I don't know if anyone has any interest in the Panama Canal because I didn't really before traversing it the first time several years ago. Been there twice, both times on a cruise ship. The first time was going from the Caribbean through the first lock of the original lock system into Gatun Lake, which is a man made lake that was created to allow ships to cruise to the actual canal portion of the journey and to locks further up the waterway, closer to the Pacific side.
The original locks were not as long or as wide as the new canal, which was built in close proximity to the original canal system. In the original locks, they employ several 'Mules', which are like train engines sort of. They run on a rail and cables are strung from the ship's bow and stern to the 4 'mules' which run at the front & back of the ship. There's only about 6-12inches between the ship's hull and the wall of the lock so they need the mules & cables to the ship to steady the ship as it moves into the lock.
Here's a few pics of that process:
Pic @1 is a ship sitting near the entrance to the canal, waiting for it's appointment time for getting into the lock. (Ship circled in red).
Here's a look at the double lock doors in the original canal. If you look closely, you'll see the rail tracks that the Mules use on either side of the lock.
In this photo you can see the Mules and the cables that run from the mule to the ship. These mules are at the front (bow) of the ship steadying it as it very slowly moves forward. If you look part way down the ship (under the name Liberty) you can see just how tight the fit is between the hull of the ship & the wall of the lock.
Here's a view at the back (stern) of the ship as the Mules back there also stead the ship's movement side to side.
That's about it for the older photos I have from the original lock system that uses the Mules on tracks. I'll post separately for my more recent trip up through the new canal lock system