[Healeys] Earthquakes and Lifts

[Alan Seigrist]

Bill -

You definitely don't want to wire the hoist to the ceiling because in an
earthquake, the higher you go the more amplitude of movement you'll get,
plus the rafters typically will be in exact opposite phase of sinusoidal
movement.  You don't want the rafters shaking your hoist one way while the
ground is shaking the other way.  Plus I doubt the rafters are strong enough
to hold a car anyway.

Front to back motion can be fixed easily by running a guy wire from the
bottom of a front post to the top of the rear post (on the same side), and
then the top of the other front post to the bottom of the other rear post.
That will keep the hoist from collapsing front to back and I assume there'd
be no problems with access or room in the garage if you do it this way.  You
could do the same wire bracing on the back (in an X) to minimize side to
side motion of the hoist, but obviously the front you need the opening clear
to drive on and off the lift.

 For front of hoist side to side motion, you could run guy wires from the
top of the front posts to the 2x4s in your wall - you'd best do it on both
sides.

something like this:

Front:
 _
|  |

Back:
  _
|X|

Left Side:
 _
|/|

Right Side:
 _
|\|

Alan

'52 A90
'53 BN1
'59 Jag Mk IX
'64 BJ8


On Fri, Dec 18, 2009 at 8:21 AM, <wilkmanracing at aol.com> wrote:

> I've thought about the same sort of anchoring, except the idea of using guy
> wires didn't occur to me.  Of course the problem with anchoring the wires to
> the ground is that they would require a considerable distance of available
> space around the car.  The wires would also interfere with movement around
> the car.  What about extending the wires upward and anchoring them to
> ceiling joists?
>
> Bill Wilkman
> BT7