Panama Canal Gone Dry

Well actually just a portion of it! What is dry is the West Lane of Miraflores Locks and it is from a vantage point that is not usually seen. The following link will take to a 2+ minute fly over of the dry West lane. I'll try and provide a description of what you are seeing so that it will make some sense, at least that's the plan!

Note: The following perhaps is on the techie end of the things and you certainly don't have to wade through it to enjoy the linked video. Maybe a bit too much info... but you can decide:).

The fly over begins at the North end of the West Lane which is Miraflores Lake. As we fly South about a third of the way down the upper level chamber you will see two miter gate recesses, without any miter gates. This is where the intermediate gates are positioned if they were in place. I'll describe the intermediate gates* below.

Continuing on down the upper chamber you come to the vicinity of the Control House, what is of interest here is on the side wall opposite of the Control House. Look in the area of the two cranes... on the lock wall notice the large black rectangular objects. These are the rising stem valves that are used to control the flow of water in the main culvert which in turn lets water into or out of the chamber. They operate in the same manner as a regular gate valve, only using a large stem (not in picture) that is connected to machinery in the operating tunnel just below the top of the lock wall where they are presently sitting. Each valve weights approximately 11 tons and two of the valves positioned side by side are needed to seal the 18' diameter culverts. There are redundant sets of these valves in most locations.

As we leave the Control House and proceed to fly over the Lower Level continuing on towards the sea entrance of Miraflores (Pacific) the tallest miter gates on the Canal are in the recess position ((directly below the mule) so they can't easily be seen. The structure that spans the chamber are the vehicular gates which permit vehicle traffic across the lock complex. The last piece of equipment is the caisson which is floated into place across the chamber and with its floodable compartments is sunk in place to dam the lock from the sea water. It is very similar to caissons used in dry docks. The pumping equipment on board is how the water is removed from the two chambers.

If you look closely during the fly over you will see "holes" (about 4.5' in diameter) in the chamber floor. These "holes" allow the water to be admitted or spilled from the chamber. There are 5 holes across the floor of the chamber, each row of 5 holes is connected to a lateral culvert which connects either to the center wall culvert or the side wall culvert. In case you were counting there are 110 holes in the floor of upper level!

* The Intermediate Gates explanation... First of all these gates (which are not presently in position) operate in the same exact manner as any other miter gate on the Canal. Their primary purpose was to section off the 1000' chamber to make smaller chambers. By operating these intermediate gates the 1000'chamber could be make into a chamber of 350' or 650' to handle smaller vessels that did not need the entire chamber. These gates were normally used to conserve water during Panama's Dry Season. As time marched on fewer ships would fit in the reduced sized chamber, so their importance was reduced greatly. Selected intermediate gates are removed to be overhauled and then added to the inventory of gates that can be used in other miter gate positions at any of the locks.

Great video and explanation. So the lane was dry for maintenance?

Exactly... but I don't have any idea as to what the primary purpose of the maintenance was or when it took place. Obviously they are working on some of the rising stem valves, but over the years they have developed methods of working on the valves without drying the chamber. Most of the normal dry work in the chambers would revolve around the miter gates, things like the quoin seals, the miter sill (not seal) or the pintle ball which is what the gate actually pivots on. There seems to be a lot of activity with parts and pieces I can't readily identify from the air at the sea end of the locks.

It's a great video in any event!

Very interesting. Thanks for posting.