There are several situations when a mobile tower scaffold must not be used on a job, and it is important to recognise the various factors that determine if it is safe to use. This article outlines situations where scaffold towers should be avoided, including the maximum mobile tower scaffold wind speed tolerance, and the safe working height tower scaffold allowance.
So let’s look closely at when a mobile tower scaffold must NOT be used on a job.
Adverse Weather Conditions
When facing difficult weather conditions such as strong winds, heavy rain, and snow, the HSE recommends not using a scaffold tower, especially with strong winds as it affects the stability of the tower. The official advice is to stop using a tower and dismantle it whenever the average wind speed reaches 17mph. This means a wind speed check needs to be part of the initial risk assessment, as well as being monitored throughout the use of the scaffold tower using a hand-held wind speed device known as an anemometer.
Also be aware that spaces between buildings, as well as inside partially open structures such as hangars and tunnels, can produce a funnelling effect which increases the wind speed above the outdoor average.
Ground Conditions
The stability and security of a scaffold tower relies heavily on the ground where it is erected. If the ground is unsuitable, then the tower can collapse with disastrous consequences. After making sure the ground conditions are suitable, always check that the tower’s castors and base plates are correctly fitted at the base of all the uprights and stabilisers are fitted as shown in the assembly instructions.
A mobile tower scaffold must never be used on any job without the proper stabilising equipment. If the castors, baseplates, or stabilisers cannot be placed on a solid surface, spread the load with wooden boards to prevent them sinking.
Height
Scaffold towers are limited in height for safety reasons, and exceeding the recommended limit will compromise the stability and therefore the safety of its user, increasing the risk of falls and accidents. A safe working height tower scaffold can be calculated using the instructions found in the BS EN1004:2020 safety directive.
Also note that adjustable legs on a mobile tower should never be used to gain extra height. The adjustable legs are purely for achieving a level base on uneven or sloping surfaces, with at least one adjustable leg always minimally extended.
Parts & Components
If the tower is broken or missing any components then DO NOT USE IT! A mobile tower used in such a condition could collapse without warning at any point. Also never attach netting, boards, or sheeting to a mobile access tower, as these can catch the wind and cause the tower to overturn, even in light and seemingly safe winds.
To learn more about when a mobile tower scaffold must not be used on a job, get in touch with the team at Ability International today.
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