Posted by Bazyle on 26/06/2023 23:16:24:
If things are too congested for an engine crane it is rather unsafe for multiple people. One option if you have a straight run from the door to the bench is two scaffold planks to make a ramp. Using two makes balancing less risky. Use a hoist or jack to pull the lathe up the ramp. Have the lathe on a sheet of ply not rollers so it can't just roll down if you need to adjust the hoist. The extra friction is of no consequence if you have a good ratio on he hoist or jack.
I think there are ways one could do a manual lift safely.
Slinging the mill from beneath with a pair of short slings connected with a d-shackle and passing a stout bar or scaffold pole through allows you to get as many people as will fit in the space round it and for them all to have a good grip with no pinch hazards.
Assuming the bench isn't too high, and the slings are short, four people lifting and a fifth person controlling the load to prevent swinging would be pretty safe, better still if that fifth person can have some blocks to hand they can slide under allowing the people lifting to reposition between the floor and full height to maximise lifting with their legs and avoid putting their core muscles under too much stress.
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If going a manual route the important thing is that everyone knows their limits, knows proper lifting form, and keeps well within both.
I remember having ergonomics training where they drilled into us that the oft quoted HSE guideline of 25Kg for a man and 20kg for a woman is based on average people of working age, and that it is perfectly acceptable for someone to lift more if they have a demonstrated ability to do so safely and it's been assessed, but it is also wholly unacceptable to ask someone to lift something they were uncomfortable with just because it was under the guideline number.
If in doubt add more people.
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Ramps do work really well, but setup is everything because there's a lot of inherent instability in using them.
I would personally be inclined to use rollers or a thin sheet of metal to minimise the static friction, having had experiences where a load jerked violently on a ramp when it overcame friction and became unstable.
But that then means you do need a progress capture mechanism or a winch/pulley system which can do the whole move in one go, and allows safe lowering.
Hiring a Tirfor for the day would give all of that very nicely, and is usually pretty cheap.