Anyone Use The Optional Fuel Rules From S&P-76?

[Solomani666]

Does anyone here use the optional fuel rules from Signs & Portents #76?

I am debating using them myself and adjusting the operational times for the standard ship types.

Any ideas on the pros and cons of this?


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[Jame Rowe]

I use it.

But then again, I *wrote* it. My concept was an expansion of the fuel usage rules in the TMB as they made fusion plants very fuel-hungry.

 

[barnest2]

Hmm... they're interesting, but the higher tl levels of them seem a bit... wrong. I don't know. The indefinite power plant especially.
There is efficient and then there is ridiculous.

 

[GypsyComet]

As it applies to only power plants and not jump drives, and is an easy overlay on existing designs, there is little reason not to use it. That it is also closer to realistic is a bonus. The fuel requirements were adjusted far more than this for TNE and GT, as our understanding of fusion processes is better than in 1976. A couple displacement tons of hydrogen IS enough to generate hundreds of megawatt-days of power, if not thousands. This is why those two editions list powerplant endurance in years...

 

[Solomani666]

Hmm... they're interesting, but the higher tl levels of them seem a bit... wrong. I don't know. The indefinite power plant especially.
There is efficient and then there is ridiculous.

Addressing the infinite part, just bleed a tiny bit of jump fuel or assume that the needed fuel is stored in the reactor itself.


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[locarno24]

Addressing the infinite part, just bleed a tiny bit of jump fuel or assume that the needed fuel is stored in the reactor itself.

It essentially becomes no different to an antimatter reactor, in fact - it has running costs but negligible fuel consumption in terms of actual mass/volume.

As it applies to only power plants and not jump drives, and is an easy overlay on existing designs, there is little reason not to use it.

Ah. If only it applied to jump drives....

Roll on the dart's onboard Teleportal.....

 

[Jame Rowe]

As it applies to only power plants and not jump drives, and is an easy overlay on existing designs, there is little reason not to use it.

Ah. If only it applied to jump drives....

Roll on the dart's onboard Teleportal.....

Ah yes, the *other* reason that I didn't write it for Jump Drives...

 

[Rikki Tikki Traveller]

I have never liked the Power Plant fuel requirements. I have always ignored it and used the Annual Maintenance as the refueling time.

For Jump Fuel, I have reduced it to 5% of the ship per Jump number BUT, I make the players buy ENRICHED fuel (think of the Tylium from nBSG). It costs a lot more, but you get twice the range. Fuel Purifiers on ships cannot make Enriched fuel, it can only be bought at Class B and A starports (some Cs as well); similar to the Refined Fuel rules in TMB.

Unrefined fuel, is not usable without refining and is free just about everywhere (gas giants, water, ice etc)

Refined Fuel costs 100 Cr/ton is available at Class D starports and better and is what is produced from an onboard Fuel Processor. By law, all ships must be built assuming Refined Fuel.

Enriched Fuel costs 500 Cr/ton and is only available at Class A and B starports, it doubles the jump efficiency of the ship. It is a TL12 development but is so important that lower TL starports (if they are big enough) have imported the technology. All military bases have Enriched fuel as well.

I have found that this compromise works well, allows me to continue to use the existing ship designs and doesn't totally break the OTU setting should I choose to use that one. Allowing a J1 ship to double-jump makes them a lot more viable in most sectors.

 

[AKAmra]

I agree Rikki Tikki Traveller; I think your rules are a good compromise and are pretty much what I would go with.

I'll have to take a look at the S&P rules for the Power Plant, but annual maintenance looks good too.

 

[zero]

The fuel requirements make alot of sense when its just for the ship stuff, especially as I'm building a v. high tech ship, where everything has a stupidly high cost.

I do plan to use them

 

[locarno24]

Allowing a J1 ship to double-jump makes them a lot more viable in most sectors.

But only along certain routes - which essentially makes any 'chain' of class A starports an 'expressway' for civilian craft, which in turn explains why said starports are there.

Enriched fuel is a nice idea, actually. Avoids house rule changes that fundamentally alter the design mechanics but provides an important logical item into the game... Plus it helps outline a 'big thing' that distinguishes starport grades. I like!

 

[Solomani666]

I have never liked the Power Plant fuel requirements. I have always ignored it and used the Annual Maintenance as the refueling time.

For Jump Fuel, I have reduced it to 5% of the ship per Jump number BUT, I make the players buy ENRICHED fuel (think of the Tylium from nBSG). It costs a lot more, but you get twice the range. Fuel Purifiers on ships cannot make Enriched fuel, it can only be bought at Class B and A starports (some Cs as well); similar to the Refined Fuel rules in TMB.

Unrefined fuel, is not usable without refining and is free just about everywhere (gas giants, water, ice etc)

Refined Fuel costs 100 Cr/ton is available at Class D starports and better and is what is produced from an onboard Fuel Processor. By law, all ships must be built assuming Refined Fuel.

Enriched Fuel costs 500 Cr/ton and is only available at Class A and B starports, it doubles the jump efficiency of the ship. It is a TL12 development but is so important that lower TL starports (if they are big enough) have imported the technology. All military bases have Enriched fuel as well.

I have found that this compromise works well, allows me to continue to use the existing ship designs and doesn't totally break the OTU setting should I choose to use that one. Allowing a J1 ship to double-jump makes them a lot more viable in most sectors.

The reason for the high fuel expenditures during jump travel is that the hydrogen is used to inflate the jump bubble which acts as a buffer between the ship and jump space.

Enriched fuel is just hydrogen doped with either tritium or deuterium. Filling a jump bubble with enriched fuel is just a waste of expensive isotopes.

IMTU I allow ships to jump with unrefined fuel safely as long as the power plant fuel is refined, with the jump time is also calculated into the power plants endurance for fuel consumption. Refined fuel simply doubles a ships endurance for the power plant only.

I am toying with the idea that the fuel needed for a jump 1 should be the fuel needed for any jump regardless of the distance.

I will be starting another thread on this topic.

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[far-trader]

The reason for the high fuel expenditures during jump travel is that the hydrogen is used to inflate the jump bubble which acts as a buffer between the ship and jump space.

Jump Bubbles?! Next you'll tell me you use Jump Grids too.



The problems with Jump Bubbles of hot hydrogen fuel (plasma) are many. Ditto Jump Grids.

The most obvious being that the jump fuel is not calculated on a bubble size but on the ship displacement. And Jump Drives (jump grid), and even hulls, are not calculated on area but simply displacement. A ship's shape is not factored which would be a big difference if you had to enclose it in an uniform sphere (i.e. a bubble) or ensure an equally uniform hull grid. Even if you waffle and suggest the Jump Bubble is not an actual bubble (a sphere) but simply a uniform (1m is often used) conformal shield around the hull you still have something bigger than the hull and varying in volume by the actual shape of the hull.

I am toying with the idea that the fuel needed for a jump 1 should be the fuel needed for any jump regardless of the distance.

I won't say don't, but I will point out that the reason the fuel use increases with jump distance, canonically, is because more energy is required to access the higher dimensions. The energy for a J1 simply won't crack the dimension that permits a J2 or more.

Misjumps break this rule by some weird maverick harmonics or something. Yeah, they don't make a lot of sense but they are a fun McGuffin

I did once toy with the idea of all jumps (J1-36) being possible with the fuel and drive requirements (and the rest) of only J1. A controlled misjump drive essentially. It would be a setting breaker for the OTU but certainly something possible for an ATU.

 

[DFW]

I won't say don't, but I will point out that the reason the fuel use increases with jump distance, canonically, is because more energy is required to access the higher dimensions. The energy for a J1 simply won't crack the dimension that permits a J2 or more.

I have this covered for MGT "bubbles" in a similar fashion. More H is needed around the ship to protect against the higher energy level that exists in J-Space as your Jump distance increases...