This discription has been edited by a Navy Captain who has made port at
Rodman and crossed the Panama Canal in both directions, several times

Ships approaching the Panama Canal from the Pacific must remain on the anchor in Panama Bay.  Government ships have head of the line privileges for canal transit.  On continuing into the Canal Zone, a pilot is taken aboard. Transiting the Panama Canal is unusual in that unlike virtually everywhere else, the ships master is not responsible for the navigation of the vessel.  The pilot has the responsibility.  It is only in the Canal and (entering a drydock) where the Old Man is off the hook and can, to a certain extent, lean back and watch the show.

Continuing, the Bridge of the Americas and the city of Balboa is immediately encountered. On the north side of the canal, military ships may make port at the Rodman Naval Station, an important WWII  installation. It has three finger piers and like the rest of the Canal Zone and tropical military bases in general, Rodman is well kept and did offer all the usual amenities for overseas servicemen and their families before it closed in 1999.

Eight miles past Rodman, Ships leaving the salty waters of the ocean, will travel in fresh water upon entering the first chamber of two Miraflores locks. The full transit is more than 50 miles, taking about eight hours. The distance a ship is raised from the Pacific Ocean level varies. The tidal range at the locks on the pacific is twelve and a half feet. On the Caribbean side it is about two feet. Mix the tidal differences and the fluctuating level of Lake Gatun and you get a pretty dynamic situation.  Theodore Roosevelt got his money’s worth out of those engineers!

After the first set of locks and a one mile transit of Lake Miraflores, ships come to the Pedro Miguel Locks. This one chamber locks raises a ship 31 feet to the 85 foot level of Gatun Lake. As the ship enters the first lock, wires are passed from shore and put on the ship’s bitts.  On the shore side, the wires were attached to the Canal’s famous “mules”; heavy electric traction engines which run next to the canal.  The ship is powered into the lock using her engine and the mules are used for holding distance off the sides of the lock.  For ships designed to optimize lock size (Panamax), considerably more power is needed since they must push themselves into the lock, squeezing the water ahead of them out the very limited space alongside and under the ship.  It is a very graphic example of the hydraulic effect in action.

Once the lock gate is closed behind the ship, the lock is filled with water from the next lock above it.  This takes from 8-15 minutes depending on the size of the ship and how much water must be used.  When the water level is the same as in the next lock, the gate ahead of the ship is opened and it is pulled by the mules into the next lock.  That in turn is flooded by the next lock.

Ships now being in fresh water, the ship engineers may have the firemain activated and have as many fire stations on the open decks as possible, have their hoses lead over the side and opened up.  The freshwater in the firemain kills the salt water critters that have taken up residence there and flushes them out.

On leaving the Pedro Miguel Locks, the spectacular run through Culebra Cut is immediately encountered. Some of the cut is a one way traffic zone and a choke point of the canal. It is seven point eight miles long and 500 feet wide with a depth of 42 feet. The steep terrain reinforces the point that you are crossing a continental divide. The cut was completed in 1913.

About a mile or so in is the new Centennial Bridge which opened in 2004. It supports the Pan American Highway. After passing the Cut, comes the village of Bamboa on a bend in the canal. The next section is a short fairway into Lake Gatun.

In 1977, the overriding impression of this area was that you were cruising through someone’s very large, well manicured garden.  It was beautiful and made one proud to be a U.S. citizen.  The locks are deceptive in their simplicity, but when you look close up and consider the engineering and effort that went into the project it readily becomes the turn of the century version of the man-on-the-moon program.

At the north end of Lake Gatun are the Gatun Locks, but just as you enter, off the left is Gatun Dam which actually controls the level of the lake. It also supplies power to the locks. There are no pumps.  The canal depends on the continuous rain replenishing the lake and allowing enough waterflow to keep the locks operating on their continuous discharge to the oceans.

The Gatun Locks lower the ship about 85 feet in three steps.  After the three drops the ship heads for the Caribbean through a two mile channel. You may notice the ship passing the old channel cut by the French in their attempt to dig a canal.

This web site has several pages that display the TOWING  of vessels. Here are rules that apply to towing of the ships to be scrapped.

International Rules of the Road.  Rule 24 (e): A vessel or object being towed, other than those mentioned in paragraph (g) of this Rule, shall exhibit: (i) sidelights  (ii)  a sternlight  (iii) when the length of the tow exceeds 200 meters, a diamond shape where it can best be seen.

In day time, measures shall be taken to ensure its all-around visibility by display a flag on each ships mast.
The flag will be BLACK, at least 0.6 meter wide and 1.2 meters tall. 

From the words of Capt. Patrick Moloney