GONDOLA (Suspended Working Platform)
Suspended Working Platforms (SWP), commonly known as the gondola or cradle, is an electrically-operated, temporary suspended access equipment used for working at heights. A movable platform driven by a motor is suspended along the vertical surface of the building by steel wire ropes through a suspension mechanism placed at the top of the building. The SWP features enable strong construction adaptability, higher constructions, less occupation of construction land, high construction efficiency, easy erection, and need for less manual labour.
The suspended working platform is an easy-to-use and efficient solution, and is being widely used for installation of billboards, windows, window cleaning, external renovation, painting and plastering jobs, decoration of bridges, building facades, chimneys, silos and other tall structures, and can be reused for different jobs. As it is permissible to use the SWP for working at heights, it is now the key for big project tendering. Workers are more confident using the SWP due to its large size and flexible dimensions of the working platform.
However, accidents and incidents involving gondola on construction sites have raised concern over site safety. Contractors must ensure construction workplace safety, properly supervise and carefully manage operations on site at all levels to prevent accidents. Therefore, contractors should step up vigilance, strengthen site supervision and conduct regular inspection and testing of suspended working platform in compliance with regulatory requirements. Below are key points which contractors must observe:
- Ensure those suspended working platforms are of good mechanical construction. Contractors should check all SWPs have suitable anchorage and support providing stability against overturning. Counterweights, suspension and wire ropes, drums & pulleys, working platforms, brakes, and control levers & switches must all be in good working order and compliant with regulatory requirements. All such SWP components must be suitably protected from corrosion; electrical components should also have adequate insulation to protect them from the weather. Workers should be provided with a safe means of access to SWPs.
- Develop Method Statements for the erection and dismantling of SWPs in accordance with manufacturer’s assembly manuals. Erecting and dismantling SWPs should only be carried out by trained and experienced personnel under the supervision of a competent person. Any alteration of SWPs should only be carried out by a competent person under the advice of a professional engineer. Examine SWPs thoroughly and perform load tests by a competent examiner as appropriate. SWPs must be examined by a competent person, prior to commencement of any work, to ensure that they are in safe working order.
- Provide SWPs—that are raised/lowered by means of climbers, winches and suspension wire ropes at each end—with a back-up safety rope mounted with an automatic safety device at each suspension point. The safety rope with the automatic safety device must be able to support the working platform in the event of failure of the primary suspension rope, winch or climber.
- Ensure that SWPs are not overloaded and clearly mark the safe working load and maximum number of persons that may be carried on the working platform itself.
- Provide every person working on SWPs with a fall arrest system including a full body harness, fall arrestor and fittings, and an independent lifeline anchored to suitable anchorage—separate from the SWP suspension system.
- Avoid using SWPs under adverse weather conditions likely to endanger its stability or cause danger to the persons carried thereon, such as during strong winds and/or thunderstorms. After exposure to adverse weather conditions, SWPs should be load tested and thoroughly examined by a competent examiner as soon as practicable before they are used again.
- Maintain SWPs properly and keep a detailed maintenance record of such. Regular inspection, examination and testing should be carried out by a competent person and competent examiner in accordance with the applicable standards. Functional tests for control, emergency stop, manual descending facility, limit switches, automatic safety devices and braking systems should all be included in such tests as well as those relating to the mechanical structure of the SWP. Certificates should be obtained from the competent person and competent examiner for retention and display on the relevant SWP.
- Examine wire ropes to ensure that it is in good condition. Thoroughly check if there are no broken wires, no kink or distortion in the rope and if there is no sign of wear or corrosion.
- Provide sufficient information, instruction, training and supervision to ensure the safety and health of all personnel involved.
- Make sure that platform is installed and maintained according to job requirements, safety regulations, standards and the manufacturer's specifications.
- Inspect all equipment before erecting and before each shift.
- Use appropriate fall arrest systems (e.g., a separate safety harness attached to an independent lifeline) for each worker. Maintain lanyard attachment at the highest point possible. If fall arrest systems are necessary, workers must be appropriately trained before use.
- Make sure that suspended platform roof beams and attachments are secure.
- Make sure that the roof or parapet wall is structurally sound to support either outriggers or cornice hooks.
- Check for kinked or damaged ropes.
- Secure all ropes at anchor ends.
- Make sure that all safety equipment, stops, override switches and brakes function properly.
- Prevent contact between welding or grinding equipment and wire safety or suspension ropes.
- Secure hand tools to the platform.
- Make sure that the power source is secured and properly grounded.
- Secure platform when not in use.
- Make sure that guardrails and toe boards are in place.
- Extend suspension ropes completely to the ground or terminate with wire rope clips to prevent the stage from running off the end of the ropes.
- Test by raising the fully loaded platform a few feet off the ground before going aloft.
What should you not do?
- Do not exceed platform load capacity.
- Do not enter or leave the platform other than at ground level or at other safe access points.
- Do not allow electric cables or connections to lie in gutters or other areas where water can collect.
- Do not work near exposed electrical circuits or equipment.
- Do not join platforms unless they are designed for this purpose.
- Do not use the damaged or defective equipment.
- Do not alter, substitute or remove components of the platform.
- Do not use fall arrest systems (e.g., the lifeline) for raising or lowering tools or materials.
- Do not move work platform unless all workers on it are protected by an appropriate fall arrest system.Bottom of Form
Safety aspects of Suspended Working Platform
A safe system of work should be established for every operation of a suspended working platform. The safety parameters and aspects should be prepared and endorsed by project engineers, safety professionals, related personnel at jobsites, and the building management, and should be distributed to all involved in the job. The safe system of work should be monitored and supervised by a competent person, who must ensure that each and every operation of the suspended working platform does not pose any risk to people working inside or near the working platform.
Safe Systems of Work
- Planning and assessment of the operation including selection of a suitable suspended working platform for the type of job and working environment.
- Following tested method of installation and means of securing the stability of the suspended working platform.
- Testing and thorough examination of the suspended working platform by a competent examiner.
- Periodic maintenance including on-site maintenance.
- Operation and maintenance manual, log book, repair record, and certificates of test and examination of the suspended working platform.
- Competent person for erection, repositioning and dismantling of the suspended working platform.
- Termination of the use of the suspended working platform during unsafe conditions.
- Monitoring and supervision of the implementation of the safety precautions and measures.
Safety Rules for Operator
- Every person on the working platform should be at least 18 years old, fit and agile, and not be phobic of heights.
- He must be suitably trained and have a certificate of training.
- He must be authorized by the controlling officer to operate.
- He must wear a safety helmet and safety harness when working; the self-locking buckle on the safety harness must be fastened independently, and fixed on the life rope that is tied on top of the building or structural member. The top end of the life rope is not allowed to be fixed on the suspended mechanism.
- Any operator who drinks, is under great stress, or of unusual mood is not allowed to operate.
- He is not allowed to wear shoes with a hard/plastic sole, slippers or any footwear that could slip.
- During operation, it is prohibited to use the ladder, bench, wooden stool and other tools for climbing in the range of the suspension platform, or design or place hoisting devices out of the suspension platform.
- The operator must access the suspended equipment from the ground or at other safe access points, and never from a window high up.
- It is absolutely prohibited to access the suspension platform from another suspended platform when working.
Sources:
https://www.ccohs.ca/oshanswers/safety_haz/platforms/suspendedwork.html
https://www.labour.gov.hk/eng/public/os/B/platform.pdf
