For completeness mods needed to engine crane, not necessary for 650Kg but useful are
1. Shorten jib support tube at an angle (makes it fold tighter) get top brace rewelded professionally unless you’re good. Mark support tube up with deratings.
2. Make a set of shorter bracing legs mit casters (timber will do with angle iron reinforcement) , for when you’re lifting < 2 tons in a confined space. Put a shelf in the back space where you can permanently store heavy objects to help counterbalance crane. This is self safetysising, wen you lift if the short legs/counterweight are not enough and the back of the crane starts slowly lifting, stop pumping and add longer legs or more counterweight.
3.Make a second ,shorter pump lever from old tube for use when space confined.
4. Shorten hook chain (to give higher lift under van roofs.)
t5. Timber , rope and slings will groan and give you a warning that steel won’t.
6.Use shims, spacers to tighten sloppiness between structural members of crane, particularly to center jib on ram. This as a guess will increase the safety factor of the crane by another 25 % and decrease buttock clenching by the same factor.
7.Clarkes make the biggest range . They are not cheap and IMO there is not a decent design among them. I think it might be possible to get a 3 tonner which is a good design and folds tightly but I’ve never seen one. You need six casters , a top brace and leg locks for when they are folded. If a leg falls on your head due to a sudden move you’ll know all about it.
8 a 6 foot preferably pry bar is almost essential. When you’ve got a ton and a half suspended those easy rolling multidirectional csters won’t be . A six foot gentleman’s persuader will return the casters to compliance so small slow moves are possible. A ton and a half swinging is impressive but not good for maintaing the colour of the trousers.
Most of the above can be done at leisure and will not be de rigeur for 650 Kg.
EDit-Lots of helpers are not good unless you are an ex-sergant major and they are used to working as a team. Two reasonably strong men, used to working together, can move practically anything with the right equipment and much more safely. Watch riggers, theres not usually a bunch of them but they know what they are doing and work as a team. Steel toecaps and gloves are good but I must admit I rarely put mine on.
best of luck and regards.
Edited By alan frost on 27/11/2011 19:27:53
Edited By alan frost on 27/11/2011 19:29:41