King George V Reservoir Works

King George V Reservoir was constructed between 1908 and 1912.
It opened in 1913 and is the largest reservoir within the London area, measuring 170 ha (420 acres) in size and holding 2,740,000,000 gallons of water. To enable the reservoir to continue to operate safely, Barhale were engaged by eight₂O (SMB JV) to carry out two essential elements of work:

  • Strengthening of the existing kneeler beam
  • Installation of a hardcore access road round the crest of the reservoir

Kneeler beams are built into the upstream shoulders of the reservoir
embankment. They provide support to the concrete slabbing, which
protects the embankment from wave erosion around the top of the
water level. When reservoir levels were very low, there was the risk
of erosion undermining these kneeler beams, which could cause the
concrete slabs to fall away.

Coppermills Water Treatment Works Upgrades

As part of the upgrades at Coppermills Water Treatment Works,
Barhale were contracted by eight₂O to undertake the civil works for
the installation of 12 Rapid Gravity Filter Tanks (RGF Tanks), construct
a new weir chamber and pipework to two adjacent pipe galleries and
install new draw pits and ducting for HV/LV cables running into the
newly constructed MCC base slab. These upgrades will significantly
improve water purification capacity into Thames Water’s Ring Main,
and help to meet the demands of London’s rising population.

The scope of work on this project included all the earthworks for the
installation of the RGF Tanks and North and South pipe galleries. The
initial work plan required us to excavate the pipe galleries before
constructing the piling mat between them.

Warwick Tunnel Inspections

As part of eight₂O’s Tunnels and Aqueducts Programme, Barhale conducted the enabling works for tunnel inspections by Thames Water engineers. This included:

  • Structural integrity surveys of specified tunnels
  • Designing, supplying and installing secondary isolation
  • Tunnels drainage and cleaning
  • Primary inspection of tunnels

After Thames Water engineers inspected the tunnels, Barhale also carried out the required repairs. The scope of work covered 4 tunnels of which significant sections had been built in the 1800s. The tunnels were accessed via 5no shafts (3m ID, and depths ranging from 16 to 25m), which were located inside the reservoirs. The reservoirs themselves are situated on land that is open to public access via the Wetlands project.

Laser scanning covers the points (Featured in Tunnels and Tunnelling)

The Thames Water Ring Main (TWRM) was one of the engineering  achievements of the 1980s. Some 80km of concrete pipeline, mostly 2.54m in diameter, surrounds the capital and acts simultaneously as a reservoir and as a distribution system, supplying around 3.5 million Londoners. At the time of its construction, the TWRM was the longest tunnel in the UK – longer by 30km than the Channel Tunnel, which had opened less than six months earlier.
It was excavated by TBM, mainly through the easily-tunnelled and forgiving London clay – though at one point under Tooting Bec Common it unexpectedly passed through a bed of the Thanet Formation, which led to flooding and the temporary abandonment of a TBM.
The initial ring main was constructed by Thames Water between 1988 and 1993. Extensions and branches have been constructed, and further extensions are planned.

Battersea Chamber

As part of a pressure management scheme for Thames Water, Barhale
were contracted to carry out improvement works on 2no water mains
within a Thames Water compound on Cringle Street, near Battersea
Power Station. The works entailed replacing sections of old pipework
and the installation of new plug valves on both Putney and Crouch
Hill mains, and the construction of a new chamber for the pipework.

These works allow Thames Water to better monitor and manage the
pressure inside their water distribution network and thus to create an
accurate profile for the pressure management of clean water for this
area. This will ultimately result in more efficient asset management
and an improved water supply for Thames Water’s customers.

Counters Creek Flood Alleviation Scheme

The Counters Creek Flood Alleviation Scheme (CCFAS) was developed
following widespread basement flooding caused by intense rainfalls
in the Royal Borough of Kensington and Chelsea and the London
Borough of Hammersmith and Fulham. Thames Water appointed
Barhale to design and construct the local sewer upgrades. The scope
of works, which covered seven local schemes, included the installation
of new sewers, the construction of two new pumping stations and
sewer networks, and the installation of three FLIP devices utilising
Combi approved systems.
The original design raised several challenges, including closure of
main roads in a densely populated area, importing approx. 2000t
aggregates and removal of 1800t of spoil, and potential settlement
issues affecting nearby structures and utilities. Barhale proposed a
new, innovative and cost-effective design and safely completed the
project by June 2020, in line with Thames Water’s commitment.

Brentford Waterside Sewer Diversion

Barhale were required to install a new sewer system to facilitate the
construction of a mixed use residential and retail development, on a
4.79 hectare brown field site in Brentford, west London.
Barhale’s works involved the installation of 190m of new 600mm
diameter concrete pipeline, along with 6no 1500mm diameter
manholes along the run. This will enable flows from the new
development to tie into the existing Thames Water network.

All works were undertaken via open cut techniques. The pipeline was
installed at depths of between 3.5 – 4.5m throughout the site, using a
combination of methods, including:
• Drag boxes
• Trench boxes
• Trench sheets and frames

Millharbour Sewer Diversion

To facilitate the construction of several new apartment blocks,
providing 766 new homes, Barhale were engaged by the Ballymore
Group to divert an existing 1600mm sewer outside of the footprint of
the future building.

In order to provide a valuable solution to the client from the outset, Barhale
undertook extensive design feasibility studies in collaboration with their
design partner, Nicholas O’Dwyer. Through undertaking Early Contractor
Involvement at tender stage, Barhale were able to challenge the outline
design and provide an alternative solution which would be constructed
faster, cost less and reduce disruption to the surrounding area.

Brindwood Road

Barhale were employed to upgrade the existing 225mm storm water
pipeline to a 375mm concrete pipeline in order to relieve the flooding
to property number 14, Brindwood Road and increase storage
capacity of the storm water network.

The scope of work consisted of installing 360m of new pipeline along with 8 new manholes, 2 new inspection chambers and the abandonment of the old sewer. The project was always going to be challenging due to its location on a busy residential street.

Careful planning and constant liaisons with the local council allowed it to be successfully completed. Through continuous communication with the residents of Brindwood Road, the project was made easier and in turn positive relationships were formed.

Sussex Gardens – Trunk Water Mains Relay

Barhale were contracted By Thames Water and Crossrail to re-lay
several 200 year old Victorian Cast Iron trunk water mains in Sussex
Gardens, which is situated in close proximity to the Paddington tube
and main line stations.

Works were required to provide mitigation to any settlement, which
may have been caused as a result of the Crossrail Tunnel Boring
Machine (TBM), which passed through the area a year earlier. Barhale
were awarded this work due to their experience of working on large
diameter water mains in heavily congested trenches within central
London locations.