The MacGregor C8A-HC is a twistlock, a mechanical device used for securing intermodal containers. This manual provides operating and maintenance instructions for the C8A-HC twistlock, specifically designed for dry cargo applications.

Function Description:

The primary function of the C8A-HC twistlock is to securely connect containers to a ship's structure or to other containers, preventing movement during transport. It operates in two main modes: Auto-mode for general loading and unloading, and Lashing Protection Mode for specific situations where twistlocks are located on the lashed end of container stacks. An emergency operation procedure is also detailed for situations where the twistlock has been mounted backward.

In Auto-mode, the twistlock is designed for efficient loading and unloading operations. For loading, the yellow cone of the twistlock is inserted into the ISO socket of the container with the wire handle facing outwards. The twistlock is then turned anticlockwise until it drops into place, securing the container. For unloading, the container is simply lifted, and the twistlock automatically releases. A crucial safety note for Auto-mode is that the handle MUST always be in the centre position when loading a container.

The Lashing Protection Mode is specifically for twistlocks located on the lashed end of container stacks. In this mode, the handle is pulled to either the left or right and locked into the 3 o'clock or 9 o'clock position. This provides additional security in situations where lashing is applied.

Emergency Operation:

An emergency operation procedure is provided for instances where the twistlock has been mounted backward. This involves using a specialized emergency tool, which consists of a fork and hooks. The fork is connected to the wire handle, and the tool is pushed to pull out the wire handle. The handle should be at the bottom of the fork gap, and the hook attached to the twistlock. The tool is then straightened, and a second hook is connected to the other side of the twistlock. Finally, the tool is locked with a latch, securing the twistlock in an open position so the container can be lifted. It is essential to ensure that all arms and hooks remain in position when locking the tool. To remove the emergency tool, the latch is simply opened.

Maintenance Features:

The manual outlines comprehensive inspection and service procedures to ensure the longevity and safe operation of the C8A-HC twistlock.

Inspection:

Regular inspections are crucial. Key areas to inspect include:

Top cone: Check for visible blue paint.
Bottom cone: Check for visible yellow paint.
Housing and/or handle: Inspect for cracks and/or deformation.
Wire: Check for damage.
Handle guide: Assess its condition.
End knob: Check for damage or if it's missing.
Bolts: Ensure they are properly tightened.

Function Test:

A function test involves pulling the handle three times to verify that the shaft rotation is undisturbed and that the twisting spring function is satisfactory. The handle should also be tested by locking it in the 3 o'clock and 9 o'clock positions.

Service:

Servicing involves cleaning all parts, removing old grease, and re-greasing. In case of any malfunction, the twistlock should be disassembled, and faulty or missing parts should be replaced.

Scrapping Criteria:

A twistlock should be scrapped if it exhibits bad corrosion, defined as more than 10% material loss.

When to Inspect:

A visual check should be performed every 10 months.
Maintenance should be carried out every 6-12 months.
Inspection is also required if any malfunction or damage is noted.

Disassembly for Maintenance:

Disassembly begins by placing the twistlock on a base plate (or in a bench vice) with the bolts facing upwards. An allen key is used to remove the bolts of the yellow cone and then the bolts of the body. The upper spring is removed, and all parts are detached to free the shaft. All parts must be thoroughly cleaned.

Handle Removal:

For handle removal, the twistlock shaft is placed on a base plate. A C-ring detachment tool is pressed against the C-ring, and a ball pein hammer is used to release the C-ring from the shaft.

Handle Mounting:

To mount the handle, the twistlock shaft is again placed on a base plate. The handle is attached to a C-ring attachment tool, and a ball pein hammer is used to mount the C-ring onto the shaft.

Body Assembly:

Body assembly involves placing the left half of the twistlock body with the shaft on the base plate. The ends of the spring are placed on the stoppers, and the mouth of the handle is positioned on the twistlock body. An allen key is then used to secure the right half of the twistlock body.

Cone Assembly:

For cone assembly, the upper spring is placed into its hole. A spring tool is attached to the free end of the spring to tension it. Finally, an allen key is used to mount the yellow cone, keeping the spring tool between the halves for as long as possible during this step.

Tools Required for Maintenance:

The service kit includes several specialized tools:

Twistlock base plate (optional if a bench vice is available)
Shaft base plate
Ball pein hammer
Allen key (M8, M10)
C-ring detachment tool
C-ring attachment tool
Spring tool
Grease nozzle
Grease pump
Grease drum

The C8A-HC twistlock is a robust and essential component in container handling, and adherence to these operating and maintenance instructions is vital for safe and efficient cargo operations.

MACGREGOR Dry Cargo C8A-HC - Table of Contents

Table of Contents