Marine Engineering: The Panama Canal: A Man-Made Engineering Marvel

The Panama canal is an engineering wonder constructed between the North & South America. Know the layout of the canal, how the ships get lifted-up above the sea level for transit, the lock gates, its construction and importance in shipping industry, as well as the dimensions of the lock chambers.

Panama Canal Facts

The Panama Canal is importnat to both merchant ships and passenger liners. This is not just an ordinary canal, but an engineering wonder. In this article we will learn some interesting facts like it's location between North and South America. More precisely it extends from the Caribbean region on the mid-atlantic ocean to the Gulf of Panama in south-pacific ocean. Two ports found on either ends of the canal are Cristobal (on the Caribbean sea) and Balboa (on the Pacific Ocean).

Construction of Panama Canal:

As the trade flourished between various countries, there was a need for mass transportation of goods, for which different types of ships catered. There was always a need to ship these enormous quantity of goods quickly, for which the canal construction was adopted. The route adopted before the construction of the Panama canal was to travel round the "Cape Horn" (located in southern most tip of South America), covering a distance of approximately 24000 Kms. This travel takes approximately a month. But after the construction of the Panama canal, which cuts between the North and South continents of America, a ship has to travel only 10000 Kms to reach California, which is not even half the distance via Cape Horn. This substantially saved lot of time and costs. Thus the construction of Panama Canal made a great impact on shipping and world trade.

Layout:

The Panama Canal connects the Atlantic and Pacific oceans. The landmass is slightly above the mean sea level, which creates the need to lift the vessel upto 26 meters above mean sea level. As the vessel is lifted and after reaching the other end of the canal, it has to be dropped down to the mean sea level, to enable the ship continue its sea passage. To facilitate the lifting and dropping of the vessel, Lock Gates are provided.

The Lock Gates are located at 3 different places over the length of the canal. Entering the canal from pacific ocean, we have

1. Miraflores lock gates,

2. Pedro Miguel lock gates,

3. Gatun lock gates.

The locks are in 6 steps. Three locks lifting the ship up and three locks dropping the ship back to sea level. Eack lock has two lock chambers, thus enabling two way transit of ships, reducing the traffic at the canal. These lock gates lift the ship literally upto 26 meters above the sea level.

Looking at the picture, when entering the canal from Atlantic ocean side, we have three Gatun locks, which lifts the ship up 26 meters in 3 steps. Once the ship is lifted up, it reaches the Gatun Lake, which is a fresh water lake supplying water to the lock chambers, enabling the ships to be lifted up and dropping down. Then comes the Pedro Miguel locks, where it has one step, lowering the ship down. The ship transits through The Miraflores Lake, entering the Miraflores locks which again lowers the ship by two steps, thus reaching the Pacific Ocean. As we can see in the picture, two ships transit through lock gates. The two lock chambers accommodates two ships, in a lock gate.

How the Lock Gates Work

• The ship approaches the lock gates at a reduced speed.
• The "Pilot" boards the ship and he instructs the ships speed and direction.
• The ship enters the lock gates which is narrow when compared to the size of the ship.
• The lock gates are then closed enclosing the ship inside it. To lift up the ship, water has to be pumped into the lock chambers.
• When water is pumped, the level of water increases inside the lock chamber lifting the ship up.
• The lifted height equals the height required for the ship tp proceed to the next lock chamber.
• Thus the ship gets lifted up above the sea-level from the pacific ocean. It reaches The Gatun lake after getting lifted up through Miraflores and Pedro Miguel locks. The ship has to be lowered down to get to the level of Atlantic ocean through the Gatun locks.
• The ship enters the Gatun lock chamber, where the gates again gets closed enclosing the ship in the lock chamber. The water gets pumped out of the lock gates, decreasing the water level in the lock chamber.
• When the water level equals the level of the Atlantic ocean side, the outward lock gates open up, leading the ship to the sea passage.
• The lock gates are opened and closed by an electric motor, which drives a huge wheel, which in turn attached to a connecting rod and to the middle of the gate. But recently, these electric motors are replaced by hydraulic equipments. The hydraulic power supply unit has two electric motors of moderate capacity, can be in service for ever even when one motor fails.

Transition Through Lock Gates in Images

How do Ships get Lifted & Dropped ?

The lock chamber gets its water from the dams which are used to hold back water in the two artificial lakes, Gatun and Madden. The lock chamber is constructed with large diameter pipe culverts, which acts as supply/drain for the lock chambers. The water level increases in the lock chamber when the large pipeline valves are opened correspondingly. The water gets filled up due to gravity. The dimensions of the culverts are given in the diagram. Each lock chamber may get filled or emptied in less than 10 minutes. A heavy fender chain at the end of each lock prevents ships from ramming the gates before they open.

Locomotive "Mules":

The locomotives, called as "Mules" are very important for guiding the ships in and out of the lock gates. But the Mules are not responsible for the forward motion of the ships, which is provided by the ship's engines. The Mules have a hydraulic winch operated by the driver, to take in or pay out the cables, which are adjusted to adjust the sidewards movement of the ship inside the lock gates. The Panamax vessels are very tight fit into the lock gates where the skill of the Mule drivers are highly essential to avoid ramming of ship sides in the lock chambers. The Mules are geared to the track beneath them, which guides the movement of the Mules.

Dimensions:

The lock chambers: They are 33.5 meters wide,320.0 meters long, usable length of 304.8 metres. These dimensions determine the maximum size of ships which can use the canal; this size is known as Panamax.

The Panamax vessel dimensions are as follows:

Length: 294.1 meters

Beam: 32.3 meters

Draft: 12 meters

Air draft: 58 meters.

Displacement: 65000 MT approx.

As you can see, the Panama Canal played a vital role in the shipping industry. It has also become an important tourist spot. Plans for making the canal wider and longer in order to accommodate super-tankers and post panamax vessels are in the planning stage and once re-constructed, the Canal will be able to host even larger ships.