Do you know what a stop log is?

They are used at a dam to block the water at one of the gates that control flow over the dam. This allows for maintenance of the respective gate. Stop logs are about 4 feet tall and 16-20 feet wide. They are stacked in channels until the stack is above the water line. Depending on the respective lake level, that could take a bunch of stop logs! Then the gate is operated and is now dry.

Maintenance can be performed, and then the stop logs can be removed. These logs are heavy, about two tons each.

The dam in the photo above has a cart which rolls out and can reach over to place or remove the logs.

Meadows Analysis & Design, LLC was commissioned to design a new cart since this one is 50 years old and does not have the capacity required for improved logs. Mechanical engineering problems often have inherent constraints. For our project, we must roll on the existing rails, and we must be aware of the loads on those rails as part of the analysis and design.

Our design took several months, and we will share information and photos when the new cart is built.

Note that the photo above shows them on top of the dam.

The picture below is looking down in the channel:

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And this last picture is from the lake.

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Next time you are near a dam, just note that there are a lot of moving pieces to make the control of flowing water happen and the movement of all these mechanisms under heavy loads has to be accounted for in solid engineering practices.