In article ,
Evan Gatehouse wrote:

"Karl Denninger" wrote in message
news:W7tsd.793$Nx2.646@lakeread06...

In article ,
Dave Richardson wrote:


On a recent haul out I asked the TravelLift operator if his weight
scale read the displacement of my foriegn built sloop. He said he had
two scale's - one for each strap on the lift and by adding the two
weight reading's I would know the vessel displacement. It added up to
about 10,000lbs..

Would that be a correct way to weigh a boat? Thank's.

They're not real accurate, but for larger boats they're the best bet
you've
got.


That's what I found out when I talked to a travellift operater. I think
they are probably calibrated at the factory and never again....my guess
would be +/- 10% or so.

The purpose of the gauges on the lift is to allow the operator to know that
the hoses, pumps, and other items involved are not about to collapse/break
and drop your boat!

They are simple hydraulic pressure gauges, basically, and they read the
static pressure in the system when "locked up", which is, of course, caused
by your boat being in the slings.

There are all kinds of inaccuracies in the system, not the least of which is
the diameter of any cable winches which changes with the amount of cable
"stacked" on the drum - and thus changes the reading vis-a-vis what's really
there. Basically these gauges are not intended to provide you with an
accurate weight - they are there to let the lift operator know that he's
lifting within the limits of the equipment.

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