During AMP 6 United Utilities invested £20m into Preston WwTW to improve performance and resilience. Flowtite GRP Biaxial and Pressure Pipes have been installed to assist with achieving project objectives.

Preston WwTW serves a population in excess of 250,000 within the Borough of Preston and the South Ribble Districts. The Preston Storm Tank Project was awarded to specialist design and build contractor Mott MacDonald Bentley (MMB) with objectives to reduce stormwater spills and improve both the underperforming inlet works and the primary settlement stage.

All of the inflows to the WwTW were pumped and the catchment generated high concentrations of screenings, particular during storms after long dry periods, resulting in the existing inlet works struggling to deal with the peak screenings load, exacerbated by many recent UID (Unsatisfactory Intermittent Discharge of Storm Water ) projects undertaken locally.

The solution was to construct a new storm storage tank with a capacity of 51,000m³ comprising two compartments utilising the same fill/empty pipework for the majority of the pipeline.

A 530m long pipeline was required to transfer screened and degritted storm water from the inlet works to the new storm tanks during storm events. When the new storm tanks reach capacity, this pipeline provides 800m³ of additional storage, before the existing storm tanks begin to fill.

Flowtite GRP PN6 pressure rated pipes were used for the installed pipeline route which comprises 445m of 1400mm diameter pipe (fill and empty) and 90m length 1200mm diameter (empty only). Then a further 80m of 1200mm diameter pipe connects into the existing storm water return pump sump. Once the storm flows cease, the pipeline transfers this storm water to the storm return pumping station.

• Country/City: UK, Preston
• Year of Construction: 2018
• Application: Sewer
• Installation: Open Cut
• Technology: Flowtite
• Total Length of Pipe: 530m
• Nominal Diameter DN (mm): 1400 & 1200
• Nominal Pressure PN (bar): PN6
• Nominal Stiffness SN (N/mm²): 5000
• Client: United Utilities
• Contractor: MMB
• Consulting Engineer: MMB

Amiblu’s Flowtite filament wound pipes provide capacity to resist high internal pressures and maintain excellent long-term stiffness, corrosion and abrasion resistance and are engineered for 150 year’s service.

Where changes of direction in the pipeline were required, Flowtite Biaxial Pipe and Lock Joints were installed. This removed the need for expensive concrete thrust blocks and ultimately saved time on programme.

The Flowtite biaxial pipe and lock joint system is reinforced in the hoop and axial directions to resist pressure, end thrust and bending loads and is suitable for applications where transfer of load between pipes is required.

Measures to improve operability and resilience at the inlet works have been accomplished. Route cause and analysis techniques were adopted to ensure the best outcome and was delivered to a full PAS 1192-2 information delivery cycle. With Preston being a collaborative 3D BIM project, a federated model was compiled by amalgamating several different models from MMB, GHD and Longwood into one which proved advantageous.

Jonathan Edwards, Contracts Manager with MMB, commented:

"Choosing a GRP pipe solution provided a significant materials cost saving, when compared to the alternative ductile iron option.”

Contact Amiblu in the UK: [email protected]

Hydropower supplies more than 70% of all renewable electricity worldwide.  For over a century the UK has generated hydroeletric power by harnessing fast flowing  water to turn turbines to generate electricity.

In 1898 during the reign of Victoria,  the first hydroelectric turbine was installed to provide electric light to Balmoral Castle, since then two further turbines have been installed and in 2020 contractor GPHL Ltd installed  two more harnessing the water flows from the River Muick.

With the estate being situated in the Cairngorms National Park, Scotland, an area of outstanding natural beauty, careful consideration had to be taken with the design and construction of the project so as not to disturb the landscape in the process. 

Having successfully delivered several previous projects, Gilkes Energy and GPHL were confident in the technical support and delivery service provided by Amiblu, so engaged our services for the supply of some 3,000m of Flowtite GRP Pipes and Fittings to the  Balmoral Estate which is now owned by Queen Elizabeth II.

1000m of the pipe was laid within a narrow track of less than 4m wide which follows the meanders of the River Muick; here there was no space to install bends or thrust blocks, so the flexibility granted by using the Flowtite sequenced FPCA (angled pressure coupling) allowed for up to 3 degrees deflection in the pipe joints, removing the need for at least 15 bends and thrust blocks.

A near 50:50 combination of 1.5m and 1.6m diameter was chosen to minimise transport costs as they were shipped delivered to site 'nested' in a range of PN16, PN10 and PN6 pressure ratings.

Fully operational the pipe now runs at 8 bar with 81m head and has been tested to 13bar allowing for transient pressure.

• Country: UK, Scotland
• City: Balmoral Estate
• Year of Construction: 2020
• Application: Hydro Energy
• Installation: Open Cut
• Technology: Flowtite
• Total Length of Pipe: 3000m
• Nominal Diameter DN (mm): 1500 & 1600
• Nominal Pressure PN (bar): PN6
• ominal Stiffness SN (N/mm²): 5000
• Client: Balmoral Estates
• Contractor: GPHL Ltd
• Consulting Engineer: Gilkes Energy

Amiblu’s Flowtite filament wound pipes provide capacity to withstand high internal pressures and maintain excellent long-term stiffness, corrosion and abrasion resistance and are engineered for 150 years‘ service life.

Amiblu GRP hydropower solutions are easy to install and adapt to all kind of terrains. They help achieve more kWh with better returns and lower water hammer than any other pipe. With environmentally friendly raw materials in the pipe production (e.g. PET resins) as well as CO₂ savings in transportation and installation. Amiblu GRP penstocks support and speed up the industry’s transition to fossil-fuel free energy production.

David Crozier, Contract Manager with GPHL Ltd, commented:

“The project was completed within programme and budget and as a part of the legacy of the scheme, improvements were made to the Linn of Muick fish pass to further improve migratory fish movements upstream on the River Muick.

“Within 6 months of completion site has regenerated to a point where the pipeline is almost indistinguishable from the surrounding undisturbed terrain.”

Contact Amiblu in the UK: [email protected]

Gipsy Patch Lane, Bristol is a main road forming part of a new Cribbs Patchway Metrobus route in South Gloucestershire. As part of an asset assesment programme a few years ago, a CCTV survey showed many defects throughout the length of the surface water culvert at Gipsy Patch Lane. The defective sections ran under the busy carriageway so, as an interim maintenance measure the local authority excavated a section of the road and installed a concrete slab over the pipe to protect it from further deterioration or collapse.

During heavy rainfall over the summer of 2020, the same pipe was found to have suffered structural defects and root ingress through open joints and connecting laterals resulting in localised blockages of up to 90%. A new man-entry survey showed the pipe beneath the concrete slab to be deformed.

Major works were already under way in the area to replace a railway bridge on Gipsy Patch Lane, so South Gloucestershire Council took the opportunity to make improvements to the sewer in conjunction with the Network Rail works to minimise disruption, which was further aided by lighter traffic due to the regulations set in place for Covid-19 pandemic.

Under the Council’s Climate Resilient Scheme, the task was to find and deliver a suitable solution before opening the road up to traffic and risking a pipe collapse; two options were considered; open-cut to replace the section of pipe or trenchless technology to reline the affected pipe with little disruption to the area.

Doug MacKay, Project manager, South Gloucestershire Council consulted with Julian Britton, Critical Sewers Manager, Wessex Water and Matt Durbin Associates; specialist confined space and GRP structural relining installer to determine the most efficient and economic technique. As with many suburban roads, Gipsy Patch Lane is laden with many services within the carriageway, so rehabiliatation of the existing pipeline through trenchless installation of 210m x DN800 structural GRP jacking pipe supplied by Amiblu was decided upon. As the contract was classed as emergency works, subject to time constraints and speed of execution the use of Amiblu’s GRP pipes meant that MDA were able to remove the need for costly over-pumping and install the pipes in live flows, whilst minimising their work area to a single lane closure for uninterupted access to local businesses.

During the installation of the initial contracted 210m, a further 70m section of the pipe downstream required attention, so MDA undertook the additional works saving additional costs and disruption at a later date.

Amiblu jacking pipes are often utilised in pipe rehabilitation projects such as this as they offer a high compressive strength and, compared with conventional materials, an improved hydraulic coefficient. The hydraulic analysis carried out for Gipsy Patch Lane showed no reduction in hydraulic performance and as the pipes are designed to offer a service life in excess of 150 years with minimal maintenance, the life expectancy of this asset is greatly improved.

Doug MacKay, Project Manager with South Gloucestershire Council, commented:

"For this project, the Council had concerns about the risk of potential pipe collapse under traffic loading. The fact that road was already under a full closure due to an adjacent project to replace an old railway bridge meant that timing was critical for this project. It was essential that the work had to be completed before the proposed re-opening of the carriageway. Additionally, there was a limit to the funds available through the Climate Resilience budget to complete the scheme. We worked very closely with MDA and our designers to review the site constraints, risks to programme delivery and budget constraints to determine the most appropriate remedial solution. I was grateful for the time, input and patience spent by MDA during this period to explain the construction process and provide answers to all our questions and concerns in advance of making the final decision on the preferred option.

Once the decision was made to proceed with the pipe-jacking option the process was relatively straight-forward and stress-free from the Council side of things. In the main this was down to the excellent communication, planning and execution of the works by MDA. Both projects were completed on-time, within budget and with minimal disruption to the public and businesses that rely on using Gipsy Patch Lane.”

• Country / City: UK, Bristol
• Year of Construction: 2021
• Installation Time: 4 weeks
• Application: Sewer Rehabilitation
• Installation: Trenchless Technology
• Technology: Hobas
• Total Length of Pipe: 280m
• Nominal Diameter DN (mm): DN800
• Nominal Pressure PN (bar): PN1
• Nominal Stiffness SN (N/mm²): 32,000
• Client: South Gloucester Council
• Contractor: Matt Durbin Associates Ltd
• Consulting Engineer: South Gloucester Council

Amiblu pipes have a smooth, resin rich internal surface with high abrasion resistance which consistently prevents fouling and build up, leading to low maintenance costs and high flow rates even at low gradients. Both Jacking and relining pipes are supplied with in-line flush joints which prevent the intrusion of roots and further ensure the integrity of the asset. Available in diameters from DN300 to DN3600, in varying strengths and lengths. Amiblu’s systems are cost effect, durable alternatives to traditional pipe systems.

Contact Amiblu in the UK: [email protected]

East Budleigh is a small village in East Devon, UK located about 2 miles (3.2km) north of Budleigh Salterton. The village features a bypass culvert, constructed in the 1970s. The culvert is approximately 280 metres in length, of Armco construction, oval shaped and constructed from corrugated metal sheeting (with a concrete floor laid over it during the last 10 years).

The existing culvert was in a poor condition, with joints failing and large voids appearing in the material outside the culvert structure. These failures led to a small localised collapse in the road above during flooding in 2012 and there were concerns that in the future that a larger collapse could occur, causing a failure in the highway surface.

It was decided that this culvert required structural strengthening due to minimal cover to the busy road above, and to maintain flows through the culvert in storm conditions.

The Environment Agency employed Atkins to design the culvert rehabilitation, with Kier appointed as main contractor who in turn appointed specialist contractor Matt Durbin Associates to consult on rehabilitation options and carry out the work. Given that the location was a highly trafficked residential area with minimum cover to the road, it was decided that lining with a structural GRP segment lining system offered the best solution and Amiblu‘s NC Line, non-circular GRP Structural Relining system was selected for the project. In total some 300 metres of Amiblu NC Line Arch Shape liner, 2360mm wide x 1350mm high was manufactured to the required WRC Type II standard and ISO 16611.

Amiblu’s application engineers worked in partnership with Matt Durbin Associates to understand specific performance criteria required in order to create the optimal shaped pipe to fit the needs of the project and production started in January 2022 at Amiblu’s Gdansk factory in readiness to commence February deliveries.

The culvert meandered with the local water course, and on inspection for the design of the linings was found to include long radius bends which were designed for pre-manufacture so that they would install without issue on site.

Despite the apparent loss of cross-section in the culvert the design and smooth internal finish of the linings ensured that the flow capacity requirements for the culvert would be met.

Given the small village size and the traffic management requirements for the installation works, coordination with local residents and parish councils regarding the large deliveries to site was essential and worked extremely well.

Work commenced on site on 14 February with site preparation works. Installation into the culvert commenced in March. In total, all installation and annulus grouting operations were completed in just 8 weeks.

Amiblu’s NC Line provides structural rehabilitation to existing non- circular culverts and host pipes that have reached a point in their service life where the asset owner must decide to renovate or replace.

GRP pipe systems made by Amiblu maintain excellent long-term stiffness, corrosion and abrasion resistance and are engineered for 150 years‘ service life.

• Country: UK
• City: East Budleigh
• Year: 2022
• Application: Culvert reline
• Installation: Trenchless
• Technology: Amiblu NC Line
• Total Length of Pipe: 300m
• Nominal Diameter DN (mm): 2360 x 1350mm
• Nominal Pressure PN (bar): PN1
• Nominal Stiffness SN (N/mm²): As per design criteria
• Client: Environment Agency
• Contractor: Matt Durbin Associates Ltd
• Consulting Engineer: Atkins

Daniel Gay, Project Manager for the Environment Agency:

“From a client perspective, the GRP liner solution has provided a cost and time-effective approach to prolonging the asset life. We were hopeful to avoid any requirement for open cut solutions to minimise the impact to the local community and meet delivery deadlines. We also needed to ensure that the flood risk standard of protection was not altered to upstream or downstream receptors. The structural GRP liner allowed for a bespoke unit to be installed which optimised the culvert capacity to retain the flow performance and extended the life. The outcome of improvements to the culvert have reduced flood risk to 27 residential properties, significantly reduced future maintenance costs and health and safety risks to the public.” 

Adrian Parker, Senior Project Manager, Kier:

“This project is a great example of how accelerated delivery can be achieved under the Environment Agency’s Collaborative Delivery Framework. From identification of the scheme for fast tracking in June 2021, the scheme was on the ground in February 22 and complete by June 22. MDA have done a great job and thanks also to Amiblu.” 

Kent County Council‘s programme of planned highways maintenance works to be carried out during 2019 – 2021 included strengthening works to structures such as the Raigersfeld Culvert situated beneath the A20 Ashford Road, Maidstone, Kent.

Following on from previous culvert rehabilitation works for Kent County Council, Steadline Ltd. were once again commissioned to make the required improvements to an existing historical brick and steel beamed culvert which was showing signs of deterioration resulting the restriction of flow capacity.

With the same project team comprising Steadline Ltd., BdR (Civil & Structural Engineering) Ltd. and Amiblu, a bespoke, non-circular GRP liner was designed with specific challenges to overcome, including:

• Steel cross sections to the soffit of the culvert
• Inconsistent shape
• Traffic loads
• Restricted access
• Environmental considerations

The result, 16m x 1m length sections, 1244mm x 754mm Eliptical shaped NC Line with a 27mm wall weighing just 175kg per metre with a push fit bell & spigot socket, was designed to maintain the required cross section and flow capacity.

Steadline Ltd and BdR (Civil & Structural Engineering) Ltd worked in conjunction with Kent County Council, to ensure all works were carried out safely and efficiently whilst meeting the requirements set out by the client in respect of strength, durability and finished aesthetics.

Forward planning of this scheme was critical as the culvert runs beneath the main A20 which is a major arterial route through Maidstone and a road closure was never an option, so the team at Steadline worked closely with park rangers within Mote Park to secure the downstream access and with residents of a gated housing estate for the upstream access.

The stream was damned and over-pumped with precautions in place to ensure that no unwanted debris found its way into the natural water course. The 1m long NC Line sections were then craned onto the upstream landing area before being installed using a purpose built roller system to accommodate for the inconsistent internal condition of the existing culvert.

Once all 16m of NC Line had been installed, grouting was carried out in stages as per Amiblu’s recommendations and the headwalls were finished in keeping with the original culvert construction.

Amiblu relining pipes are particularly suitable for pipe and culvert rehabilitation, as they are light in weight, corrosion resistant, quality assured, easy to install and engineered to give 150 years’ service life, they are manufactured in a wide range of sizes in both circular and non-circular options and with varying strengths to cater for all locations and performance criteria.

Amiblu NC Line pipes are produced to ISO16611. The non-circular cross-sections are ideal for relining and strengthening aging sewer networks, culverts and channels. Non-circular pipes are also used for open trench applications where capacity is required, but allowable depth to invert is limited. They can be customised according to project requirements and easily be adapted to different types of shapes and geometries.

• Country: UK
• City: Maidstone
• Year of construction: 2021
• Application: Storm sewer
• Installation: Trenchless
• Technology: Amiblu NC Line
• Total length of pipe: 16m
• Nominal diameter DN (mm): 1244mm x 754mm
• Nominal pressure PN (bar): PN1
• NC Line shape: Elliptical / 1m lengths
• Client: Kent County Council
• Contractor: Steadline Ltd
• Consulting Engineer: BdR (Civil & Structural Engineering) Ltd

Aaron Harber, Contracts Manager, Steadline Ltd.

” All in all the scheme was very successful and certainly improved the flow of the stream/small river and with the new rag stone head walls looked very pleasing to the eye.”