Every year, more than 11 million containers arrive at US ports. Moving these containers from the ships coming to the mainland requires one extraordinary piece of equipment: a ship-to-shore crane.
Without these cranes, it would be impossible to get containers to where they need to be. But what makes them different from other kinds of cranes?
Read on to learn about ship-to-shore cranes.
What They Are
Ship-to-shore cranes, also known as quay cranes, can transport a container to and from a ship and are located on the port’s quayside for this purpose.
These kinds of cranes come in two types: high and low profiles.
The high-profile crane has an A-frame and a hinged boom that makes navigating ships easier when leaving the dock or berthing. On the other hand, the low-profile crane has a fixed boom made to load containers on and off the boat.
The low-profile cranes are the better option near airports or other locations where the cranes might otherwise block passage.
How Ship-to-Shore Cranes are Powered
These cranes usually have two motors, using alternating current (AC) and direct current (DC). However, you can expect most of them to use AC motors since they provide more reliable power and higher torque than the DC options.
Port cranes require different motors because of the various specific crane functions they must perform. For example, some motors provide power for the hoisting maneuver, while others focus on the gantry and trolley or moving the boom.
Depending on the ship classes, there are different types of crane sizes. As you may expect, large ships require larger cranes, which, in turn, need larger motors to function.
A boom motor, for example, can offer 100-500 kW of power, while you can expect a hoist motor to produce anything from 200-1000 kW. Keep in mind that if you are not getting that much power.
How Much Can a Port Crane Lift?
On average, a ship-to-shore crane can lift 40-80 metric tons. There are instances where a quay crane may lift even up to 120 metric tons, but that is not the standard capacity.
A port crane’s efficiency is measured in the number of “moves” it can perform in a given amount of time. A move is equal to an entire movement of a container from the ship to the port or from the port to the ship.
The speed and motor power of a crane will substantially influence how many moves the crane can perform. Most cranes can make between 30 to 50 moves per hour.
Get the Most Out of Your Port Crane
If you notice that the ship-to-shore cranes you depend on are not working efficiently, it may be time for new parts or repairs.
Contact us today to speak with an expert.