USING its extensive experience in manufacturing reliable and durable large excavators for the mining industry, Hitachi is now supplying a wide range of models for dredging projects. The excavators are mounted on pontoons which are stabilized in the water by means of spuds.

Hitachi marine
Hitachi has adapted its excavators to be used in marine environments.

Hitachi was the first manufacturer in the Japanese market to produce an excavator for use on a pontoon. It has supplied about 240 excavators for such applications, mainly in Japan for port construction or maintenance projects.

Demand from Europe and China for excavators on pontoons is also increasing and Hitachi has sold four EX1200s to a sector of the Chinese Government. Among the reasons this industry is growing is expansion of the Panama Canal and the increase in vessel sizes, which means major ports need expansion.

A wide range of Hitachi models can be found on pontoons and the most popular are the EX1200-6, EX1900-6 and EX3600-6. The largest is the EX8000-6 backhoe, a new model launched in 2013 providing customers with an 800-tonne option.

The company says the excavators share many similarities with standard mining models, delivering high levels of productivity and durability, operator comfort and easy maintenance. They are designed to work in challenging environments and have the same advanced technological features, including onboard computer, which monitors engine and hydraulic system performance.

Some design aspects have been modified allowing for easy maintenance. The excavators have a new fast-fill system at the front allowing easy access to refill fuel and lubricants. On a standard excavator this system is under the counterweight. They can also be customized to meet the needs of individual customers.

For example, an EX1900-6 excavator was recently delivered to the Jan De Nul Group with a custom-modified front attachment by Belgian dealer Luyckx to work on dredging and marine construction in Dubai. The front attachment provided a maximum digging depth of 18 metres. It had additional piping for a breaker attachment and was delivered with two arms, measuring 8 metres and 5.5 metres, which can be used with the breaker.

Working in a marine environment has after-sales implications. The EX1900-6 is equipped with an anti-seawater specification but working in the ocean can cause corrosion. Cylinders require extra care, additional painting is required and lubricants must be refilled at least every four to five hours to prevent wearing of pins and bushes because more earth and sand enter the bucket pin due to water pressure.

One of the most challenging aspects of supplying this excavator was the fact the pontoon had been built for use with a competitor’s machine. To make it fit on the pontoon and for swing clearance, Hitachi’s engineering department had to adjust the front attachment several times.

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