Foldable Marine Crane – Knuckle Boom Crane SWL 1–20 t

The foldable marine crane is a knuckle boom crane that folds into a compact package on deck when it is not in use. It leaves the working deck free and still gives long reach when unfolded. Marine Crane builds foldable cranes in Türkiye for fishing vessels, work boats, aquaculture service boats and yachts.

The main boom, knuckle boom and telescopic extensions are driven by hydraulic cylinders and controlled with two proportional joysticks.

FOLDABLE KNUCKLE BOOM CRANE
3D model of the foldable knuckle boom marine crane
3D design model
Foldable crane linkage and cylinder layout drawing
Linkage layout
Foldable marine crane design rendering
Design rendering

Technical specifications

Capacity range SWL 1–20 t
Lifting moment 5–150 t·m (up to 1,500 kNm)
Maximum outreach Up to 35 m
Boom system Main boom + knuckle boom + telescopic sections
Stowage Folded on deck with transport lock
Hook Rotating hook with hydraulic winch
Control Two proportional joysticks, local or remote
Construction Pedestal, slew ring, hydraulic cylinders, bolts

Features

  • Tip control mode moves the boom tip in straight lines, radially and vertically
  • Fold-and-stow sequence with transport lock for sea passages
  • Load moment indicator with wave-height derating
  • Hook rotation and winch on the same console
  • Marine paint system; stainless fittings available for yachts

Capacity range and options

Typical foldable cranes in our range are 1 t, 3 t, 5 t, 10 t and 20 t SWL. The outreach and the number of telescopic sections are chosen for the vessel and the job.

Options: hydraulic winch, rotator, grab or net handling tools, remote control, and a pedestal designed for your deck.

Typical vessels and applications

  • Fishing vessels and trawlers
  • Aquaculture and fish farm service boats
  • Work boats and tugs
  • Yachts and tenders
  • Small cargo and supply vessels

Engineering details

Structure

  • Main boom, knuckle boom and telescopic sections in high-strength structural steel
  • Pin joints with replaceable bushings and greasing points
  • Slewing via slew ring or rack-and-pinion with hydraulic drive

Hydraulics and control

  • Load-holding valves on all cylinders
  • Proportional valve bank with two-joystick control, local or radio remote
  • Optional hydraulic winch, rotator and tools (grab, net handling)

Safety

  • Load moment indicator with wave-height derating
  • Transport lock for sea passage
  • Emergency stop and overload protection

Testing and documentation

  • Static load test with test weights according to the applicable class or national rules (for cranes up to 20 t SWL typically 1.25 × SWL)
  • Functional test of all motions, limits, brakes and the emergency stop
  • Delivered with general arrangement, load chart, hydraulic and electrical diagrams, foundation loads, operation and maintenance manual, spare parts list and test certificates

Frequently asked questions

What is the difference between a foldable crane and a telescopic crane?

A foldable (knuckle boom) crane has a second boom that folds over the first one, so it stows very compactly and can reach over obstacles. A telescopic crane has a straight boom that extends in sections.

Which foldable crane size do I need for a fishing vessel?

Most fishing vessels use 3–10 t foldable cranes for nets, fish containers and stores. Send the vessel length, deck layout and heaviest load and we propose a size.

Is the crane locked during sea passage?

Yes. It folds into a stowed position and a transport lock holds the booms.

Related pages

Request a quotation

Send the vessel type, required SWL and outreach. We reply with a preliminary load chart and an offer.

Phone: +90 530 662 66 45
Email: info@marinecrane.com.tr
Address: Pendik / İstanbul, Türkiye

Quotation request form

Fill in the form and our engineers will reply with a preliminary load chart and an offer.

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