Kent AirValve Chamber
Urgent reactive repair to a burst rising main within an enclosed chamber at Manston, Kent
Client
MTS Cleansing (for Southern Water)
Value
£60k
Duration
3 months
GLE was called to site as part of a P1 reactive response to a burst rising main within a chamber in Kent. A large DN800 T-section was severely corroded and required urgent repair. GLE’s team mobilised immediately to stabilise the failure, ensuring continuity of service and safe containment of the system.
Following an initial survey using visual and ultrasonic techniques, GLE determined that the remaining pipe thickness could not support a conventional repair. Over the following days, GLE implemented a series of temporary and permanent measures, including:
- Design and fabrication of a bespoke stainless-steel collar to secure the damaged section.
- Composite wrap reinforcement to temporarily seal the defect and allow safe isolation.
- 3D point-cloud scanning and digital modelling of the chamber to design the permanent repair solution.
Using the 3D model, GLE designed a new DN800 T-section and access cover complete with supporting steelwork.
All components were fabricated in-house at GLE’s Rochester facility, ensuring full control of quality, material traceability and programme.
This project involved several high-risk activities which were identified, planned and controlled under GLE’s Management System and detailed task-specific RAMS.
All risk assessments and method statements were reviewed and approved prior to works, with daily briefings and point of work risk assessments undertaken on site.
Entry into the valve chamber was classed as a high-risk confined space due to restricted access, potential gas build-up and limited egress.
GLE deployed its in-house confined-space-trained operatives and rescue team, using continuous gas monitoring, forced-air ventilation, top-man supervision and dedicated rescue equipment.
All personnel held current City & Guilds confined-space and rescue certification.
The removal of the corroded PCC cover slab and installation of the new DN800 T-section, air valve and precast access cover required complex lifting within a restricted environment.
All lifts were planned, coordinated and supervised in-house by GLE’s Appointed Person (AP), who prepared detailed lifting plans and risk assessments in accordance with LOLER 1998 and BS 7121. GLE utilised its own certified lifting plant and accessories.
This in-house capability ensured complete control over safety, sequencing and quality, removing reliance on third-party lifting contractors.
The installation of the new DN800 T-section was performed under Safe Control of Operations (SCO).
GLE liaised closely with Southern Water teams to plan isolations and sequence activities, ensuring zero issues and full-service continuity.
The works carried out during the shutdown were to demolish the existing chamber, safely access and remove and then replace the damaged section of pipe.
Where work at height was unavoidable, GLE installed temporary edge protection, certified access platforms and fall-arrest systems in accordance with our Work-at-Height Procedure, supervised by a competent person and verified through pre-use inspections.
The concrete chamber was reinstated in accordance to the design.
GLE designed and fabricated the galvanised steel cover in-house. The steel connections were pre-cast into the PCC ring in the workshop to eliminate working at height.
This project showcased GLE’s ability to provide a complete design-and-build service, combining civil, mechanical and structural disciplines.
Through innovative use of 3D scanning and digital design, GLE delivered a solution that eliminated the need for full asset replacement, reducing downtime, risk and cost to the client.
All work was completed safely, on time, and to specification, demonstrating GLE’s ability to respond rapidly to emergency conditions while maintaining the highest engineering and safety standards.
All works within GLE’s scope — survey, design, temporary works, fabrication, lifting, installation and reinstatement — were delivered entirely in-house, giving full control over safety, quality and programme
