Promethium Weight

By Phi6891, in Only War Rules Questions

I have a strange question, what does 1 liter of promethium weight?

That is somewhat of a difficult question since flamer fuel (which I assume is what most instances of "promethium" refer to) is 1) not typically measured in liters, 2) packaged only as 10% of a weapon's weight, and 3) flamer weapons are not described as having an X-liter capacity. As far as I know, there's no textbook answer on how much a liter of promethium weighs. Come to think of it, I do not know of any items measured in something other than kilograms or doses. Maybe someone else has a more concrete answer for you, but what would a liter of promethium accomplish other than to be used for reloading or demolition purposes?

Well I'm trying to calculate the damage of 200 liters of promethium being blown up.

In the Inquistior's Hand book on page 178, for every kilogram of promethium it does 2d10 E and had a blast radius of 4x it's weight.

I want to know how many d10s must be rolled and what the radius of the blast is. It's a strange question I know because as you said nothing is measured in liters, the flamers in the book doesn't list how much it takes. Otherwise I would have to guesstimate using napalm as the equivalent of promethium to figure out it's weight per liter.

Edited by Phi6891

Ooof. That's going to be a large one.

As a comparison, 200 liters of water is nominally 200kg.

At half water density, you're looking at 100kg.

At double water density, you're looking at 400kg.

if it's a player, it's burn fate point time. Anything else .. there are going to be a lot of secondaries touched off.

Oh wow. At that point, I would just defenestrate the mechanics and dice and cook up narrative destruction without them. I mean, it's not like anyone is double-checking that your damage roll of 287 is doing exactly what it's supposed to. The damage-rolling is more of an abstraction/guideline than a worldly law, I figure, so feel free to have people turn into orange soda in however big an area you want.

Well if we use 1 litre = 1 kg

Then that would have to be 200 kg which means about 400d10s with a radius of 800m / diameter of 1600m.

We were ambushed by a group of Dark Elder in a Hive city through a passage called the Murder Hole. It was on a mission to save a general in the pleasure district. Our Chimera was too damage to repair so we took what could and blew up the rest with the promethium barrel. I'm trying to tell my friends that the 1 barrel of promethium could have destroyed the casino with the hundreds of Dark Eldar in the building. And also that we are actually dead because we blew the barrel up and we all were too close to the blast.

Edited by Phi6891

Well if we use 1 litre = 1 kg

Then that would have to be 200 kg which means about 400d10s with a radius of 800m / diameter of 1600m.

We were ambushed by a group of Dark Elder in a Hive city through a passage called the Murder Hole. It was on a mission to save a general in the pleasure district. Our Chimera was too damage to repair so we took what could and blew up the rest with the promethium barrel. I'm trying to tell my friends that the 1 barrel of promethium could have destroyed the casino with the hundreds of Dark Eldar in the building. And also that we are actually dead because we blew the barrel up and we all were too close to the blast.

Yeah ... it's more than enough to blow up the place, or, at minimum, take out structural supports, causing at least part of the building to collapse.

Anybody without Fate Points to burn is gone. Presumably, the PCs have Fate left and burn it to survive the explosion. They're probably buried in the rubble, but can be dug out again. If there's a General or other VIPs known or suspected to have been in the building when it went up, there will be a search and rescue effort made, rather than just search and recovery.

I strongly suggest blaming the explosion on the Dark Eldar, rather than claiming responsibility for blowing up the place.

The Dark Heresy Inquisitor's Handbook has the answer to that somewhere, as I recall it featured promethium as a stackable resource complete with a rule of how X kilos would blow up with a blast radius of Y causing Z damage. The effects were rather pathetic, though, and could probably use with a buff.

Just consider this as an option for inspiration, though. There is no need not to use your own method for calculating/statting these things, and indeed usually I recommend taking stuff from other games (although DH and OW are probably rather close in narrative combat style).

Have you checked out the weight of modern kerosene which is an approximate equivalent? Promethium just happens to double as napalm as well as a fuel.

Promethium would be closer to diesel fuel so 200 liters would be 170.16Kg

http://www.aqua-calc.com/calculate/volume-to-weight

If it was kerosene 200 liters would be 160Kg

Edited by SMKeyes

See I was looking all over for the weight of napalm and I couldn't find it, so I just used the weight of gasoline and ended up with 150 kg (rounded up, +/- 1 kg). I didn't know that kerosene was the equialent, thanks.

So that leaves me with 340d10s with a radius of 680 m / diameter of 1360 m. I knew the promethium barrel would be able to blow up the casino.

No it probably won't play out that way, I think it's just going to be ignored. And after that ambush in the Murder Hole by the Dark Eldar two of our guys lost two fate points, several comrads died, our Chimera Armoured Transport ruined. So we are pretty screwed up and that blast would've have finished us.