On the shore side of the chain that connects the pontoon with concrete floats to the shore, there are steel springs that protect the chain and the components of the dock. The function of the spring is to dampen shocks from storms or the pressure of ice on the dock. The springs should be renewed every 10 years or when a spring breaks. It is easy to exchange the spring by yourself. All you need is some rope, a tie down strap, a new steel spring, and shackles.
Replacing the steel spring is commenced by lifting the chain out of the water with the rope. Attach the rope to the chain next to the spring and tie the rope to the gangway of the dock.
Attach one end of the strap to the chain on the shore side of the spring, and the other end to the dock end of the chain. Tighten the strap until there is a loose section on the chain and the spring is hanging in the rope going to the gangway. Now detach the old spring. You might need an iron saw for removing the spring. If the spring has broken and cannot be removed, the old spring can be left hanging on the chain.
Now attach the new spring to the chain so that seven loose chain links remain. Use shackles that are large enough and secure the shackles with wire. Once installation is complete you can detach the rope and loose the strap. The new steel spring is now in place.