May 22 – How a Lock Works

Ilion Marina and RV Park

We traveled 44 miles, locked up 104’ in six locks and pumped 200 gallons of diesel...in the rain today. The countryside was beautiful, but not a good day for photography, so I thought I'd use today's blog to explain how a lock works for those who might not understand or can’t quite picture it in their mind. 

A lock is a device used for raising and lowering boats between stretches of water of different levels on a river or canal. The difference in elevation from the Hudson River to Ithaca on Cayuga Lake is 383’; in order for us to get there we will go through 25 locks. The largest lift at one time was in lock 17 today…40’.

A boat enters a fixed chamber of the lock where it can be raised or lowered to meet the next section of the river or canal. Water flows into and out of the lock through underground plumbing by the force of gravity; there are no pumps involved in the process. That means in order to climb hills there has to be a natural supply of water from either a lake or a river above the lock. The supply has to be enough to work the locks during dry summers and periods of high traffic when the lock is cycled more frequently. Finding these sources was one of the key challenges of the early surveyors of the Erie's route across New York State.

You can see how far a boat has to be raised or lowered to get to the next part of the river. In this picture a boat is entering on the high side, the gates will close behind it and the water will be released until the boat is at the lower level. Then the front gates will open and the boat will move on...it's like a water elevator.

 Here a boat is entering the lock chamber

This picture shows the water entering the lock chamber 

This is a picture of the top of a lock with water at the higher level 

In a flight of locks, like this picture shows, a boat moves from one lock chamber into the next. This enables a boat to move up or down a hill.

Information boards like this one are at each lock 

Here is a simple video of how a lock works