Dutch heavy lifting specialist Mammoet has completed a lifting operation in Vietnam for Dung Quat Shipyard (DQS) using a custom-made gantry system, a first of such operation for the company’s Vietnam office.

With no readily available lifting system in the current market that can lift a weight of 1100 tons on a crane barge with millimetre accuracy, DQS approached Mammoet to provide a customised solution for the replacement of a pintle bearing located at the bottom of the crane.

The customised gantry was first designed by the Breda office and made from gantry components which are readily available at multiple Mammoet locations in Europe and Asia. The system comprised of four tower gantries, four SJ850 strand jack model each with 850 tons lifting capacity. As for the millimetre precision required, this was delivered by the team using a special software to operate and control the strand jack model.

For execution, building of the gantry itself was done mostly at various heights from 15m-36m. When the gantry was fully constructed, it was assembled onto the crane which was lifted to 20mm and then placed on stand-by for checking of the system. Next, the crane was then lifted to 1300mm and set in a position for two weeks. DQS then proceeded to replace the pintle bearing and the crane was subsequently lowered back to its original position once the replacement is complete.

The operation was completed despite challenges faced by the team with regards to mobilisation of gantry components and manpower due to frequent changes in local COVID-19 restrictions. Once all upgrades are completed for the crane barge, DQS will be able to use it for piles layout and lifting of modules onto platforms.