Safety of Suspended Working Platform (SWP)

by The Jardine Engineering Corporation, Limited. – John Leung (Author); Albany Tam (Co-Author)

The recent fatal accident in Hong Kong on a temporary Suspended Working Platform (SWP) not only sparked society’s concern for all aspects of SWP including design, condition of components and whether work procedures were strictly complied with statutory safety requirements, but also initiated an extensive discussion about the safe and proper use of SWP.

SWP has been widely used for providing means of access for maintenance to the external wall, curtain wall, external cladding, roof of a building and building projections such as sunshade, planter box or water tank etc., enabling workers’ access to these external building elements for maintenance safely. As a result of the implementation of Building (Construction) Regulation (Cap.123Q) (B(C)R) by the Government of HKSAR on 1 February 2021 which mandatorily requires Maintenance and Repair (M&R) access to the external building elements shall be provided, nearly all new buildings have been designed and constructed to install a permanent SWP whilst a few new buildings designed to install SWP at a later stage or older buildings with poor or no M&R access will use temporary SWP to provide proper M&R access for workers to use. There is no doubt for the new B(C)R is driving the increase member of installation on both permanent and temporary SWP. It is more important now to have a proper understanding on the safe use/operation of SWP.

Serious and fatal SWP accidents are commonly caused by poor design of SWP and lack of a safe system of work. To strengthen the control, the Labour Department first introduced in 1995 the Factories and Industrial Undertakings (Suspended Working Platforms) Regulation. This Regulation applies to any industrial undertakings in which a SWP for carrying persons is used and provides a list of safety precautions and instructions for design of components in SWP. It also defines the action items such as inspection, testing and examination, reports and records for SWP that should be included in the safe system of work set-up by the owner. Both permanent and temporary SWP consists of similar components such as lifting appliances, counterweight, or automatic safety devices etc. but with different arrangement of these components. The Regulation governs the design of these components and provides the safety precautions for their arrangement applicable to either permanent or temporary SWP. ?The same action items in the safe system of work shall be applied to both groups of SWP.

The Regulation also identifies the responsibilities of the owner and worker to ensure that they will only do the action items good for the safe operation of SWP. It is also their responsibilities to ensure that they will not do the things which are harmful to the safe use of SWP or are strictly prohibited by the Regulation.

Safe System of Work

Responsibility of Owners

Do’s:

(a)???Arrange for registered professional engineer to carry out load test and examination after the installation, repositioning of SWP and at regular intervals. Ensure the SWP is inspected every 7 days.

(b)???Arrange a competent person to inspect the SWP and submit forms containing statements stating the SWP is in safe working order at specific time before the use of SWP.

Time

Form required

7 days prior to use

Form 1

6 months prior to use

Form 2

12 months prior to use, or after substantial repair, re-erection

Form 3

(c)????Provide adequate and safe access to the Suspended Working Platform.

(d)???Post a notice showing the maximum personnel allowed and safe working load of SWP.

(e)???Ensure the SWP is in a good condition, installed with necessary safety devices and free from defects.

(f)?????Arrange regular maintenance for the SWP.

(g)???Keep a maintenance logbook, operation and maintenance manual, history of repairs and test and examination records for the workers and competent person.

(h)???Provide suitable communication equipment for the workers.

(i)?????Provide enough and appropriate protective personal equipment to the workers.

Don’ts:

(a)???Allow modification of SWP without approval from manufacturer and competent examiner.

(b)???Employ workers who did not receive suitable training to operate the SWP.

(c)????Allow operation of SWP under unstable weather.

(d)???Ignore the defect report from competent person.

Responsibility of Workers

Do’s:

(a)???Ensure all components of SWP is adequate and secure before an actual operation.

(b)???Wear full body harness and attach them to independent lifelines.

(c)????Workers should be at least 18 years old and have undergone SWP training and obtained a certificate.

Don’ts:

(a)???Overreach or overload a SWP.

(b)???Use rusty or damaged ropes.

(c)????Tamper or interfere with such safety rope and automatic safety devices.

Safe Precautions for Design of Components in SWP

1. Construction & Maintenance

-?????????All components in SWP shall be corrosion resistant and designed for only one specific track profile to ensure that they cannot be incorrectly assembled or taken off.

-?????????Structural supporting frames, members and fixings shall be designed to withstand all combinations of loads imposed (including wind load) by the system.

2. Anchorage and Support

-?????????All SWP shall be adequately and securely supported to ensure its safety.

-?????????One or more permanent cast-in anchors shall be provided on the roof for anchoring the personal fall arresting devices by each worker.

3. Suspension

-?????????Only wire ropes should be used for the suspension and the points of suspension should be at adequate horizontal distance from the face of a building.

4. Counterweights

-?????????The counterweights on outriggers should not be less than 3 times the weight when the platform is fully loaded.

-?????????Water, earth, clay, chippings shall not be used as counterweights.

5. Platforms

-?????????The platforms shall be at least 440mm wide and provided on all sides with toe boards at height not less than 200mm to ensure safety of workers.

6. Safe access

-?????????Convenient and safe access to the gondola system shall be provided.

7. Drums and Pulleys

-?????????Every rope which terminates at the winding drum shall be properly secured. At least 2 turns of the rope shall remain on the drum.

8. Brakes

-?????????Every winch or climber devices shall be provided with 2 independent braking system, and they are capable to prevent SWP from falling out of control.

9. Control levers and Switches

-?????????All control levers, switches, or other devices shall be arranged to prevent accidental movement and clearly marked its purpose.

10. Protection of Climbers

-?????????Every winch, climber or similar devices of SWP shall be protected against the effect of weather, dust, or material likely to cause damage that can result in a malfunction.

11. Safety Ropes and Safety Devices

-?????????A safety rope having an automatic safety device mounted on it shall be provided at each suspension point.

-?????????Adequate restraint shall be provided to prevent undue sway or motion of the gondola system on all areas of the fa?ade of a building which can be exposed to wind.

-?????????In case a permanent SWP is not proposed, consideration should be given for the installation of permanent mechanical booms or anchorages on the roof for installation of temporary SWP at a later stage.

Inspection, Testing and Examination

1.??????Inspection

-?????????Conduct inspection 7 days before work. Inspect and ensure all the suspension ropes and safety ropes are in safe condition by competent person before work every day.

-?????????Display the message “All wire ropes shall be inspected prior to commencement of daily work” on the SWP.

2.??????Testing, thorough Examination including keeping of records on such testing and examination

?-?????????Conduct thorough testing and examination at specific time as mentioned previously.

?3.??????Duties of competent examiner

-?????????Competent examiner shall deliver certificate or relevant reports to the owner after the test and examination.

-?????????If repair is needed, the report should send to both the owner and the Commissioner for Labour.

4.??????Marking of Safe Working Load and Number of Persons Allowed

-?????????Information about the safe working load and number of persons allowed shall be clearly shown on the SWP. Unless tests are conducting by competent examiner, the safe working load shall never be exceeded. The maximum number of persons should never be exceeded.

5.??????Construction of Wire Rope

-?????????A wire rope shall not be used if there is any damage, e.g., wear, corrosion, kink, distortion.

-?????????If the total number of visible broken wires exceeds 5% of the total number of wires in any length of 10 diameters, that wire rope shall not be used.

?Reports and Records

1.??????Keeping of records of Maintenance

-?????????Keep the records of Maintenance for at least 6 years after the SWP is taken out of use. Occupational safety officer shall be able to inspect the records at all reasonable times.

2.??????Keeping and Displaying of Reports

?-?????????The certificates and reports of examination and test shall be kept for 3 years after they are received.

-?????????The SWP shall display the most recent certificates or reports.

-?????????The owner needs to keep the most recent certificates and reports for at least 2 years after the SWP was taken out of use.

-?????????Occupational safety officer shall be able to inspect the certificates and reports at all reasonable times.

3.??????Reports or Records to be furnished to Occupational Safety Officer

-?????????A copy of the reports shall be sent to occupational safety officer upon his request.

Manage Risk by Technology

Safe system of work should be drilled into our mind and adopt to every project. SWP owners, the engineers, safety professionals and workers, shall perform their responsibilities and duties to establish a safe operation for SWP as required by regulations. Moreover, with today’s technology, additional layer of safety can be added to ensure regulation compliance or elimination of risks that could arise from the operation of SWP.

1.??????Use IoT to Monitor the Safe System of Work

?-?????????Use various type of Sensors / Measuring Devices to collect status info or operation data, e.g., hydraulic pressure, noise levels, digital image, wind speed etc.

-?????????Analyse data and conclude if owners or workers have fulfilled their responsibilities in the Safe System of Work.

?2.??????Automatic System for Fa?ade Cleaning

-?????????Use robotic device to replace workers in SWP and workers control remotely from ground

-?????????Workers will no longer need to expose to risky work environment

References:

(1)?????Safety, O., & Branch, H. (n.d.).?Overview of Work- at-Height Safety Overview of Work- at-Height Safety. https://www.hkrca.org/wp-content/uploads/ld_2018_06.pdf

(2)?????Code of Practice for Safe Use and Operation of Suspended Working Platforms. (n.d.). https://www.labour.gov.hk/eng/public/os/B/platform.pdf

(3)?????Code of Practice on Access for External Maintenance. (n.d.). https://www.bd.gov.hk/doc/en/resources/codes-and-references/code-and-design-manuals/cop_on_access_for_external_maintenance_2021.pdf

(4)?????(2018).?Guidance Notes on Classification and Use of Safety Belts and their Anchorage Systems?(Occupational Safety and Health Branch, Labour Department, Ed.) [Review of?Guidance Notes on Classification and Use of Safety Belts and their Anchorage Systems]. Labour Department. https://www.labour.gov.hk/eng/public/os/C/belt.pdf

(5)?????(2004).?Guidance Notes on the Inspection, Thorough Examination and Testing of Suspended Working Platforms?(Occupational Safety and Health Branch, Labour Department, Ed.) [Review of?Guidance Notes on the Inspection, Thorough Examination and Testing of Suspended Working Platforms]. Labour Department. https://www.labour.gov.hk/eng/public/os/C/SWP.pdf

(6)?????(2004).?A guide to the Factories and Industrial Undertakings (Suspended Working Platforms) Regulation?(Occupational Safety and Health Branch, Labour Department, Ed.) [Review of?A guide to the Factories and Industrial Undertakings (Suspended Working Platforms) Regulation]. Labour Department. https://www.labour.gov.hk/eng/public/os/A/SWPreg.pdf