Never been through a lock? Read on....

[ttmott]

One thing I completely forgot to mention above is where to position you boat in a lock if you have your choice of where to go. This info below is ONLY applicable when you are going UP in a lock because there will be currents inside the lock as it fills.

Now picture this: Let's say you are the only boat in the lock so no problem picking where you want. If you go all the way to the far end of the lock, when they start to fill it that water comes in near the center of the lock and will push against the stern of your boat. That push on the stern will make your bow move toward the lock wall, making control of your boat more difficult.

If you take the first bollard when you enter, as the water enters the lock and moves toward the ends, it will push against the bow of the boat. In doing so, it doesn't cause the "push" against the boat as it does when pushing on the stern.

The Florida locks sometimes raise and lower the water by opening the lock gates. Locking is usually a couple of feet or less. Regardless, the boat moves around quite a bit so man the lines and fenders. Never a floating bollard so never tie off the lines.

 

[Ericinmich]

...

Now picture this: Let's say you are the only boat in the lock so no problem picking where you want. If you go all the way to the far end of the lock, when they start to fill it that water comes in near the center of the lock and will push against the stern of your boat. That push on the stern will make your bow move toward the lock wall, making control of your boat more difficult.

...

This must vary based on the lock and/or the size of the lock. The one I'm familiar with has simple sluice gates on the upstrean doors near the bottom and they are control to open a little, then a lot. The incoming water always pushes the boat rearward.

 

[Maggieiscrazy]

The Florida locks sometimes raise and lower the water by opening the lock gates. Locking is usually a couple of feet or less. Regardless, the boat moves around quite a bit so man the lines and fenders. Never a floating bollard so never tie off the lines.

The only lock I’ve ever been through in Florida was the Chiquita lock in Cape Coral.

 

[blaster]

How about this for getting your boat through an elevation change.

 

[Ericinmich]

How about this for getting your boat through an elevation change.

I've been through it twice in the late 70s with my parents in a 24/26 sundancer. It's basically the high point on the Trent Severn, on one side the water goes to Lk Huron and the other it goes to Lake Erie. As a kid it was a great memory watching it work, and keeping itself level!

The Peterbourgh lift is even more exciting as you stay on the boat on that one!

 

[Flyer5]

How about this for getting your boat through an elevation change.

Damn I'd be nervous having that much hanging off the back.

 

[DaveKamp]

Some locks do fill from the center... but not all are built that way - depends on the time and circumstances of the build, and some have been modified. The most frequent used on the midwest uses a 'tunnel' located BEHIND the base of the lock walls, that goes from the upper to lower end of the lock, with inlet and outlet valves at the ends of the tunnel, and a series of ports cut through the lock wall into the tunnel.

Library of Congress has build prints and photos for MOST of the locks built, and in some cases, they also show where a lock built in one fashion was altered as they found performance enhancements needed. They've used concrete-cutting hydraulic chainsaws to cut additional ports into the walls on many, and the explanation I got, was that having ports along the entire length reduces deposition of sediment onto the lock floor, and also cuts down on the frequency of waterlogged trees from getting pulled into the crotch of a mitre gate.

In this article, about halfway down the page is a really great picture of Upper Mississippi River Lock #2 in Hastings, MN during a dewatering... you can see the tunnel ports along the bottoms of the walls.

Working below the water line: Crews drain Lock and Dam 2 at Hastings for periodic inspection

Among the jobs: Replacing four valves believed to date to the 1940s.

www.twincities.com