Lashing system that plays a vital role in container ship operations is the Twistlock lashing system. Container ships are a crucial part of the global shipping industry, responsible for transporting goods across oceans. These ships are designed to carry large containers, which are secured in place using various lashing systems to ensure they remain stable during transit.
Twistlock Lashing Systems
The twistlock lashing system is a mechanism used to secure containers to the ship’s deck or to each other. It consists of twistlocks, cones, sockets, and foundations, all of which work together to hold the containers in place. Twistlocks are devices that twist into the corner fittings of containers, while cones are placed on top of the twistlocks to distribute the load evenly. Sockets are fixed to the ship’s deck, and foundations are used to secure the sockets in place.
Twistlock lashing systems are essential for maintaining the stability and safety of container ships. They prevent containers from shifting or falling overboard during rough seas or when the ship is maneuvering. Without these systems, containers could become loose, causing damage to the ship, its cargo, and potentially endangering the crew.
Components of a Twistlock Lashing System
A twistlock lashing system consists of several key components, including twistlocks, cones, sockets, and foundations. Twistlocks are the devices that lock containers into place by twisting into the corner fittings. Cones are placed on top of the twistlocks to distribute the load evenly. Sockets are fixed to the ship’s deck, and foundations are used to secure the sockets in place.
How Twistlock Lashing Systems Work
Twistlock lashing systems work by securing containers to the ship’s deck or to each other. The twistlocks are inserted into the corner fittings of the containers and twisted to lock them in place. Cones are then placed on top of the twistlocks to distribute the load evenly. Sockets on the ship’s deck are used to hold the twistlocks, and foundations secure the sockets in place.
Twistlock is a device used to fix containers. It is suitable for containers installed on decks and hatch covers. The container twistlock ends are mushroom-shaped.
When using twistlock, try to insert the twist locks into the bottom holes of the four bottom corners of the container before pushing the handle Twist the mushroom head 90 degrees to lock the container.
- The twistlock was an important innovation in the field of container lashing equipment.
- It not only prevented horizontal shift but also lashed the containers vertically.
- This not only made a reduction in lashing wires, rods and chains possible but also permitted the coupling of two containers together vertically during the loading/unloading process (subject to weight limitations), thus saving considerable time.
- The twistlock consist of a steel body through which a central shaft passes which has cones at both ends.
- The shaft and cones can be rotated by approximately 90° by means of a lever which protrudes through the housing.
- The cones are placed in the longitudinal direction through the container corner fittings and then rotated to a transverse direction by means of the lever thus locking the containers vertically.
- Variations in the movement of the upper and lower cones are possible in different types of twistlocks but the general principle remains the same
- The twistlocks are generally made of cast steel and have a minimum breaking load >50 tonnes.
- The twistlocks provide vertical connection of container stacks.
- However transverse connection can also be achieved by the use of linkage plates which allow the twistlocks to work as double stackers thus transmitting horizontal forces between stacks
- The use of twistlocks permits a great reduction and possible elimination of all wires, rods, chains and tensioners.
Advantages of Twistlock Lashing Systems
Twistlock lashing systems offer several advantages, including:
- Quick and easy to use
- Secure and reliable
- Can be used to secure containers in stacks
Common Challenges with Twistlock Lashing Systems
Despite their advantages, twistlock lashing systems also face some challenges, such as:
- Corrosion and wear
- Malfunctioning twistlocks
- Incorrect use or maintenance
Safety Considerations
Safety is paramount when using twistlock lashing systems. It is essential to:
- Inspect twistlocks regularly for wear and tear
- Ensure twistlocks are properly secured
- Follow manufacturer’s guidelines for use and maintenance
Maintenance and Inspection
Regular maintenance and inspection of twistlock lashing systems are crucial to ensure they remain in good working condition. This includes:
- Checking for wear and tear
- Lubricating moving parts
- Replacing damaged components
Regulations and Standards for Twistlock Lashing Systems
There are various regulations and standards that govern the use of twistlock lashing systems, including those set by the International Maritime Organization (IMO) and the International Organization for Standardization (ISO). These regulations ensure that twistlock lashing systems meet certain safety and quality standards.
Innovations in Lashing System
There have been several innovations in twistlock lashing systems in recent years, aimed at improving their efficiency and safety. These include:
- Self-locking twistlocks
- Electronic twistlock monitoring systems
- Improved materials for increased durability
This makes the lashing of containers easier and quicker resulting in large economics of cost and time. The first lype of twistlocks were manual type, later semi-automatic type twistlocks were developed which were much easier to use.
Real life Use of Twistlock Lashing Systems on Containers
Today automatic twistlocks have been developed and are in use. The twistlock was an important innovation in the field of container lashing equipment. It not only prevented horizontal shift but also lashed the containers vertically.
This not only made a reduction in lashing wires, rods and chains possible but also permitted the coupling of two containers together vertically during the loading/unloading process (subject to weight limitations), thus saving considerable time. The twistlock consist of a steel body through which a central shaft passes which has cones at both
ends.
The shaft and cones can be rotated by approximately 90° by means of a lever which protrudes through the housing.
The cones are placed in the longitudinal direction through the container corner fittings and then rotated to a transverse direction by means of the lever thus locking the containers vertically.
Variations in the movement of the upper and lower cones are possible in different types of twistlocks but the general principle remains the same
The twistlocks are generally made of cast steel and have a minimum breaking load >50 tonnes.
The twistlocks provide vertical connection of container stacks.
Today automatic twistlocks have been developed and are in use:
The twistlock lashing system also plays a crucial role in maintaining the efficiency of container shipping operations. By securely fastening the containers to the ship’s deck, the system allows for the safe and efficient loading and unloading of containers, reducing the risk of delays and ensuring that cargo arrives at its destination on time.
Read More: Everything about Container Ships