Project Location: Ministry of Defence (MOD), Shoeburyness, Essex
Project Timeframe: October 2019 – July 2020
Havengore Bridge opened in 1988, spans Havengore Creek and provides the only vehicle access road to Foulness Island. The bridge is managed by QinetiQ as part of the MOD Shoeburyness Range infrastructure and is required to lift to allow direct passage for marine traffic from the River Roach to the North Sea and Thames Estuary via the tidally restricted Havengore Creek. The bridge is a single leaf, counter-weighted bascule bridge raised by a pair of double acting hydraulic cylinders. Following many years of service, QinetiQ identified that the bridge lifting mechanism and associated control system were in need of refurbishment and upgrading and appointed Fairfield to conduct the works.
Scope of Works
Fairfield Engineering Solutions Ltd was appointed under an NEC4 contract to deliver the work package in conjunction with its sister company Fairfield Control Systems Ltd. The wide-ranging refurbishment works included:
- Comprehensive survey and inspection of the hydraulic systems, mechanical components and control systems
- Refurbishment and upgrade of hydraulic control, including redesign and replacement of cylinder manifold blocks and HPU control manifold
- Replacement of the two 4m main lifting cylinders
- Repair of tail-locking bolts and fixings
- Installation of upgraded lifting control, control desk, safety and diagnostic systems
- Replacement wigwag warning lights and barrier repairs
- Refurbishment of ancillary steelworks
- Provision of Technical File incorporating a full parts list, drawings and design parameters, hydraulic schematics, inspection reports, NDT reports for retained items and an O&M manual.
“Given the age of the structure and the very restricted access to the lifting machinery, as well as the key requirement to maintain road access to Foulness Island throughout the works, this was a complex project, made even more challenging by the restrictions imposed by the COVID pandemic. We were delighted by the way the Fairfield team overcame these difficulties to deliver a successful project.”
Kev Meleady, Group Leader, Ordnance Munitions and Explosives, Shoeburyness
Key Deliverables and Successes
The major part of the works had to be carried out in the confined space beneath the roadway where the lifting gear is located. The refurbishment required hot works and forced ventilation meaning that phases and tasks had to be carefully planned to minimise disruption to road traffic as the bridge is the single route on and off for the operational and residential community.
To further reduce disruption, the new designs were configured to re-use existing wiring and pipework where feasible, which had the added advantage of minimising costs.
To reduce project risk and keep the schedule on track, Fairfield conducted a comprehensive Factory Acceptance Testing programme on all the control and hydraulic system components, including the two main lifting cylinders (each of which weighed 7 tonnes), prior to delivery to site. This also minimised the on-site installation and commissioning timescales.