"Owen Duffy" wrote in message
...
On Sun, 18 Jun 2006 00:31:54 -0400, "J. Mc Laughlin"
wrote:


I do not recognize the "30 Lb of ICE" specification. Most often, ice
loading is specified in terms of size such as 12 mm of ice all of the way
around each element (12 mm of radial ice).

Given the looseness of use of the unit lb to specify mass and
(incorrectly) force, it is a bit ambiguous... but he probably means
mass.

lbs is always force as far as i know. slugs is mass.

so long as we are confined to the planet earth, there is no difference
really. 1 kg (mass) always weighs 2.2 lbs (force). obviously if you go to
the moon ...

kilogram, slug -- mass
newton, pound -- force

Gravity

30lbf of windage from ice loading isn't much on an antenna of
that type!

(We sin in the metric system as well! If someone asks me what I weigh
(being a force) I will answer in Kg (being a mass) instead of N
(force).)

Having said that, the impact of ice on the wind forces is probably
much more significant than the gravitational force due to the mass of
the ice.

Mac, I agree, radial ice loading is a more relevant specification.

Owen
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