And a good reason to ask Christopher Mock, construction manager at Aarsleff, and Michael Draband, construction manager at Schwalm Kanalsanierung, about their recipe for success.

"Right now, we are meeting or at the very least talking every day," explains Christopher Mock. "This is due to the large number of orders that we have been working on together, including in the fourth quarter of 2015. This makes continuous discussions unavoidable – but Michael Draband and I now know each other like the back of our hands. We are both very flexible and always do everything we can to satisfy the requirements of our clients across the board. This is what our successful collaboration involves. Even if we start an assignment straight away, i.e. without advance planning, we can still rely on each other 100%. A solution is always found."

The two construction managers got to know and value each other in 2010, since when they have taken shared responsibility for numerous construction sites both large and small. And even if the size of the two companies bears little direct comparison, and the constellation in question sees AARSLEFF functioning as a general contractor towards the client, the collaboration at the construction site and towards the customer always takes place on an equitable basis. This is further supported by the fact that AARSLEFF and SCHWALM are both experts in the required and interfacing areas of work at the construction site. "We can rely on each other on an unconditional basis," highlights Michael Draband, "because both AARSLEFF and we ourselves only want one thing: to be able to complete the work at the construction site to which we are assigned to the customer's complete satisfaction."

The positive collaboration is confirmed by Thorsten Anacker, technical specialist for the waste water division, Rotenburg a. d. Fulda municipal utilities. "Here in Rotenburg, our sewer system is old, cracked (with category 3, 4 and 5 damage) and in urgent need of maintenance. There is an urgent need for action, because our sewer network here in Rotenburg a. d. Fulda is considered to be a valuable asset. It is an investment with a value that runs into the millions. We have been rehabilitating it on a closed construction, area-by-area basis for almost 20 years. With 15 sub-areas, we have so far been able to complete the work on four with our clients in the area of open and closed sewer rehabilitation. Among other companies, AARSLEFF has also cooperated here with SCHWALM. We both were and are extremely satisfied with their performance. Since spring 2015, the "Rotenburg II" site, with a 12 kilometer long network of sewers has been "undergoing treatment," says Anacker.

"After the tendering and then considering the incoming offers, we decided on the 'most cost effective' offer, which meant AARSLEFF. And the best offer doesn't just mean the best price, but the fulfillment of three key factors: expertise – performance – reliability. Our exceptionally reliable collaboration with AARSLEFF / SCHWALM in recent years was the reason behind our decision to award the bid to them."

The project plan

Step 1

SCHWALM / AARSLEFF

• Measure feed lines
• Initial milling work, removal of deposits
• Measure mounting lengths

Time outlay: 6 weeks

Step 2   

AARSLEFF

• Liner installation (45 units in total)

Simultaneously     

SCHWALM 

• After the hardening of the liner – milling out the feed lines, house connectio
• Cleaning of sewer lines and video inspection
• Removal of possible blockages which could prevent the liner installation

Time outlay: 4,5 weeks

Step 3

AARSLEFF / SCHWALM                                                            

• Inspect the liner supports – partial repair
• Connecting the house connections (with top-hat profile, Schwalm, compressing in the short-cycle procedure, Aarsleff)
• Shaft rehabilitation 100 units, 60 of which complete, 40 individual cases of damage

in processing

Step 4 

AARSLEFF

• Attach shaft connection to liner / fit liner end sleeves

in processing

Step 5  

SCHWALM

• Video inspection of all rehabilitated channels with corresponding documentation

Dec. 2015

At both AARSLEFF and SCHWALM, completing the work according to the schedule set by Rotenburg municipal utilities (December 2015) has top priority. "Despite some uncertainties, we will be able to keep to the time frame and are sure that our work will satisfy our customers," which is something to which both Mock and Draband agree. "We have been working together very reliably for several years, and already have plenty of things planned for next year, and the orders are already there. Of course, we are pleased about this, but in trenchless sewer rehabilitation, it is increasingly a case of ever faster, ever further and ever bigger. This means that we will be working continuously on the basis of our shared development into the future."

Info box AARSLEFF Rohrsanierungs GmbH I SCHWALM Kanalsanierung

For more than 20 years, AARSLEFF has been the national and international market leader in the field of trenchless pipe and sewer rehabilitation with its core areas of expertise in the fields of hose lining, shaft regeneration, large profile regeneration and connection regeneration with the use of robotic technology.

SCHWALM Kanalsanierung, which was founded in Bad Hersfeld-Asbach in 1938, has regional roots and is owner-managed. Now in its third generation, Martin Schwalm has been the director of the company since 1999. Under his leadership, in 2008, the medium-sized family business was split into Schwalm Kanalsanierung (respectively Willi Schwalm, owned by Martin Schwalm e.K.) and Schwalm Robotic GmbH. With Schwalm Robotic, Schwalm is focusing more strongly on the area of the production and development of systems that are used in partial sewer rehabilitation on the basis of closed construction. Schwalm Kanalsanierung continues to operate as a services company. It has two focal points: sewer cleaning and clearing, as well as partial sewer rehabilitation on the basis of closed construction.