HSENI Safety Alert: Mast Climbing Work Platforms

HSENI have issued a safety alert on mast climbing work platforms. The alert is intended to tell industry, employers, duty holders and workers that use Mast Climbing Work Platforms (MCWPs) that a serious technical fault has been identified by the Health and Safety Executive (HSE) in Great Britain.

Mast climbing work platforms (MCWPs) are used widely across construction projects. These can be used in other industries for access and to maintain large plant. Platforms could fall from height where mechanical faults in drive units go undetected.

If not rectified quickly, the fault could cause serious injury, or even death. The safety alert has information and advice on what to do if you supply, install, use, inspect, service, maintain or examine MCWPs for use at work.

HSE has discovered that some MCWPs, which rely on two independent motor drive units per mast as the means to prevent the platform falling with overspeed, are not fitted with suitable and sufficient controls to manage this risk.

This means work platforms could fall from height where mechanical faults in drive units go undetected. If not rectified quickly, the fault could cause serious injury, or even death.

Failures in drive units can be such that neither the centrifugal brakes (intended to limit the speed of descent) nor the automatic brakes (intended to engage when powered travel is stopped) within the drive units are able to have an effect.

Malfunctions in drive units which endangers proper function are foreseeable and unless a means of detection of such malfunctions is provided there is a risk of platforms falling with overspeed.

Immediate action required

You are advised immediately to check that the necessary control measures are in place for all MCWP in use or available for use at a work. If the control measures are not in place, you need to withdraw the MCWPs from use until those responsible for supply, installation, use, inspection, servicing, maintenance and for thorough examination of MCWPs ensure that:

-there is the means to identify a loss of mechanical integrity in each drive unit where this is the system to prevent falling with overspeed

-each individual drive unit is fitted with a mechanical device, eg centrifugal brake, that automatically prevents the work platform descending at excessive speed

-damage to drive units due to platforms being powered onto buffers/base frames is prevented

-platforms and associated equipment are not damaged by physical overloading

-thorough examinations, inspections and tests, and visual and functional checks are appropriately planned and carried out.

Detect malfunctions in each drive unit which endanger proper function: Where two or more drive units are installed as the system to prevent falling with overspeed, you should ensure that:

-there is the means to detect malfunctions in each drive unit that could indicate a loss of mechanical integrity which results in a differential in the current demand between each drive unit, exceeding 25% of the full load current

-detection is in accordance with the manufacturer’s instructions, eg it initiates a stop command and generates audio-visual alarms

-the means of detection is functionally tested in accordance with the relevant technical standard or the manufacturer’s instructions.

Prevent falling with overspeed: Where two or more drive units are installed, you should ensure that each individual drive unit is fitted with a mechanical device, eg a centrifugal brake, that automatically prevents the work platform exceeding 0.4 m/s descent speed.

Prevent failure of the automatic brakes you should:

-ensure operators are competent and conform to the manufacturer’s instructions for emergency lowering of the platform, eg to prevent overheating

-check brakes for wear and assess them against discard criteria in accordance with manufacturer’s instructions

-carry out functional checks of the individual automatic brake on each of the paired drive units in accordance with the manufacturer’s instructions.

Prevent damage to drive units caused by contact with buffers or base frames due to the platform being powered down onto them, you should:

-ensure limit switches are appropriately positioned such that the lowest level that stopping is initiated by a terminal switch is achieved before contact with the buffers (and before contact with the final limit switch)

-Include functional tests of limit switches in checks and maintenance inspections.

Prevent damage due to physical overloading you should:

-clearly and indelibly affix to the platform the safe working load for configuration of the platform

-include functional testing of the overload warning device(s), if fitted, in maintenance inspections

Prevent failure due to defects or deterioration being undetected, as part of your risk management and control arrangements, you should:

-review your risk assessment with a focus on periodicity of inspections and thorough examinations and tests, with reference to national regulations and the manufacturer’s manual

-ensure periodic inspections, measurements and checks include those items listed by the manufacturer in their maintenance and service schedule

-ensure checks and inspections are undertaken only by those competent to do so. Or you need to take equally effective measures required to comply with Regulation 4 of the Provision and Use of Work Equipment Regulations 1998.

HSE action

Where MCWPs are found in use or available for use without suitable controls to manage the risk set out above HSE enforcement action will be taken in line with enforcement policy and procedures.