Do you remember playing tug-of-war with your friends? Bollard pull is kind of like tug-of-war, but with a big boat and a really strong rope instead of people.
You see, boats need to be able to move around, even when the water is pushing against them. So, they use something called an engine, which is like the boat's muscles, to help them move. But sometimes, the water is really strong and the boat's engine needs some extra help.
This is where bollard pull comes in. A bollard is basically a big strong post, kind of like a really sturdy tree. Sailors tie their boats to bollards when they want to stop them from moving. But sometimes, sailors will tie a really strong rope to a bollard and then attach the other end of the rope to the boat's engine. Now the engine can use the bollard for extra leverage and pull the boat through the water, even when it's really tough.
Bollard pull is the amount of force the boat's engine can exert on the rope, which is the same as how strong the boat is at tug-of-war. The more bollard pull a boat has, the stronger its engine is and the easier it can move through the water, even when the water is pushing against it.