P-Plant Fuel and Drive Stages

[Sapphiremagus]

Apologies if this has been addressed already, but I didn't see anything in the errata and was unable to search-fu an answer.

First, for clarification, is the tonnage for operational fuel per year, or per month? The PDF I have, on page 382 under How Fuel Works, states that a P-Plant requires tons equal to the hull tonnage times the P-Plant Potential, divided by 100, for 12 months of operation. So, H/100 * P (easier to read as hulls come in 100 ton multiples) for one year.

However, on page 383, in the sidebar giving three power plant examples, the P-Plant example indicates that the plant requires that tonnage per month.

I'm assuming the example is correct in this case - otherwise fuel other than for jumps is trivial.


Second question regards tech level stages with a P-Plant: does the fuel modifier apply to the operational fuel usage? Would an improved P-Plant, for example, require 90% of the above fuel per operating period?

Thanks in advance!

 

[robject]

Right on both counts.

The fuel requirement is per month, and stage effects alter that fuel requirement per month.

Caveat - I believe that antimatter fuel is operational power per year.

 

[aramis]

Right on both counts.

The fuel requirement is per month, and stage effects alter that fuel requirement per month.

Caveat - I believe that antimatter fuel is operational power per year.

I thought Fusion also was per year, in line with TNE and T4.

 

[whulorigan]

I thought Fusion also was per year, in line with TNE and T4.

I believe under T5 the idea was introduced that Fusion P-Plants that can be made small enough to serve as a Ship's Power Plant do so via the ability to "overclock" for brief periods (i.e for J-Drive, M-Drive, et al), and that as a consequence of this ability they use fuel very inefficiently all of the time. Large Installation-sized Fusion plants still consume fuel in "per year" rates of efficiency.

T5.09 p.348:
Overclock. Starship Power Plants are “small” generators compared to the standard plants used on world surfaces. The key to their importance is called Overclock. The Power Plant can increase its output by several orders of magnitude for a period of seconds, with great inefficiency. This ability even makes normal operation relatively inefficient, with fuel usage measured in tons per week rather than tons per year. In addition, each use of Overclock increases the chance of failure (which is why starship Power Plants require annual maintenance).

These Overclock inefficiencies are reflected in the Drive Tech Level Stage Effects table (in Ship Design) which significantly reduces efficiency and increases tonnage for lower tech levels (and increases efficiency and reduces tonnage for higher techlevels).

However, even Ship's P-Plants can be run at low consumption rates, but generally lose the ability to use their M-Drive (and J-Drive), and can be further lowered for long term operation (i.e. Life support and other essentials only), or even lower at mothballing rates (no life support, bare minimum's for critical systems). (See T5.09 p. 383 - POWER PLANT OPERATIONAL MODES in the Fuel Section).


Remember also that the P-Plant is primarily for running the M-Drive and J-Drive (and perhaps weapons). The rest of the ships systems are often locally powered by Fusion Plus modules, which run on water and have fuel reservoirs good for about a year (and are topped off during annual maintenance).

 

[nobby-w]

I believe under T5 the idea was introduced that Fusion P-Plants that can be made small enough to serve as a Ship's Power Plant do so via the ability to "overclock" for brief periods (i.e for J-Drive, M-Drive, et al), and that as a consequence of this ability they use fuel very inefficiently all of the time. Large Installation-sized Fusion plants still consume fuel in "per year" rates of efficiency. [ . . . ]

In another game I wrote once, I had the concept of an 'open-mode' or 'closed mode' fusion plant. You could also have hybrid plants that could run in either mode.

A closed mode plant runs coolant through a generator and heat exchanger to radiate waste heat. Coolant is then re-cycled back through the plant, much as one might see in today's reactors.

An open-mode plant generates plasma and then mixes it in with reaction mass that is vented to the outside through a MHD generator. This allows large amounts of power to be generated, and waste heat is handled by dumping it into the reaction mass just before it goes into the reactor. This generates a large amount of power at the expense of going through reaction mass quickly.

Unrefined reaction mass has some cross-section to neutron flux, so it will be slightly radioactive, potentially contaminating the reaction chamber with radioactive detritus over time. Eventually the chamber lining will become degraded by the radioactive contamination, and will be dangerously radioactive. Refined reaction mass (liquid hydrogen of reasonable purity) does not cause this problem and can be used safely for long periods without causing radioactive degradation of the plant.

 

[pendragonman]

I thought Fusion also was per year, in line with TNE and T4.

Ditto

 

[Sapphiremagus]

Year, Month, Week?

I had missed page 384's discussion of inefficiency, but this adds another option to the list as well.

Is the fuel usage per year, month, or week?

If it's per year, that makes fuel usage trivial, but compatible with TNE / T4

If it's per month, fuel usage has more impact on the resource mini-game. Not sure what the compatibility is.

If it's per week, fuel usage is a major component of the resource mini-game, (and compatible with MgT? Looks like fuel is listed as per week consumption there).

 

[robject]

Ah right. Standard fusion power (not the Power Plant kind) is refueled yearly... and not sufficient for jump drives.

And fuel usage in starships should be very similar to MgT, since MgT borrows from T5.

 

[AnotherDilbert]

MgT2 ships require very little PP fuel.

E.g. a very basic 1000 Dt ship with J-1 and M-1 would need about 2 Dt PP fuel for 4 weeks.

 

[Sapphiremagus]

Yeah, I'm noticing MgT seems to be a bit light compared to T5. J drives will consistently be 5 tons cheaper, and their M-drives will tend be a ton heavier (edge cases will vary).

 

[robject]

Yeah, I'm noticing MgT seems to be a bit light compared to T5. J drives will consistently be 5 tons cheaper...

Really? I thought we had that nailed down. With nine-inch nails. Alas.

 

[Fovean]

Don’t have T5.09 to hand at the moment but I know in MGT High Guard v2 jump drives have a minimum 5 tons displacement before calculating for Hull size.

 

[AnotherDilbert]

They're the same?

E.g. a 100 Dt ship with J-2:
MgT2: 5 Dt + 100 × 5% = 10 Dt.
T5: Jump Drive A = 10 Dt.

 

[aramis]

They're the same?
MgT2: 5 Dt + 100 × 5% = 10 Dt./QUOTE]

No. MGT2 HG p 14: (2.5% * Jn) +5Td = 7.5T for J1 *100Td.

MGT2 matches CT Bk 2 drive rates, which are 98% identical to MGT1 core tables. You may thank (or curse) me for that later.

 

[robject]

No. MGT2 HG p 14: (2.5% * Jn) +5Td = 7.5T for J1 *100Td.

MGT2 matches CT Bk 2 drive rates, which are 98% identical to MGT1 core tables. You may thank (or curse) me for that later.

CT Book 2 drive rates are not the same as 5 + 2.5Jn for the 100t hull. Close, but the 100t hull gets short shrift on purpose.

Nor are Book 2 and MGT2 drives the same as MGT1, if only because the potential table in MGT1 is different than everything else.

 

[aramis]

CT Book 2 drive rates are not the same as 5 + 2.5Jn for the 100t hull. Close, but the 100t hull gets short shrift on purpose.

Nor are Book 2 and MGT2 drives the same as MGT1, if only because the potential table in MGT1 is different than everything else.

technically, CT 1 and 2 don't match, either.

They diverge above drive K.

Tons Rating = Drive_rating*Tons_hull
Rating = TonsRating/Tons_hull
2.5% is the low end, and 200 TonsRating per drive letter works for MGT1, CT1, and CT2 to a given point, which is 1000 Td and Drive K, IIRC.

 

[AnotherDilbert]

E.g. a 100 Dt ship with J-2:
MgT2: 5 Dt + 100 × 5% = 10 Dt.
T5: Jump Drive A = 10 Dt.

No. MGT2 HG p 14: (2.5% * Jn) +5Td = 7.5T for J1 *100Td.

A T5 Jump drive A (10 Dt) gives J-2 performance in a 100 dT hull.
A MgT2 J-2 takes 2 × 2.5% + 5 Dt ⇒ 100 × 5% + 5 = 10 Dt.

So, they are the same size.

 

[robject]

A T5 Jump drive A (10 Dt) gives J-2 performance in a 100 dT hull.
A MgT2 J-2 takes 2 × 2.5% + 5 Dt ⇒ 100 × 5% + 5 = 10 Dt.

So, they are the same size.

For Jump-2, yes. The edge case appears to be odd-numbered jump ratings on the 100t hull.

Aramis was quoting MgT2 for a Jump-1 drive in a 100t hull... in T5, 10 tons is the minimum size. In MgT2, it's 7.5 tons.

 

[AnotherDilbert]

MgT2 jump drives has a minimum size of 10 Dt, just like T5.

T5 Drive . . Size . . . . MgT2 Size
Drive A . . . 10 Dt . . . 10 Dt
Drive E . . . 30 Dt . . . 30 Dt
Drive K . . . 60 Dt . . . 55 Dt
Drive Q . . . 80 Dt . . . 75 Dt

Sure, they are completely unconnected and different.

 

[robject]

Ah, that's what I get for not checking the data myself.