Harpfnerwand (AT)

The 2,597-metre-long Harpfnerwand tunnel in the Zillertal valley was built in 1965 as part of the construction of cement works to handle construction traffic. The tunnel bypassed the Dornauberg Gorge, which at the time was undeveloped and unsuitable for heavy freight traffic. Most of the tunnel was built without an inner lining. The tunnel was designed to carry power plant components. The roadway was designed as a concrete carriageway. Reinforced concrete cable ducts were constructed on the emergency lanes, in which a power supply system could be installed.


The installation of new jet fans required a total of 6 ceiling cut-outs above the road surface. To ensure the most uniform airflow possible, the recesses are designed with longitudinal chamfers to reduce flow losses.

The jet fans are suspended in pairs in the recesses. The fans must be mounted to the tunnel ceiling using a special mounting frame as a system accessory.

Scope of supply

In total, Zitron will supply and install 12 jet fans with a diameter of ø1120 mm, including suspension frames, vibration monitoring, deflection grilles and fall protection.

Zitron Nederland B.V. is a company that occupies a leading position in the European market as a manufacturer of ventilation systems for railway and road tunnels. Zitron Nederland B.V. can justifiably call itself “Specialists in tunnel ventilation“.