Bern | Switzerland
In 2024, the expansion of the Bolligenstrasse tram depot, which had existed since 2011, was completed by "Bernmobil".
The building, roughly the size of three football fields, now offers space for 60 trams.
The building's architecture is award-winning. Due to its spectacular shape, the building is also called "Papillon" (butterfly).
Construction and facade:
A key feature of the automatic overhead doors used is the elimination of supports, meaning the doors are attached exclusively to the lintel of the structure. In this case, particular attention had to be paid to deflection or roof sag of up to [value missing].
In addition to the technical requirements, architectural specifications also had to be considered, stipulating that when the gates were closed, only a uniform profiled glass facade without any visible gate mechanism was permitted. These glass units ensure maximum safety and protection for people in the immediate vicinity of the glazed gates in the event of glass damage.
Drive technology and guidance:
A particular challenge during the planning phase was finding a suitable drive concept. Limited installation space precluded the use of conventional gate drive technology. The alternative cable winch drive, thanks to its cable guidance and engagement with the gate leaf, was able to meet these specific requirements. The deflection mechanism and electronically controlled adjustment ensured consistent cable tension even when the gate was stationary.
The upper gate guides were implemented using linear guides made of high-quality steel. Only with the matching 3D roller mechanisms was it possible to absorb the radial and axial loads in such a small space.
When the gates are open, the upper half of the gate leaf protrudes beyond the roof surface, which can lead to increased wind loads on the gate.