuel tankers.
The landing numbers are all dependent on speed of your unit. Fighters should require far less fuel for a single thrust point to keep the fighter in the air. So low altitude, high altitude and space would be like 3 points. Same with launching, which is odd, but the game was not meant to be a math challenge for everything. Dropships would or should use alot more. Spheroids using the most.
As most space flights that I have heard about, you only use thrust for about half the actual flight. Accelerate/decelerate is the only time, other then course corrections that you would use fuel. Granted, if you wanted gravity for the whole flight, then thrust would be applied for the full trip.
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Retry
07/28/18 12:49 PM
174.70.184.145
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Fuel points by weight of the fighter I could go with, though many larger fighters would need redesign since almost everything of every weight has a 5 ton fuel tank. Either way, I think fighters need lots more points per ton for the distances at which they operate to make sense.
I'd like most any change that would mean you could expect a fighter to go out and patrol or run an attack and not be concerned overmuch about how much time the pilot has to get stuff done and get back to base. The Germans had 15 minutes. 1000 years later, an aerotech fighter should be able to go a lot farther than that, have an hour or more to hang around and fight and not run out of gas. Or come down from orbit and go back and not run out of gas. And it should be something you can do and it be within the rules instead of largely just ignoring the fuel entirely.
Dropships and jumpships. Well, when I make one it has more fuel in the tanks than anything canon does. Since fuel for these units is expressed as not just points, but how many days or normal and combat ops will it have, I have an easier time ignoring fuel points when there is an actual space battle. Except that there are canon dropships out there that if they make a one week run in from the jump point and back out again, at normal speed, their tanks are dry.
One thing never done, is a statement on how much fuel a dropship expends when landing on a planet, or taking off from a planet. This would be important, esp. with a dropship that only have 50 tons of fuel on it, much less 100. A Leapard with 137 tons of fuel uses 2 weeks of fuel and normal speed to go in and out from the jump point, we can do that math and see how many tons that is. But how many tons of fuel did it cost to land and take off? No combat maneuvers in atmosphere, just land and take off. We have no number for that.
Why a redesign for heavier fighters? The heavier ones just become short ranged designs and new heavy designs with large fuel tanks can be retconned in as long-ranged fighters.
I don't agree that an Aerospace fighter should necessarily have longer endurance than random propellor fighters from WWII. That's not even true today with more than a half-century as jet engines are just more fuel intensive to get their extremely high performance. Rocket engines, like which you'd need for an aerospace fighter, would be even less efficient than that since they don't breathe air and a certain % of their reaction mass has to contain oxygen instead of getting it for free from the atmosphere. This is reflected in the construction rules for ASF vs ConvFighters a bit.
A millenium of progress is rather misleading. In the BT setting, much of the big tech boosts happened in a period of 200-300 years after now; a city in 3050 isn't a whole lot more advanced than a city in 2750. There's also innumerable limitations due primarily to practical issues and the hard limit of the laws of the universe. A bridge in 3145 is distinctly a bridge and would not be so superior to a bridge in 2020, which isn't a world-beater compared to a bridge in 1950. ICE engines are rather close to their practical maximum thermodynamic cycle efficiencies so their room for improvement is effectively limited by the laws of thermodynamics unless you introduce some sort of unobtainium into the mix (which BT tries to limit, AFAIK the only very obvious example is the K-F drive.)
I think Ghostrider covered the drifting dropship part pretty well.
How much fuel a dropship takes to take off and enter orbit or land is probably something calculable via current rules, I don't have those on hand though.
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happyguy49
08/04/18 02:30 AM
173.199.65.62
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I think it would be useful to equip one dropship of an invading flotilla as a tug. It pushes a big mass of tens or hundreds of thousands of tons of fuel along with all the Q-ships, assault ships, and mech/vee/troop/fighter carriers it travels with. When they all 'flip' to do their deceleration burn, they all hook up to the tug, gas back up to %100 fuel levels and the tug ejects the empty tank. Then the flotilla has much more fuel available for the fighting and planetfall part.
In battlespace, isn't there a lower limit on how big a tug can be? If so this should be discarded. One should be able to use anything with a transit-capable drive (so even Small Craft like a dropshuttle or long-range shuttle) to push a fuel tank to extend its range, or to gas up some attached daisy-chained fighters or a few landing craft.
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ghostrider
08/04/18 03:24 PM
66.74.61.223
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You can make a fuel ship to do what you want a tug for. There is in the fluff of the mammoth that the IS tends to have a tanker version of it to keep fleets in fuel when outside friendly territory.
Though a tug would be an idea, if you think you will take an enemy dropship or might lost the drive on one of yours.
Now there may be an issue with trying to refuel while on a decel burn. Even accelerating would be a problem.
It is probably to dangerous to do so during these times, but then I don't think there is anything in the rules for it.
Not sure why you would have fighters deployed during such times, as saving fuel by having them in the bays on dropships would be the idea.
And having the tug moving the fuel tank would mean it couldn't latch on to a dropship and dock normally. The tanks would probably get in the way.
But is it an interesting idea.
One more thing about this. Not sure how long the IS normally burns for accel/decel. They may well not do the 1/4 burn.
Though I have seen in one story, the dropship was doing a 3g burn. Hell on the crew.
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