Knuckle boom crane cylinders

Safe, lifting and handling of goods on drill ships and other offshore rigs. With this solution of knuckle boom cranes the risk of swinging loads especially under rough weather conditions will become minimized. The lifted loads are under permanent hydraulic control. Special load control valves directly mounted on the cylinders guarantee that there are no uncontrolled movements of main boom or knuckle boom arms. Typical knuckle boom crane is operated with four cylinders in total: two knuckle boom cylinders and two main boom cylinders.

Main boom cylinder (example)
Bore diameter:470 mm
Stroke:5.080 mm
Rod diameter:360 mm
Load capacity:600 t per cylinder


Knuckle boom cylinder (example)
Bore diameter:380 mm
Stroke:3.800 mm
Rod diameter:250 mm
Load capacity:350 t per cylinder


Main features of the Hunger offshore crane cylinders are:

  • Different corrosion resistant rod coatings are available, exactly adjusted to the application in question (Ni/Cr layer, thermic sprayed Carbides and Oxides or Ultraplate coating)
  • Cylinder components, critical regarding corrosion, are special treated to optimize corrosion resistance
  • Stainless steel piping and manifold block for safety and load control function
  • Equipped with wear resistant Hunger seal and bearing elements for low wear and friction and stick-slip free crane movement
  • Cylinders designed for high working pressure over 400 bar

Certification according to DNV lifting appliances 2008, DNV standard for certification No. 2.9 hydraulic cylinders and DNV offshore standard E101/D101 or alternatively according to ABS rules for building and classing, steel vessel. Part 4, Lloyds register, GL or Bureau Veritas.

HUNGER Hydraulic Solutions – Successfull Operating Worldwide