Petrel Knuckle Boom Cranes are designed to operate at full capacity, even in rough sea conditions.  For this reason over-size slew bearings and high specification slew motors are used.  The crane structure is based on Lloyds classification society requirements and is tested to over-load conditions prior to being shipped.

The main boom and knuckle booms feature large section b ox-structures and wide pivot pin locations to give a rigid and reliable working platform.  The integral counter balance valves in the hydraulic cylinders hold the crane in position in the event of a vessel hydraulic failure.  Elevation of the main boom and knuckle boom is operated by one or two hydraulic cylinders which are load protected by double acting counter balance valves.

A compact planetary drive winch is fitted with suitable wire rope and weighted swivel hook.  The entire crane structure is shot blasted, metalised and painted with a high specification marine coating system prior to assembly.
Petrel can customise the reach and lift capabilities of the cranes to suit particular application requirements.

The Petrel Knuckle Boom Crane range includes 10, to 250 ton/meter cranes.  The cranes are specifically designed for marine environment applications and shipboard operations in severe list conditions.  This allows operation with 15° - 20° list or lateral pull at maximum safe working load (SWL).

Electric-hydraulic Power Packs:  These are available for each model.  Either separate stand alone units, or incorporated into the pedestals of cranes 20t-meter upwards.  Optional second winches are available (1,8 ton to 5,0 ton).  Further options are available, such as remote control, cabin, stainless steel piping and cylinder rods and different mast heights.  See 'Features and Options' section of the attached 'Specification and Performance Data'.