In the past, before the invention of trains, planes, and automobiles, people around the world used boats and ships to move themselves and their goods around. The problem was that while boats move quite easily on flat lakes and gently sloping rivers, they tend not to go over huge rapids or waterfalls without getting smashed to smithereens. So the problem of moving boats between waterways at different heights presented a problem – and the solution was shipping locks. If you’re thinking of locking up your ship to keep pirates from stealing your things, think again! Shipping locks lock up water and allow ships to move up and down over steps.
1. To move up to a different level, a boat first enters a lock, which is a part of a channel or canal with 2 great big doors. The upstream door is closed to stop water flow, while the downstream door opens to let the boat in. A culvert flows around the lock to make sure water doesn’t fill up and overflow over the upstream door.
2. Once the boat (or boats) is inside the lock, the downstream door is also closed. Then the fun begins! The culvert is blocked downstream so that water from upstream instead starts to flow into the lock, slowly filling it up until at last the water level in the lock, with the boat floating on it, is at the same level at the water upstream from the lock.
3. Finally, the upstream door is opened and the boat can float right out of it, now one step up from where it started. Boats going downstream can get into the lock and when the doors are closed, water is drained out to lower them down a level.
Find out more about gear trains!