Bulker safety clearly depends on a variety of factors, one of
which is effective cargo hatchcovers. These must be
watertight at all times during the voyage. Cargotec has
developed a new electric-drive innovation which makes hatch
operations easier and safer.
Cargotec’s focus on environmentally-responsible
engineering solutions is evidenced by its new MacRack.
This electric-drive innovation for MacGregor side-rolling
hatch covers which combines two operations: raising a cover,
and moving it sideways to open or close the hatch
Cargotec’s MacRack, a new economical, competitive and
environmentally-friendly electric-drive system, 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 just one electric motor per hatch cover panel.
“This is a significant advance in electric-drive technology,”
highlights Torbjörn Dahl, senior naval architect for bulk ships
at Cargotec. MacRack, like the other electric drives in the
company’s portfolio, provides a sustainable and efficient
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.
Development work is a continuous process and does
not happen overnight. Work on the electric-drive siderolling
hatch cover started in 2001 in response to the
Japanese car industry’s ambition to make its supply
chain as ‘green’ as possible.
The company’s answer to this challenge was to launch the
‘E-Roll’ side-rolling hatch cover system. E-Roll’s components
and control system were essentially developed from
scratch because similar systems for the marine and bulk
carrier environments did not exist. After extensive tests and
a lengthy component selection process, the first orders were
signed in 2006. Twelve ships using E-Roll systems are in
service but this number is growing rapidly: a further 11
shipsets of equipment are on order and about 30 more are in
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.
Other recent electric drive successes for MacGregor
equipment includes the breakthrough order for 24
electrically-operated cargo cranes for a series of eight
16,900dwt bulker carriers being built in China for Polish
shipowner Polsteam (PZM); they are scheduled for installation
from the end of 2010 to 2012. For more details on this
contract, please see p43 of this issue.
Drive innovation simplifies hatch cover operations
MacRack represents a significant advance
in electric drive technology, employing only
one electric motor per hatch cover panel
and a further-enhanced control system.