Fuel Purification Plant

[Supplement Four]

Originally posted by Tinker:
It breaks the deckplans, because you have to put part of the M-drive tonnage in the centre, with another part at the edge of the ship (the actual plates).

[snip]

On the other hand, it explains why you only need M-drive at the back-end of the ship, rather than small adjusters on the top, bottom & sides to allow the ship to steer.

Actually, having re-read the appropriate section of the SOM, the gyro doesn't have to be in the ship's center. It could very well be in the M-Drive itself.

And, the SOM does specifically state that the T-Plates can be anywhere. They could be mounted on the front of the ship, or even in the center of the ship.

The problem is heat. They generate a lot of heat. So, the most logical place to mount them is on the aft end of the ship. (Too much heat to sink if you mount them internally, and better to have the heat trail off the aft end instead of always "following" the heat wake, as it were).

 

[Supplement Four]

Originally posted by Tinker:
It breaks the deckplans, because you have to put part of the M-drive tonnage in the centre, with another part at the edge of the ship (the actual plates).

[snip]

On the other hand, it explains why you only need M-drive at the back-end of the ship, rather than small adjusters on the top, bottom & sides to allow the ship to steer.

Actually, having re-read the appropriate section of the SOM, the gyro doesn't have to be in the ship's center. It could very well be in the M-Drive itself.

And, the SOM does specifically state that the T-Plates can be anywhere. They could be mounted on the front of the ship, or even in the center of the ship.

The problem is heat. They generate a lot of heat. So, the most logical place to mount them is on the aft end of the ship. (Too much heat to sink if you mount them internally, and better to have the heat trail off the aft end instead of always "following" the heat wake, as it were).

 

[Supplement Four]

You know, it's interesting how the M-Drive and related technology keeps getting re-invented with each version of Traveller.

There's no real "canon" explanation for he M-Drive in CT.

In MT, the canon is Thruster Plates (with the gyro!).

In TNE, it becomes HEPLAR and contra-grav.

In T4, there's FusionPlus powerplants.

Etc.

No wonder this topic is so controversial. There's plenty of canon examples from different versions of Trav to choose from.

 

[Supplement Four]

You know, it's interesting how the M-Drive and related technology keeps getting re-invented with each version of Traveller.

There's no real "canon" explanation for he M-Drive in CT.

In MT, the canon is Thruster Plates (with the gyro!).

In TNE, it becomes HEPLAR and contra-grav.

In T4, there's FusionPlus powerplants.

Etc.

No wonder this topic is so controversial. There's plenty of canon examples from different versions of Trav to choose from.

 

[Supplement Four]

Originally posted by far-trader:
Yep, it's a massive gyro (the only way it makes sense) of superdense composite, spinning at ridiculous speed and the ship changes its orientation by focusing a surrounding cage of grav modules on it.

[snip]

Do you still think this is some baseball or even basketball sized array that can be squeezed into a bulkhead or tween decks? Presuming your ship is so well designed and balanced that the center of mass ends up in such a space and not in say the middle of the Captain's fresher?

BTW, if DGP intended the gyro to be something so big that it must be seen on the deckplans, then they would have included it on the deckplans of the Beowulf class Free Trader featured in the SOM.

Given that, my guess is the gyro is small and fits between decks or in a pylon or something. Or, it's a component of the M-Drive itself.

 

[Supplement Four]

Originally posted by far-trader:
Yep, it's a massive gyro (the only way it makes sense) of superdense composite, spinning at ridiculous speed and the ship changes its orientation by focusing a surrounding cage of grav modules on it.

[snip]

Do you still think this is some baseball or even basketball sized array that can be squeezed into a bulkhead or tween decks? Presuming your ship is so well designed and balanced that the center of mass ends up in such a space and not in say the middle of the Captain's fresher?

BTW, if DGP intended the gyro to be something so big that it must be seen on the deckplans, then they would have included it on the deckplans of the Beowulf class Free Trader featured in the SOM.

Given that, my guess is the gyro is small and fits between decks or in a pylon or something. Or, it's a component of the M-Drive itself.

 

[far-trader]

Meh, you may be right enough after-all S4. After recalling this morning the Skylab gyro trouble one mission I went fishing with the net...

Turns out the gyros (specifically Control Moment Gyroscopes), 3 in the case of Skylab (2 primaries and 1 backup), were not too large. They were 22" diameter flywheels (and associated hardware) spinning at 5950rpm. Taking the size of Skylab to be about 40dton each CMG was maybe 0.01dton total.

But that was for simply fixing and maintaining the attitude of an essentially drifting body. It had its orbital speed of course but that's small potatoes compared to the speed even a 1G ship can reach in a short time.

So a little scaling up may be in order, maybe something on the order of 0.1% of ship volume is enough. Which is small enough that I can concede making it part of the maneuver drive assembly (though I am loathe to just go adding more jobs to an already magic tech assembly at least this one is real ). That also handles the whole "EJECT THE GYRO!" scenario nicely since it is on the hull and I'm not so sure they'd need to be at any center of mass either.

However...

The RPM still sounds ridiculously dangerous. Taking 900,000 rpm on a 22" wheel comes to something like 60,000mph

I'll concede that having that kind of momentum to use would be enough to provide very quick attitude adjustment even with the ship having a high load of potential momentum. But hey, dangerous can be fun

And it gives the Engineer something to point at for the curious Traveller...



<opening up the inspection window hatch the Engineer comments...> "There it is, the heart of the maneuver drive, the CMG."

"Umm, it doesn't look like much, just a big shiny sphere."

"Here let me set the diagnostic strobe, right now its spinning at almost 1 million rpm, too fast for the human eye to see the parts."

<the strobe cycles up until it nearly matches the frequency of the spinning gyros>

"Oooooh, that IS cool! There's like three wheels all turning one inside the other in different planes. So, what happens if it breaks?"

<closing the inspection window hatch the Engineer very seriously says...> "It's not so much if as when. And when it does no one wants this hatch open. The whole inside of the chamber becomes a white hot stream of molten superdense composite. It'd burn right through that window, and everything short of the bulkhead, including anyone standing in front of it. Only ever heard of that happening once though. Most of then time when one fails the hatch is closed and the explosion safely exits the back of the ship through the blowout hatch at the other end."

Naturally the minds of most PCs are turning to the weaponization of this feature right about now

I'd indulge it, if they can contrive a way to make it self destruct when they want I'd probably allow it as a single missile attack with a USP equal to the hull size code (in B5 parlance). Not much for a small ship, but pretty impressive for say a Tigress

 

[far-trader]

Meh, you may be right enough after-all S4. After recalling this morning the Skylab gyro trouble one mission I went fishing with the net...

Turns out the gyros (specifically Control Moment Gyroscopes), 3 in the case of Skylab (2 primaries and 1 backup), were not too large. They were 22" diameter flywheels (and associated hardware) spinning at 5950rpm. Taking the size of Skylab to be about 40dton each CMG was maybe 0.01dton total.

But that was for simply fixing and maintaining the attitude of an essentially drifting body. It had its orbital speed of course but that's small potatoes compared to the speed even a 1G ship can reach in a short time.

So a little scaling up may be in order, maybe something on the order of 0.1% of ship volume is enough. Which is small enough that I can concede making it part of the maneuver drive assembly (though I am loathe to just go adding more jobs to an already magic tech assembly at least this one is real ). That also handles the whole "EJECT THE GYRO!" scenario nicely since it is on the hull and I'm not so sure they'd need to be at any center of mass either.

However...

The RPM still sounds ridiculously dangerous. Taking 900,000 rpm on a 22" wheel comes to something like 60,000mph

I'll concede that having that kind of momentum to use would be enough to provide very quick attitude adjustment even with the ship having a high load of potential momentum. But hey, dangerous can be fun

And it gives the Engineer something to point at for the curious Traveller...



<opening up the inspection window hatch the Engineer comments...> "There it is, the heart of the maneuver drive, the CMG."

"Umm, it doesn't look like much, just a big shiny sphere."

"Here let me set the diagnostic strobe, right now its spinning at almost 1 million rpm, too fast for the human eye to see the parts."

<the strobe cycles up until it nearly matches the frequency of the spinning gyros>

"Oooooh, that IS cool! There's like three wheels all turning one inside the other in different planes. So, what happens if it breaks?"

<closing the inspection window hatch the Engineer very seriously says...> "It's not so much if as when. And when it does no one wants this hatch open. The whole inside of the chamber becomes a white hot stream of molten superdense composite. It'd burn right through that window, and everything short of the bulkhead, including anyone standing in front of it. Only ever heard of that happening once though. Most of then time when one fails the hatch is closed and the explosion safely exits the back of the ship through the blowout hatch at the other end."

Naturally the minds of most PCs are turning to the weaponization of this feature right about now

I'd indulge it, if they can contrive a way to make it self destruct when they want I'd probably allow it as a single missile attack with a USP equal to the hull size code (in B5 parlance). Not much for a small ship, but pretty impressive for say a Tigress

 

[far-trader]

Originally posted by Supplement Four:
...BTW, if DGP intended the gyro to be something so big that it must be seen on the deckplans, then they would have included it on the deckplans of the Beowulf class Free Trader featured in the SOM.

You mean the deckplans that show beds for giants in the staterooms (3m long) and a ship somewhere between 300dton and 400dton

Yes, the deckplans were a major disappointment in the SOM. Very cool looking but a "bit" off scale wise. Unless you ignore the scale and treat the squares as 1m squares. Then I think it comes out a bit better.

 

[far-trader]

Originally posted by Supplement Four:
...BTW, if DGP intended the gyro to be something so big that it must be seen on the deckplans, then they would have included it on the deckplans of the Beowulf class Free Trader featured in the SOM.

You mean the deckplans that show beds for giants in the staterooms (3m long) and a ship somewhere between 300dton and 400dton

Yes, the deckplans were a major disappointment in the SOM. Very cool looking but a "bit" off scale wise. Unless you ignore the scale and treat the squares as 1m squares. Then I think it comes out a bit better.

 

[Supplement Four]

Originally posted by far-trader:
Meh, you may be right enough after-all S4. After recalling this morning the Skylab gyro trouble one mission I went fishing with the net...

We seem to be convincing each other of a lot of stuff in this thread.

Good thread.

The RPM still sounds ridiculously dangerous.

Don't forget the gyro is encased in grav modules. Their attempt at frictionless rpms...or maybe the particle manipulation is the key to the high rpms...

<opening up the inspection window hatch the Engineer comments...> "There it is, the heart of the maneuver drive, the CMG."

"Umm, it doesn't look like much, just a big shiny sphere."

"Here let me set the diagnostic strobe, right now its spinning at almost 1 million rpm, too fast for the human eye to see the parts."

<the strobe cycles up until it nearly matches the frequency of the spinning gyros>

"Oooooh, that IS cool! There's like three wheels all turning one inside the other in different planes. So, what happens if it breaks?"

<closing the inspection window hatch the Engineer very seriously says...> "It's not so much if as when. And when it does no one wants this hatch open. The whole inside of the chamber becomes a white hot stream of molten superdense composite. It'd burn right through that window, and everything short of the bulkhead, including anyone standing in front of it. Only ever heard of that happening once though. Most of then time when one fails the hatch is closed and the explosion safely exits the back of the ship through the blowout hatch at the other end."

We're on the same page. I'm already starting to think how I can mess with the gyro and make is sound like good techspeak with my players.

If they get hit in combat, and the M-Drive is disabled, I may tell them how the power overload shorted one of the grav modules in the sphere around the gyro causing the gyro to tear out of its mount.

"Look here. This this lump in the M-Drive? That's a bullet ding. The bullet being the gyro fired internally through the M-Drive."

"Can you fix it?"

"No skip, the M-Drive is toast."

 

[Supplement Four]

Originally posted by far-trader:
Meh, you may be right enough after-all S4. After recalling this morning the Skylab gyro trouble one mission I went fishing with the net...

We seem to be convincing each other of a lot of stuff in this thread.

Good thread.

The RPM still sounds ridiculously dangerous.

Don't forget the gyro is encased in grav modules. Their attempt at frictionless rpms...or maybe the particle manipulation is the key to the high rpms...

<opening up the inspection window hatch the Engineer comments...> "There it is, the heart of the maneuver drive, the CMG."

"Umm, it doesn't look like much, just a big shiny sphere."

"Here let me set the diagnostic strobe, right now its spinning at almost 1 million rpm, too fast for the human eye to see the parts."

<the strobe cycles up until it nearly matches the frequency of the spinning gyros>

"Oooooh, that IS cool! There's like three wheels all turning one inside the other in different planes. So, what happens if it breaks?"

<closing the inspection window hatch the Engineer very seriously says...> "It's not so much if as when. And when it does no one wants this hatch open. The whole inside of the chamber becomes a white hot stream of molten superdense composite. It'd burn right through that window, and everything short of the bulkhead, including anyone standing in front of it. Only ever heard of that happening once though. Most of then time when one fails the hatch is closed and the explosion safely exits the back of the ship through the blowout hatch at the other end."

We're on the same page. I'm already starting to think how I can mess with the gyro and make is sound like good techspeak with my players.

If they get hit in combat, and the M-Drive is disabled, I may tell them how the power overload shorted one of the grav modules in the sphere around the gyro causing the gyro to tear out of its mount.

"Look here. This this lump in the M-Drive? That's a bullet ding. The bullet being the gyro fired internally through the M-Drive."

"Can you fix it?"

"No skip, the M-Drive is toast."

 

[Supplement Four]

Originally posted by far-trader:
You mean the deckplans that show beds for giants in the staterooms (3m long) and a ship somewhere between 300dton and 400dton

I don't know why that happens in every edition of Traveller. You'd think the writers would be more careful.

What about the Type A2 Far Trader? In the beginning of Sup 7, it plainly states that Book 2 design rules were used to design the ship, and Book 2 mapping method was used to map them.

Then, you see the Type A2 is rated at 200 tons, but if you count the squares to find the vol., it's obviously a 400 ton vessel.

I don't know what the bigger outrage is, that, or the fact that the Type A2 was NEVER corrected. They kept reprinting the same mistake in each version of Traveller (although MT has a 400 ton Type A2 ).

I've got a set of GURPS Traveller deckplans for the Type A2. It plainly states that the vessel is a 200 ton ship. And, again, if you count squares and figure vol. it's a 400 toner.

Yes, the deckplans were a major disappointment in the SOM.

It is damn good looking, though. I first saw the SOM deckplans and said, "Wow. Now THIS is how all deckplans should be drawn."

I think they're still the best looking deckplans I've seen for Traveller, even including the nice ones that have come out of QLI and Avenger lately.

 

[Supplement Four]

Originally posted by far-trader:
You mean the deckplans that show beds for giants in the staterooms (3m long) and a ship somewhere between 300dton and 400dton

I don't know why that happens in every edition of Traveller. You'd think the writers would be more careful.

What about the Type A2 Far Trader? In the beginning of Sup 7, it plainly states that Book 2 design rules were used to design the ship, and Book 2 mapping method was used to map them.

Then, you see the Type A2 is rated at 200 tons, but if you count the squares to find the vol., it's obviously a 400 ton vessel.

I don't know what the bigger outrage is, that, or the fact that the Type A2 was NEVER corrected. They kept reprinting the same mistake in each version of Traveller (although MT has a 400 ton Type A2 ).

I've got a set of GURPS Traveller deckplans for the Type A2. It plainly states that the vessel is a 200 ton ship. And, again, if you count squares and figure vol. it's a 400 toner.

Yes, the deckplans were a major disappointment in the SOM.

It is damn good looking, though. I first saw the SOM deckplans and said, "Wow. Now THIS is how all deckplans should be drawn."

I think they're still the best looking deckplans I've seen for Traveller, even including the nice ones that have come out of QLI and Avenger lately.

 

[Supplement Four]

Originally posted by far-trader:
Drive Failure: Each week, throw 13+ for drive failure; apply the following DMs: +1 if using unrefined fuel (and not equipped to do so), +1 per engineer missing from the crew list, +1 per week past annual maintenance overhaul date.

If a malfunction occurs, then throw 7+ for each drive in use (jump, maneuver, power plant) to determine which actually fail, (if any). Failed drives cease operations completely; maneuver drives will no longer thrust, jump drives will fail and indicate that they cannot support jump; power plants stop delivering power.

Back to the original post, the question was: How common do you think purification plants are aboard civilian craft?

Given what Book 2 says above, and what is said in Book 5, I don't think fuel purifiers are all that common in civilian craft (or even military craft if produced from modular parts).

The question now is: Why?

It was mentioned by somebody else earlier in the thread. Starship economics provides for very thin margins. Time is money. And, it's a long trip out to the gas giant. Mechants typically can't afford to spend that much time, every system they stop, going to and fro the gas giant.

It's got to be a major reason for no fuel purifiers.

And, I'm happy with that.

I want to bring up the danger of gas giant skimming, but it doesn't seem to be like that's what GDW intended. They've had ample opportunity to put GG skimming rules in place. They haven't done it.

Beside the Lightning Class example, I can't find a single CT canon example of a throw being needed, or a ship being damaged, while skimming fuel.




But, let's say we accept that option. That the main reason civilian ships don't skim is because of the time required. A day out there. 8 hours to skim. A day back. You tack on 3 days journey to your trip, and you've added almost 50% extra time. With the high cost of space travel, merchants can't afford this.

OK. Let's say we buy that.

It still leaves one issue.




And, that issue is: Why not have a fuel purfier for (A) when the main world orbits the GG (like Regina), but more importantly...(B) A fuel purifier would allow merchants to save 400Cr per ton at downports by buying unrefined fuel and purifying it themselves.

Fuel purifiers are relatively cheap. They don't take up that much space.

Why wouldn't a civilian ship have one for this sole reason?

 

[Supplement Four]

Originally posted by far-trader:
Drive Failure: Each week, throw 13+ for drive failure; apply the following DMs: +1 if using unrefined fuel (and not equipped to do so), +1 per engineer missing from the crew list, +1 per week past annual maintenance overhaul date.

If a malfunction occurs, then throw 7+ for each drive in use (jump, maneuver, power plant) to determine which actually fail, (if any). Failed drives cease operations completely; maneuver drives will no longer thrust, jump drives will fail and indicate that they cannot support jump; power plants stop delivering power.

Back to the original post, the question was: How common do you think purification plants are aboard civilian craft?

Given what Book 2 says above, and what is said in Book 5, I don't think fuel purifiers are all that common in civilian craft (or even military craft if produced from modular parts).

The question now is: Why?

It was mentioned by somebody else earlier in the thread. Starship economics provides for very thin margins. Time is money. And, it's a long trip out to the gas giant. Mechants typically can't afford to spend that much time, every system they stop, going to and fro the gas giant.

It's got to be a major reason for no fuel purifiers.

And, I'm happy with that.

I want to bring up the danger of gas giant skimming, but it doesn't seem to be like that's what GDW intended. They've had ample opportunity to put GG skimming rules in place. They haven't done it.

Beside the Lightning Class example, I can't find a single CT canon example of a throw being needed, or a ship being damaged, while skimming fuel.




But, let's say we accept that option. That the main reason civilian ships don't skim is because of the time required. A day out there. 8 hours to skim. A day back. You tack on 3 days journey to your trip, and you've added almost 50% extra time. With the high cost of space travel, merchants can't afford this.

OK. Let's say we buy that.

It still leaves one issue.




And, that issue is: Why not have a fuel purfier for (A) when the main world orbits the GG (like Regina), but more importantly...(B) A fuel purifier would allow merchants to save 400Cr per ton at downports by buying unrefined fuel and purifying it themselves.

Fuel purifiers are relatively cheap. They don't take up that much space.

Why wouldn't a civilian ship have one for this sole reason?

 

[boomslang]

Originally posted by Supplement Four:
Fuel purifiers are relatively cheap. They don't take up that much space.

Why wouldn't a civilian ship have one for this sole reason?

Because, as I have shown, under Book 2 they're implicit in the design of civilian drives -- which drives themselves are effectively a completely optional, special-case specification. Seriously; that's your answer.

Plus, "that much space" is a highly relative judgement, sensitive to both TL and profit margins.

Also, while we're in thread-in-review mode, in addition to the aforementioned lack of acceleration compensation mechanism and the absence of micrometeroid and cosmic ray shielding, a high-intertia gyro is going to undergo a potentially-catastrophic change in energy state every time it enters or exits jumpspace, depending on which theory of inertia you subscribe to; jumping rimward a couple of parsecs just might alter its angular momentum enough to rip it right out of its mounts...

 

[boomslang]

Originally posted by Supplement Four:
Fuel purifiers are relatively cheap. They don't take up that much space.

Why wouldn't a civilian ship have one for this sole reason?

Because, as I have shown, under Book 2 they're implicit in the design of civilian drives -- which drives themselves are effectively a completely optional, special-case specification. Seriously; that's your answer.

Plus, "that much space" is a highly relative judgement, sensitive to both TL and profit margins.

Also, while we're in thread-in-review mode, in addition to the aforementioned lack of acceleration compensation mechanism and the absence of micrometeroid and cosmic ray shielding, a high-intertia gyro is going to undergo a potentially-catastrophic change in energy state every time it enters or exits jumpspace, depending on which theory of inertia you subscribe to; jumping rimward a couple of parsecs just might alter its angular momentum enough to rip it right out of its mounts...

 

[Supplement Four]

Originally posted by boomslang:
Because, as I have shown, under Book 2 they're implicit in the design of civilian drives -- which drives themselves are effectively a completely optional, special-case specification. Seriously; that's your answer.

The problem is, I'm not buying that Book 2 allows starship drives built "specifically to use unrefined fuel". I don't buy that at all.

The sentence in Book 2 that refers to "specially built drives" is speaking of drives with fuel purifiers, imo.

You read that sentence differently, I do understand. But, I don't see it that way at all. Because, if we went your way, Book 5 would contradict Book 2. I don't think GDW intended that--especially when it is made clear in Book 5 that B5 design did not replace B2 design, but only offer an alternative.

GDW went to the trouble to keep all of the tech consistent between Book 5 and Book 2 when they were writing Book 5 except the part about "specially built drives that can use unrefined fuel"?

No, I'm sorry, I can't buy that. They added the fuel purifier with B5, and they felt they were covered with that sentence in B2.

I think GDW "explained" why the drives were "specially built to handle unrefined fuel" with the addition of the fuel purfier in B5.

Otherwise, if this isn't true, we've got a contradtiction between the books. And, in reading Book 5, it seems clear to me, by some of the things mentioned, that they never intended anything in Book 5 to contradict what was already started in Book 2.

So, given that, I can't accept your reasoning for why civilian ships don't use purifiers.

 

[Supplement Four]

Originally posted by boomslang:
Because, as I have shown, under Book 2 they're implicit in the design of civilian drives -- which drives themselves are effectively a completely optional, special-case specification. Seriously; that's your answer.

The problem is, I'm not buying that Book 2 allows starship drives built "specifically to use unrefined fuel". I don't buy that at all.

The sentence in Book 2 that refers to "specially built drives" is speaking of drives with fuel purifiers, imo.

You read that sentence differently, I do understand. But, I don't see it that way at all. Because, if we went your way, Book 5 would contradict Book 2. I don't think GDW intended that--especially when it is made clear in Book 5 that B5 design did not replace B2 design, but only offer an alternative.

GDW went to the trouble to keep all of the tech consistent between Book 5 and Book 2 when they were writing Book 5 except the part about "specially built drives that can use unrefined fuel"?

No, I'm sorry, I can't buy that. They added the fuel purifier with B5, and they felt they were covered with that sentence in B2.

I think GDW "explained" why the drives were "specially built to handle unrefined fuel" with the addition of the fuel purfier in B5.

Otherwise, if this isn't true, we've got a contradtiction between the books. And, in reading Book 5, it seems clear to me, by some of the things mentioned, that they never intended anything in Book 5 to contradict what was already started in Book 2.

So, given that, I can't accept your reasoning for why civilian ships don't use purifiers.