JGL Corporate brochure - Flipbook - Page 68
06.
Case studies, our projects
BRIGHTON & HOVE
WASTEWATER TREATMENT
PROJECT, WEST SUSSEX
A challenging project with a successful outcome
saw Joseph Gallagher Ltd nominated as
‘Contractor of the Year’ by Costain.
Client:
Southern Water
Sector:
Utilities infrastructure
Project duration:
48 months
Scope of works
Recovery from the sea bed
Work on the £300 million project, designed
to treat 95 million litres of wastewater daily.
In addition to the 4m diameter on-shore flow
transfer tunnels, was the requirement to
discharge the treated effluent into the sea via
a one kilometer, 1800mm diameter tunnel and
diffusers on the sea bed.
The microtunnelling was completed in 26
weeks, but additional resources were required
to recover the Iseki tunnelling machine.
The project was unusual, as the thrust shaft
at Peacehaven was located at cliff top level,
some 40m above the beach, which required a
tunnel with 1200m radius curve to be installed,
to connect into an intermediate shaft on the
promenade. This shaft was constructed to
check the condition of the roller cutters on the
TBM, before relaunching the machine.
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This was achieved by driving into the
reception pit, which had been back filled with
sand to support the machine. Divers were able
to install a lifting beam to the machine cans
before pushing the machine off the pipes with
jacks operated by remote control.
The recovery was then completed by marine
specialists using 12 buoyancy bags to float the
machine to the surface. A tug took over the
operation at this stage to tow it to Newhaven
Harbour.
Joseph Gallagher Group | CORPORATE PORTFOLIO | 2026
