This is a simple prop designed to aid manual lifting and positioning of heavy or awkward items. Typically used in pairs, they allow each end of a item to be lifted and propped - slowly increasing the overall height without undue effort or risk.
Example dimensions are given here, but these can be changed for different applications as required.
The base is made from two pieces of 100 x 50 mm sawn timber. The wide part is approx 1m long, and the short part is approx 50cm. The short part is connected to the large part by a hinge such that the short part of the base can be folded up for transport, once the retaining strut has been taken off. The retaining struts for the main section on the wide base can be permanently attached.
The main column is made from a couple of sections of 50x25mm timber. These are set into rebates cut in the base section for added strength. Total length shown here is 50" (i.e. 48" protruding above the top of the foot). The sides are made from 12mm ply, and 12mm holes have been drilled every 4" up the side. The ply sides are glued and screwed to the column front and back timbers. Together they make a strong central box section.
The prop is made from 50mm square PAR timber with a gallows bracket section at the top. This is placed into the central box section, and the depth to which it will fall is limited by a bolt passed through the sides of the box section in the holes provided.
A prop of this type can be used flat against a wall, and would be ideal for the temporary support and lifting of a heavy beam, or piece of equipment such as an air conditioner. The item to be lifted is placed on a pair of props with them set to a comfortable initial height. The operators can then lift an end by a small increment and extend the prop to take the weight. Moving from end to end to raised the whole item.
Remove the front brace and fold up the front leg. Take the main prop our of the box section, rotate a quarter turn and replace it back in. The props are now basically "flat".