Lock & Dam #7

Saturday, September 16, 2023

Today, we had one of the most incredible experiences. Just by chance, we stopped by Lock & Dam #7 in La Crescent, MN, and it happened to be their Applefest celebration. In conjunction with Applefest, the U.S. Army Corps of Engineers had an “open house” at the Lock & Dam. They gave the public the opportunity to tour the grounds and gave us absolutely incredible access to so much of the workings of the place. A huge shout-out to the Corps of Engineers; they always keep the grounds so well maintained for the public, and to provide this opportunity was just amazing. We can’t say enough good things about EVERY Corps of Engineers employee we have ever had the opportunity to meet. Such nice folks and always happy to answer our many questions.

Just as we arrived the La Crosse Queen was locking on their tour headed north. Here is the pilot house with the captain maneuvering the boat into the locking chamber.

The captain steers the boat by alternating which of the two paddle wheels turn and in what direction. It was interesting to see this mechanism in action as one wheel was spinning in a forward direction and the opposite was in the reverse direction and the result was a rather impressive course correction.

Here is where the unprecedented access to the Lock & Dam becomes apparent. As they were locking the La Crosse Queen into the chamber, they offered us the opportunity to ride on the gate as it closed on the south end of the chamber. What an incredible experience.

This is the walkway atop the south gate of the lock. This is the gate that we stood upon as they closed the doors to lock the La Crosse Queen into the chamber. Once the gates are closed, this walkway provides access to the dam portion of the property.

With the water level in the chamber raised, the Queen was once again on her way north.

Once across the locking chamber, we had an unobstructed view of the dam. These are the five larger Roller Gates that are closest to the locking chamber. Further out, across the river, are numerous smaller Tainter Gates.

This wider view shows the Roller Gates on the left of the image and the smaller Tainter Gates to the right.

The Mrs. P is a “helper tug” that is used to assist the larger tugs and barges as they maneuver into the locking chamber or through narrow bridge supports. The Corps of Engineers live on this tug for 9 months out of the year and they have up to 4 men on the tug 24/7. They told us a typical schedule is to work 21 days on the boat and then have 14 days off. The tug has four small bedrooms, two showers and toilets, and a kitchen and laundry. We were given full access to wander around the tug and it was so fascinating.

The pilot house of the Mrs. P tug.

The Captain told us some amazing stories of the things he had seen in his over 20 years working on the tugs.

He said that Lock & Dam #7 is one of the most dangerous to maneuver for the barges. They have a particularly difficult time when traveling south. The river narrows immediately above this point and the result is the same amount of water has to flow through a smaller channel. This creates some currents that can push the barges in directions they don’t want to go. The Mrs. P is used to help guide the barges into the narrow channel and locking chamber. Apparently, the trip south is much more treacherous because when traveling north the southbound flow of water acts as a natural break, but when traveling down river it actually pushes them rather aggressively - especially when the river is high and running fast.

Some of the massive ropes on the deck of the Mrs. P. They use these to attach to the barges when they run aground and help pull them back into the main chamber.

These are the larger Roller Gates in the foreground. This is immediately above the dam. This is a vantage point you probably don’t ever want if you are in a boat!!

The Roller Gate submerged at a rather low level because the flow of the river is so low due to the dry conditions. As the river rises and the flow increases they will raise the Roller Gate and that is the mechanism you can see on the left. In a moment you will see the gears used to raise these gates.

Immediately below the Roller Gates. The flow is turbulent, as you would expect, but rather subdued as a result of the drought conditions. This past spring, when we had flooding, we could see the turbulence below these gates and hear the roar of the water all the way from across the property at the observation deck. We can only imagine how wild it would have been standing here in April of this year!!

We have now climbed up into the tower where the mechanism is located to raise the Roller Gate; seen here from above.

Each of the Roller Gate towers has this machine room where the gears used to raise and lower the Roller Gate are located. These motors are attached to massive chains which raise or lower the Roller Gate below.

On the right is the gauge which indicates the level at which the Roller Gate is located.

The top reads, “MINUMUM DISCHARGE OPENING UNDER GATE IN FEET”

Below that reads, “ELEVATION TOP OF DRUM - M.S.L.”

To the left of the gauge is the massive gear mechanism used to raise and lower the gate.

Looking across the top of the dam toward the far side of the river. You can see a crane that runs on a track on the upriver side of the dam. This crane is used to lower huge cement blockers into slots below. When put into these slots the cement blockers will prevent water from going through that portion of the dam. This allows them to work on that portion of the dam without water flowing through.

The view from the Roller Gate tower back toward the locking chamber is something we may never get the chance to experience again.

Another view from the tower.

The view from above the dam looking south. Like everything else on this day, this is not generally a vantage point the public can access except for this one special opportunity.

At each end of the locking chamber, there is one of these gauges which they use to assess the depth of the pools. This one is at the north end.

This is the gauge at the south end.

We spent so much time enjoying the tour of the grounds that we were still there when the La Crosse Queen made its return trip headed back south through the lock. There were also a number of very nice fishing boats in the locking chamber at the same time. We suspect there might have been some type of fishing tournament going on as part of the Applefest celebration.

The Queen headed back south to La Crosse, WI.

This is one of the Corps of Engineers’ tugs and barges with equipment for woking on the river.