A requirement to strengthen the lock walls in preparation for construction of new lock gates. The works were designed by Atkins and comprised drilling through the existing walls and injecting cement grout to consolidate the fill behind.
Quantum’s works involved drilling of 117 55mm diameter injection holes, 2.5m deep, through masonry and concrete, followed by the injection of 15 tonnes of cement grout at low pressure through reusable mechanical packers. Localised, rapid setting concrete repairs were then carried out.
Operations included working below the mean high water level. By scheduling around peak spring tides we were able to complete the works using one of our lightweight pneumatic drill masts mounted on a negative reach MEWP eliminating the need for marine plant and accelerating the works.
The lock was able to remain active throughout the works. We followed the daily procedure below before commencing works in the lock channel:
- Completed Quantum Daily Task Briefing and submitted a signed copy to the Main Contractor (MCLH) supervisor.
- Obtained a Permit to Work from Milford Haven Port Authority.
- Notified Pier Head Control before entering the lock.
- Notified Marina Control.
- Carried out daily inspections of plant.
- Carried out daily inspections of life jackets.