Single pull macgregor type hatch cover.pdf - Cochin University of ...

2.2 SIDE ROLLING
2.2.1 Description
Figure 2.2 side rolling hatch cover
Source: - Walter Vervloesem - IMCS
Rolling covers usually consist of two large panels at each hatchway. They are fitted
with wheels which roll along a track at both sides of the coaming top. Stowage rails,
which may be portable, extend this track via pillars welded to the deck. In some
installation, the wheels are not attached to the hatch cover but to the coaming and to
fixed pillars on the deck, and the cover rolls across them. Apart from stowage
location, the principal difference between side end rolling covers is that the joint in
between side rolling panels is longitudinally and between end rolling panels is
athwatships.
These covers are usually fitted to large ships. They are often extremely heavy
owing to their large dimensions and require hydraulic pot lifts (rams) to raise them
into the rolling position. These hydraulic lifts are fitted to the coaming below the
wheels (in their closed position) and are illustrated in fig. There is no limit to the size
of the covers, and panels 20 metres square (20 m*20 m) have been installed in ships.
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