Three long river crossings for fibre optic backbone using HDD Trenchless technology proved indispensable for the 2024 fibre optic expansion in Szczecin, Poland, where three demanding river crossings were essential to connect districts across the Oder to the new distribution network. Using a GRUNDODRILL 28Nplus from TRACTO and the expertise of contractor Hydropex, the culverts were completed in record time under highly challenging conditions.
Szczecin, a Hanseatic port city with nearly 400,000 residents, is shaped by its rivers and canals, which divide its dense urban fabric. For general contractor Up-Telekom Sp. z.o.o., constructing an 11.3 km fibre optic trunk cable meant tackling three major water crossings: 231 m under the West Oder, 210 m beneath the Parnicki Canal, and 426 m across the Regalica River – Hydropex’s longest HDD bore to date.
Technical and environmental challenges
Founded in 1989, Hydropex has just seven years’ trenchless experience but faced conditions that would test even the most seasoned contractors. Local geology included sand, clay, peat and moraine soils, while work had to be carried out in tightly constrained urban and harbour environments, sometimes alongside live shipping traffic.
Each bore required careful tracking and problem-solving. For the West Oder crossing, monitoring from a motorboat proved difficult due to steel quay reinforcements, but the team successfully steered through a 40 cm-wide corridor at 14 m depth. The Parnicki Canal crossing faced repeated signal losses, eventually resolved after several days of adjustments. The Regalica crossing demanded extensive preparation, with pipes butt-welded and laid out in limited space, and shipping temporarily halted to minimise interference. Despite its record 426m length, the pilot bore was completed in just two days.
Reliable equipment, efficient process
The GRUNDODRILL 28Nplus proved critical to success. Its 280 kN output, automated rod handling, and low fuel consumption enabled efficient and precise drilling while reducing operator fatigue. Noise levels were also kept low, helping crews maintain communication on site. In all three cases, HDPE casing pipes (200mm) were installed to house the fibre optic trunk cables, with Hydropex completing each undercrossing in around two weeks using teams of six to nine people.
Trenchless as the only option
Given the urban density, riverbank structures, and environmental sensitivities, open-cut methods were not feasible. HDD delivered a fast, minimally invasive, and cost-effective solution, enabling Szczecin’s fibre optic backbone to be expanded without major disruption.
For Hydropex, the project was both a milestone and a learning opportunity. “There was virtually no alternative to trenchless technology here,” noted the team, who now plan to invest in additional rigs to take on larger projects.
