[UT] Plasma Torch vs. big metal door on a spaceship?

[Nereidalbel]

Originally Posted by vicky_molokh

That's an effect that applies to wood, stone, brick and concrete. I'm looking for cutting through huge metal obstacles.

Nothing in the text says that this only applies to wood and stone, only that wood and stone have a cap on how much DR can be ablated. The lack of a minimum DR for metals seems like an oversight, however.

[vicky_molokh]

Originally Posted by Nereidalbel

Nothing in the text says that this only applies to wood and stone, only that wood and stone have a cap on how much DR can be ablated. The lack of a minimum DR for metals seems like an oversight, however.

That * sign in the beginning of the paragraph on page 559 is a footnote from page 558. Notice that the DRs of wooden, concrete, stone and brick objects come with an *.

[Joseph Paul]

Looking at the hvy plasma torch in UT - 4d+1(5) - I think the problem is that you need a real industrial torch or water jet cutter for anything over an inch in steel. And that should have an AD(10) and a much larger damage.

Also are you attacking the whole surface (112 DR/inch) or the Cover DR (~70DR)? I would rule that these tools are continuously piercing the Cover DR in a very small space. RAW doesn't seem to include metals in the semi-ablative/ablative note so move onto a better tool.

[Anthony]

Originally Posted by Joseph Paul

Looking at the hvy plasma torch in UT - 4d+1(5) - I think the problem is that you need a real industrial torch or water jet cutter for anything over an inch in steel. And that should have an AD(10) and a much larger damage.

Not over the course of a single GURPS combat turn.

[Joseph Paul]

Originally Posted by Anthony

Not over the course of a single GURPS combat turn.

I am not sure I understand your objection. Care to expound?

[Fred Brackin]

Originally Posted by Joseph Paul

I am not sure I understand your objection. Care to expound?

You appear to be looking for something that will penetrate very high DRs in a single round i.e. as in normal combat.

We can definitely say that HT torches don't work that way though they can penetrate very high DRs over a longer period of time. Possibly much longer. It took the Mythbusters many minutes to burn into a safe with a TL 8 "plasma" torch. It is to be hoped that UT torches will do at least a little better on that time/DR relationship.

So, modeling TL8 performance we need some kind of cumulative damage paradigm such as making metallic DR ablative or semi-ablative v. Burning damage or treating Burning as Corrosive and that's what has made up the bulk of discussion in this thread.

[Joseph Paul]

Originally Posted by Fred Brackin

You appear to be looking for something that will penetrate very high DRs in a single round i.e. as in normal combat.

We can definitely say that HT torches don't work that way though they can penetrate very high DRs over a longer period of time. Possibly much longer. It took the Mythbusters many minutes to burn into a safe with a TL 8 "plasma" torch. It is to be hoped that UT torches will do at least a little better on that time/DR relationship.

So, modeling TL8 performance we need some kind of cumulative damage paradigm such as making metallic DR ablative or semi-ablative v. Burning damage or treating Burning as Corrosive and that's what has made up the bulk of discussion in this thread.

All plasma torches have thickness limits generally tied to the amperage they can put into the arc but the relevant industries seem to like plasma up to the 6 inch range. They find it more economical to use oxy-fuel cutting torches for really thick material – up to 40 inches. With a plasma cutter properly matched to the task at hand you will see very fast initial piercing and high cutting rates – because that makes it profitable to use. Last night I watched an industrial demonstration of cutting a part out of 2 inch thick material. The pierce took all of 2 seconds and the linear run was better than 20 inches in a minute. Every second that torch moved through a third of an inch or more of material completely annihilating it. That is several times the amount of material the initial pierce dealt with and I think that definitely shows that the torch is not only dishing out enough damage to overcome the DR but it is doing it several times a second. I can't speak to Jamie and Adam's experience because my googlefu is failing me (Got a URL?) but it seems we have seen very different examples of plasma torches. I know that hand held torches are designed to cut their max thickness at no slower than 10" per minute and the thinner stock goes much faster. CNC rigs can do 80 or more IPM.

I think the line of thought on having to treat the DR as semi or fully ablative is misguided and based on the relatively weak stats of tools that are light duty and meant to be highly portable. Neither the HT nor UT plasma torches detail how thick of a material they should be used for and that is what should be noted as well as the cutting speed in that thickness. Those stats answer the important story questions “Can we breach it?” and “How long will it take?”.