Jib Sections

Jib sections are individual, interlocking structural components that assemble to create the telescoping or lattice framework of a crane's jib (boom). They enable the jib to extend to various lengths for different lifting ranges and are designed to withstand bending moments, compression, and torsional forces during operation. These sections are typically fabricated from high-strength steel and are available in a range of standard dimensions, with custom lengths available upon request. Key parameters include section length (3000–12000 mm), width and height (300–800 mm each), wall thickness (4–12 mm), and section weight (500–3000 kg). Material grades range from Q345B to Q690D per GB/T 1591, with corresponding yield strengths of 345–690 MPa and tensile strengths of 470–940 MPa. Surface treatment includes blast cleaning to Sa2.5 per ISO 8501-1 and paint thickness of 80–120 μm per ISO 19840. Dimensional tolerance is ±1 mm per ISO 2768-1, and straightness tolerance is ≤2 mm/m per ISO 1101. Operating temperature range is -40 to 85°C, and corrosion protection classes C3 to C5 per ISO 12944 are available, with C5 suitable for offshore environments. These sections are designed for use in various crane types, including mobile, crawler, and tower cranes. They are critical for load-bearing capacity and operational safety. When selecting jib sections, it is essential to verify model-specific values and standards with the legal manufacturer or supplier, as actual specifications may vary based on the crane model and application. Proper installation, maintenance, and inspection are necessary to ensure structural integrity and safe operation.

Jib sections are connected via pins, bolts, or hydraulic mechanisms. In telescopic booms, sections slide within one another, powered by hydraulic cylinders to extend or retract. In lattice booms, sections are bolted together on-site to achieve the desired length. The sections transfer loads from the lifted object through the jib structure to the crane's base. The interlocking design ensures load distribution and stability during lifting operations. Regular inspection of connections and structural integrity is required to prevent failures.