The two Miraflores Locks lift each vessel about 60 feet. Part of the magnitude of the lift is lost since the water depth when you enter each lock is already about 40 feet. So each of the doors isn't just what you see but at least another 40 feet under the water. Each "leaf" is about 55 feet
wide (a little more than half the width of the lock) and about 70 feet tall. Each one is about six feet thick but hollow. So, even though each leaf weighs something like 60 tons, they have some buoyancy in the water and can be moved with minimal power. The first motors were 40 hp electric motors. The leaves are not moved until the water level is equal, or very nearly equal on each side. The original mechanisms to open and close the doors were all mechanical and driven by GE 40 hp motors. They have been retrofitted now and run on huge hydraulic cylinders (photos later) but apparently still on the same capstans (I think that's what a vertical shaft is called in marine lingo) and bushings.
Every vessel is somehow restrained within the lock. The big ships are attached to the mules shown earlier. Smaller boats are simply tied, for and aft, to bollards that are distributed along the top of each lock.
The second photo shows a Canal employee heaving what Oregon loggers would call a hay wire, but what is here a 3/4" line with a weighted end. A hand on the boat ties the boat's hawser to the line and the employee hauls it ashore and loops the end loop over a bollard. Each end of each smaller boat is secured this way, even tugboats, except some boats tie one to the land and secure a second boat to the tied boat. There is a good reason for securing the boats. It takes about 52,000,000 gallons of water for a complete transit or roughly about 8.5 million gallons in each lock, either flowing into the lock or being let out of the lock. Underneath the lock floor, 40 or so feet under the lowest level anyone sees unless serious maintenance is being conducted, there are what they call culverts (very large pipes) that transfer the water. These pipes have enough capacity to let in or let out about a million gallons a minute, all gravity flow. The turbulence within the lock is visible, especially when the water is coming into the lock and you are rising.
The photo above shows how turbulent the water is. It this same photo, you can see that our lock is many feet fuller than the adjacent lock where the WW is also beginning to rise up.
Between the first and second Miraflores locks there are double doors that must be even a little higher than the end doors since they must accommodate both rises in the water's level. The floor rises at this point also, so there are additional safeguards to guard against a ship hitting the doors or possibly smashing into the wall of the elevated floor in the upper lock. Originally, there was even a cable in front of the doors that was raised and secured so an out of control vessel would hit the cable before it could hit a door. When the ship was stopped and ready the cable was lowered and lay on the floor of the lock.
So, in this photo of the double doors, we are at the top level of the lock we are in but at the low level of the lock we will enter. It takes about a minute for the doors to open or close. It's hard to get the scale right unless you're there. I think the panels on the doors are each about four feet high, so these doors are something like 28 feet high, plus at least 40 feet under the water. The short, geometric looking apparatus on the top of each door comprise a hand railing that raises when the locks close and lowers when it opens.
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