Peter Crosland wrote:
"Jules" wrote in message
news
On Mon, 24 Aug 2009 20:46:20 +0100, Peter Crosland wrote:
Sounds like you need the services of qualified structural engineer to
advise
you.
Quite possibly - although what would they do (purely out of curiosity)?
Would they cook up some 3D model of the structure, take samples of
materials and weigh, and work it out from that? I'm intrigued by what the
exact process would be... (mainly because I'm surprised anyone can give an
exact answer without a truly enormous - and perhaps impractical - amount
of work, although I'm sure a reasonable estimate based on a few
calculations and a lot of experience could be attaioned)


The problem is that there are a lot of variables to consider and the job is
not all calculation. I only suggest it because of the potential for disaster
if you try and DIY it.

Peter Crosland


Ive seen substantial stuff jacked up on Acrow props.

The rule seems to be 'if you cant get enough force on the Acrow to jack
it, its too heavy'

I do remember the 6x4 beam across an old shed we used to put a 5 tonne
yacht pulley and hoist on to lift a Morris 1500 engine out..only when
the 5 tonne pulley bent, and the beam deflected about 6 inches, did we
realise that the whole front of the car was 3 " off the deck.. 'er I
think the engine has caught on something chaps'