Pir F, an extension to Terminal 5 at Stockholms International Airport Arlanda, was on a tight schedule to be built within 12 months. The current air traffic control centre at the time was within the terminals construction area. The air traffic control centre was due to be moved but the new centre was delayed for another year. There was no choice but to leave the control centre in place and blast around it making this one of the most complex blasting projects known.
The construction required blasting of an area 400m long, 40 wide and an average of 12m deep in hard rock. The proximity of the air traffic centre required blasting only 0.5m from the building. Generally this is not too much of a problem but in this case OP stations (eyes of the traffic controllers) and all the servers controlling the airspace of central Sweden were just on the inside of the wall. The importance of the equipment and their age required 3 months of discussions with the authorities to get permission to blast. The result was an acceleration limit never seen previously…. 0.2g. As if that was not bad enough an alarm level of 0.1g was set which we needed to aim to stay under. Any blasting over 0.1g required a written report with reasoning and actions to be taken to prevent it happening again. An exceedance of the limit would stop the project with no guarantee to continue unless the authorities were satisfied with our recommendations.
The seemingly impossible obstacles in the project resulted in the construction of the worlds largest known drilled slot, over 150m long and over 15m deep. Up to 97% dampening of vibrations were achieved with the slot making excavation possible but this was not the only obstacles in our way. To the left we had the air traffic centre, 5m away to the right we had planes parked up all day. 50m behind we had planes being taxied in and 20 to 30m in front of the blasts we had the foundation of the terminal being built due to the projects time constraints. An enor mous QA/QC under taking, close project management and permanent presence on site helped pull through this one of a kind project on time.