Client: Network Rail
Principal Contractor: Amalgamated Construction Ltd
Paint Manufacturer: Jotun Paints
Contract Value: £250,000
Contract Period: April to July 2013
Rockingham Street Bridge is situated in a residential area within the Central London Congestion Charging Zone, the main concern was from noise pollution as an apartment block was situated a meter from the bridge.
In order to win the competitive tender bid, EPIC had to take ownership of the scaffolding package, making them responsible for the design and installation of the Scaffolding and the Encapsulation of the bridge. Part of the design was to install pedestrian walkways and a cycle path for residents to access the other side of the bridge.
To overcome the noise from the grit blasting, they installed acoustic panelling inside the encapsulation and split the works into 2 phases to supress the “echoing” to a minimum. Other obstacles to overcome included having to remove and reinstate bird mesh and sealing the bridge from above to stop debris from contaminating the paint system, and to help weatherproof the bridge.
As the bridge had been previously painted in Lead based paints, CLAW regulations (Control of Lead at Work), had to be adhered to at all times. Samples of the existing Lead coatings had be sent away for analysis to determine the percentage of Lead remaining on the bridge, to ascertain the levels of Lead that the Operatives had the potential to be exposed too, and to ensure that the waste generated by the works were disposed of correctly by a licensed Waste Management Company
Before works commenced all Operatives had to have Lead blood level tests carried out, to see how much Lead was currently in their body. They would then undergo further testing every 4 – 6 weeks to monitor exactly how much Lead was finding its way into their bloodstream.
A large amount of time and money was spent on training the Operatives, as anyone working on the project had to be ICATTS approved, attend the Network Rail Personal Track Safety Course and have Lung function tests, in order to be issued with a Face Fit respiratory mask, to comply with Network Rail safety requirements.
EPIC’s Site Inspectors also had to be trained to achieve their Painting Inspector ICORR Level 2 licence.
Daily climatic temperatures had been checked every 3 hours to ensure that all works were being carried out in line with the Specification.
Works to trackside parapets had to be planned and carried out on nights under approved Network Rail Possessions.
All Structures were washed by high pressure water jetting to remove all Salts and other contaminates.
Salt testing was carried out prior to commencing with the preparation stage. Pull off Dolly tests were also undertaken to check how well existing coatings had adhered to the structure.
Preparation was carried out by grit blasting to a Sa2.5.
The Painting works where carried out by Airless Spray, with stripe coating undertaken to area’s where the spray gun could not access properly.
Network Rail M20 specification was used for the coating system, which consisted of:
1 coat of Aluminium Primer to a DFT of 100 microns.
1 coat of High Build Intermediate to a DFT of 100 microns.
1 coat of Polyurethane Finish to a DFT of 50 microns.
The Wet Film Thickness readings were recorded using Wet Combs and checked with a Elcometer gauge to check the Dry Film Thickness were in line with the specification, before being offered to Network Rail to sign off.