Poor Mans' Come-along All you need is a chain and a Fat Friend
The principle of leverage can move heavy objects with minimal equipment.
graphic above shows a blue Chain tightened between a Tree and a Rock.
Putting a red weight in the middle of the Chain will budge the Rock.
The heavier the weight, the farther the Rock will move. The weight can
be concrete blocks, your body, all the neighborhood kids, or even a
Bumper Jack (lifting the chain up).
Most of the pulling advantage is in the initial deflection of the
chain. The farther the chain is deflected, the more weight is required
to produce that same amount of deflection. If moving the Rock 1"
30 pounds, then moving it another inch requires more than 60 pounds. So
it is most efficient to keep the chain tight to get the maximum work
from the least weight.
A Chain is suggested because it will not stretch like a Rope. And
unlike a Cable, it is quick and easy to tighten the chain one link at a
time. You can use a strong Rope or Cable with a Chain fastened to the
end for link adjustment. It can be fastened to any immovable object
like a fence post,
Utility Pole or Car. But if you use a car, you may not need the weight
If you can put steel pipes or round river stones under the object to be moved,
they will act like rollers, and making moving much easier.
Even wetting the sliding area with water may help.