[LT] Portcullises

[Figleaf23]

Hello,

I'm loving Low-Tech. I'd read it for the info alone, even if I weren't a GURPSer.

However, I wonder if there is a bit of a problem, perhaps an erratum, regarding portcullises on page LT119. The example suggests that a mechanism to lift a 450lb. grate requires 8 men to operate. But 8 average men would have a combined XHvy-encumbrance lifting capacity of 1600lbs, so what would be the point of the mechanism?

[malloyd]

Originally Posted by Figleaf23

However, I wonder if there is a bit of a problem, perhaps an erratum, regarding portcullises on page LT119. The example suggests that a mechanism to lift a 450lb. grate requires 8 men to operate. But 8 average men would have a combined XHvy-encumbrance lifting capacity of 1600lbs, so what would be the point of the mechanism?

It lets them lift it higher than they can reach? And of course they don't have to squeeze in 4 on each side of it, blocking the gate with their bodies, to do it. But yeah, that's a pretty inefficient mechanism.

[Figleaf23]

Drawing raw ropes over a rough beam would be more efficient than this mechanism!

[vicky_molokh]

Originally Posted by Figleaf23

Drawing raw ropes over a rough beam would be more efficient than this mechanism!

Strictly speaking, how much they can lift is a function of their weight, not their strength.

[Figleaf23]

Originally Posted by vicky_molokh

Strictly speaking, how much they can lift is a function of their weight, not their strength.

The depends on the mechanism, but, yes, it's true of a pure conversion of the force to a downward pull. But that points up even more the questionablity of needing 8 men to draw up 450 lbs.

[vicky_molokh]

Originally Posted by Figleaf23

The depends on the mechanism, but, yes, it's true of a pure conversion of the force to a downward pull. But that points up even more the questionablity of needing 8 men to draw up 450 lbs.

I was referring to raw rope(s) over a beam that you mentioned.