ISO 11660-4:2008 Boom Crane Access System Safeguarding Guide
ISO 11660-4:2008 "Cranes — Access, Guards and Restraints — Part 4: Jib Cranes" is the governing standard for access systems and safeguarding on jib cranes. It specifies requirements for walkways, platforms, ladders, handrails, and fall-arrest systems on portal base decks, mast decks, and floating cranes.
Portal Base and Mast Access Systems
Vertical access ladders inside the portal base are at least 400 mm wide with rung spacing of 250–300 mm. A landing platform of at least 0.5 m² is provided every 6 m, complete with guardrails. Horizontal walkways between portal base legs are at least 400 mm wide with handrails on both sides at a minimum height of 1100 mm. The maintenance platform at the top of the mast is at least 1.0 m² and is fitted with guardrails and a toe board. The walkway connecting the mast to the boom is at least 400 mm wide with a slip-resistant tread surface and is equipped with a grab line or handrail. Kelude Heavy Industry designs its jib crane access systems in full compliance with ISO 11660-4.
Fall-Arrest and Rescue Systems
A continuous safety rope runs the full height of the vertical access ladder inside the portal base. Made of stainless steel with a steel core, the rope is at least 8 mm in diameter and is anchored at both the top and bottom with a minimum anchorage strength of 15 kN. Additional safety ropes are installed between the top of the mast and ground level, as well as between both ends of the boom walkway. Operators connect a shock-absorbing lanyard safety belt to the safety rope and traverse the system hands-free. Ladders exceeding 3 m in height are fitted with a fall-arrest back cage. Platform guardrails at the top of the mast are at least 1100 mm high, and access openings are equipped with self-closing gates. The controlled descent device has a rated load capacity of at least 150 kg, a slow descent speed not exceeding 2 m/s, and a descent height of at least 50 m. It undergoes a monthly inspection and an annual load test.
| Part | width | Protection | Application |
|---|---|---|---|
| Portal base Internal | ≥400mm | Guardrail+platform | Portal base |
| mast Internal | ≥400mm | Guardrail+Cage | mast |
| boom walkway | ≥400mm | Guardrail/Tie Rod | Portal base/mast |
| Tower Topplatform | ≥1.0m² | Standard Guardrail | All |
| Deckplatform | ≥0.5m² | Anti-Skid+Guardrail | Deck/Floating |
Ladder and Handrail Requirements
Access ladders on the boom are classified into three types. Vertical ladders inside the portal base mast have a minimum width of 400 mm with rung spacing between 250 and 300 mm. For heights exceeding 6 m, a landing platform or safety cage is required. Inclined ladders connecting the mast to the boom are installed at an angle of 45° to 60°, with a minimum width of 400 mm and handrails on both sides. Deck access ladders have a minimum width of 300 mm and are made of corrosion-resistant Stainless Steel. Handrails are constructed from circular steel tubing with a diameter of Φ30 to 50 mm, available in Stainless Steel or Hot-Dip Galvanizing. They run continuously without interruption, with curved sections having a turning radius of R≥100 mm. The surface is knurled or coated with anti-slip material. Fixing points are spaced at intervals of no more than 1500 mm and must withstand a lateral Load of at least 1 kN. Folding handrails feature a self-locking mechanism with an unlocking force not exceeding 50 N. Kelude Heavy Industry configures all access systems and safety facilities according to the standard.
| ladder Type | width | Rung Spacing | safety facilities |
|---|---|---|---|
| Portal base Vertical Ladder | ≥400mm | 250~300mm | >6mlanding platform |
| mast Vertical Ladder | ≥400mm | 250~300mm | Fall Arrest Cage |
| Connecting Stair | ≥400mm | 200~250mm | Double-Sidedhandrail+Anchor Point |
| Deck Access ladder | ≥300mm | ≤300mm | Stainless Steel/Anti-Skid |
FAQ
Q: What are the fall protection requirements?
A: Safety rope inside the portal base/mast: steel core, ≥8 mm, running from bottom to top. Controlled descent device: ≥150 kg capacity, ≤2 m/s descent speed. Anchor points: ≥15 kN. Connect via full-body harness with energy absorber to the safety rope.
Q: How is the boom walkway configured?
A: When boom cross-section height ≥800 mm, a full-length walkway is provided with width ≥400 mm, guardrail on the outer side, and safety rope on the inner side ≥12 mm. Anti-slip coefficient ≥0.6. Anchor points at both ends ≥15 kN.
Q: What are the controlled descent device requirements?
A: One unit at the tower top and one in the high-level operator cab, each rated ≥150 kg, ≤2 m/s, with ≥50 m of cable. Monthly inspection and annual testing required.
Q: What does Kelude offer as standard?
A: Kelude Heavy Industry equips its jib cranes with a comprehensive access system and fall protection package per ISO 11660-4, including safety rope systems, controlled descent devices, boom walkways, and maintenance platforms to ensure safe access for work at height.
