Esso have now entered “Stage 4” of the phasing I originally described in July 2022 here.

I’ve reproduced it below, there are also some notes at the bottom on vibration levels that might be useful:

Stage 4 – Date TBD: Balmoral Drive closed from 2nd Sandringham Road roundabout to Pevensey Way. This is shown on ‘Map 1‘ (below).

Access to Sandringham Way shall be via the first roundabout. Access to Pevensey Way and offshoots shall be via Peel Avenue to Sandringham Way. Residents and businesses affected directly by this closure (Braemar Close, shops) will be contacted directly by the contractors who will do all they can to maintain access:

Stage 5 – Date TBD: Most Westerley end of Balmoral Drive closed from Pevensey Way junction to end. This is shown on ‘Map 4’ (below).

Access to Pevensey Way and offshoots will be via Peel Avenue and Sandringham Way. Residents on Penhurst Rise will be contacted directly by the contractors who will do all they can to maintain access in the least disruptive way:

Concerns about vibration levels

I am seeing reports about vibration concerns from those in homes adjacent to the current work. This has been a significant concern to residents at the North West end of Sandringham Way.

Esso are obliged to take measurements of vibration and noise and ensure they are within limits. Initially they did not want to share this data with anyone, but the morning of the site visit by Michael Gove they released some data to the Borough Council. There are queries whether this data is being measured in the best way, but Esso insist they are measuring correctly. The data I have seen does indicate measurements are within prescribed limits.

I  have pressed Esso multiple times to give us permission to share this data with residents, but so far they have refused. I am sure your Frimley Councillors will pick up the batten on this as those roads north of Balmoral Drive are affected by the remaining work (Balmoral Drive is the border between the Wards of Frimley Green and Frimley).

It may come as some comfort to share the following extract from BS 5228-2:2009 “Code of practice for noise and vibration control on construction and open sites”, B2 Human response to vibration says

“Human beings are known to be very sensitive to vibration, the threshold of perception being typically in the PPV range of 0.14 mm·s−1 to 0.3 mm·s−1. As vibrations increase above these values they can disturb, startle, cause annoyance or interfere with work activities. At higher levels they can be described as unpleasant or even painful.

In residential accommodation, vibrations can promote anxiety lest some structural mishap might occur. Guidance on the effects on physical health of vibration at sustained high levels is given in BS 6841, although such levels are unlikely to be encountered as a result of construction and demolition activities.

BS 6472 sets down vibration levels at which minimal adverse comment is likely to be provoked from the occupants of the premises being subjected to vibration. It is not concerned primarily with short-term health hazards or working efficiency. It points out that human response to vibration varies quantitatively according to the direction in which it is perceived. Thus, generally, vertical vibrations are more perceptible than horizontal vibrations, although at very low frequencies this tendency is reversed.

A kindred problem is that vibrations can cause structure-borne noise which can be an additional irritant to occupants of buildings. Loose fittings are prone to rattle and movement.”

BS 6472-1 identifies that above 0.8 to 1.6mm/s adverse comment is probable:

The limits above which cosmetic damage could occur are shown in BS 5228-2 Table B.2 :

The maximum vibration level calculated by Esso that I have seen is 2.8mm/s.

In summary:

  • Human’s are very sensitive to vibration levels: we perceive them from 0.14 – 0.3mm/s and at 0.8 – 1.6mm/s we are likely to become concerned.
  • The maximum level Esso have calculated is 2.8mm/s
  • The threshold for cosmetic damage to residential buildings is 15-20 mm/s

I hope this is helpful.

Stuart Black, April 2023