Is it right to silence Big Ben for workers’ hearing?
- Date: Tuesday 15th August 2017
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On Monday 22 August the most famous clock bell in the world will stop chiming to protect workers from its loud noise during restoration work. SHP assesses the case.
Although national news stories have inevitably focused on the fact the 156-year old structure even ‘kept chiming during WW2 and the Blitz’, this is not the first time the bells have fallen silent. And it happens fairly regularly, as birds, faults and other issues have meant workers need to get it going again.
In terms of long-term silent periods, this has also happened before. The bell did not chime for a period of around nine months when the clock underwent a major overhaul in 1976. Significant conservation work was carried out between 1983 and 1985, and it was silenced for a time during this period.
Again, in 2007 the bells were stopped for a period of 6 weeks, while essential maintenance works were carried out.
Safe Noise Levels
The previous periods of silence were not to protect workers’ hearing though. This makes the current restoration project unique.
So how loud is Big Ben? The answer is, unsurprisingly, very loud.
Big Ben’s chimes have been measured at 118 decibels. This makes it louder than a hammer drill and the majority of regularly used construction and industrial equipment.
Official guidance by the Health and Safety Executive states that any regular exposure of more than a minute to sounds in excess of 110 decibels would cause permanent hearing loss. Big Ben easily falls into this category.
The level at which employers must provide hearing protection and identify hearing protection zones is now 85 decibels (daily or weekly average exposure). The level at which employers must assess the risk to workers’ health and provide them with information and training is now 80 decibels.
There is also an exposure limit value of 87 decibels, taking account of any reduction in exposure provided by hearing protection, above which workers must not be exposed.
A spokesperson for the parliamentary authorities said the chimes were being stopped to provide a safe environment for the workers that will be on scaffolding.
Constant proximity to the chimes would ‘pose a serious risk to their hearing, and prevent efficient working’, they said.
But can’t the workers just wear ear defenders?
There are probably are fair number of readers who are thinking: ‘Why not just buy some PPE and get the team to wear ear defenders on site?’
Well, this question has indeed been answered by the Restoration Team.
A spokesperson for the work told the Evening Standard that clock mechanics who work on Big Ben are currently provided with ear defenders, but are exposed to the ringing bells for only short periods of time each week.
“People will be working on the scaffolding day-in day-out throughout the works, and, while protective headgear could be provided, it is not desirable for individuals working at height to have their hearing overly compromised, as there are concerns relating to the ability to hear each other and any alarms.”