The Handy Billy is one of those simple pieces of equipment which, will on occasion prove to be worth its weight in gold.
With two blocks and a bit of rope you could move heaven and earth.
Usually made up of one single and one double block, it can be set up with two double blocks.
Whether you have hook or tail on each end is a matter of preference, I have mine set up with snap shackles.
Having one set up ready to go means it will save time in any emergency situation.
The obvious use is to gain mechanical advantage when lifting heavy objects.
It can also be used to take the strain off another line.
With a rope tail on the block tied to a line with a rolling hitch, strain on the line can be eased in order to,
The mechanical advantage gained from using a block and tackle is, in theory a multiple of the number of falls.
However, in practice there is a certain amount of friction generated at the sheaves.
Also the length of rope needed to move the load a certain distance will be increased by the number of falls.