ISO 23811:2019 Crane Safety Guide Standard Interpretation
ISO 23811:2019 — Cranes — Safe Use — Guidelines is the operational standard governing the safe use of cranes. It provides a complete, step-by-step framework for crane operations, covering pre-lift preparation, lifting procedures, hand signals for load handling, hazard area management, and emergency situation protocols.
Pre-Lift Preparation and Inspection
ISO 23811:2019 mandates the following preparations before any lifting operation begins — equipment inspection (the operator performs a Daily Inspection in accordance with ISO 9927 Cranes — Inspections, covering visual condition, functionality, and safety devices, to confirm the crane is in serviceable condition), site assessment (ground must be level and firm, free from underground utilities and overhead line interference, with no obstructions within the working radius), lifting accessory verification (hooks, lifting eyes, lifting slings, wire ropes, and other rigging components must be correctly selected for the application and within their valid inspection period), and lift plan confirmation (the lifting procedure, lifting point positions, load weight, and center of gravity must be clearly established, and hand signals agreed upon for multi-person operations).
A pre-shift safety briefing should be held before work begins (led by the site supervisor, covering the day's tasks, hazard points, and control measures, and confirming that all personnel are in position and equipment is ready). When environmental conditions do not meet requirements — wind speed exceeding the rated working wind speed limit, visibility below 10 m, thunderstorms, or abnormal ground conditions — lifting operations must be suspended or cancelled. A Trial Lift must also be performed before each lifting operation (raise the suspended load approximately 200 mm above the ground and hold for at least 30 seconds to verify the brake, hoisting mechanism, and lifting accessories are functioning properly before proceeding with the full lift).
Safe Lifting and Load Handling Requirements
The standard sets out safety requirements for lifting operations — hoisting must be slow and steady (first tension the wire rope to confirm secure rigging, then lift slowly to approximately 200 mm above the ground, check stability, and only then continue hoisting). Jerking or sudden release of the load is prohibited. The suspended load must remain stable during lifting and transport (the hook must be positioned directly above the load's center of gravity to prevent swinging). Once the load is off the ground, the operator must stay focused and continuously monitor the load's condition. Slewing must be smooth and controlled (acceleration at start and stop must not exceed 0.5 m/s² to prevent the load from swinging outward due to centrifugal force).
No Personnel Under Suspended Load — when a load must pass over personnel, a dedicated spotter must be assigned and all activity in that area halted. Loads must not be left suspended for extended periods (if unavoidable, a warning barrier must be placed underneath). Tandem lifting operations require a dedicated lift plan (each crane's load must not exceed 75% of its Rated Lifting Capacity, and all crane movements must be synchronized under the direction of a single lift supervisor). Using the crane for side pulling (when the hook is not directly above the load's center of gravity) or dragging loads is prohibited. Night operations require adequate illumination (work area illuminance of at least 50 lux).
| operating phase | safety requirements | prohibited operations |
|---|---|---|
| Lifting | pre-tension Trial Lift200mmafter inspection Hoisting / Lifting | jerking and sudden release |
| Lifting and transport | load stabilization/Hookshaft alignment/smoothly Slewing | standing under suspended load |
| lowering the hook | slowly align with landing point Loweringdunnage | impact landing |
| multi-cranetandem lifting | ≤75%rated/unified command | over75%rated |
| special environment | night lighting≥50lux | lightning/heavy fog/high wind |
Crane Hand Signals & Communication
The standard crane hand signal system covers three communication methods: hand signals (universal standard gestures—Hoisting: arm extended upward with index finger pointing up; Lowering: arm extended downward with index finger pointing down; Stop: arm extended horizontally with palm facing down; Emergency Stop: both arms extended horizontally with side-to-side waving), whistle signals (one long blast for stop, two short blasts for hoisting, three short blasts for lowering, and rapid short blasts for emergency stop), and wireless communication (dedicated channel, caller announces their code before speaking, and all commands must be repeated back for confirmation). A designated, certified Signaller must be assigned to direct lifting operations, with one person in charge of all commands.
Communication confirmation protocol—after every command is issued, the operator must repeat the instruction to confirm receipt (e.g., when the Signaller gives a hoisting command, the operator responds "hoisting received"). Multi-person lifting operations must use a standard radio communication channel (avoiding channels used by other nearby sites that could cause interference). If communication is lost, all operations must halt immediately. During nighttime work, hand signals and whistle signals are used together. Kelude Heavy Industry offers crane hand signal and communication training services for operators.
Emergency Stop Procedures
Standard emergency stop procedures—an emergency stop signal (emergency stop hand gesture plus rapid whistle blasts) must be issued immediately if any of the following conditions occur: abnormal wire break or kinking in the Wire Rope, uncontrolled swinging of the suspended load or imminent collision with an obstacle, unusual noise or vibration from the crane, an operator receives a ground-level alarm, or sudden weather deterioration (rapidly increasing wind speed or a sudden drop in visibility). After an emergency stop, the operator must remain calm—slowly lower the suspended load to a safe position (if lowering is not possible, keep the load suspended and establish a restricted zone), then shut down the engine or disconnect the Power Supply. An incident report must be completed afterward.
| emergency situation | stop signal | follow-up handling | reportrequirements |
|---|---|---|---|
| Wire Ropeabnormality | Emergency Stop | lower to safe position | report immediately |
| suspended loadloss of control | Emergency Stop | steadysuspended load | operation log |
| Abnormal noisevibration | Emergency Stop | investigate cause | maintenance record |
| weather deterioration | cease operation | lockoutcrane | operation log |
| personnel injury | Emergency Stop | first aid and call for help | incident report |
FAQ
Q: What are the pre-operation preparation requirements under ISO 23811:2019?
A: Equipment inspection (daily inspection passed), work area assessment (site conditions, obstacles, weather), lifting spreader verification (selection and validity), and lifting plan confirmation (hoisting method and hand signals). A pre-shift safety meeting communicates risks and control measures. A trial lift of 200mm for 30 seconds is required.
Q: What are the safety requirements during lifting operations?
A: Lift smoothly and perform a trial lift to verify hook alignment, center of gravity, and stable slewing (acceleration ≤0.5m/s²). Never stand under a suspended load. Avoid angled pulls or dragging. For tandem lifting, each crane must operate at no more than 75% of its rated capacity under unified command. Night work requires illuminance of at least 50 lux on the work surface.
Q: What are the regulations for hoisting hand signals?
A: Hand signals (per the general standard), whistle signals (coded by short and long blasts), and wireless communication (dedicated channel with repeat-back confirmation). A certified signaller provides unified command. Operations must stop immediately if communication is lost. At night, hand signals and whistle signals are used together.
Q: What is the procedure for handling an emergency situation?
A: Upon detecting an abnormality, activate the emergency stop signal, lower the suspended load slowly to a safe position, cut off the power supply, and file a report. Common emergency situations include wire rope abnormalities, loss of load control, abnormal noise or vibration, deteriorating weather, and personnel injury. Kelude offers operator training for safe operation.
