ISO 4306-4:2020 Jib Crane Terminology Explained
ISO 4306-4:2020 "Cranes — Vocabulary — Part 4: Jib Cranes" is the international standard that defines terminology for jib cranes. It standardizes terms and definitions for jib cranes—including portal cranes, mast cranes, deck cranes, and floating cranes—across four key areas: type classification, main structure, mechanism systems, and safety devices.
Jib Crane Type Classification Terms
The standard classifies jib cranes by structural type and application into the following categories: Portal cranes—slewing jib cranes mounted on a portal base, widely used in ports and shipyards; semi-portal cranes—portal cranes with one side traveling on ground rails and the other on a runway beam of an existing building; mast cranes—cranes comprising a mast, jib, and cable system; deck cranes—slewing cranes installed on ship decks for cargo handling; and floating cranes—cranes mounted on pontoons or barges for marine lifting operations.
By jib type, the standard distinguishes between straight jibs, knuckle jibs (luffing jibs with a folding arm), and telescopic jibs. The standard also unifies core terminology for jib cranes, covering luffing mechanisms (wire rope luffing vs. hydraulic cylinder luffing), slewing angles (full-circle slewing vs. partial slewing), and traveling modes (rail traveling vs. wheel traveling).
Main Structure Terminology
The standard standardizes the terminology for the primary structural components of jib cranes: the portal (gantry)—the A-shaped steel structure that supports the entire upper slewing structure and jib system, consisting of four legs and connecting cross beams, with electrical equipment and counterweight rails arranged inside; the slewing platform—the rotating structural platform that carries the jib hinge points, hoisting mechanism, and luffing mechanism; the mast—the central vertical structural member of a mast crane that supports the jib and secures the cable system; and the jib (boom)—the projecting structural member of the crane, with the hook or lifting spreader attached at its front end.
The standard also defines cable system terminology: pendants—load-bearing cables connecting the jib to the top of the mast; back stays—load-bearing cables connecting the mast to the counterweight or anchoring point; and spreader guys—lateral cables that maintain mast perpendicularity. Auxiliary structural terms include ladders and platforms, operator cabs, counterweights (counter-jib ballast), and anchor devices (tie-down devices).
| Term Category | Number of Terms | coverage Scope | Standard Item No. |
|---|---|---|---|
| type classification | 18Clause | Portal base/mast/Deck/Floating | §2.1 |
| main structure | 25Clause | Portal base/Slewing platform/mast/Boom | §2.2 |
| mechanism system | 15Clause | Hoisting / Lifting/Luffing/Slewing/traveling | §2.3 |
| cable system | 10Clause | Forward Stay/Aft Stay/Stabilizing Line | §2.4 |
| safety device | 8Clause | Load moment limiter (LML)/anti-collision/anchoring | §2.5 |
Mechanism Systems and Safety Device Terminology
The standard defines terminology for the mechanism systems of jib cranes, covering the hoisting mechanism (including the hoist drum, wire rope system, and hook block), the luffing mechanism (available in both wire rope luffing and hydraulic cylinder luffing configurations), the slewing mechanism (comprising the slewing bearing, slewing drive, and slewing lock), and the travel mechanism (rail-mounted travel via bogies or rubber-tire travel via a hydraulic drive system). The standard also standardizes terminology for internal components of each mechanism, such as the jib anti-tipping device and the rope equalizer.
Safety device terminology includes the load moment limiter (LML), radius limiter, hoisting height limit switch, slewing angle limiter, anemometer, and anti-collision device. The standard further defines safety devices specific to jib cranes, including the wind speed limit for anchoring, the portal wind protection device (rail clamp), and the auxiliary support. Kelude Heavy Industry strictly follows the terminology specified in ISO 4306-4:2020 when preparing its jib crane technical documentation.
Key Parameter and Performance Terminology
The standard standardizes the terminology for key performance parameters of jib cranes, including the rated lifting capacity (the maximum allowable load at each working radius), the maximum load moment (the peak product of rated load multiplied by its corresponding radius), the maximum radius (the farthest working outreach), the minimum radius (the closest working position), the lifting height (the vertical distance from ground or rail level to the highest hook position), the rail gauge (the distance between the centerlines of the crane rails), and the wheelbase (the distance between the front and rear wheels of the travel bogie). The standard also defines terminology for operating conditions and application limits.
Jib-crane-specific terms include the portal clearance height (the maximum height of passage beneath the portal base), the portal width, the tail swing radius (the distance from the slewing centerline to the outermost point of the rotating superstructure), and the counterweight projection. Kelude Heavy Industry uses this standardized terminology throughout its jib crane manuals and nameplate data to ensure accurate technical communication.
| Parameter Name | Unit | Definition | Applicable Crane Models |
|---|---|---|---|
| Rated Lifting Capacity | t | Each Working radius Corresponding Maximum Lifting Mass | All |
| maximum load moment | t·m | rated load×Working radius Maximum Value | All |
| Maximum radius | m | Hook Furthest Horizontal Reach | Boom Slewing Floating |
| portal clearance height | m | portal frame Maximum Allowable Clearance Height | Portal crane |
| tail swing radius | m | From Furthest Tail Point to Slewing Center | Slewing Floating |
FAQ
Q: Which jib crane types are covered by ISO 4306-4:2020?
A: The standard covers portal cranes, mast cranes, deck cranes, floating cranes, and semi-portal slewing cranes. It also defines terminology for rail-mounted jib cranes and loader cranes with a jib configuration. All these types share a common feature: a boom structure used for hoisting and moving loads.
Q: How does the standard define cable system terminology?
A: The pendant connects the boom to the mast top and carries tensile loads; the back stay connects the mast to the counterweight or anchoring point; and the spreader guy maintains mast perpendicularity. The standard clearly distinguishes the terms and functional definitions of these three cable types.
Q: How do safety device terms for jib cranes differ from those for general cranes?
A: In addition to the common load moment limiter (LML), radius limiter, and limit switches, the standard defines safety devices specific to jib cranes—including wind speed limits for anchor devices, rail clamps for portal bases, and auxiliary support systems. These reflect the tall, large-footprint structural characteristics of jib cranes.
Q: Does Kelude manufacture jib cranes?
A: Kelude Heavy Industry offers design & manufacturing and technical consultation for jib-type cranes, including portal cranes and mast cranes. Our technical files and product manuals strictly follow the terminology specified in ISO 4306-4:2020. For specific product parameters, please contact us.
