Post by Mystique R333 on Jan 14, 2009 9:33:17 GMT 10
Hollands don't have a central crane lifting point but as our yacht would be on hardstand for a while until a pen becomes free, we decided a lifting point would be needed. A rectangular section was cut out of the cabin roof as the RYCV's crane "C" lifting plate that allows going in via the doorway, would not reach far enough forward. With use of 2000kg rated ring nuts screwed onto the keel bolts, a trial lifting was set up. It turns out that of the six 5/8" keel bolts (one at rear, then two, then two then one at front) the closest to the lifting point is the most rearward one. We used the rear bolt and one of the next set forward of that as we were not willing to trust one bolt and ring nut.
The old lifting point, using two stainless steel ring nuts, was not secure enough and needed a more permanent solution. The rear keel bolt took most of the strain but only half the thread, of the ring bolt, was covered by the too short bolt.
A stainless steel plate and lifting point was fabricated to cover the rear three keel bolts. Although this is an expensive solution, we could never be sure when we might get a pen in the water and so may have to be on hard-stand for a while. This makes a secure lifting point important to be able to access the water easily and rapidly by simple crane rather than travel lift.
To obtain access to the subsequent lifting point we had to cut a hole in the roof of the cabin and through the garage roof as well and these are now accessed by top an bottom screw-in 6" ports. With a new three ton ISO lifting strap and two Spectra strops to the back of the boat we get a nice flat lift and crane access will now be easy and safe for yacht and people.
Basically, if you intent to create a lifting point I'd suggest the rear three keel bolts with a hole in the roof directly above the rear keel bolt.
Note: we have a Volvo MD5 inboard that has to be considered as condideravble weight towards the rear. If you use an outboad, your lift may be forward of the rear bolt but not past the next set of bolts at the seat edge. Our lifting point on the floor is actually closer to the double set of bolts than the rear bolt so as to spread the load, so I'd suggest that is a good location.
The old lifting point, using two stainless steel ring nuts, was not secure enough and needed a more permanent solution. The rear keel bolt took most of the strain but only half the thread, of the ring bolt, was covered by the too short bolt.
A stainless steel plate and lifting point was fabricated to cover the rear three keel bolts. Although this is an expensive solution, we could never be sure when we might get a pen in the water and so may have to be on hard-stand for a while. This makes a secure lifting point important to be able to access the water easily and rapidly by simple crane rather than travel lift.
To obtain access to the subsequent lifting point we had to cut a hole in the roof of the cabin and through the garage roof as well and these are now accessed by top an bottom screw-in 6" ports. With a new three ton ISO lifting strap and two Spectra strops to the back of the boat we get a nice flat lift and crane access will now be easy and safe for yacht and people.
Basically, if you intent to create a lifting point I'd suggest the rear three keel bolts with a hole in the roof directly above the rear keel bolt.
Note: we have a Volvo MD5 inboard that has to be considered as condideravble weight towards the rear. If you use an outboad, your lift may be forward of the rear bolt but not past the next set of bolts at the seat edge. Our lifting point on the floor is actually closer to the double set of bolts than the rear bolt so as to spread the load, so I'd suggest that is a good location.