New landmarks in Tampere
After the completion of Tampere Lakeside Route tunnel, the city will have entirely new landmarks. 40 meter-tall ventilation chimneys will challenge the Näsinneula Tower in terms of color rather than height.
After construction work scheduled for 2013–2017, a section of 2.3 kilometers of main road 12 traversing Tampere will be placed in a tunnel running from Santalahti to Naistenlahti. Near the tunnel entrances, two handsome ventilation chimneys were erected in November 2015.
“This project is being carried out using an alliance model, explains Jari Humalajoki from Lemminkäinen Infra, the main partner in the construction project. Saarijärven Säiliövalmiste Oy was the contractor supplying the ventilation chimneys, which were made from Corten B steel. Painting work was subcontracted out to KST-palvelut Oy.”
The western entrance to the tunnel is in the Santalahti district. The 39.8-meter-tall ventilation chimney has been placed between the lanes, approx..30 meters from the tunnel entrance. The eastern entrance is located in the Naistenlahti district, with the 41.3-meter-tall chimney placed in the middle of the loop-like exit ramp. Both chimneys have a diameter of 6.2 meters.
Reflection of the Tampere landscape
To make the chimneys blend in and please the eye, the City of Tampere organized a competition for the best artwork to create unique landmarks and add a human touch to the massive steel constructions. Practical issues such as care and maintenance were also an important consideration.
The winner of the competition was artist Jan-Erik Andersson with his proposal “Fire and Rain”. “The key criterion in the selection of the winning artwork was compelling artistry. The implementation method, which is based solely on painting, ensures a masterful outcome that is easy to maintain, relatively inexpensive to produce and requires no technology,” said the jury.
The artist himself describes his work as follows: “The theme of the Santalahti chimney is inspired by fire, and the colors and feel of the red-brick industrial architecture so characteristic of Tampere. At the Naistenlahti end of the tunnel, the color theme reflects water and the surrounding lake scenery uniquely identifiable with Tampere.”
Colors from Tikkurila
Working in the premises of Saarijärven Säiliövalmiste, KST-palvelut test-painted a scale model made of steel using the same system that was later used to paint the life-size chimneys. Matti Hoppula was entrusted with the demanding task of laying the tapes for the large patterns.
“The paint system used in the ventilation chimneys was a slight modification of the SILKO-approved TIEL 4.10 system featuring Tikkurila's epoxy-polyurethane combination TP27-EPPUR250/2-FeSa2½. This will give a 15 years’ maintenance interval in corrosivity category C5, explains Mika Viita-aho, Key Account Manager responsible for Tikkurila sales to the metal industry in south Finland.
Before the coating was applied, the steel surfaces were sand-blasted to preparation grade Sa2½. The low-solvent, modified Temabond ST 300 epoxy paint was used as a primer, in two 100µm thick coats. For finishing, one 50µm coat of semi-glossy Temadur 50 acrylic polyurethane paint was used.
“For the chimneys, the system was modified as follows: On top of the finishing coat, a 30µm coat of glossy Temadur Clear acrylic polyurethane varnish was applied for slowing down the fading of colors. With this combination, a total film thickness of 280µm was achieved, Viita-aho concludes.
Text Arja Schadewitz
Photo Tampere Lakeside Route tunnel alliance