This arrangement isolates the electrical equipment and operator from the noisy and
oil/fuel contaminated power compartment. Specific design features include:
The boom is required to be comprised of sections of manageable
lengths suitable for lifting. The boom walkway is required to be sectioned in the
same manner. Platforms and ladders are required for access to both sides of all
sheaves and sheave nest pins, and all lighting fixtures. The boom walkway must be
accessible with the boom horizontal (or other specified maintenance position).
The A-frame connection to the machinery deck is required to be by
means of structural pins and outboard of the machinery house. The
A-frame front and back legs are also required to be pinned at their apex and a
pinned brace installed between them to prevent their folding when lifted from the
machinery deck. Stairs, ladders, and platforms are required for access to all
sheave and pin maintenance points. Lifting padeyes are required to permit removal
of the entire A-frame as a unit.
The counterweight is required to be all steel and pinned or
interlocked with the main beams of the machinery deck. It is required to be
segmented so that it can be reduced to maintain crane stability when the boom is
removed. Each segment includes lifting padeyes for easy removal and
Roofs of the power and control compartments are required to be
removable as one-piece units or in large sections. With either arrangement, the
roof openings must be adequate to lift out the diesel
engine-generator set, as a unit on its foundation, or any electrical control
The roof over the hoist machinery compartment (underneath the A-
frame) is required to include removable access hatches to facilitate removal of
major hoist drive components (including the wire rope drums), rotate drives
(preferably as complete units), and the collector ring assembly. The machinery
house structure and the A-frame should be equipped with padeyes for
maneuvering/transporting these components to the access hatches.
Complete hoist drives on their foundations are required to be
removable after the removal of the A-frame and the hoist machinery compartment
roof. The hoist drive foundations are required to include padeyes for this
Both ends of all internal and external rotate bearing bolts or studs
must be accessible for tensioning and retensioning. The size of the hydraulic
tensioners must be confirmed to ensure adequate space for their connection to the
bolts or studs.
The top of the portal base and the underside of the machinery deck
are required to include provisions for jacking-up of the upperworks and removal of
the rotate bearing.