Wloclawek, April 2017

A customized one-of-a-kind solution: Trenchless egg-shaped section helps rehabilitate a main sewer

The unique project to rehabilitate the sewage system in the agglomeration of Włocławek began in January 2016 when a contract was signed between the supplier F.H.I. “Instbud Stanislaw Boguta” and the Polish city of Włocławek following an open tender. The aim of the project was to develop a complex rehabilitation concept and carry out the planned rehabilitation work in expert fashion.

In addition to cleaning, conducting a TV inspection, evaluating the state and technical efficiency of the existing pipes, and taking recordings, the comprehensive package of services included selecting rehabilitation technology and carrying out the rehabilitation work itself. The plan was to rehabilitate two sections of the sewage system with house connections and manholes. The first construction phase in ul. Kapitulna involved the following work on over 600 m of the main sewer:

  • · Rehabilitating a waste water pipe with an egg-shaped section of 1,000/1,500 over approximately 470 m with the SAERTEX-LINER® type S+
  • · Rehabilitating a waste water pipe with an egg-shaped section of 600/900 over approximately 130 m with the SAERTEX-LINER® type S+
  • · Rehabilitating waste water pipes DN 150 and DN 200 with a total length of 113 m
  • · Rehabilitating a total of 13 manholes 

Existing transport structure raises organizational challenges

This unique project unfolded in ul. Kapitulna and ul. Zielony Rynek in the city of Włocławek. With almost 120,000 inhabitants, the city lies in the Kuyavian-Pomeranian voivodeship of Poland. Ul. Kapitulna is one of the main roads in the western part of the city and one of the primary thoroughfares into the city center. It sees a very large volume of traffic, since the western part of the city is cut off from the center by a railway line running from Toruń to Kutno. The road has four lanes – two heading west and two east – and is one of the few access routes to pass under the railway line. Ul. Zielony Rynek, on the other hand, is right in the city center and has two lanes that are still paved with ancient cobblestones.

Picture one: The traffic had to continue to flow unhindered while rehabilitation work was carried out on these major traffic routes.

The main sewer in ul. Kapitulna was designed by an engineering firm from Danzig back in 1959 in order to drain waste water from all southwestern quarters of the city on the River Vistula over a total length of around 2,000 m. Prior to this, parts of Włocławek were either not properly connected to the existing sewage system or only had substandard drainage pipes in certain buildings. The project included an underpass beneath the railway line at a depth of 8 m so as not to disrupt the functionality and operation of the sewage system. The main sewer was built from brick over 50 years ago in the 1960s. 

Picture 2: Existing collection of partly historical planning documents.

A legal ruling on traffic was requested in order to carry out high-pressure cleaning on the sewage pipes. Since the roads involved were very busy, the project coordinators had to guarantee that a single lane of traffic could continue to flow while the work was being done.

New surprises accompanied the project from start to finish

The process to gage the current state of the network was initiated after the project was given the go-ahead in May 2016. The build-up of sludge in some sections of the pipe had led to a 70% reduction in diameter. A high-pressure cleaning vehicle was brought in to clean and remove the deposits in the pipe over a period of 30 or so days, during which project workers stumbled across some surprising finds: Colossal mounds of trash that should never have been sent through the sewers in the first place were only the beginning. Troublesome little rags and disposable towels also caused issues and became notorious for stubbornly blocking up the vehicles’ sieves and pumps’ baskets. This interrupted the flow of work, which kept having to be broken off in order to clean the machines at short intervals. This posed a major challenge right through to the end of the project.

After cleaning and exposing the surfaces of the existing pipes, the project workers took an inventory and evaluated the technical condition of the pipes. The deposits in the base of the pipe had left the bottom section in very good condition, while the upper portion had been corroded by aggressive waste water vapors. The evaluation of the pipe revealed that almost no deformation had taken place, placing it in category II. As part of the inventory, a full review was conducted and recordings made using a self-propelled TV camera unit.

Precision planning, organization, and implementation

Due to the design and choice of technology, the single pipe lining made of GRP pipes (GRP modules) was dropped in favor of pipe lining technology that could be cured on site by means of a resin-soaked GRP pipe liner. The main argument for choosing this type of rehabilitation technology was that the cones in the top of the manholes did not need to be dismantled. When it came to laying the pipe liner, the SAERTEX-LINER® type S+ was chosen for its excellent mechanical properties, including its significantly higher elastic modulus (short-term elastic modulus = 20.500 N/mm2) in comparison to other GRP products. This meant a GRP liner with the lowest possible wall thickness could be used and thus optimally meet the customer’s stringent requirements.

Picture 3: Hauling in the SAERTEX-LINER® using the SAERTEX® multiBelt belt conveyor developed for large sections.

The implementation work began in October 2016, whereby the rehabilitation project on the main sewer was divided into three construction phases. Waste water was successfully diverted using pumps and monitored by means of a three-shift system. Each construction phase was not permitted to exceed a working length of 110 m. The work had to be split up this way because of the high volumes of traffic and the associated requirements of the legal ruling on traffic to ensure minimal disruption to public transport. Another key aspect of the work was delivering the GRP pipe liner itself: An ideally suited loading position had to be found as the work had to be carried out using a crane on a very busy road. The heaviest GRP pipe liner weighed 15 metric tons.

Picture 4: Challenge accepted: 15 t SAERTEX-LINER® delivered to the construction site with great precision.

The SAERTEX-LINER® type S+ with egg-shaped sections of 1,000/1,500 over approximately 470 m and 600/900 over approximately 130 m was cured using a chain of 12 x 1,000-Watt UV lights at a speed of 15 cm a minute. It took 16 hours to fully cure the longest GRP pipe liner.

While this work was taking place, the manholes also had to be rehabilitated. The rehabilitation work on the main sewer took six weeks before it was successfully completed, once again proving the outstanding quality of the SAERTEX-LINER®. After the liner samples had been removed, they were sent to a testing institute and achieved excellent results.


Back to the overview

Saerbeck, 15th February 2018


There is a lot going on in the grounds of SAERTEX multiCom in Saerbeck: The clean-up of the warehouse and production hall, which burnt down during the major fire on January 25, 2018, is in full swing. At the same time, in the area of dry production, everything was disposed of, tidied up, cleaned and the damage caused by the flooding has been repaired.


Saerbeck, 05th February 2018


One week after the major fire at SAERTEX multiCom GmbH in Saerbeck, all employees met for an informational meeting in the dry production hall on February, 01st 2018. This area was almost spared by the fire. During the one-hour event, the shareholders and managing directors made a clear commitment to SAERTEX multiCom.


Saerbeck, 31st January 2018


We are all still trying to come to terms with the events of last Thursday. Above all, we are pleased that the evacuation ran in exemplary fashion and that no-one was injured.


Saerbeck, 26th January 2018


Almost 24 hours to the minute after the fire alarm was triggered, operations at SAERTEX GmbH & Co. KG have resumed at 100 per cent. Employees in the administration and production have been back on the job since 06:00 a.m. The same applies to the administration of SAERTEX multiCom GmbH. Clean-up operations have commenced at the SAERTEX multiCom production plant. Management is relieved that no one was injured, and would like to thank the more than 300 responders of the fire department, the THW (Technical Relief Service) and the German Red Cross – as well as all SAERTEX employees.


Saerbeck, 25th January 2018



The fire on the factory premises of SAERTEX multiCom has been brought under control by the fire department. The warning to the local residents has been lifted. Thankfully no was harmed and only material damage result from the fire.


Saerbeck, 25th January 2018


Since the early morning, the production hall on the factory premise of SAERTEX multiCom in Saerbeck has been burning. Currently the fire is being fought by the fire department. The factory premise has been evacuated and according to the most recent status no one has been harmed. We will give updates on the status here as well as through our communication channels.


Saerbeck, 05th January 2018


In early October, more than 20 visitors from local authorities, engineering firms, and associations from northern Emsland right through to the south of the Ruhr district braved the autumnal weather, with its storms and torrential rain: They accepted an invitation from SAERTEX multiCom GmbH and took the opportunity to find out more about the installation of shaft liners at first hand at the first “SF shaft-liner showcase”-


Saerbeck, 22 December 2017


Shortly before the end of the year, the 60,000th (produced at the Saerbeck plant)  SAERTEX-LINER ran from the production line. Reason enough for the SAERTEX multiCom team in Saerbeck to meet before the holidays for a group photo on the training facility in order to document this success.


Saerbeck, 04 December 2017


Viva con Agua de Sankt Pauli e.V. is a charitable association that is committed to ensuring that everyone around the world has access to clean DRINKING WATER. To achieve this goal, we are once again sponsoring a water project in the Chitwan region of Nepal this year and donating EUR 5,000 instead of...


Saerbeck, November 2017

7th Saerbeck Pipe Symposium: A complete success!

 The end of September, we opened the doors to our 7th Saerbeck Pipe Symposium in this, the twentieth year of our company’s history under the best weather conditions, and we are now finishing off the follow-up work. There is only one thing to say: The event under the title: “Trenchless pipe rehabilitation: sustainable – economical – innovative!” as a complete success! And many thanks to our team who prepared and supported this unforgettable event!


Saerbeck, 19th October 2017

New production and warehouse facility for SAERTEX multiCom

The construction work began early October on a new warehouse and production facility for SAERTEX multiCom at the site in Saerbeck. The project involves the installation of additional new production systems to expand the capacity for GRP-liners at the facility, which covers a surface area of  4,500 m2. The field of house connection liners (HASE) is being expanded with new areas, especially for the packaging, the impregnation, and the storage of the new light-cured liner.


Saerbeck, 25th September 2017

May we introduce...
Stephan Raab who is taking over responsibility for sales management in Europe and Africa at SAERTEX multiCom

On September 1 2017, Mr. Stephan Raab took on the position of Sales Manager for Europe and Africa at the international GRP liner manufacturer SAERTEX multiCom.


Saerbeck / Stavanger, 14 Juni 2017

Unique worldwide: Tab connection succeful installed to a rehabilitated potable water pipe!

Today, together with the company Hawle Water Technology Norge, we have achieved THE breakthrough and installed a tab connection to a potable water pipe, which has been trenchless rehabilitated using the SAERTEX-LINER H2O.


Saerbeck, May 2017

Organizational Change: Dipl.-Ing. Roland Hahn

Dear Friends and Partners

Our colleague Roland Hahn has decided to accept a new challenge as a partner in a consulting office in our industry. His new working environment will be closer to his home city and requests less travel. Therefore Roland Hahn is leaving SAERTEX multiCom at his own request as of June 30, 2017. 


Wloclawek, April 2017

A customized one-of-a-kind solution: Trenchless egg-shaped section helps rehabilitate a main sewer

The unique project to rehabilitate the sewage system in the agglomeration of Włocławek began in January 2016 when a contract was signed between the supplier F.H.I. “Instbud Stanislaw Boguta” and the Polish city of Włocławek following an open tender. The aim of the project was to develop a complex rehabilitation concept and carry out the planned rehabilitation work in expert fashion.


Saerbeck / Berlin, March 2017

Technology and research in practice: rehabilitating a DN 225 potable water pipeline with SAERTEX-LINER® H2O on Schöneberger Ufer for WASSER BERLIN INTERNATIONAL trade fair.

Subtitled “Technology and research in practice,” the exhibition “Experience Water” will be held on March 30, 2017, as part of the WASSER BERLIN INTERNATIONAL trade fair. Visitors from around the world will get an insight into innovative pipeline construction methods. 


Saerbeck, February 2017

Trenchless rehabilitation of a mouth-shaped sewer: a special project for the 50,000th SAERTEX-LINER®

In the past year, we not only celebrated the 20th anniversary of SAERTEX multiCom®, but also the production of the 50,000th SAERTEX-LINER® for the trenchless rehabilitation of pipes at our location in Saerbeck in the region of Münster, Germany.


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