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Unique storm water solution

Unique storm water solution

Our English pipe producer Polypipe Civils in Loughborough, UK has provided a stormwater attenuation solution for a luxury residential development in the heart of the idyllic Bedfordshire countryside in eastern England.

construction site

Renowned developers, Taylor Wimpey, called upon Polypipe to provide an engineered drainage solution, designed to work with a sloping gradient found on site. Set in the countryside town of Houghton Regis, the Regent’s Place large-scale residential development comprises of a mix of 180 two, three and four bedroom houses nestled in a tranquil area that offers stunning views of the landscape. The landscape surrounding the Regent’s Place development features a large public open space with limited footprint for drainage design and sloping gradients. Taking on the challenge, Polypipe worked closely with Taylor Wimpey and Consultant Engineers JPP Consulting, to design a KRAH storm water solution, incorporating staggered legs to take requirements and adopted elements laid out under Section 104 agreement for approving site conditions into account that also met site water company, Anglian Water. 

construction site2construction site3excavator

The attenuation tank supplied for the Regent’s Place project boasts a 3m diameter offset
RIDGISTORMCheck Vortex Flow Control Chamber which controls discharge water from the tank at an agreed rate of 10l/s, so the local watercourse is not overwhelmed. To control additional flow when required, the chamber also features a penstock flow control.
Project ValPolypipe supplied over 500m of Ridgistorm-XL to form 14 pipe runs in 2100mm diameters. Polypipe’s technical team engineered and designed the pipe to ring stiffness SN2 to meet the ground conditions, burial depths, native soil pressures and loading on-site. The system was tested to pass required deformation and buckling checks in accordance with BS EN 1295-1.
To accompany the pipe runs, the Ridgistorm-XL system incorporated 34 pre-fabricated modularised fittings which included 90° bends and ‘F’, ‘T’ and double ‘T’ fittings to fit the limited on-site dimensions perfectly.
The socket and spigot nature of these engineered fittings kept jointing to a minimum allowing for easy pipe alignment and speedy installation using electro-fusion jointing. This in turn significantly reduced on-site installation time and cost.
To achieve this closed loop system all pipe and fittings needed to be manufactured to a tolerate of +/-10mm on any length dimension. Due to limited storage space on site, manufacturing and delivery slots were planned with minimum safety gaps. This only allowed 3 days from completion of manufacturing to the installation of product.


Polypipe has worked on many residential projects in the past and understand the implications surrounding routine maintenance work. In order to make maintenance work less strenuous and overall safer for installers, Polypipe also supplied x10 RIDGISTORMAccess. Manholes in diameters 1200mm and 1800mm. The manhole access assists workmen by providing easy access to a pipeline.

Author: Polypipe Civils Head Office, Loughborough, UK


Retirement yes, but not retired

Retirement yes, but not retired


For 42 years he has been loyal to the company Krah. Now the passionate design engineer Wolfgang Schneider has gone into retirement. We interviewed him about his time at the Krah company..

Clear brew, a thundering Corvette and a “Mahlzeit” (German salutation for every day situations; literally translated “meal”) any time of day. If you mention these words every employee of Krah knows we’re talking about Wolfgang. For the past 4 dcades there has always been a loud roaring when Wolfgang drove onto the car park of Krah. One of his passions are cars, preferably old and special…or especially loud.

However,since February it has been more silent in front of the company building. On January 31st at 5 p.m. Wolfgang clicked “shut down” for the last time ever on his computer. A last soup from the automat in the kitchen, a last chat with colleagues and Wolfgang ends 42 years of working at Krah.

“I’m feeling good”, he says while walking over the car park which he has crossed thousands of times. “I’m looking forward to what comes next.”
He was very delighted about the farewell party which had been organized by his colleagues, with lots of presents some days before. “A personal highlight was a treasure chest from aluminium, made in the tool manufacture, with brass inserts to slide it open. Engraved were some figures which represented my 42 years at Krah. When I opened the chest there was a Krugerrand anniversary edition from 2017 from fine gold, a troy ounce. That was a successful surprise for my goodbye into retirement.“


Wolfgang Schneider is a primary rock of Krah. When Karl-Heinz Krah wanted to get him for his company “Werkzeug-&Vorrichtungsbau” in 1975 Wolfgang didn’t hesitate and accepted a job as tool manufacturer.

“A decision I have never regretted”, says 63-year-old Wolfgang. “Since I can think I liked to build things and felt gravitated to technical things. In my childhood I had always wished for an electric motor.” No wonder he describes the tasks in the company more as ‘hobby’ than work.

Karl-Heinz Krah spotted this excitement for technical things and offered him a job as design engineer only a few years later. Initially he was responsible for drawing Bihler tools. His tasks changed when Krah pursued increasingly to special machine construction and finally sold the complete Bihler area.
A highlight in his career was the decisive contribution to the development of the first gravity pipe machine in 2003/2004.

Back then there was lots to fiddle. For a tinkerer like him this was a great challenge.

He described his work as “goal-oriented”. “When the things you constructed worked in the end you were happy”, says Wolfgang. “As design engineer you work for goals, not tasks.” These results are known to many Krah customers all over the world. However, Wolfgang himself is only known by very few customers. His “territory” was always the engineering office in the Westerwald. According to Wolfgang he feels way more comfortable in his office with drawing board and measurement chart than being on a business trip abroad. Still today he remembers one of the few business trips with beads of sweat on his forehead. He had almost missed his flight back then. “I almost got stuck in Russia. That was nothing for me”.  He always felt very homey at Krah. “Otherwise I wouldn’t have stayed for that long. I turned my hobby into a career. A great time!”, so Wolfgang.


He now is one of almost 21 Mio. pensioners in Germany. But he surely isn’t afraid of boredom: His answer to the question what he will miss most he smiles and says “Actually nothing. I have worked for 47.5 years now and have never been ill for a long time. I now have more time for my other hobbies.”
He will continue crafting and building, especially on his home theatre audio system. But what he is most looking forward to are long trips with his Corvette and meetings with other car-fans. And if he’ll drive past KRAH during one of his tours, he will be happy to stop by and have a chat with his old colleagues. . .


Intake pipeline DN/ID800mm

Intake pipeline DN/ID800mm with submerged chamber of DN/ID2000mm

96m of ID800 intake pipeline + ID2000 submerged chamber. Installed partly into a trench to a depth of approximately 3m

 stress diagramstress diagramproject planning

One of our customers from Finland approached us with a request for 96m of SN8 pipes for a project. After the initial price quotations we were asked more technical questions and we actually found out that the pipes were meant for a intake pipeline. After convincing the customer that the regular SN8 pipes might not be the correct choice for such a project, we were asked to provide a technical solution for this exact task. 

storage closedstoraage tank

As a first step we calculated the theoretical profile that would be sufficient in such installation conditions. After receiving the customer’s approval on the price, we then carried out more thorough analyses of the situation and three FE simulations in order to approve the profile design:
1.    Concrete connection and GRP flanges deflected to max radius of 48 meters (24h parameters)
2.    Pipeline deflected to 48 m radius (24h parameters)
3.    Pipeline afloat with 6kN concrete weights on distance 6m btw the centres (1 week parameters)

Pipe endpipeline onsoilpipeline in waterpipeline installation

After the FE simulations we approved the profile PR54-007.00 (14/4/120) with the following technical parameters given to the construction company:
Total uplift of the pipe: 564,4 kg/m
Uplift of the submerged pipe, 100% water filled: 49,75 kg/m
Minimum bending radius in submerging process: 48 meters
Concrete ballast blocks (dry weight): 600 kg/piece
Mounting distance of the ballast blocks on the pipeline: 3meters (between the centres)
Dimensions of the ballast blocks (based on the option chosen by the construction company): inner diameter 938mm, outer diameter 1300mm, width 400 mm
The prewelded pipe together with the ID2000 chamber was successfully sunken in December 2016.



Potable water plant

Potable water plant of municipal utilities

2x 150 m³ pipe containers made of PE100 pipe by FRANK FTW- as storage tanks for the new waterworks “Vogelhölzle”


The municipal utilities in Dillingen-Lauingen (DSDL) started to replace the old waterworks “Vogelhölzle”, originated in 1962, by a new construction in autumn 2015. The old waterworks were situated in the setting range (ground water protection zone), which is, under current regulations, not permitted anymore. Since October 2016 up to 30.000 people are provided with drinking water from the new waterworks.
The planning engineering company PfK Ansbach GmbH planned a reinforced concrete building with a pent roof for the waterworks. In this building the complete piping, water treatment (oxidation) and the pumps are stored. The natural water is pumped to the waterworks from two 12m deep wells. If needed, up to 40 l can be conveyed per second. In the new waterworks the water flows through the oxidation and is then stored in two storage tanks. From there the potable water is pumped into an elevated tank and then reaches the consumer.

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The two storage tanks, each with 150 m³ capacity, were planned as pipe containers completely made from PE100. The connection of the two pipe containers was already made during the shell construction into the outer wall of the waterworks.

Ausschnitt ROHR

In order to do so, do so, a ground water tight and tensile cross-wall junction of the system FRANK Kunststofftechnik was used. Due to the pliable material behaviour of PE, pipelines or tanks of this material can be connected to concrete buildings without articulation pieces. The following advantages of pipe containers from PE were decisive for the planning:

Fabrication only with materials that are approved for the contact with potable water
Easy geometry
High level of prefabrication; short installation time
Long operating life
Smooth surface;easy cleaning
Easy connection / combination with cast-in-place concrete structure


After public tendering, the order for the construction of the new waterworks was awarded to the company Carl Heuchel GmbH & Co. KG from Nördlingen.

After ordering the two pipe containers from the Frank GmbH the FRANK Kunststofftechnik GmbH in Wölfersheim started the construction documentation. For the technical equipment of the containers there were exact specifications, which were implemented by a production drawing and released by the planner. Significant equipment features of the two containers were:

Spiral pipe made from PE100 with co-extruded blue inner layer – raw material with approval
Inner diameter DN 3000 – 150 m³ effective volume
Construction length approx. 23.6 m
End cover and functional wall
Completely factory-made prefabricated and delivered to the construction site in one piece
Pressurized door stainless steel DN 1000 for underwater entry
Stairs with platform from stainless steel 1.4571
Complete piping of the container from the inside with connection flanges of the functional wall – in detail:

  • Bottom outlet
  • Extraction with strainer
  • Filling pipe
  • Air tube and vent line
  • from stainless steel            
  • Inspection glass
  • LED lights

After approval of the construction documentation the two pipe containers were fabricated in one piece in the factory. After performed factory approval test by the planner and the client the two pipe containers were delivered with special transport. The containers had an outer diameter of 3, 3 m and a length of 24 m.

On site the company Heuchel
had already completed the shell construction in such a way that the two pipe containers could be unloaded and transferred with a mobile crane.
As support for the pipes a gravel base layer with sand bedding below was made. During the transfer the pipes were placed correctly into the respective block-outs in the building.

These block-outs were concreted later on.

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During the installation the containers were covered with the high-load fabric ‘Kortex’ by FRANK GmbH. By doing so the buoyancy safety can be assured during the production of the embankment.
This was necessary since the construction site was in a flood area.

After finishing the ground and structural works the expansion of the waterworks started with plant engineering and piping. The two functional walls of the pipe containers were integrated into the plant engineering through grids, so that an excellent operability could be achieved. Due to the short construction time, avoidance of budgetary overruns and the quality of the construction, the client and planner were completely satisfied.

IMG 2928IMG 2894

Planner: Engineering office PfK Ansbach GmbH
Construction company:  Carl Heuchel GmbH & Co. KG, Nördlingen
Settlement partner: Richter + Frenzel TBU GmbH

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Open House at Krah

On the 22nd and 23rd March Krah had an Open House in their factory in Schutzbach, Germany.

Open House at Krah

Global customers and interested companies were invited for a test run of the machine with its new features and advantages. While watching the machine running, they were able to understand how Krah technology works and which advantages it implicates.

In our newly designed “Krah-Lounge” we had a little buffet in the factory with typical German “Schnitzel” and “Currywurst”, prepared from a local butcher.

When lunch was done our colleague Marina used our “pipe bar” from the K exhibition 2016 to mix some cocktails for everyone.

The design of the new lounge took us a lot of time and patience, but in the end we went from a „naked“ storage room to a nice, comfortable lounge.

Our technicians and designers in the plant construction department worked hard on the development of this machine and were happy to see that all customers - and the board of management- were really impressed by the development of the machine compared to the first edition of the KR800, which was developed in 2014.

New KR800-MAX

We have already built 3 of these new machines and are looking forward to build many more.
It only implicates advantages for the customer.