Pfannenberg and Swibox Partner to Develop Custom Cooling Units for Switzerland's New Gotthard Tunnel


– Under construction for 15 years, the 35 miles

Gotthard tunnel located in Switzerland is finalized and is due to open in 2016. For this huge project, two competent partners - Electrical Enclosure Manufacturer, Swibox and Thermal Management Specialist, Pfannenberg - developed a unique electrical enclosure system that

withstands the alternating pressure load in tunnels.

Operating a tunnel poses a huge challenge for engineers and operators time and time again. All products and solutions have to meet the highest requirements and have to work perfectly even under harsh ambient conditions. In particular, this applies to electrical enclosures and their thermal management, which are subject to extreme alternating pressure loads, temperature differences and are also exposed to dust and moisture.

In close collaboration, Swibox and Pfannenberg have developed a special climate control concept for tunnel applications. The electrical enclosures have a specially developed pressure body designed to protect the cooling circuit with the Pfannenberg side mounted cooling unit, integrated controller and heater to guarantee reliable and maximum uptime.

These electrical enclosure cooling units - which are situated, in the 176 cross passages amongst other places - ensure that the thermal pressure of the electronic components integrated inside the electrical enclosures does not become too high and that they work safely and reliably throughout their whole service lives.

The largest technical challenges were the high requirements to the system of protection of the electrical enclosure, IP65, and also the high alternating pressure load - of up to +/- 5 kPa - which is caused by the trains passing through. It had to be ensured that all devices can withstand this alternating pressure mechanically, simultaneously implementing the high system of protection. Thanks to the custom construction of the mechanical unit, developed especially in cooperation with the company Swibox, it was possible to meet these requirements. This construction ensures a leak-proof separation of the surrounding also under pressure load. A special feature here is the developed pressure body inside which the components of the inner cooling circuit are housed. Therefore, it was not enough to use reinforced sheet metal: the selection of a suitable material and the increased material thickness in combination with specially installed stiffening plates led to the desired compressive strength.

In addition to the cooling units, Pfannenberg's heaters and new generation of controllers, designed especially for this project, were also installed to ensure the best climate control and maintenance of the enclosure. This is especially important to prevent unplanned failures and downtime and, by planning maintenance works in advance, to guarantee a high level of system uptime.

About Pfannenberg, Inc.

Pfannenberg, Inc. is a global manufacturer of thermal management, liquid cooling solutions and signaling technologies. Pfannenberg's enclosure thermal management products help some of the largest companies worldwide stay cool and safe, protecting and keeping electronic equipment running to avoid costly downtime. In addition to our thermal management products Pfannenberg also manufactures visual and audible signaling devices for security, industrial fire, building, industrial process, disaster warning, hazardous areas, light art and illumination. Pfannenberg is proud to provide solutions as a single source to its customers. Our business philosophy – Protecting man, machine and the environment.

To learn more about Pfannenberg's Cooling Units visit


Jon LaPorta

Telephone 716-685-6866



All Topics