The overall work scope involved repairing, refurbishing and strengthening the structure, therefore increasing the capacity of the bridge significantly from 7.5 tonnes to 40 tonnes.
Jack Tighe Ltd was awarded the contract to provide surface preparation and protective coatings to the bridge in February 2019. Our work was completed in three phases: –
Phase 1 in March/April 2019 involved washing down all existing steel using rotary heads in order to remove all surface contaminates and loose coatings. We then grit blasted the bottom flange, which gave the steel fabricators an indication of their programme for the Christmas possession and how they could replace the steel plates.
Phase 2 in November 2019 enabled us to UHP and remove any heavy scale and lead based coatings.
Phase 3 was completed during the Christmas possession towards the end of 2019 (Road closure was now in place.) Before the scaffold was erected, we completed a freshwater wash to remove any salts/contaminates. The scaffold was then erected to the underside of the bridge. From this point, we had an 8-hour window to grit blast the 16 bottom flanges, sweep blast the remaining paint and apply the approved coating system as per the specification.
All Jack Tighe Ltd operatives received a site induction from Osborne to ensure safe working practices and PPE requirements were complied with, including emergency arrangements and on-site muster points.
Access to the track to work on the underside of the bridge
Access to the underside working area was via Mobile Track Mounted Trolley Towers connected by Youngman’s boards with fixed handrails in place. In addition, MEWPS gained access to areas that MTMTT couldn’t cover. This was constructed by PASMA/IPAF certified Jack Tighe Ltd personnel and full checks were completed and documented by SSSTS accredited Supervisors. All Jack Tighe Ltd operatives working trackside were PTS/DC & AC certified and had their Sentinel card on their person to show proof of competence to work trackside.
Access to the track to work on the outside Parapets of the bridge
Access to the outer sections was via 85ft MEWP and Mobile Track Mounted Trolley Towers to the centre sections where the MEWPS could not reach on maximum boom extension. The MEWPS were positioned on the roadside/path leading to the multi-storey carpark, and this was the same for each side of the bridge.
A footpath management system supplied and controlled by Osborne was put in place to control the public pedestrians and to create a safe work environment. The chain link barrier fence was removed by Osborne to ensure it did not interfere with the extension booms of the MEWPS.
Access to the roadside faces of parapets
Access to the inside faces of the bridge parapets was via the roadside access. No specific access was required, and all relevant traffic management requirements were undertaken by Geoffrey Osborne.
Herras fencing with attached sheeting was used as a barrier and localised containment for the blasting works. We installed the sheeting from the mesh panel on the side of the bridge and secured it to the chapter 8 barriers to form a temporary encapsulation for the introduction of heating (diesel heater) to improve environmental conditions.
Working near high voltage power lines:
All works were undertaken during a possession, this avoided the need to work near high voltage power lines and 3rd rails were protected with 3rd rails specified approved covers.
Due to the significant lead content present in the existing paint system on site and the potential risk to operatives during the removal of the paint system, the Control of Lead at Work Regulations 2002 applied. Accordingly, we undertook face fit testing and blood tests for lead levels throughout the Contract.
It was identified that 22.46% of the trackside existing paint system contained lead, and 31.01% of the roadside contained lead. No lead was identified on the underside substrate sections of the bridge.
We worked closely and communicated effectively with Osborne, Network Rail and all other Contractors to ensure works were completed safely and on time.
The main risks identified with the project included: –
The number of workers peaked at 20, with generally 10 men working on days and 10 men working on nights. During the Christmas possession, we also had one apprentice working under the guidance of an SSSTS qualified Supervisor and an IOSH Managing Safely accredited Contracts Manager.
From Osborne Rail: –
”Congratulations to everyone, including our suppliers and customers, working at Farnham Road Bridge for safely and successfully completing the critical strengthening and refurbishment works during a Christmas Possession of the railway lines.
Working around the clock from Christmas Eve until New Years Eve, the collaborative team came together to erect a bespoke scaffold access, containment and noise enclosure system that facilitated the installation of steel strengthening plates and painting of the bridge.
Once fully enclosed the strengthening and refurbishment of the structure took 4800 man-hours to complete, used 8.5 tonnes of steel and 1300 bolts – and all undertaken without a single incident, accident or complaint from the local residents.
Despite the time of year there was great positivity and commitment from the whole team, including a real focus on everyone returning home safely after every shift.”
Due to the night work and the cold weather, particularly around the Christmas possession a decontamination / welfare unit was set up on a night by night basis to provide heating.
Works were completed on time to the value of £350,000.