How long does it take to scoop fuel
- Thread starter mr31337
- Start date
Here's a summary of what's been written thus far:
Traveller Core Rules (p144) states that scooping takes 1-6hrs and requires a successful pilot check.
Starports (p111) Fuel Transfer equipment allows a fuel tanker to pump 1Dton/turn of fuel
Fuel scoops for ships are 1MCr. Streamlined ships get one for free.
The rules do not mention how many ‘scoops’ a ship has. They reference a fueling ship is at its most vulnerable when in a gas giant, but no definition/stats are provided.
Hydrogen is stored in gaseous form as the standard. It can be stored in liquid form (as L-Hyd) in special tanks that convert the frozen hydrogen to gas as needed.
Captain Jonah wrote: A single fuel scoop can skim 300Dtons of Hydrogen per hour (or 5Dtons per minute). Each additional fuel scoop can add 300Dtons/hr fuel skimming capabilities.
Minimum time to perform any fuel skimming operation is 1hr. Which involves finding an adequate hydrogen-rich area to skim from, and flight time to/from the area.
Ships refueling in a gas giant have 0 agility bonuses and attackers get an automatic +2 to hit. A natural 12 on the die indicates the attack went in through the open fuel scope and all damage is applied as internal hits.
Specialized fuel skimmers would have multiple scoops, aero fins and a lot of fuel tanks.
For example a 200Dton fuel skimmer, streamlined with Aero fins, 2G and a bridge plus a small cabin and a few days of power plant fuel would have tanks for 165Dtons of fuel, at 5Dtons a minute that would be 34 minutes and the aero fins add +2 to the pilot checking giving 2 extra effects and dropping the total skim time by two hours. Add a second scoop and it would take 17 minutes to fill its tanks. A bare bones and fairly cheap ship, all it does all day is skim and return to off load at a set of fuel tanks in orbit above the gas giants atmosphere where the customers can buy it or ship it to the main world or refueling points at the 100D limit.
Did I miss anything?
If anyone is interested, I'd be happy to come up with a more formal thought-process to the whole concept of refueling, vulnerability of refueling ships, tankers in general, etc. I've submitted to MgT an article based around fueling, so I'm very interested in coming up with a reasoned consensus for this.
Traveller Core Rules (p144) states that scooping takes 1-6hrs and requires a successful pilot check.
Starports (p111) Fuel Transfer equipment allows a fuel tanker to pump 1Dton/turn of fuel
Fuel scoops for ships are 1MCr. Streamlined ships get one for free.
The rules do not mention how many ‘scoops’ a ship has. They reference a fueling ship is at its most vulnerable when in a gas giant, but no definition/stats are provided.
Hydrogen is stored in gaseous form as the standard. It can be stored in liquid form (as L-Hyd) in special tanks that convert the frozen hydrogen to gas as needed.
Captain Jonah wrote: A single fuel scoop can skim 300Dtons of Hydrogen per hour (or 5Dtons per minute). Each additional fuel scoop can add 300Dtons/hr fuel skimming capabilities.
Minimum time to perform any fuel skimming operation is 1hr. Which involves finding an adequate hydrogen-rich area to skim from, and flight time to/from the area.
Ships refueling in a gas giant have 0 agility bonuses and attackers get an automatic +2 to hit. A natural 12 on the die indicates the attack went in through the open fuel scope and all damage is applied as internal hits.
Specialized fuel skimmers would have multiple scoops, aero fins and a lot of fuel tanks.
For example a 200Dton fuel skimmer, streamlined with Aero fins, 2G and a bridge plus a small cabin and a few days of power plant fuel would have tanks for 165Dtons of fuel, at 5Dtons a minute that would be 34 minutes and the aero fins add +2 to the pilot checking giving 2 extra effects and dropping the total skim time by two hours. Add a second scoop and it would take 17 minutes to fill its tanks. A bare bones and fairly cheap ship, all it does all day is skim and return to off load at a set of fuel tanks in orbit above the gas giants atmosphere where the customers can buy it or ship it to the main world or refueling points at the 100D limit.
Did I miss anything?
If anyone is interested, I'd be happy to come up with a more formal thought-process to the whole concept of refueling, vulnerability of refueling ships, tankers in general, etc. I've submitted to MgT an article based around fueling, so I'm very interested in coming up with a reasoned consensus for this.
I wouldn't mind seeing such an article, too.
Rules-wise:
Things to note, as it's a skill check:
So an unstreamlined ship (which suffers a DM-2 in an atmosphere) would be at a Net -4 on a scooping run test (making it very difficult). Moving it two time steps up (so an unmodified check) would take 1-6 days (!).
By comparison, a streamlined ship with aerofins (net +0) can afford to push the time increment down by one and still get a check that's not too daunting to a good pilot, doing the run in 10-60 minutes.
Essentially the former represents a ship lowering itself on grav drive only into the upper atmosphere and opening a small hatch, whilst the latter is a ship opening a bloody huge bucket ramscoop during a hypersonic dive through the atmosphere and still managing to stay in control despite the resulting turbulent shock wave forming under its nose. Which - as noted - will draw in enough atmosphere to fill the tanks, at a very high pressure, in seconds, even with a large ship.
The big question in both cases, of course, is "what's the penalty for failing the check?". Obviously it's dependent on the level of negative effect, but a worst case scenario for the latter is much worse than the former..
Rules-wise:
Things to note, as it's a skill check:
So an unstreamlined ship (which suffers a DM-2 in an atmosphere) would be at a Net -4 on a scooping run test (making it very difficult). Moving it two time steps up (so an unmodified check) would take 1-6 days (!).
By comparison, a streamlined ship with aerofins (net +0) can afford to push the time increment down by one and still get a check that's not too daunting to a good pilot, doing the run in 10-60 minutes.
Essentially the former represents a ship lowering itself on grav drive only into the upper atmosphere and opening a small hatch, whilst the latter is a ship opening a bloody huge bucket ramscoop during a hypersonic dive through the atmosphere and still managing to stay in control despite the resulting turbulent shock wave forming under its nose. Which - as noted - will draw in enough atmosphere to fill the tanks, at a very high pressure, in seconds, even with a large ship.
The big question in both cases, of course, is "what's the penalty for failing the check?". Obviously it's dependent on the level of negative effect, but a worst case scenario for the latter is much worse than the former..
\F33D said:
You are correct F33D. I found a reference that basically says if you want metal hydride, it's safer, but takes up twice the storage space.
@Locarno24 - I would think that any ship wishing to efficiently collect hydrogen would be under thrust. But since a) you are in an atmosphere, and b) you are under a heavier gravity influence and c) you have your pod bays open Hal, err, I mean you have your fuel intake scoops open (or even deployed... there a number of ways to do this), you simply can't take any sort of erratic maneuvers or dodges.
So perhaps during the first combat round (assuming surprise, as maybe there is too much EM interference when doing a fuel run?) that the attacker gains +2. Also the defenders defenses would be limited to passive only, such as armor. No maneuverability bonuses, no sandcaster, no anti-missile fire. A natural 12 means your attack penetrated the armor through the open sections of your armor.
It then takes 1 combat round to retract your scoops and prepare for normal combat operations, which would give the attacker a +1 for the 2nd round. During the 2nd round you can deploy defensive systems, but on a roll of 1-2 they are ineffective/you weren't fast enough, 3-4 their effectiveness is halved, and 5-6 its normal defense. Maybe sand should be ineffective in a gas giants atmosphere? And you also get only half your normal agility, with a role for Pilot skill (skill points are a +DM). Maybe roll 8 or better to get full agility, miss the role and you just get half.
During the 3rd round the defending ship would have no penalties associated with refueling.
As to aerofins, I'm of mixed opinion if they should be of use in a refueling operation. They really woudn't do much for the actual sucking in of the gases (I don't think at least). And you would not want to do any sort of hard maneuvering in a GG atmosphere, as you are probably a few kilometers or more down in the soup to get the concentrations required, and that means its denser and you could essentially be flying through a gaseous/liquid atmosphere. I suppose some maneuverability bonus should be applied.
And speaking of depth... I'm wondering just how far down into the GG atmosphere one would need to go? 100km? 500km?
I feel you mean you shouldn't. This is an important difference :mrgreen:
Surprise is surprise; the rules for getting an automatic 12 on initiative if one side's ready and the other isn't works more than well enough - it's merely a case of defining what sort of negative DM a gas giant's atmosphere applies to sensor checks.
I agree sand should be ineffective in an atmosphere, but that should be the case anyway, refuelling or not.
Aerofins are useful if you're going deep enough - essentially giving you the ability to cope with turbulence. As you say yourself, in a dense atmosphere they'll help keep control, and flying through an atmosphere with a bucket scoop open is an inherently turbulence-generating activity - which is why, I guess, the penalty to piloting checks is equivalent to making a streamlined ship non-streamlined.
Depth?
Not too deep. I refer you to Secrets of the Ancients: The Hunt, where our plucky heroes are poking around in the depths of a gas giant for assorted things that any sane person wouldn't touch with a hundred-foot long bargepole.
Note that this is flying searching for a sensor 'ping' rather than fuelling - so fuelling would be -2 worse than the DM's listed!
According to the text in the article, for the gas giant in question:
Vacuum (to any meaningful definition) at 38,000 km
Upper edge of the atmosphere is 37,000 km
fuel scooping is generally done at a 0.5 atmosphere pressure level - 36,500 km.
The cloud layer is 36,000 km (1 atmosphere) and is full of ammonia and methane ice squalls. At this point, there's a -2 penalty for pilot checks and 2D6 damage if you fail (none if you pass)
35,000 km is 300 atmopsheres, a DM-4 to pilots and the damage starts to get seriously terminal (6D6!)
34,000 km is 1,000 atmospheres, DM-8 and is essentially death to anything that's not an armoured capital ship whether you pass or fail the check. 6D6 damage is the good result when you pass the check...
Sensor wise - the sensor DM is -2 at 34,000, which is as low as it goes, and at the surface is -10, dropping in increments of 2. Assuming that works the same both ways, that means there would be a DM-2 to see things at the surface for every 1,000 km you drop into a gas giant's atmosphere.
If those figures are taken as read, that means that failing the pilot test for refuelling is likely to cause about D6 to 2D6 damage to a ship - a real screw-up of the pilot test, though, will send you deeper into the atmosphere - and there'd be a DM-3 or so to spotting a ship up in space on your sensors.
Captain Jonah
Mongoose
I think we have covered everything fairly well.
Try writing it up Phavoc.
Oh and don't forget to credit everyone for contributing :lol:
Try writing it up Phavoc.
Oh and don't forget to credit everyone for contributing :lol:
Well.... what I thought my not be too much of a big deal has decidedly changed. I used my google-fu and went a-searching for similar discussions. And found them. Many of them in fact.
So I now have 15 pages of comments, some in this thread, some that go at least 10yrs back. Evidently this topic has come up more than once.
So I'm going to sift through everything I've found and see what I can come up with that I not only like, but that makes sense and could be utilized if you want to use it in your game.
Wish me luck!
So I now have 15 pages of comments, some in this thread, some that go at least 10yrs back. Evidently this topic has come up more than once.
So I'm going to sift through everything I've found and see what I can come up with that I not only like, but that makes sense and could be utilized if you want to use it in your game.
Wish me luck!
IanBruntlett
Emperor Mongoose
Good luckphavoc said:
Ok, I've been busy with life, but I've been trying to put a little time here and there for this effort.
I wanted to share what I've done thus far. It's rougher than rough, but it's a start.
Be nice!! I don't wanna cry....
Refueling
* Types
• Starport (refined & unrefined)
• Ocean
o Ship must have proper configuration and capabilities to land under gravity
o Planet must have a Hydro rating of 1 or better
• Gas Giant
o Ship must be equipped with fuel scoops
o Only streamlined or standard configurations
• Ice
o Takes 10x as long as GG refueling w/o specialized equipment. Ships equipped for ice refueling take 4x as long.
o Can include comets, ice rings, Oort cloud or ice caps
* Failing your refueling roll indicates a longer time is required to perform the operation.
* Catastrophic failure indicates damage, pressure leaks, radiation, debris collision, ship collision, etc.
Gas Giant Hazards
• Dense/Light pressure pockets – Occasionally pockets of rare gases will form that are more/less dense than the surrounding atmosphere. Flying through these pockets can cause problems with your refueling operation as the atmospheric density changes. Roll 1D6, a natural one indicates a malfunction in your pressurization pipes, and your ship must spend 1D6 turns purging your fuel scooping system.
• Corrosive gas – The ship has been exposed to extremely corrosive gases, causing damage to fuel tank and machinery seals. Requires a complete purging of the fuel system and replacement of seals. Cr10,000 at a Starport.
• Electrical storms – Severe electrical storms temporarily blinds your sensors, cause damage to external systems, or electrical shorts to electronics. Roll on electrical damage table.
• Ionization from refueling – The act of refueling (i.e. having open fuel scoops) causes ionization interference around the ship. This causes localized interference with a ships’ sensors, shortening their effective range, causing sensor echoes, and even blinding the ship beyond visual range.
• Pressure – Civilian ship hulls are rated at 1,000 atmospheres (includes auxiliary vessels), military ships at 1,500 atmospheres and SDB’s with their specialized hulls at 3,000 atmospheres. Standard space suits are good for 100 atmospheres, and enhanced/armored ones can withstand 400 atmospheres.
Altitude Pressure Temp Notes
38,000km Vacuum -
37,000km Trace 150k Clouds, requires 1G maneuver
36,000km 1 300k Clouds, requires 2G maneuver
35,000km 300 1,000k Requires 4G maneuver
34,000km 100,000 2,000k
Note – most ships refuel at altitude between 36,500km and 36,000km
• Thrust requirements – In order to have enough escape velocity to counteract the gravitational and atmospheric pressure, ships exiting a gas giant’s atmosphere must have at least 1G maneuver capability. The chart above lists the minimums for the altitude a ship chooses to travel at.
Refueling Procedures
General Refueling notes
* Civilian ships are equipped to refuel from an external source at 25% of their total fuel capacity per/hour. Small ships, (under 100Dtons) can generally be fueled in 20-30min.
* Military ships are equipped with more robust refueling systems that permit faster refueling (35% of their total fuel capacity per/hour). Military small craft (under 100Dtons) can be refueled within 2 combat turns).
* Fuel systems are designed to operate within a specified operating pressure range. Pumping systems can very how fast they pump liquefied hydrogen. While it is possible for tankers or starports to pump fuel at higher rates, it is not advised. Transferring fuel faster than the receiving ship is rated for can cause leaks within the fuel system, and the ship will start venting liquefied hydrogen that quickly becomes gaseous. Exposure to liquid or gaseous hydrogen is potentially deadly, and explosive. Most starports and refueling ships will not allow vessels to take on fuel in an unsafe manor.
* Ships equipped with fuel scoops gather fuel in 1D6hrs +4. This allows for the randomness of gas giant atmospheres having richer pockets of hydrogen gas. But all ships will take a minimum of 5hrs to fill their tanks, with the average being around 8hrs.
* Fuel scoops are built into the hull of the ship and must be deployed at the proper altitude within a gas giant to function correctly. Deploying them at too high of an altitude and there is not enough atmosphere to be processed. They can be deployed at lower, more dense atmosphere, however due to air pressure the ship must decrease its speed or risk damaging the scoops. Ships are equipped with a sufficient number of scoops to gather fuel. The scoops are extended from the hull approximately 3 meters that channel the gas through openings in the hull, into pipes and eventually into the fuel tanks. Internal baffles and valves prevent gas from flowing back out (the speed of the ship provides positive pressure to keep gas flowing into the tanks. Ships at rest with deployed fuel scoops can actually vent fuel into the atmosphere if the valves are open or damaged).
Gas Giant Refueling Procedures
* Pilot/sensor operator scans atmosphere for area that does not have storms or excessive electrical activity (roll against sensor skill)
* If using civilian sensors, +0 to DM
* If using military, scout or survey sensors, +1 to DM
* Failure of roll, add +2DM to 2D roll to determine if hazard is encountered.
* Once an area has been identified, Pilot directs the ship to the refueling area to begin refueling. (Task - Easy)
* Upon arrival at area and proper altitude pilot opens fuel scoops and sets ship velocity to 500 Kph. During the refueling operation, speed increases or anything more than minor course corrections can cause damage to the internal fuel systems through over-stressing of their components.
* Increasing your speed by 100 Kph increases your fuel collection rate by 10%, up to a maximum of 50%. Any increase in speed beyond 1000 Kph will cause damage to the fuel system and risks internal ruptures.
* Maneuvering beyond basic actions risks damaging your fuel scoops. Scoops may become damaged and cannot be closed/retracted, limiting a ships speed in atmosphere. Exceeding the maximum safe speed will result in the destruction of the external fuel scoops.
I wanted to share what I've done thus far. It's rougher than rough, but it's a start.
Be nice!!
I don't wanna cry....Refueling
* Types
• Starport (refined & unrefined)
• Ocean
o Ship must have proper configuration and capabilities to land under gravity
o Planet must have a Hydro rating of 1 or better
• Gas Giant
o Ship must be equipped with fuel scoops
o Only streamlined or standard configurations
• Ice
o Takes 10x as long as GG refueling w/o specialized equipment. Ships equipped for ice refueling take 4x as long.
o Can include comets, ice rings, Oort cloud or ice caps
* Failing your refueling roll indicates a longer time is required to perform the operation.
* Catastrophic failure indicates damage, pressure leaks, radiation, debris collision, ship collision, etc.
Gas Giant Hazards
• Dense/Light pressure pockets – Occasionally pockets of rare gases will form that are more/less dense than the surrounding atmosphere. Flying through these pockets can cause problems with your refueling operation as the atmospheric density changes. Roll 1D6, a natural one indicates a malfunction in your pressurization pipes, and your ship must spend 1D6 turns purging your fuel scooping system.
• Corrosive gas – The ship has been exposed to extremely corrosive gases, causing damage to fuel tank and machinery seals. Requires a complete purging of the fuel system and replacement of seals. Cr10,000 at a Starport.
• Electrical storms – Severe electrical storms temporarily blinds your sensors, cause damage to external systems, or electrical shorts to electronics. Roll on electrical damage table.
• Ionization from refueling – The act of refueling (i.e. having open fuel scoops) causes ionization interference around the ship. This causes localized interference with a ships’ sensors, shortening their effective range, causing sensor echoes, and even blinding the ship beyond visual range.
• Pressure – Civilian ship hulls are rated at 1,000 atmospheres (includes auxiliary vessels), military ships at 1,500 atmospheres and SDB’s with their specialized hulls at 3,000 atmospheres. Standard space suits are good for 100 atmospheres, and enhanced/armored ones can withstand 400 atmospheres.
Altitude Pressure Temp Notes
38,000km Vacuum -
37,000km Trace 150k Clouds, requires 1G maneuver
36,000km 1 300k Clouds, requires 2G maneuver
35,000km 300 1,000k Requires 4G maneuver
34,000km 100,000 2,000k
Note – most ships refuel at altitude between 36,500km and 36,000km
• Thrust requirements – In order to have enough escape velocity to counteract the gravitational and atmospheric pressure, ships exiting a gas giant’s atmosphere must have at least 1G maneuver capability. The chart above lists the minimums for the altitude a ship chooses to travel at.
Refueling Procedures
General Refueling notes
* Civilian ships are equipped to refuel from an external source at 25% of their total fuel capacity per/hour. Small ships, (under 100Dtons) can generally be fueled in 20-30min.
* Military ships are equipped with more robust refueling systems that permit faster refueling (35% of their total fuel capacity per/hour). Military small craft (under 100Dtons) can be refueled within 2 combat turns).
* Fuel systems are designed to operate within a specified operating pressure range. Pumping systems can very how fast they pump liquefied hydrogen. While it is possible for tankers or starports to pump fuel at higher rates, it is not advised. Transferring fuel faster than the receiving ship is rated for can cause leaks within the fuel system, and the ship will start venting liquefied hydrogen that quickly becomes gaseous. Exposure to liquid or gaseous hydrogen is potentially deadly, and explosive. Most starports and refueling ships will not allow vessels to take on fuel in an unsafe manor.
* Ships equipped with fuel scoops gather fuel in 1D6hrs +4. This allows for the randomness of gas giant atmospheres having richer pockets of hydrogen gas. But all ships will take a minimum of 5hrs to fill their tanks, with the average being around 8hrs.
* Fuel scoops are built into the hull of the ship and must be deployed at the proper altitude within a gas giant to function correctly. Deploying them at too high of an altitude and there is not enough atmosphere to be processed. They can be deployed at lower, more dense atmosphere, however due to air pressure the ship must decrease its speed or risk damaging the scoops. Ships are equipped with a sufficient number of scoops to gather fuel. The scoops are extended from the hull approximately 3 meters that channel the gas through openings in the hull, into pipes and eventually into the fuel tanks. Internal baffles and valves prevent gas from flowing back out (the speed of the ship provides positive pressure to keep gas flowing into the tanks. Ships at rest with deployed fuel scoops can actually vent fuel into the atmosphere if the valves are open or damaged).
Gas Giant Refueling Procedures
* Pilot/sensor operator scans atmosphere for area that does not have storms or excessive electrical activity (roll against sensor skill)
* If using civilian sensors, +0 to DM
* If using military, scout or survey sensors, +1 to DM
* Failure of roll, add +2DM to 2D roll to determine if hazard is encountered.
* Once an area has been identified, Pilot directs the ship to the refueling area to begin refueling. (Task - Easy)
* Upon arrival at area and proper altitude pilot opens fuel scoops and sets ship velocity to 500 Kph. During the refueling operation, speed increases or anything more than minor course corrections can cause damage to the internal fuel systems through over-stressing of their components.
* Increasing your speed by 100 Kph increases your fuel collection rate by 10%, up to a maximum of 50%. Any increase in speed beyond 1000 Kph will cause damage to the fuel system and risks internal ruptures.
* Maneuvering beyond basic actions risks damaging your fuel scoops. Scoops may become damaged and cannot be closed/retracted, limiting a ships speed in atmosphere. Exceeding the maximum safe speed will result in the destruction of the external fuel scoops.
Awesome stuff, phavoc! Thank you for posting it.
However... :wink:
It leads me to the question of how does the addition of Reinforced Structure and Reinforced Hull from the High Guard supplement affect the depth a ship can hang around at? Material published in the past regarding system defense boats have mentioned how some of them can go deeper into a gas giant atmosphere to hide from hostile forces. Anyone have any thoughts on that? I can move the question to another thread if need be.
However... :wink:
It leads me to the question of how does the addition of Reinforced Structure and Reinforced Hull from the High Guard supplement affect the depth a ship can hang around at? Material published in the past regarding system defense boats have mentioned how some of them can go deeper into a gas giant atmosphere to hide from hostile forces. Anyone have any thoughts on that? I can move the question to another thread if need be.
I need to change that reference to being armor factor levels. You are correct the old assumptions and writings referenced something similar. By tying it to armor factors then its possible to include SDB's, but also all other armored starships.
The main problem I'm running into here is that I'm probably making this TOO detailed... but I decided to err on this side since I actually like more information, rather than less. Then I can discard or change what I don't like. And sometimes that's easier than coming up with something new on my own.
The main problem I'm running into here is that I'm probably making this TOO detailed... but I decided to err on this side since I actually like more information, rather than less. Then I can discard or change what I don't like. And sometimes that's easier than coming up with something new on my own.
