On the Scaffold

Scaffolding to the Green Moor Quarry RIGS

Six months after I had submitted my report, and the Scheme of Work to clean the quarry face was agreed with the local authority, I was again commissioned to supervise the work on site, to write a report and to take a good set of photographs that would record the condition of the RIGS (Regionally Important Geological Site).

Clearing vegetation from the top lift

With the greatest part of the old Rock Inn site prepared for the installation of the infrastructure and services, construction work to the estate started immediately and was largely completed, when I returned to site a year later.

At a pre-contract meeting attended by the developer, specialist contractors and the geotechnical engineer, I outlined the purpose and scope of the work and recommended the techniques to be used to clean and conserve the RIGS.

By now, most of the old waste rock and soil had been removed from beneath the old quarry face and, once the full height and lateral extent of the RIGS had been exposed, the problem of providing a safe means of access to undertake the programme of work had to be resolved.

Although access to the rock face using a mobile platform was considered, it was rejected on Health & Safety grounds and a decision was made to carry out the cleaning work from a fixed scaffold.

Having extensive experience of working on scaffolds, in the specialist building cleaning and restoration industry, I had always thought that this was going to be the best option for providing good access, although perhaps the most expensive one.

With trees and saplings to be removed, where they interfered with the geological features, and the root systems of brambles and ferns penetrated deeply into fissures within the rock, a good solid working platform was needed.

The developer and the site clearance contractor didn't have any previous experience of undertaking a project like this but, when I climbed up to the top lift of the scaffold to start work on the first morning of a planned 3 day programme of work, it seemed like second nature to me.

Views along the scaffold

Working from the top down, a team of 3 - supervised by myself - set to work using a wide variety of hand tools that are familiar to a gardener: a spade, shovel, trowel, croppers, shears, secateurs and a wood saw, amongst others. All of the soil and loose or unstable rock was carefully removed from the quarry face and ledges were formed, to arrest the fall of small blocks of stone, which might later be washed down by rainfall.

A root ball of bracken

The uppermost section of the quarry face, comprising weathered rock and soil, was not disturbed and only the dead vegetation was removed, with the plants cut back down to the ground. However, at lower levels, it soon became evident that the removal of deeply penetrating plants from  the beds and joints would cause substantial damage to the very friable rock face and - where these were encountered - they were left growing in situ. The use of biocide to treat residual roots was not considered to be appropriate, for good environmental reasons.

The top and 2nd lift after cleaning

 

The 1st lift after cleaning

Finally, all ledges and faces were cleaned down with soft brooms and hand brushes, ready for an inspection by the Geotechnical Engineer...