When you load cargo onto the ship, it is at rest but once the ship starts moving, the containers onboard are subject to 6 different types of movement. The ship moves backwards and forwards, up and down and twists around its central axis. The ship itself may bend and twist as it moves over the waves. It is only by using the right lashing materials and building an efficient lashing system that you can keep your cargo safe and secure for the entire duration of the trip. There are two halves to the types of materials required to design such as system – material attached to the ship and loose fittings.
Fixed Fittings
Lashing materials that are fixed to the ship are also known as fixed fittings. These may be integrated into the structure of the ship’s hull or fitted to the hatch covers or double bottom. Each of these fittings plays a unique role. Flush sockets and raised sockets help locate base twistlocks or stacking cones in the ship’s cargo hold. A lashing plate acts as a tie-down for turnbuckles. If this is not available, a D ring may be used as an alternative to the Lashing plate. There rea subtle differences you should be aware of. While lashing plates are designed only for in-plane loading, A D ring may be used for in-plane and out-of-plane loading. A dovetail foundation is designed as a base for sliding dovetail twistlocks. Some fixed fittings have very specific purposes. For example, a fixed stacking cone keeps 20-foot containers from making horizontal movements in a 40-foot cell guide. Similarly, a mid-bay guide is used to keep a 20-foot container from transverse movements in a 40-foot guide.
Loose Fittings
When loose fittings are used, they must conform to ship cargo securing manual. There are many different types of loose fittings. A lashing rod is used to support the container stacks on deck. It is usually used with a turnbuckle that connects the rod to a lashing plate or D ring. Tightening the turnbuckle adds tension to the lashing rod. If the lashing rods are not long enough, they may be attached to an extension piece This is typically used for high cube containers. Twistlocks used for container lashing may be fully automatic or semi-automatic. These are placed between containers. In addition to this, you may also use loose fittings like a stacking cone and a mid-lock. A mid-lock helps resist horizontal and separation forces. It is usually locked to the corner castings.
Having access to all the different types of material is only one half of the solution to keeping cargo secure. You must know how to select the right type of material for each container and how to use them. For example, every ship uses only one type of twist lock but there are many instances where right hand and left hand twist locks find their way onboard. Using the wrong type of twist lock can seriously undermine the security arrangement’s integrity. As the ship moves, using the wrong twist locks may loosen the lashings.
Also Read: Honeycomb Packaging and Its Uses
Lashing the containers securely to the ship is the only way to keep cargo secure. There have been a number of instances when using the wrong lashing materials or using them in the wrong way has resulted in containers slipping out of lace and falling overboard. Not only does this result in valuable cargo being lost, it also puts the people onboard in danger. For this reason, it is always best to work with professionals. Not only will they know the best type of fitting required, they will also use fittings that meet high quality standards.
