A twistlock and corner casting are now the standardized method for securing shipping containers internationally. Twistlocks were developed in the 1950s by American engineer Keith Tantlinger, who is responsible for revolutionising shipping practices.

Currently it is possible to obtain manual, semi-automatic or automatic twistlocks. As you would expect, manual twistlocks need to be locked and unlocked manually using operating rods, while semi-automatic and automatic twistlocks automate some of the process.

Manual twistlocks are frequently used when securing second tier containers in double stacking configurations.

Manual Twistlock

How to Use Manual Twistlocks

To use a manual twistlock, simply place the bottom cone of the lock in the top corner casting of a container that has already been loaded into place. At this point it should be in the unlocked position, with the operating rod either to the left or the right, depending on whether it is a left or right operating twistlock.

When a second container is lowered on top of the first, the top cone of the twistlock will slot into the open mouth of the lower corner casting of the second-tier container. When the second container is in place, move the operating rod from right to left, or left to right, depending on the lock configuration.

A container should be secured with four manual twistlocks, one in each corner of the connected containers. Select right to left or left to right locks so that all operating rods sit in the same position when locked. This makes it easier to visually ensure that containers are locked in place, and to unlock the containers in batches when it is time for removal.

To unlock the containers for removal, return the operating rods to their original position before removing the top container.

Container Ship at Port

Features of a Good Manual Twistlock

A good quality twistlocks should include a number of essential features:

  • Meet ISO strength requirements and other specifications;
  • Properly secured operating rids that do not fall down from the container;
  • Easy to determine whether the twistlock is locked or unlocked from the position of the handle;
  • Feature shock absorbers;
  • Compatible with both hinged head and fixed head lashing rods;
  • Symmetrical to be used upside down when required;
  • Easy to maintain, assemble and disassemble.

Manual Twistlock Maintenance and Repair

All twistlocks should be inspected, cleaned and lubricated on a regular basis to ensure that they are safe for use. If during inspection, one of the cones of the lock is found to be damaged, the lock can no longer be used and should be disposed of. All other lock mechanisms are replaceable, and parts can be secured from the supplier.

Manual Twistlock Supplier

Here at Container Lock we are the leading container lock supplier worldwide. Our expert staff can advise on exactly which type of container lock offers the best security and the best value for your particular needs. While our head offices are in Romania, a member country of the European Union, we can ship products to ports around the world. We currently ship to the United States, Australia, Europe and China.

Port of Los Angeles

Ports in the United States

There are currently approximately 360 active ports in the United States, and many of them number among the busiest in the world. The Port of Los Angeles located in San Pedro Bay, California is the largest on the west coast and is responsible for the majority of transpacific trade. On the east coast the Port of New York and New Jersey is the largest, offering access to one of the most concentrated consumer markets in the world. The ports of Savannah in Georgia, of Seattle and Tacoma in Washington state, and of Huston in Texas are some of the country’s other leading US ports.

Ports in Australia

Despite its relatively modest population, Australia is serviced by around 50 ports. The largest ports are unsurprisingly in Sydney and Melbourne, but the third largest port, in Brisbane, is also the fastest growing container port in the country.

Ports in Romania

Romania is services by 25 ports located in the Black Sea, the Danube Black Sea Canal and the Danube River. The Port of Constanta is the largest on the Black Sea, the largest in Romania, and the 17th largest in Europe.

Ports in France

France is served by more than 330 ports. The Marseille Fos Port is the country’s busiest handing 88 million tons of cargo in 2011. La Havre follows closely receiving 75 million tonnes of cargo in the same year, but is in fact the largest container port in the country.

Port of Hong Kong

While Hong Kong’s small size means that it is served by only one port, it is one of the busiest in the world in terms of all three main categories: shipping movement, cargo handled, and passengers carried. Its location on the South China Sea and the naturally deep waters of Lake Victoria provide ideal shipping conditions.

Ports in China

China has 34 major ports, but over 2,000 minor ports spread across the country. The five busiest ports serving the economic superpower are the ports of Shanghai (the world’s busiest container port), Shenzhen, Ningbo, Qingdao and Guangzhou.

Port of Shanghai
Port of Shanghai


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