Running A Steam Engine with Powers

[Minuteman37]

Originally Posted by Kax

Steam takes up 1600 times the volume of liquid water, no matter its temp. The hotter it is the more useful energy it contains, especially if you are using multiple staged cylinders. 383 F (195 C) is a reasonable normal operating temp. (taken from documentation).

From High-pressure_steam_locomotive: "A high-pressure steam locomotive is a steam locomotive with a boiler that operates at pressures well above what would be considered normal. In the later years of steam, boiler pressures were typically 200 to 250 psi (1.38 to 1.72 MPa). High-pressure locomotives can be considered to start at 350 psi (2.41 MPa), when special construction techniques become necessary, but some had boilers that operated at over 1,500 psi (10.34 MPa)."


If you're doing steampunk you can veer to the high side.

Of course if you have 'special' construction techniques you can go higher.

Also note: the spells Create Steam and Create Air are pretty killer when combined with pressure tanks that can hold the pressure and valves that won't explode under 1,600 atmospheres pressure....

Ok so assuming a 350 psia cap our max tempature is 421 degrees so about 20 points worth of tempature control.

[Kax]

Originally Posted by Minuteman37

Ok so assuming a 350 psi cap our max tempature is 421 degrees so about 20 points worth of tempature control.

And that's a starter for efficient steam power. But the temp for a 1,500 psi engine isn't hugely higher. A lot of the difference is engineering as much as heat. A reasonable steam turbine, for example, runs at only double that heat.

[Fred Brackin]

Originally Posted by Kax

Also note: the spells Create Steam and Create Air are pretty killer when combined with pressure tanks that can hold the pressure and valves that won't explode under 1,600 atmospheres pressure....

No, Create Steam produces steam at 1 atmosphere. You want Boil Water instead. Possibly in tandem with Condense Steam.

No, it's not a Perpetual Motion machine it's a probably overly elaborate Mana Engine.

[Anaraxes]

Originally Posted by Minuteman37

Well that tool caps out at just over 700 degrees.

Yep. Or 3200 psi (or so says the calculator text), which is maybe twice what any real-world steam engine used. Most of the historical locomotives were under 300 psi.

Also, don't forget that iron and steel get weaker at higher temperatures, even when significantly lower than their melting point. At 700 C, iron and steels have around 25% of the tensile strength they do at room temperature.

So it seems like a reasonable useful range. But if you want to stretch further, then Wikipedia will give you the equation to calculate the values for whatever temperature or pressure you like. Perhaps throw in some more metal-mages or super-tech to strengthen the boilers, if need be.

Do you want to set the CP investment for your pyromancers, and then work out what they're capable of, or do you want to define the problem (running a steam locomotive, for instance) and then work out how powerful the mages have to be?

[whswhs]

Originally Posted by Anaraxes

Yep. Or 3200 psi (or so says the calculator text), which is maybe twice what any real-world steam engine used. Most of the historical locomotives were under 300 psi.

Also, don't forget that iron and steel get weaker at higher temperatures, even when significantly lower than their melting point. At 700 C, iron and steels have around 25% of the tensile strength they do at room temperature.

This is why you want Essential Metal steam engines. Essential Metal has more or less whatever physical properties you need it to have, I think. . . .

[Anaraxes]

Originally Posted by whswhs

Essential Metal has more or less whatever physical properties you need it to have, I think. . . .

"Triple strength", according to GURPS Magic. So it'd be an improvement, certainly, but not really whatever arbitrarily high value you might like it to be. You couldn't build, say, a space elevator from an Essential Metal cable, at least while keeping that definition. (Just enchant a bunch of steps with Levitate instead, or build a big cistern to hold potions of Walk on Air and hire alchemists instead of mages.)

But the title says "Powers", so we probably don't get to use anything from Magic anyway.

[whswhs]

Originally Posted by Anaraxes

"Triple strength", according to GURPS Magic. So it'd be an improvement, certainly, but not really whatever arbitrarily high value you might like it to be. You couldn't build, say, a space elevator from an Essential Metal cable, at least while keeping that definition. (Just enchant a bunch of steps with Levitate instead, or build a big cistern to hold potions of Walk on Air and hire alchemists instead of mages.)

But the title says "Powers", so we probably don't get to use anything from Magic anyway.

I have the impression that "Create Metal (Cosmic, +50%)" could let you create Essential Metal.

I agree that triple strength as such isn't a huge improvement. But triple strength that doesn't weaken as the metal gets hotter would be seriously impressive in some applications. And "doesn't weaken as the metal gets hotter" might be inside the resolution of the definition of "essential."

[starslayer]

Originally Posted by whswhs

I have the impression that "Create Metal (Cosmic, +50%)" could let you create Essential Metal.

I agree that triple strength as such isn't a huge improvement. But triple strength that doesn't weaken as the metal gets hotter would be seriously impressive in some applications. And "doesn't weaken as the metal gets hotter" might be inside the resolution of the definition of "essential."

Perhaps more practically 'can tolerate 3x at much temperature before weakening' would be excellent as well.

However if you have the ability to create metal you could also have insanely thick boilers or use some normally very difficult to access metals like nobium, tungsten, or tantalum

[Anaraxes]

Originally Posted by whswhs

I agree that triple strength as such isn't a huge improvement. But triple strength that doesn't weaken as the metal gets hotter would be seriously impressive in some applications. And "doesn't weaken as the metal gets hotter" might be inside the resolution of the definition of "essential."

True enough. A factor of four from strength (or no loss thereof) times the base 3 makes Essential metal 12 times as strong in that 700 C application.

The Powers text for Create doesn't seem to cover exactly what you can create. The example categories seem to come only from our real-world Earth. But then, even Snatcher is prohibited from Snatching elements that obey different physical laws, even though you're Snatching from alternate worlds. Even advanced tech with the same physical laws isn't allowed with that Advantage. Presumably either base Advantage is meant to work with anything "normally" available in the setting, not just our Earth.

But GMs could of course allow Creators to Create metals with arbitrary properties if they choose, even if those elements couldn't be replicated by any other means. A Cosmic +50% ought to cover breaking the implied "must be a 'real' material in the setting" rule. Though I'd probably get annoyed if the Creator's player insisted they they could therefore create "metals" that were rubber bands, extend themselves indefinitely thing and arbitrarily far, emit photon beams of arbitrary intensity, thermotropic so their arrowhead barbs were guidance fins to make the arrows heat-seekers, were impervious to any physical force when electroplated over steel, etc. There's got to be some limit to just specifying the properties you want Created material to have.

[Refplace]

Originally Posted by Anaraxes

The Powers text for Create doesn't seem to cover exactly what you can create. The example categories seem to come only from our real-world Earth. But then, even Snatcher is prohibited from Snatching elements that obey different physical laws, even though you're Snatching from alternate worlds. Even advanced tech with the same physical laws isn't allowed with that Advantage. Presumably either base Advantage is meant to work with anything "normally" available in the setting, not just our Earth.

But GMs could of course allow Creators to Create metals with arbitrary properties if they choose, even if those elements couldn't be replicated by any other means. A Cosmic +50% ought to cover breaking the implied "must be a 'real' material in the setting" rule. Though I'd probably get annoyed if the Creator's player insisted they they could therefore create "metals" that were rubber bands, extend themselves indefinitely thing and arbitrarily far, emit photon beams of arbitrary intensity, thermotropic so their arrowhead barbs were guidance fins to make the arrows heat-seekers, were impervious to any physical force when electroplated over steel, etc. There's got to be some limit to just specifying the properties you want Created material to have.

First paragraph under Special Enhancements, Powers p. 94 is what Bill was referring to with Essential Materials and thats not real world.
I agree some materials should cost more but that gives us a RAW precedence and starting point. Marvel Comics Adamantium and Vibranium I might make +300% for example.