Panama Cruise 2025 Day 12 November 8, First Locks in the Canal

 

This is the timeline for the building of the canal. 

French Failure & U.S. Acquisition

 

Well I woke up at around 4 in the morning and headed up on deck to see what was happening. We had docked out in the middle of the entrance to the canal, waiting inline with other ships. It takes approximately 8 hours to transit the canal depending on how many ships are transiting. There were a number of boats waiting, sometimes they wait for days waiting for their companies to pay the toll. Ours was paid already so we had priority. The only thing that could bump us is a military ship or one with hazardous goods like oil.

Another cruise ship coming into port as we are leaving

 

The Panama Canal locks lift ships up 85 feet to the main elevation of the Panama Canal and lowers them down again.

On the Pacific side, the Pedro Miguel and Miraflores Locks (1914) and the Cocoli Locks (2016) link Lake Gatun to the Pacific Ocean.

On the Atlantic side, the Gatun (1914) and Agua Clara (2016) locks link the Caribbean Sea and Lake Gatun..

We started our journey through the canal by sailing under the Bridge of the Americas.

Port area for container ships to be offloaded

Our first set of canal pilots coming aboard. There were different pilots for every section of the canal. Before the locks, after the locks and the lake.

The old locks consist of twelve locks (six pairs) in total. A two-step flight at Miraflores and a single pair at Pedro Miguel lift ships from the Pacific up to Gatun Lake; then a triple flight at Gatun lowers them to the Atlantic side. All three sets of locks are paired; that is, there are two parallel flights of locks at each of the three lock sites. 

The lock chambers are 110 ft wide by 1,050 ft long, with a usable length of 1,000 ft. These dimensions determine the maximum size of ships that can use the canal; this size is known as Panamax.

The lock chambers are massive concrete structures. The side walls are from 45 to 55 ft thick at the bases; toward the top, where less strength is required, they taper down in steps to 8 ft (2.4 m). The center wall between the chambers is 60 ft thick and houses three galleries that run its full length.

Each lock chamber requires 26,700,000 US gal of water to fill it from the lowered to the raised position; the same amount of water must be drained from the chamber to lower it again.

Embedded in the side and center walls are three large water culverts that are used to carry water from the lake into the chambers to raise them, and from each chamber down to the next, or to the sea, to lower them. These culverts start at a diameter of 22 ft) and reduce to 18 ft in diameter, large enough to accommodate a train. 

The water is moved by gravity and is controlled by huge valves in the culverts. Each cross culvert is independently controlled. A lock chamber can be filled in as little as ten minutes.

This is the ship ahead of us going through the left side of the Miraflores Locks

This is the high tech signal they have to tell the ship which side to go. 

This little boat with two workers on it row between each side of the canal and they row up to the ship to capture the tow lines that hook up to the Mules on the side of each side of the locks. 

These mules are used for side-to-side and braking control in the locks, which are narrow relative to modern-day ships. Forward motion into and through the locks is actually provided by the ship's engines and not the mules. A ship approaching the locks first pulls up to the guide wall, which is an extension of the center wall of the locks, where it is taken under control by the mules on the wall before proceeding into the lock. As it moves forward, additional lines are taken to mules on the other wall. With large ships, there are two mules on each side at the bow, and two each side at the stern—eight in total, allowing for precise control of the ship. Mules are not used on the new expansion locks.

The mules themselves run on paired 5 ft railway tracks.  Each mule has a powerful winch; these are used to take cables in or pay them out to keep the ship centered in the lock while moving it from chamber to chamber.

This is looking straight down from the upper deck, this is how close to each side of the gates that the ship gets.

The gates separating the chambers in each flight of locks must hold back a considerable weight of water, and must be both reliable and strong enough to withstand accidents, as the failure of a gate could unleash a flood of water downstream.

These gates range from 47 to 82 ft high, depending on position, and are 7 ft thick. The tallest gates are at Miraflores, due to the large tidal range there. The heaviest leaves weigh 662 tons the hinges themselves each weigh 16.7 tons. Each gate has two leaves, 65 ft wide, which close to a "V" shape with the point upstream. This arrangement has the effect that the force of water from the higher side pushes the ends of the gates together firmly. The gates can be opened only when, in the operating cycle, the water level on both sides is equal.

The original gate machinery consisted of a huge drive wheel, powered by an electric motor, to which was attached a connecting rod, which in turn attached to the middle of the gate. The gates are hollow and buoyant, much like the hull of a ship, and are so well balanced that two 25 hp motors are enough to move each gate leaf. If one motor fails, the other can still operate the gate at reduced speed.

All but one chamber contains a pair of auxiliary gates, which can be used to divide the chamber in two. This design allows for the transit of smaller vessels less than 600 ft long, such as canal tugs, without using the full quantity of water. The auxiliary gates were originally incorporated because the overwhelming majority of all ships of the early 1900s were less than 600 ft long and therefore did not need the full length of the lock chamber.

A failure of the lock gates—for example, caused by a runaway ship hitting a gate—could unleash a flood on the lands downstream of the locks, as the lake above the locks (Gatun Lake or Miraflores Lake) drains through the lock system. Extra precaution against this is provided by doubling the gates at both ends of the upper chamber in each flight of locks; hence, there are always at least two gates in each flight of locks that would have to fail to allow the higher level of water to pass downstream. The additional gates are 70 ft away from the operating gates.

We made it through the first set of locks, now on to the lake

So as were going through the old locks there was a container ship going through the new locks on the North side. 

The new locks are connected to the existing channel system through new navigational channels. The new lock chambers are 1,401 ft long, 180 ft wide, and 60 ft deep. They use rolling gates instead of miter gates, which are used by the original locks. Rolling gates are used in almost all existing locks with dimensions similar to the new ones, and are a proven technology. The new locks use tugboats to position the vessels instead of electric locomotives. As with rolling gates, tugs are successfully and widely used for these purposes in locks of similar dimensions.

The expansion project added a third lane through the construction of lock complexes at each end of the canal. One lock complex is located on the Pacific side, southwest of the existing Miraflores Locks. The other is located east of the existing Gatun Locks. Each of these new lock complexes have three consecutive chambers designed to move vessels from sea level to the level of Gatun Lake and back down again.

The location of the new locks uses part of the area excavated by the United States in 1939 and suspended in 1942 because of World War II.

Ships entering the new Cocoli Locks

Each chamber has three lateral water-saving basins, for a total of nine basins per lock and 18 basins in total. Just like the original locks, the new locks and their basins are filled and emptied by gravity, without the use of pumps.

Coming out at the end. You can see that the ship is at a higher elevations so they only needed one lock to raise it to the level of the lake.