Safety reps at Bank/Monument have been working on the issue of wheel screech on their platforms for many years.
The Health and Safety Executive (HSE) guidance on the issue is clear: "The level at which employers must provide hearing protection and hearing protection zones is now 85 decibels (daily or weekly average exposure) and 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." (See here.)
Recent checks by reps found the noise on the platforms at Monument to be between 91-92 decibels.
If management don't issue ear protectors to all staff, local and SRT, working on the platforms, unions need to consider action in response.