The National Library of Finland located at the center of Helsinki goes through an extensive renovation, which is the largest repair for the building in its 169-year history. The project has recently been voted for the construction site of the year in Finland.
The renovation started last November and will last for a total of two years. In addition to a thorough interior conservation, the first floor is expanded for extra rooms as well as space for heating, ventilation, air conditioning and other building service equipment. The first floor stands on top of granite bedrock, which requires 500 m³ of rock to be removed.
When working in a historical building such as this, the job has to be done without dust, water, vibration and exhaust - with the right kind of equipment
NCC Rakennus Oy on kohteen pääurakoitsija ja Metson Murskaus Oy on yksi aliurakoitsijoista. The prestigious library sets high requirements for the contractors as well as equipment. “When working in a historical building such as this, the job has to be done without dust, water, vibration and exhaust”, says Jyrki Metso from Metson Murskaus Oy. The space is so limited that the first boulders had to be excavated with a sledgehammer and a hand drill. Now the majority of excavation is done with Avant Robot 185 equipped with Doofor rock drill and a hydraulic splitter.
Less than 80 cm wide, remote controlled Avant Robot can be driven through the narrow corridors of the cellar. The robot drills one meter deep and 45 mm holes, which are then excavated with a hydraulic splitter. “Because of the limited space, the boulders have to be manually removed. So there is plenty of holes to be drilled”, says Jyrki Metso.
We have been pleased with the reliability and features of our robot and drilling.
Avant Robot 185 is equipped with a telescopic boom and continuous slewing, which are essential features for productivity. Electrically operated machine enables working in confined cellar without fumes. Otherwise, the job would enquire plenty of manual work and it would not be cost-effective.
“In such difficult conditions and tight schedule, the machines and service have to really work. We have been pleased with the reliability and features of our robot and drilling. The robot has proven itself with the 500 hours on it, and service and spare parts have been quick if we ever needed anything”, says Metso.
“With these work tools and methods we have been able to meet the challenges of the project and to proceed according to schedule”, ends Jyrki Metso.