In 2016, we traveled to Scotland. A highlight of our trip was the week-long barge journey from Inverness to Banavie. It followed the route of the Caledonian Canal allowing us to traverse Lochs Dochfour, Ness, Lochy, and Oich from the North Sea to the Atlantic side of Scotland. The canal was finished in 1822. A fascinating part of the canal is the system of 29 locks used to raise and lower boats. The highest elevation reached is 106 ft above sea level. Our post is here about the lock system. Pictured below is one of the sets of lock gates viewed with Google Maps. The water level in the upper right is higher than at the lower left.
Last week, my friend David and I traveled to the Mississippi River at the Quad Cities to do a boat tour of Lock & Dam 15 conducted by two engineers with the U.S. Army Corps of Engineers. They explained much of the history of the river and early attempts to navigate boats through this region. They also described the maintenance of the dam and locks to further their useful life. They also discussed some of the history of the Rock Island Arsenal as we passed by.
The multiple gates of the dam are on the left in the next image. They control the river flow from upper right to lower left. There are two locks for river traffic just right of center. Our tour boat passed through the smaller of the two locks. Large tugboats and their barges pass through the larger lock.
It is interesting to compare the sizes of the locks in Scotland with these on the river. Satellite images from Google Maps were set to nearly the same scale. A Caledonian Canal lock image is superimposed on the river lock image. Dimensions of the canal lock are 150’x35′. The smaller of the river locks we used is 360’x110′.
Heading Down River
We boarded the Channel Cat to begin our tour. The second picture looks downstream toward the construction of the new I-74 bridge. Several minutes later we passed under the new construction. Click to embiggen.
Once past the bridge we could see a railroad bridge in the distance where the lock and dam are located. Some buildings of downtown Davenport are on the right.
The front, or upstream, gates of the lock were open and a traffic signal indicated it was okay for our boat to enter. We pulled alongside the wall of the lock and watched the gates close.
After the gates closed, water started to drain out of the lock chamber through a large pipe under the downstream gates. The water flow is entirely by gravity. We watched some writing on the lock wall rise as we descended with the water level. Our level dropped by about 12 ft in a few minutes. The downstream gates opened and we passed out of the lock. We turned around to look back at where we had emerged left of the divider. The railroad bridge from an earlier picture passes over the top. It can be pivoted to allow passage of tall boats and tugs with barges in tow.
Below Dam 15
Our boat made a right turn putting us directly below dam 15. Most of the gates were closed due to low later levels in the river. The engineers monitor water levels daily to maintain at least the minimum depth of 9 ft in the channel.
Several kinds of birds were flying and on the water just below the spillways that were flowing. Stunned fish were there for easy catches by the White Pelicans.
The boat was turned downstream toward Centennial Bridge. There we turned around and headed back toward the lock. We needed to pass through again and have the chamber fill to raise our boat to the higher level where we started our tour.
Virtual Lock Passage
If you are familiar with Google Maps Streetview, use the following link to drive a boat just as you would drive a car on a street. Click the screen in the view in front of the boat to advance forward. You can also drag the screen to look left, right, up, and down. Use your mouse wheel to zoom. You are on your own for tablet and phone controls.