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.
Category: Sectors
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.
Maida Vale Flood Alleviation Scheme
Hundreds of homes and businesses in Maida Vale have experienced dramatic flooding from heavy summer rainfall over a number of years. Thames Water and our contractor Optimise devised a solution to reduce the flooding risk for over 350 homes and businesses. The scheme includes new sewer tunnels under local, Central London roads and two new storage tanks to be constructed under local parks. It had the potential to cause widespread nuisance and disruption.
The importance of providing timely, targeted information on the project’s progress to MPs, councillors, community leaders, businesses and residents was recognised and care was taken to keep customers informed by a variety of means. As well as traditional letters and face-to-face meetings we held weekly surgeries, a web page, a quarterly magazine for residents and a text messaging service update fortnightly or when something needed to be communicated.
Kilmarnock Phase 1
Barhale were engaged to provide civils work to facilitate upgrades to the existing Kilmarnock South Substation which could no longer provide sufficient capacity. The existing substation was located to the South of the town of Kilmarnock, East Ayrshire, and consisted of 400/275/132kv compounds.
Phase 1 of the works consisted of construction and installation of 360 reinforced concrete foundation bases and approximately 2000m of concrete cable trough. These foundations were for a variety of structures such as a new transformer bund and base, GIB structures, breakers, height restriction barriers and new fencing.
Great Moor Sailing Club
As part of the legally binding Undertakings and Assurances (U&As) for HS2, Barhale were contracted by Fusion JV (Morgan Sindall, BAM Nuttall and Ferrovial Agroman) to construct a temporary road, a vehicle and boat car park, a drainage system, and a new pontoon with a concrete slipway at Great Moor Sailing club in Buckinghamshire.
The team innovated to resolve several constraints related to the project, and in the process saved money and finished construction on programme, while fully complying with stringent client specifications. The team also reduced the import of virgin materials’ by eliminating the need to remove spoil from site.
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.