How tough is ice?

[dcarson]

Pyrkete isn't just ice. As the link explains it's a composite with sawdust or some other wood pulp. Twice the crushing strength and four times the tensile strength as plain ice. What that is in DR I have no idea.

[Purple Haze]

Originally Posted by ClayDowling

Also known as the personal canon. It's physically painful to shoot one in an enclosed shooting box, and you can always tell when somebody has them at the range. Don't notice the noise when I'm shooting it, but I was at another part of the range one day and somebody was shooting one. About the loudest thing I'd heard out there, and I was on the skeet range at the time.

The kick isn't fun either. I'm told the 7.62×54mmR (which is actually a 7.7mm as well) is worse, but I haven't had the pleasure.

[Anthony]

Originally Posted by dcarson

Pyrkete isn't just ice.

The link I gave mentioned the penetration in ice. Based on that link, pyrkete is probably DR 4 per inch.

[ssveter]

I didn't think to look in the 3rd ed books. Thanks.

[B9anders]

Originally Posted by Bruno

Oh, that's not something special to the US measurement system. And in this case it's actually the UK you should blame - they decided to change the size of their ounce one day, not the US. But the current situation (Three different legacy systems sharing the same or similar unit names - don't forget Troy weights :P) is much better than it used to be. Each country used to have its own standard.

Meanwhile, in the rest of the world, 1 litre of water weights one kilo, a cubic meter is exactly 1000 litres, water boils at 100 degrees and freezes at 0 and all units neatly divide and multiply by factors of 10.

[smurf]

Originally Posted by B9anders

Meanwhile, in the rest of the world, 1 litre of water weights one kilo, a cubic meter is exactly 1000 litres, water boils at 100 degrees and freezes at 0 and all units neatly divide and multiply by factors of 10.

That didn't used to be the case. Water boiled at 0 and froze at 100 until they changed it IIRC.

[smurf]

BTW how think does the ice have to be to support say a ton? Or is that in the 3rd Ed Supers book too?

[JCurwen3]

Originally Posted by smurf

That didn't used to be the case. Water boiled at 0 and froze at 100 until they changed it IIRC.

At sea level... will vary based on pressure.

[Bruno]

Originally Posted by B9anders

Meanwhile, in the rest of the world, 1 litre of water weights one kilo, a cubic meter is exactly 1000 litres, water boils at 100 degrees and freezes at 0 and all units neatly divide and multiply by factors of 10.

Ayup. Canadian here. *wave*

Originally Posted by smurf

BTW how think does the ice have to be to support say a ton? Or is that in the 3rd Ed Supers book too?

A good source for this is literature on Ice Roads, an arctic/sub-arctic phenomenon. A little research says the legal guidelines are 2 long tons for 7.9 in (Sweeden), 2.5 long tons for 8.7 inches (Estonia), 3 tons for 16 inches (Finland)...

For all of these, there are strict speed limits. The ice is on water and supported by water - you're floating. It flexes even at these thicknesses, and causes ripples which cause more flexing, which can result in cracks and your vehicle (or the vehicle behind you) going through the ice.

[Bruno]

Some other recommendations (Alaska Fish and Game dept):

Ice Thickness (inches): Max. Load
02: 1 man on foot
03: Group, single file
08: Automobile (2 tons GVW)
12: Heavy truck
25: 45 tons
36: 110 tons

EDIT: And from Work Safe Alberta a very detailed guide, dedicated to the memory of a man who broke through the ice and drowned.

All of this is, again, on water.

I would double thicknesses for unsupported segments, and require Architecture rolls to make arches, space supporting pillars appropriately, and so forth.

EDIT: Gold's Formula, the standard in Canada and defined in 1971, is P = A x h^2 where:
P is the allowable load in kilograms
A is a parameter that depends on the strength of the ice
h is the effective thickness of good quality ice (cm)

A values of 3.5 and 4 are "acceptable or tolerable", higher numbers are bad quality. Create Ice type powers likely creates some pretty darn good ice (no air pockets or cracks), and I'd give that an A value of 2.5 or so.