# NG Tunnelling > The Specialists in Drain & Sewer Connections --- ## Pages - [Blog](https://www.ngtunnelling.co.uk/blog) - [Thank You](https://www.ngtunnelling.co.uk/thank-you) - [Terms and Conditions of Contract](https://www.ngtunnelling.co.uk/terms-and-conditions-of-contract) - [Testimonials](https://www.ngtunnelling.co.uk/testimonials) - [About Us](https://www.ngtunnelling.co.uk/about-us) - [Request a Quote](https://www.ngtunnelling.co.uk/request-a-quote) - [Services](https://www.ngtunnelling.co.uk/services) - [FAQs](https://www.ngtunnelling.co.uk/faqs) - [Projects](https://www.ngtunnelling.co.uk/projects) - [Health & Safety](https://www.ngtunnelling.co.uk/health-and-safety) - [Contact](https://www.ngtunnelling.co.uk/contact) - [Home](https://www.ngtunnelling.co.uk/) --- ## Posts - [Tilbury Docks Foul and Storm Sewer Diversions](https://www.ngtunnelling.co.uk/tilbury-docks-foul-storm-sewer-drain-diversions): NG Tunnelling recently completed a comprehensive foul and storm sewer diversion project at Tilbury Docks — a site that presented... - [3m Deep Shaft and 11m Long Timber Heading in Cambridge ](https://www.ngtunnelling.co.uk/3m-deep-shaft-and-11m-long-timber-heading-in-cambridge): Underground construction projects require a unique blend of technical expertise, precision planning, and regulatory compliance. Our recent project in Cambridge... - [Foul and Storm sewer connection in Clapham](https://www.ngtunnelling.co.uk/foul-and-storm-sewer-connection-in-clapham): Combined Foul and Storm Sewer Connection – Clapham, South London As part of essential infrastructure upgrades in Clapham, South London,... - [North West London Project](https://www.ngtunnelling.co.uk/north-west-london-project): Clearing of an underground pipe blocked with concrete in North West London. • A 3m deep shaft was excavated to... - [Sewer Diversion Elephant & Castle](https://www.ngtunnelling.co.uk/sewer-drainage-south-london): A recent combined sewer diversion at the Aylesbury Estate regeneration project in South London by Elephant and Castle. • 100m... - [NG Tunnelling in the West End, Central London](https://www.ngtunnelling.co.uk/ng-tunnelling-in-the-west-end-central-london): Tunnelling in the West End in Central London at the 334 Oxford Street Project. • 9m of timber heading driven... - [Foul and Storm Sewer Connection](https://www.ngtunnelling.co.uk/foul-and-storm-sewer-connection): This a recent project completed for one of our many regular clients which involved a combined foul and storm sewer... - [NG Tunnelling 10 Years in Business](https://www.ngtunnelling.co.uk/ng-tunnelling-10-years-in-business): 🍾 NG Tunnelling recently celebrated the milestone of our 10 year anniversary ! 🍾 We thank everyone who's worked for... - [Foul Connection Works in London.](https://www.ngtunnelling.co.uk/foul-connection-london): Foul Connection works at London’s Queen Elizabeth Olympic Park Development. Many obstructions were encountered during the works, including concrete in... - [Sewer Connection in Berkhamsted](https://www.ngtunnelling.co.uk/sewer-connection-in-berkhamsted): NG Tunnelling have recently completed the foul and storm sewer connections for a new retirement village scheme in Berkhamsted. 230m... - [Foul and Storm Sewer Connections](https://www.ngtunnelling.co.uk/foul-and-storm-sewer-connections): Foul and Storm Sewer Connection at the Microsoft Data Centre, Bashley Road Project NG Tunnelling were contracted to carry out... - [Interceptor Traps](https://www.ngtunnelling.co.uk/interceptor-traps): What Are Drain Interceptor Traps ? When it comes to drainage systems, one crucial component often overlooked is the drain... - [Recent NG Tunnelling Accreditations](https://www.ngtunnelling.co.uk/recent-ng-tunnelling-accreditations): Recent accreditations NG Tunnelling have attained as part of our ongoing process to offer the premier drain connection services in... - [Build Over Agreements](https://www.ngtunnelling.co.uk/build-over-agreements): A build over agreement is a legal document that is required when a property owner wants to build or extend... - [Camden Roundhouse – Timber Heading Project](https://www.ngtunnelling.co.uk/camden-roundhouse-timber-heading-project): We were called out recently for an emergency repair as our client's contractor had piled through the existing sewer line,... - [Sewer Connection Maida Vale](https://www.ngtunnelling.co.uk/sewer-connection-maida-vale): Recently NG Tunnelling were asked to carry out sewer connection works in Maida Vale: Our bespoke solution comprised of •... - [Trial Hole Excavation](https://www.ngtunnelling.co.uk/trial-hole-pit-excavation): Trial hole excavation is another service provided by NG Tunnelling in London & Surrey. We recently completed a contract to... - [Central Middlesex Hospital Storm Sewer Connection](https://www.ngtunnelling.co.uk/sewer-drain-connection-middlesex): NG Tunnelling is a family-run company, offering specialist installations of drain & sewer connections in Middlesex, London & Surrey. This... - [Sewer Replacement East London](https://www.ngtunnelling.co.uk/drain-sewer-east-london): We recently attended Hallsville Quarter Development in East London's Canning Town to carry out a foul sewer replacement. Hallsville Quarter... - [Deptford Timber Yard Project](https://www.ngtunnelling.co.uk/drain-sewer-deptford): A 5. 5m deep shaft was excavated on site with trench sheets and pump out frames. A 10m long timber... - [Sewer Connection Covent Garden](https://www.ngtunnelling.co.uk/sewer-connection-covent-garden): National Portrait Gallery Project – London, Covent Garden Excavation of a 4 metre deep shaft was carried out on site... - [Wandsworth Sewer Connection](https://www.ngtunnelling.co.uk/sewer-connection-wandsworth): Wandsworth Bridge Road Project - Installation of Foul and Storm riser mains via shaft and timber headings on a very... --- # # Detailed Content ## Pages --- ## Posts - Published: 2025-10-13 - Modified: 2025-10-13 - URL: https://www.ngtunnelling.co.uk/tilbury-docks-foul-storm-sewer-drain-diversions NG Tunnelling recently completed a comprehensive foul and storm sewer diversion project at Tilbury Docks — a site that presented both technical and logistical challenges due to its operational environment. Our team approached each stage of the works with precision, collaboration, and a commitment to maintaining seamless dock operations throughout. We installed a total of 750 metres of drainage, with pipe diameters ranging from 225mm to 450mm. Excavations varied in width between 1. 5m and 2. 5m, requiring careful planning to ensure both efficiency and safety within the busy dock area. The project also involved constructing 14 manholes, each measuring between 1200mm and 3000mm in diameter, to support long-term access and maintenance. Once the underground works were completed, we reinstated the concrete road surface. This process included installing dowel bars for reinforcement before applying a durable finish of hot rolled asphalt, ensuring a high-quality and traffic-resistant surface capable of withstanding heavy port operations. Working within such a complex logistics environment demanded strong coordination. We maintained the free flow of traffic along the main road within the docks at all times and worked in close partnership with the Port Authority to minimise disruption. Throughout the project, we also liaised closely with Anglian Water to arrange for all necessary inspections and final sign-off. This project demonstrates how our expertise in drainage and tunnelling solutions allows us to deliver technically demanding works within live, high-traffic environments — safely, efficiently, and to the highest standards. --- - Published: 2025-06-26 - Modified: 2025-06-27 - URL: https://www.ngtunnelling.co.uk/3m-deep-shaft-and-11m-long-timber-heading-in-cambridge Underground construction projects require a unique blend of technical expertise, precision planning, and regulatory compliance. Our recent project in Cambridge perfectly demonstrates these principles in action, showcasing the successful completion of a complex foul drainage connection that involved both vertical and horizontal underground work. Project Overview Working for a valued repeat client in Cambridge, our team undertook a challenging underground construction project that combined both shaft excavation and timber heading installation. The scope included: Excavation of a 3-meter deep access shaft Installation of an 11-meter long timber heading Connection to existing municipal infrastructure Full regulatory compliance and inspection The Technical Challenge Shaft Construction The project began with the careful excavation of a 3-meter deep shaft, which served as both the starting point for the horizontal timber heading and the access point for the connection work. At this depth, our team had to carefully manage: Soil stability and shoring requirements Groundwater management Safe working conditions in confined spaces Precise excavation to maintain proper alignment Timber Heading Installation The 11-meter timber heading represented the core technical challenge of the project. Timber headings are a specialized form of tunneling that requires: Precision Engineering: Each timber section must be carefully measured, cut, and installed to maintain structural integrity over the full length Progressive Installation: The heading is built progressively as excavation advances, requiring careful coordination between digging and installation crews Alignment Control: Maintaining proper line and grade over 11 meters of underground construction demands constant surveying and adjustment Regulatory Compliance and Quality Assurance One... --- - Published: 2025-05-26 - Modified: 2025-05-27 - URL: https://www.ngtunnelling.co.uk/foul-and-storm-sewer-connection-in-clapham Combined Foul and Storm Sewer Connection – Clapham, South London As part of essential infrastructure upgrades in Clapham, South London, a combined foul and stormwater sewer connection was successfully completed. The project involved several complex civil engineering operations designed to connect new drainage systems to Thames Water’s existing network while maintaining site safety and minimising disruption. Scope of Works: Excavation of Shaft:A vertical shaft measuring 4 metres in depth was excavated on-site to facilitate access to the existing sewer infrastructure. This shaft served as the primary entry point for subsequent tunneling and pipe installation activities. Timber Heading Construction:A timber heading approximately 10 metres in length was carefully driven from the shaft location into an existing Thames Water manhole. This traditional method of hand-mined tunneling was chosen due to its precision and suitability in confined urban environments where vibration and surface disruption needed to be minimised. Pipe Installation and Backfilling:New 150mm diameter sewer pipes were installed along the timber heading to form the new combined connection. Upon completion of pipe-laying, the heading was backfilled using dry lean concrete to provide structural stability and protection for the pipework. Installation of Backdrops:Three new backdrops were installed within the newly constructed manhole on-site. These backdrops are essential hydraulic features that manage the vertical transition of wastewater from higher to lower levels, reducing flow velocity and minimising the risk of turbulence or structural damage within the manhole. This project required careful coordination with Thames Water, adherence to health and safety standards, and precise execution to... --- - Published: 2025-04-09 - Modified: 2025-04-09 - URL: https://www.ngtunnelling.co.uk/north-west-london-project Clearing of an underground pipe blocked with concrete in North West London. • A 3m deep shaft was excavated to locate the existing sewer. • A section of the pipe was cut out to enable jetting of the sewer. • After the blockage was cleared, the existing sewer was reinstated with bandseals. Works were undertaken within a restricted space beside a basement formation, hence the requirement for a narrow width excavation. NG Tunnelling is a family-run company, offering specialist installations of drain & sewer connections in London & Surrey for large contracting firms, property developers & domestic clients. We offer a “one-stop-shop” service for all drainage works including dealing with all the council / local water authority applications and approvals, taking the hassle away from you. We offer a fast and free quotation and site visit / consultation, where you can ask any questions you may have. --- - Published: 2025-01-15 - Modified: 2025-01-15 - URL: https://www.ngtunnelling.co.uk/sewer-drainage-south-london A recent combined sewer diversion at the Aylesbury Estate regeneration project in South London by Elephant and Castle. • 100m of timber heading was driven at a depth of 4m underneath carriageway• 600mm GRP (glass reinforced plastic) pipework was installed• 8no shafts were excavated for 1800ID and 1500ID manholes• An additional 60m of open cut was carried out for the surface water drainage --- - Published: 2024-10-28 - Modified: 2025-01-15 - URL: https://www.ngtunnelling.co.uk/ng-tunnelling-in-the-west-end-central-london Tunnelling in the West End in Central London at the 334 Oxford Street Project. • 9m of timber heading driven from basement to Thames Water culvertAs per the procedure when working on many of our basement projects, a working platform was installed, and an opening for the heading was core drilled through the existing RC wall. --- - Published: 2024-08-23 - Modified: 2024-08-23 - URL: https://www.ngtunnelling.co.uk/foul-and-storm-sewer-connection This a recent project completed for one of our many regular clients which involved a combined foul and storm sewer connection in the North West London area. • A 4. 5m deep shaft was excavated onsite with trench sheets and steel pump out frames. • 13m of timber heading was driven into Thames Water’s culvert sewer. • 300mm clay pipework was installed, and backfilled with dry lean concrete. • A backdrop was connected into a newly constructed manhole. --- - Published: 2024-08-07 - Modified: 2024-08-07 - URL: https://www.ngtunnelling.co.uk/ng-tunnelling-10-years-in-business NG Tunnelling recently celebrated the milestone of our 10 year anniversary ! We thank everyone who's worked for the company (past and present) for your insights and contribution. We would also like to thank our clients and suppliers for their business. We are proud to have navigated the challenges of the construction industry, and that our excellent team continue to meet the demands of an ever growing company. We're grateful for everyone's hard work, dedication and loyalty. Here's to the next 10 years ! --- - Published: 2024-05-05 - Modified: 2024-05-05 - URL: https://www.ngtunnelling.co.uk/foul-connection-london Foul Connection works at London’s Queen Elizabeth Olympic Park Development. 2no shafts were excavated to depths of 4m and 8m A total of 40m of timber headings were driven A new 2100ID manhole with an intermediate landing slab was constructed on top of the existing 600mm Thames Watersewer line. Many obstructions were encountered during the works, including concrete in the ground, existing live services and ground water. --- - Published: 2024-01-20 - Modified: 2024-01-20 - URL: https://www.ngtunnelling.co.uk/sewer-connection-in-berkhamsted NG Tunnelling have recently completed the foul and storm sewer connections for a new retirement village scheme in Berkhamsted. 230m of open cut deep drainage, 30m of timber headings and 4no manholes were carried out within the highway.   NG Tunnelling liaised closely with the local council due to the traffic sensitive location and close proximity to a school. Strict timelines were adhered to in order to carry out the works around the school holiday term. All pedestrian and traffic management were arranged including temporary traffic lights and a road closure.   Works were inspected and signed off with Thames Water upon completion. --- - Published: 2023-10-09 - Modified: 2023-10-09 - URL: https://www.ngtunnelling.co.uk/foul-and-storm-sewer-connections Foul and Storm Sewer Connection at the Microsoft Data Centre, Bashley Road Project NG Tunnelling were contracted to carry out sewer connections via shafts and timber headings at the Microsoft data centre campus in North Acton. The connections were made into existing Thames Water manholes approximately 4m beneath the carriageway, and new manholes were constructed onsite. Due to the nature of the project, rigorous and controlled standards were adhered to throughout the works. Following successful completion of the works, NG Tunnelling have been engaged to carry out a further two sewer connections towards the end of 2023. --- - Published: 2023-09-29 - Modified: 2024-07-26 - URL: https://www.ngtunnelling.co.uk/interceptor-traps What Are Drain Interceptor Traps ? When it comes to drainage systems, one crucial component often overlooked is the drain interceptor trap. Drainage interceptor traps are essentially devices installed in plumbing systems to prevent clogs and blockages by filtering out debris and sediment before it reaches the main drainage system. In this blog post, we will dive deeper into the world of drain interceptor traps, explaining how they work, their benefits, and why they are essential in maintaining a healthy plumbing system. How Drain Interceptor Traps Work Drain interceptor traps are typically installed in large commercial or industrial settings, such as restaurants, hotels, or manufacturing plants. Their primary function is to catch solid debris, grease, oil, and sediment that could potentially clog the drain pipes. These traps usually consist of a chamber or tank with multiple compartments. The waste water flow enters the first compartment, and as it slows down, solid debris settles at the bottom, while lighter oils and grease float to the top. The filtered water then passes through the remaining compartments before finally exiting the trap and entering the main drain. The collected debris, grease, and oil are typically removed regularly by maintenance personnel to prevent build-up and maintain the efficiency of the trap. Benefits of Drain Interceptor Traps The installation of drain interceptor traps offers several important benefits: Preventing Drain Blockages: By effectively filtering out solid debris, grease, and oil, drain interceptor traps help prevent blockages in the main drainage system. This helps maintain the smooth... --- - Published: 2023-09-28 - Modified: 2023-09-28 - URL: https://www.ngtunnelling.co.uk/recent-ng-tunnelling-accreditations Recent accreditations NG Tunnelling have attained as part of our ongoing process to offer the premier drain connection services in Greater London. --- - Published: 2023-08-30 - Modified: 2023-08-30 - URL: https://www.ngtunnelling.co.uk/build-over-agreements A build over agreement is a legal document that is required when a property owner wants to build or extend a structure over or near a public sewer or water main. This agreement is made between the property owner and the local water and sewerage company to ensure that the proposed building work does not compromise the integrity of the public sewer or water main, and to outline the responsibilities of each party in case of any future maintenance or repair work. Here are some key points to consider when entering into a build over agreement: Application process: The property owner must submit an application to the local water and sewerage company, providing details about the proposed building work, including plans and specifications. Approval: The water and sewerage company will review the application and, if necessary, may request additional information or changes to the proposed work. Once the company is satisfied that the proposed work will not negatively impact the sewer or water main, they will issue a build over agreement. Fees: There may be a fee associated with the application and processing of a build over agreement. The property owner should check with the local water and sewerage company to determine the applicable fees. Restrictions and conditions: The build over agreement will typically include specific restrictions and conditions, such as maintaining a certain distance between the building and the sewer or water main, using specific construction materials, or following specific building practices. Access for maintenance and repairs: The agreement... --- - Published: 2023-08-27 - Modified: 2023-08-27 - URL: https://www.ngtunnelling.co.uk/camden-roundhouse-timber-heading-project We were called out recently for an emergency repair as our client's contractor had piled through the existing sewer line, and as a result, the existing sewer was filled with concrete. To rectify the issue, NG Tunnelling were contracted to carry out a timber heading from inside themanhole on site, and followed the existing line to break out the concrete. Our operatives broke out afull face of concrete, and laid a new pipe run to replace the former line. Entry into the 8m deep manhole required forced ventilation and a gantry system due to the confined and constricted area. --- - Published: 2023-04-13 - Modified: 2023-04-17 - URL: https://www.ngtunnelling.co.uk/sewer-connection-maida-vale Recently NG Tunnelling were asked to carry out sewer connection works in Maida Vale: Our bespoke solution comprised of • A slightly longer shaft than usual, at 2. 5m distance, was excavated onsite to make allowance for an interceptor trap and manhole• A timber heading was driven to Thames Water’s culvert, and a flexible saddle connection was core drilled, in line with Thames Water’s requirements. The works were part of Westminster Council’s redevelopment of the Torridon House Estate car park to construct 21 new homes. NG Tunnelling is a family-run company, offering specialist installations of drain & sewer connections in London & Surrey. --- - Published: 2023-03-08 - Modified: 2023-03-08 - URL: https://www.ngtunnelling.co.uk/trial-hole-pit-excavation Trial hole excavation is another service provided by NG Tunnelling in London & Surrey. We recently completed a contract to excavate 19 trial pits of various dimensions at Belgrave Road in Pimlico, London: • NG Tunnelling arranged the necessary traffic management, suspension of parking bays, and Section 50 License with Westminster Council• We liaised with our client to record levels and findings of existing services in the carriageway to enable future installation of street furniture• All excavations were carried out by hand, backfilled and reinstated to the highway’s specification. NG Tunnelling is a family-run company, offering specialist installations of drain & sewer connections in London & Surrey. --- - Published: 2023-03-04 - Modified: 2023-03-04 - URL: https://www.ngtunnelling.co.uk/sewer-drain-connection-middlesex NG Tunnelling is a family-run company, offering specialist installations of drain & sewer connections in Middlesex, London & Surrey. This is one of a number of recent projects we're carried out at Middlesex Hospital. • A shaft was excavated onsite to a depth of 3m with steel trench sheets and pump-out frames• A timber heading was driven 17 metres in distance to Thames Water’s existing manhole in thecarriageway• A 150mm clay pipe run was laid to site and a new 1200ID manhole was constructed. The works were part of Durkan’s development of 158 new homes on their Central Way project, which is a key part of a wider regeneration plan for Old Oak and Park Royal. The area is set for major positive change and to become a transport hub where High Speed 2 will meet Crossrail. --- - Published: 2023-02-06 - Modified: 2023-02-06 - URL: https://www.ngtunnelling.co.uk/drain-sewer-east-london We recently attended Hallsville Quarter Development in East London's Canning Town to carry out a foul sewer replacement. Hallsville Quarter is a large development of over 1000 homes, and part of a £3. 7 billion Canning Town and Custom House Regeneration Programme. So our work had to be carried efficiently and with the minimum of disruption. NG Tunnelling is a family-run company, offering specialist installations of drain & sewer connections in London & Surrey. We offer a “one-stop” service for all drainage works such as this project in Canning Town, East London, dealing with all the council / local water authority applications and approvals, taking the hassle away from you. --- - Published: 2022-11-03 - Modified: 2023-02-06 - URL: https://www.ngtunnelling.co.uk/drain-sewer-deptford A 5. 5m deep shaft was excavated on site with trench sheets and pump out frames. A 10m long timber heading was then driven to the main sewer to connect 2no 225mm pipes. Due to the small diameter of the existing main, a large pipe could not be installed, hence our proposal to connect two pipes to achieve adequate capacity for the new drainage installation. NG Tunnelling is a family-run company, offering specialist installations of drain & sewer connections in London & Surrey for large contracting firms, property developers & homeowners. We offer a “one-stop-shop” service for all drainage works such as this project in Deptford, South East London, dealing with all the council / local water authority applications and approvals, taking the hassle away from you. --- - Published: 2022-09-29 - Modified: 2022-10-10 - URL: https://www.ngtunnelling.co.uk/sewer-connection-covent-garden National Portrait Gallery Project – London, Covent Garden Excavation of a 4 metre deep shaft was carried out on site together with driving a 7 metre timber heading to the main sewer. A catch pit chamber was also constructed on site. An obstruction of the existing foundation was encountered and broken through by our operatives in order to make the new connection to site. NG Tunnelling is a family-run company, offering specialist installations of drain & sewer connections in London & Surrey for large contracting firms, property developers & domestic clients. We offer a “one-stop-shop” service for all drainage works such as this project for the National Portrait Gallery including dealing with all the council / local water authority applications and approvals, taking the hassle away from you. We offer a fast and free quotation and site visit / consultation, where you can ask any questions you may have. --- - Published: 2022-09-14 - Modified: 2022-10-10 - URL: https://www.ngtunnelling.co.uk/sewer-connection-wandsworth Wandsworth Bridge Road Project - Installation of Foul and Storm riser mains via shaft and timber headings on a very traffic sensitive road between Wandsworth & Battersea. Our operatives installed 2no pumped MDPE pipes from a deep level basement onsite, and formed a break chamber in carriageway with a gravity-fed run to the main Thames Water sewer via a preformed junction. 2no headings were driven from the shaft in road, one to the basement and a second to the main sewer. NG Tunnelling is a family-run company, offering specialist installations of drain & sewer connections in London & Surrey for large contracting firms, property developers & domestic clients. We offer a “one-stop-shop” service for all drainage works such as this project in the Wandsworth / Battersea area dealing with all the council / local water authority applications and approvals, taking the hassle away from you. We offer a fast and free quotation and site visit / consultation, where you can ask any questions you may have. --- ---