High Guard 3

[mike wightman]

How about the secondhand and reconditioned market (something that has always been sadly lacking from Traveller, IMHO)

Regarding the endurance of fission plants, according to a Discovery program a Trident submarine could run for 20 years on its fuel load. I don't know how true this is, or at what rate of output (why are Traveller military power plants run at full output/fuel use all of the time?)
Great work Oz, by the way

 

[aramis]

Originally posted by Sigg Oddra:
How about the secondhand and reconditioned market (something that has always been sadly lacking from Traveller, IMHO)

Regarding the endurance of fission plants, according to a Discovery program a Trident submarine could run for 20 years on its fuel load. I don't know how true this is, or at what rate of output (why are Traveller military power plants run at full output/fuel use all of the time?)
Great work Oz, by the way

One friend, a former nuke tech, said that the 20 year quote was "+ or - 5 years", but basically says that 20 years is what a maximum operational life is told them at... assuming nothing else goes wrong. Refuelling is a major port overhaul supposedly, too. Also said Idling with the rods in actually reduces lifespan. Don't know enough details myself to judge. Worked at Hanford for the Army Corps of Engineers.

 

[aramis]

Originally posted by Sigg Oddra:
How about the secondhand and reconditioned market (something that has always been sadly lacking from Traveller, IMHO)

Regarding the endurance of fission plants, according to a Discovery program a Trident submarine could run for 20 years on its fuel load. I don't know how true this is, or at what rate of output (why are Traveller military power plants run at full output/fuel use all of the time?)
Great work Oz, by the way

One friend, a former nuke tech, said that the 20 year quote was "+ or - 5 years", but basically says that 20 years is what a maximum operational life is told them at... assuming nothing else goes wrong. Refuelling is a major port overhaul supposedly, too. Also said Idling with the rods in actually reduces lifespan. Don't know enough details myself to judge. Worked at Hanford for the Army Corps of Engineers.

 

[The Oz]

Somehow I'm just not too sure about the idea of a Second-hand ex-military nuclear reactor for my civilian starship.

Setting: A used starship parts shop, in the asteroid belt...

Salesman-"Now this baby here is a 500 MW General Atomics A4W/A1G. Only 15 years on the core and first rate controls and shielding. Used to be in the cruiser Illustrious, until they had that little run-in with the Vilani. Don't mind those patches on the pressurizer and the main coolant loop, the reactor took only minor damage compared to the rest of the ship."

It would be cheap, however.

 

[The Oz]

Somehow I'm just not too sure about the idea of a Second-hand ex-military nuclear reactor for my civilian starship.

Setting: A used starship parts shop, in the asteroid belt...

Salesman-"Now this baby here is a 500 MW General Atomics A4W/A1G. Only 15 years on the core and first rate controls and shielding. Used to be in the cruiser Illustrious, until they had that little run-in with the Vilani. Don't mind those patches on the pressurizer and the main coolant loop, the reactor took only minor damage compared to the rest of the ship."

It would be cheap, however.

 

[mike wightman]

What about the thought of travelling about in a 40+ year old Trader with a civilian nuclear (fusion) reactor, jump drive and inertial compensators?

Anyway, the reason for the post. Since T20 is based on HG but includes a TL7 fission reactor option for starships (2dt, +1EP, 6MCr and 1dt fuel/month -- all per unit), after reading your work I looked at the fuel consumption and thought it a bit too high. So I thought I'd compare it with vehicle power plants in T20.
</font>

• TL07 fission- 4.3dt, 3EPR, 1dt fuel/10 months</font>
• TL09 fusion- 1.0dt, 1EPR, 1dt fuel/3 months</font>
• TL13 fusion- 1.0dt, 1.5EPR, 1dt fuel/2 months</font>
• TL15 fusion- 1.0dt, 3EPR, 1dt fuel/month</font>
• TL16 fusion- 1.0dt, 9EPR, 3dt fuel/month</font>

I've built a 1dt size vehicle fusion power plant. According to the vehicle table the minimum size for a fission plant is 4.3dt (and yet the starship one is half that size?).
EPR stands for energy points ratio (to convert to vehicle EP multiply by ~300).
My conclusion, the starship fission plant fuel should have a fuel endurance of 1dt/~2years per starship unit rather than the 1dt/month listed.

 

[mike wightman]

What about the thought of travelling about in a 40+ year old Trader with a civilian nuclear (fusion) reactor, jump drive and inertial compensators?

Anyway, the reason for the post. Since T20 is based on HG but includes a TL7 fission reactor option for starships (2dt, +1EP, 6MCr and 1dt fuel/month -- all per unit), after reading your work I looked at the fuel consumption and thought it a bit too high. So I thought I'd compare it with vehicle power plants in T20.
</font>

• TL07 fission- 4.3dt, 3EPR, 1dt fuel/10 months</font>
• TL09 fusion- 1.0dt, 1EPR, 1dt fuel/3 months</font>
• TL13 fusion- 1.0dt, 1.5EPR, 1dt fuel/2 months</font>
• TL15 fusion- 1.0dt, 3EPR, 1dt fuel/month</font>
• TL16 fusion- 1.0dt, 9EPR, 3dt fuel/month</font>

I've built a 1dt size vehicle fusion power plant. According to the vehicle table the minimum size for a fission plant is 4.3dt (and yet the starship one is half that size?).
EPR stands for energy points ratio (to convert to vehicle EP multiply by ~300).
My conclusion, the starship fission plant fuel should have a fuel endurance of 1dt/~2years per starship unit rather than the 1dt/month listed.

 

[The Oz]

Originally posted by Sigg Oddra:
My conclusion, the starship fission plant fuel should have a fuel endurance of 1dt/~2years per starship unit rather than the 1dt/month listed.

That certainly sounds more reasonable to me. Frankly, as a former Navy nuclear operator, I know current reactor cores for ships are designed to last many years of normal operations, because ships don't constantly steam around at maximum speed. I doubt it's that different for spaceships with fission reactors.

Now, civilian electric power stations with fission reactors do burn up one load of fuel in about 1 to 2 years, because they go up to high power and stay there until they burn the core up. That's how they make money.

A civilian-fuel reactor running a starship which didn't need full power all the time would last much longer, at least for years instead of months.
Let's do some math:

We assume the core will last 1 year at continuous full-power operation, or 8760 hours of full-power.

The ship needs full power when in flight to/from destinations, and for one hour prior to jump to charge jump capacitors.

While in hyperspace, the ship need 10% of max power to maintain the jump field, ship functions, life support, etc. I have no idea if this is reasonable or not; does anyone else have any idea?

While downworld, the ship needs no power (connected to a dirtside powergrid).

From the Book 2 tables, flight time for a 1-G ship to/from a size A world is 7 hours, add one hour for jump and you get 8 hours. Using that figure to give us some cushion built-in (certainly not all planets are size-A, and you don't need the 1 hour of full power to exit jumpspace) and assuming 30 jumps a year, we need 480 hours of full-power operations a year (remember, it's 8 hours out to jump and 8 hours in from jump, for 16 hours/jump).

30 jumps a week means 30 x 168 hours (average) in jumpspace, which at 10% of full power is the equivalent of 504 more hours of full-power operation.

Total: 984 hours a year of full-power equivalent needed, which means that 8760 hours of full-power on the core will last 8.9 years.

That's how I got my figure of 10 years duration for normal operation of a civilian starship fission powerplant. I figured there was enough slack in my calculation to allow a "rough" estimate of 10 years. Military ships might get only half that, as I would expect them to spend more time in space and less on the ground, plus expending more energy on things like weapons and screens.

 

[The Oz]

Originally posted by Sigg Oddra:
My conclusion, the starship fission plant fuel should have a fuel endurance of 1dt/~2years per starship unit rather than the 1dt/month listed.

That certainly sounds more reasonable to me. Frankly, as a former Navy nuclear operator, I know current reactor cores for ships are designed to last many years of normal operations, because ships don't constantly steam around at maximum speed. I doubt it's that different for spaceships with fission reactors.

Now, civilian electric power stations with fission reactors do burn up one load of fuel in about 1 to 2 years, because they go up to high power and stay there until they burn the core up. That's how they make money.

A civilian-fuel reactor running a starship which didn't need full power all the time would last much longer, at least for years instead of months.
Let's do some math:

We assume the core will last 1 year at continuous full-power operation, or 8760 hours of full-power.

The ship needs full power when in flight to/from destinations, and for one hour prior to jump to charge jump capacitors.

While in hyperspace, the ship need 10% of max power to maintain the jump field, ship functions, life support, etc. I have no idea if this is reasonable or not; does anyone else have any idea?

While downworld, the ship needs no power (connected to a dirtside powergrid).

From the Book 2 tables, flight time for a 1-G ship to/from a size A world is 7 hours, add one hour for jump and you get 8 hours. Using that figure to give us some cushion built-in (certainly not all planets are size-A, and you don't need the 1 hour of full power to exit jumpspace) and assuming 30 jumps a year, we need 480 hours of full-power operations a year (remember, it's 8 hours out to jump and 8 hours in from jump, for 16 hours/jump).

30 jumps a week means 30 x 168 hours (average) in jumpspace, which at 10% of full power is the equivalent of 504 more hours of full-power operation.

Total: 984 hours a year of full-power equivalent needed, which means that 8760 hours of full-power on the core will last 8.9 years.

That's how I got my figure of 10 years duration for normal operation of a civilian starship fission powerplant. I figured there was enough slack in my calculation to allow a "rough" estimate of 10 years. Military ships might get only half that, as I would expect them to spend more time in space and less on the ground, plus expending more energy on things like weapons and screens.

 

[Straybow]

Many ships that PCs use are well armed and so have EP reserved for beam weapons. The only time they run at 100% is in combat or live fire training.

You can't burn up fissionables to the last bit, like running your IC engine until it sucks fumes from the gas tank. At some point the power output drops sharply. My passing familiarity with civilian nuclear doesn't include what that precise level is, but I'd guess it couldn't be any higher than 75%.

In a less politically squeemish world like OTU there would be a fuel reprocessing industry to extract unspent fissionables and byproducts of scientific or medical interest.

Meanwhile, as part of a fuel skimming discussion in Going Pirate thread I did a little calc on fusion from natural hydrogen (0.015% D2) vs concentrated D2… who needs to go back to nasty, dirty fission for low fuel power when you can get 250MW (1 EP) for 145 years out of 1 dton D2?

 

[robject]

I'm hijacking this thread slightly to do some more MT-to-CT conversion thoughts. Oz's numbers for fission plants are very useful; what I would try to do is massage the numbers (i.e. fudge them) to get the price down to MCr1/ton. I'd do this by making the higher-TL plant sizes slightly larger (don't know if that would cause more trouble tho).

Also, I'll roll in fuel replacement as part of the yearly maintenance fee. Perhaps I could set the fuel amount to be quite small?

</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;"> Fission Plants
Percent --------TL---------
times 7-9 10-12 13+
Pn 10% 7% 4%

Plant cost: MCr1 per dton
Fuel duration: 1 year
Fuel replacement cost: Cr100,000 per EP.</pre>[/QUOTE]And here's OZ's table, with the numbers slightly dumbed-down. (I thought fuel usage was per 2 weeks or so, rather than per month? But no matter).

I kind of like having four entries per drive type (fossil fuel, fission, fusion, antimatter).

What should I do about costs? Fusion and Fission are normalized to MCr1/ton, but the others...

</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Plant TL tons/EP Fuel/hr /month

IC 6 50 1.5 1000
IIC 7 30 1 700
Turbine 7 20 1 700
MHD 8 15 0.5 350

Fission 6 10 ( 10 t/year )
Fission 7-9 10 ( 1 t/year )
Fission A-C 7 ( 1 t/year )
Fission D-F 4 ( 1 t/year )

Fusion 9-B 3 1
Fusion C-D 2 1
Fusion E-F 1 1
Fusion G+ 0.5 0.5

AM G 10 ( 1 t/year )
AM H 1 ( 1 t/year )
AM J-K 0.1 1
AM L+ 0.01 10</pre>[/QUOTE]In related topics, people have suggested the following modifications to High Guard:

(0) port in the accessories from MT et al: Sickbays, fusion power, AM, etc.
(1) expand it into a vehicle design system
(2) allow higher Gs (at least for some craft)
(3) re-label the computer as the "ECS Package" -- Electronics, Computer, and Sensors.
(4) Introduce armor degradation.
(5) Missile changes: det-laser, fewer and bigger, include cost of missiles, etc.
(6) Revisit the sensor rules (this might become a messy tangle, though).

Anything else to consider?

 

[robject]

I'm hijacking this thread slightly to do some more MT-to-CT conversion thoughts. Oz's numbers for fission plants are very useful; what I would try to do is massage the numbers (i.e. fudge them) to get the price down to MCr1/ton. I'd do this by making the higher-TL plant sizes slightly larger (don't know if that would cause more trouble tho).

Also, I'll roll in fuel replacement as part of the yearly maintenance fee. Perhaps I could set the fuel amount to be quite small?

</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;"> Fission Plants
Percent --------TL---------
times 7-9 10-12 13+
Pn 10% 7% 4%

Plant cost: MCr1 per dton
Fuel duration: 1 year
Fuel replacement cost: Cr100,000 per EP.</pre>[/QUOTE]And here's OZ's table, with the numbers slightly dumbed-down. (I thought fuel usage was per 2 weeks or so, rather than per month? But no matter).

I kind of like having four entries per drive type (fossil fuel, fission, fusion, antimatter).

What should I do about costs? Fusion and Fission are normalized to MCr1/ton, but the others...

</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Plant TL tons/EP Fuel/hr /month

IC 6 50 1.5 1000
IIC 7 30 1 700
Turbine 7 20 1 700
MHD 8 15 0.5 350

Fission 6 10 ( 10 t/year )
Fission 7-9 10 ( 1 t/year )
Fission A-C 7 ( 1 t/year )
Fission D-F 4 ( 1 t/year )

Fusion 9-B 3 1
Fusion C-D 2 1
Fusion E-F 1 1
Fusion G+ 0.5 0.5

AM G 10 ( 1 t/year )
AM H 1 ( 1 t/year )
AM J-K 0.1 1
AM L+ 0.01 10</pre>[/QUOTE]In related topics, people have suggested the following modifications to High Guard:

(0) port in the accessories from MT et al: Sickbays, fusion power, AM, etc.
(1) expand it into a vehicle design system
(2) allow higher Gs (at least for some craft)
(3) re-label the computer as the "ECS Package" -- Electronics, Computer, and Sensors.
(4) Introduce armor degradation.
(5) Missile changes: det-laser, fewer and bigger, include cost of missiles, etc.
(6) Revisit the sensor rules (this might become a messy tangle, though).

Anything else to consider?

 

[The Oz]

Robject said:

In related topics, people have suggested the following modifications to High Guard:

(0) port in the accessories from MT et al: Sickbays, fusion power, AM, etc.
(1) expand it into a vehicle design system
(2) allow higher Gs (at least for some craft)
(3) re-label the computer as the "ECS Package" -- Electronics, Computer, and Sensors.
(4) Introduce armor degradation.
(5) Missile changes: det-laser, fewer and bigger, include cost of missiles, etc.
(6) Revisit the sensor rules (this might become a messy tangle, though).

My thoughts:

0) I certainly agree with importing the MT accessories. I'd allow any player to go ahead and add those to a ship under design, although I'd want to check the numbers myself.

1) I've used HG for vehicle design myself, but it is limited and I've usually imported a fair amount from MT, Striker, or FFS to do it. Usually for vehicles I just wing it.

2) I like higher Gs, but deciding on what restrictions to place would be difficult, and there's that problem of obsoleting the canon ship designs.

3) No problem here: I've always thought of it that way.

4) What do you mean by "armor degredation?"

5) The changes I've made to missiles in HG have been to allow turret missiles (only) to be used as counter-missiles, and I've added laserhead missiles to bay missile batteries (only), which are considered to detonate from outside nuke damper range and so can't be stopped by nuke dampers. What other changes are really needed, unless you want to integrate HG into a boardgame/miniatures type situation?

6) Sensors could be messy. I'd prefer (for a military, HG-type situation) to keep it simple and just have "active" and "passive" sensors with detection ranges and ships having "signatures" for each type of sensor. But that'd not be detailed enough for player characters.

 

[The Oz]

Robject said:

In related topics, people have suggested the following modifications to High Guard:

(0) port in the accessories from MT et al: Sickbays, fusion power, AM, etc.
(1) expand it into a vehicle design system
(2) allow higher Gs (at least for some craft)
(3) re-label the computer as the "ECS Package" -- Electronics, Computer, and Sensors.
(4) Introduce armor degradation.
(5) Missile changes: det-laser, fewer and bigger, include cost of missiles, etc.
(6) Revisit the sensor rules (this might become a messy tangle, though).

My thoughts:

0) I certainly agree with importing the MT accessories. I'd allow any player to go ahead and add those to a ship under design, although I'd want to check the numbers myself.

1) I've used HG for vehicle design myself, but it is limited and I've usually imported a fair amount from MT, Striker, or FFS to do it. Usually for vehicles I just wing it.

2) I like higher Gs, but deciding on what restrictions to place would be difficult, and there's that problem of obsoleting the canon ship designs.

3) No problem here: I've always thought of it that way.

4) What do you mean by "armor degredation?"

5) The changes I've made to missiles in HG have been to allow turret missiles (only) to be used as counter-missiles, and I've added laserhead missiles to bay missile batteries (only), which are considered to detonate from outside nuke damper range and so can't be stopped by nuke dampers. What other changes are really needed, unless you want to integrate HG into a boardgame/miniatures type situation?

6) Sensors could be messy. I'd prefer (for a military, HG-type situation) to keep it simple and just have "active" and "passive" sensors with detection ranges and ships having "signatures" for each type of sensor. But that'd not be detailed enough for player characters.

 

[robject]

Right you are, Oz, I think we're close to the same page of the same book.

I don't like higher G's on ships over some size Z (Z being 40 tons, plus or minus 30 tons), but I was impressed with that zippy little grav fighter from T4 (orbital craft only, but could pull 18 G's on a good day!!).

Armor degradation is: through combat or other violently adverse conditions, a ship's armor is damaged.

Good ideas for missiles.

The definitive T4 sensor rules are as you suggested (free off the web!), and they can get quite complex in a hurry. I also prefer simple.

 

[robject]

Right you are, Oz, I think we're close to the same page of the same book.

I don't like higher G's on ships over some size Z (Z being 40 tons, plus or minus 30 tons), but I was impressed with that zippy little grav fighter from T4 (orbital craft only, but could pull 18 G's on a good day!!).

Armor degradation is: through combat or other violently adverse conditions, a ship's armor is damaged.

Good ideas for missiles.

The definitive T4 sensor rules are as you suggested (free off the web!), and they can get quite complex in a hurry. I also prefer simple.

 

[The Oz]

I'm not sure about armor degredation. It's true that in the early days of armored ships, they did sometimes lose armor from battle damage (the rivets broke and the armor plate literally fell off). This problem was largely fixed with new techniques. I can't see large chunks of ship's outer hull being blown off in the future, and anyway, if a ship is taking =that= much damage, they should have much bigger problems than losing some of the hull plating! So why bother tracking the armor loss?

Now, I can see the invention of "ablative" armor; designed to be lost while absorbing damage that would otherwise hurt the ship. I toyed with the idea of creating an "ablative foam shield" for my PCs. It would have been a tank inside the hull where the foam was generated, plus a network of pipes and nozzles that would have sprayed the foam on the outside of the hull. The foam would have absorbed laser (and energy weapons) fire but been blown off the hull in doing so. This means that a hit location would be protected from the first (and maybe the second) hit but then would become unprotected unless the foam was replaced.

The foam tank would have taken up cargo space, it would have cost a fair amount to refit to an existing ship, the foam itself would cost money, and I would have put restrictions on a ship's ability to maneuver while the foam was on the hull, if you wanted to keep the foam on the hull, that is. Too many Gs too quickly and the foam would go one way and the ship would go another. It would also have interfered with sensors (or you'd have had to leave some parts of the ship uncovered). But this would be an example of an armor =designed= to be degraded in combat.

Sensors can be complicated (as I am discovering in trying to make up a set of sensor/EW rules for true fleet-level starship combat) and I'm not sure if it's possible to have "simple" and "realistic" in the same set of sensor rules.

But I'm trying....

 

[The Oz]

I'm not sure about armor degredation. It's true that in the early days of armored ships, they did sometimes lose armor from battle damage (the rivets broke and the armor plate literally fell off). This problem was largely fixed with new techniques. I can't see large chunks of ship's outer hull being blown off in the future, and anyway, if a ship is taking =that= much damage, they should have much bigger problems than losing some of the hull plating! So why bother tracking the armor loss?

Now, I can see the invention of "ablative" armor; designed to be lost while absorbing damage that would otherwise hurt the ship. I toyed with the idea of creating an "ablative foam shield" for my PCs. It would have been a tank inside the hull where the foam was generated, plus a network of pipes and nozzles that would have sprayed the foam on the outside of the hull. The foam would have absorbed laser (and energy weapons) fire but been blown off the hull in doing so. This means that a hit location would be protected from the first (and maybe the second) hit but then would become unprotected unless the foam was replaced.

The foam tank would have taken up cargo space, it would have cost a fair amount to refit to an existing ship, the foam itself would cost money, and I would have put restrictions on a ship's ability to maneuver while the foam was on the hull, if you wanted to keep the foam on the hull, that is. Too many Gs too quickly and the foam would go one way and the ship would go another. It would also have interfered with sensors (or you'd have had to leave some parts of the ship uncovered). But this would be an example of an armor =designed= to be degraded in combat.

Sensors can be complicated (as I am discovering in trying to make up a set of sensor/EW rules for true fleet-level starship combat) and I'm not sure if it's possible to have "simple" and "realistic" in the same set of sensor rules.

But I'm trying....

 

[robject]

OK, point taken with armor. Note that T4 has something like armor; it has hull points, then structure points. Hull damage is surface damage, and surface damage rules apply; when the hull points are exhausted, though, all hits are structural, which means internal.

And I knew about sensors. Have you seen the T4 version? Even that is too much for me, but I think it has a good foundation.

Funny, the T4 concepts for starships seem pretty good, but the starship rules themselves seem too much like FFS2, Abridged.

 

[robject]

OK, point taken with armor. Note that T4 has something like armor; it has hull points, then structure points. Hull damage is surface damage, and surface damage rules apply; when the hull points are exhausted, though, all hits are structural, which means internal.

And I knew about sensors. Have you seen the T4 version? Even that is too much for me, but I think it has a good foundation.

Funny, the T4 concepts for starships seem pretty good, but the starship rules themselves seem too much like FFS2, Abridged.