First side-rolling hatch cover ordered

Chinese company Zhenghe Shipyard has ordered the all-electric system to open and close hatch covers on a 47,000dwt bulk carrier being built for a Chinese owner and scheduled for delivery in July 2012. The order was agreed in September and Cargotec is delivering the first MacRack components in December.

MacRack is said to be an economical, competitive and environmentally-friendly system that unites the lift and drive operations for side-rolling hatch covers and so makes separate hatch cover lifters obsolete. The combined rack-and-pinion drive and lifter employs an enhanced control system and one electric motor per hatch cover panel.

“Cargotec anticipates that MacRack will become the standard system for side-rolling hatch covers,” said Esko Karvonen, vice president of Cargotec’s marine dry cargo business line. “Inspired by a commitment to the environment and improving overall cargo system performance, the initiative for this development came from shipyards and shipowners.

Work on the electric-drive side-rolling hatch cover started in 2001 in response to the Japanese car industry’s ambition to make its supply chain as ‘green’ as possible. The MacGregor answer to this challenge was to launch the ‘E-Roll’ side-rolling hatch cover system. As with all first-generation technology, improvements were needed and the development project focusing on the safety, technical limitations and cost of electric drives resulted in the launch of MacRack. No hydraulics are needed and installation of the system is simpler than with hydraulic systems. When opening hatch covers a lever mechanism converts the electric motor’s rotating motion into a vertical movement, providing the lifting force needed. When closing, the mechanism lowers the covers and pushes them together to achieve the correct amount of rubber compression and tightness.