During summer 2011, a crew of 250 men worked in three shifts, 24 hours per day replacing scrap iron with brand new rails, sleepers, points and contact lines from Brynsbakken to Skøyen. NOK 180 million has been spent on new railway infrastructure and 60% of the total renewal, which has a budget of NOK 1.6 billion, has been completed thus far.
The extraordinary train-free period during the summer would have been equivalent to 18 months of ordinary production. Nor would it have been possible to carry out such extensive works without closing the line. The total renovation of Oslo Central Station and the Oslo tunnel takes place throughout the year during the brief train-free periods each night.
Among other tasks, track replacement work will be undertaken in the 4.5 km Oslo tunnel during the summer of 2012.
New methods
– As a consequence of the methods applied by skilled German railway engineers at Oslo Central Station and in the Oslo tunnel, it will be possible to undertake extensive replacement of heavy points and tracks without closing Oslo Central Station for more than six weeks, explains Vibeke Aarnes of the Norwegian National Rail Administration in the company magazine.
Blank steel
– Regarding railway maintenance in Norway, we have now put behind us the most intense and extensive shut down in recent years, concludes track manager, Guttorm Moss. He illustrates the progress made with two types of rail: An old, slender 49 kg rail and the new 60 kg rail, the same dimension used on high speed railway lines in Europe – and on the Gardermoen Line.
Scrap iron
– After 30 years of the type of high traffic volumes that Oslo Central Station has become regularly used to, even the most sturdy tracks and points will have been subject to considerable wear and tear. A total renovation was long overdue. Worn out traction motors and power cables had taken quite a beating from tamping machines and maintenance work.
Dirty and finely ground ballast stone, coupled to poor drainage, also affected train comfort, as well as increasing the risk of frost heave and other undesirable problems, explains Guttorm Moss.
– Finally, the old wooden sleepers have been replaced with concrete sleepers, which will considerably increase the efficiency of future maintenance. During the summer, 34 points, three crossings and four kilometres of track, sleepers and ballast were replaced in Brynsbakken and at Oslo Central Station.
The level of activity in Project Oslo has never been higher, in a project that will reach its peak next summer and should be completed by the turn of 2012/13.
More trains
– Is the major initiative in Oslo only concerned with redressing neglected maintenance work or could ‘Project Oslo’ lead to more trains?
– Basically, this is a straightforward maintenance project. However, capacity-increasing measures will be carried out in the Oslo tunnel by moving signals and exchange loops in 2012, explains Guttorm Moss.
New developments
The conductor rail from last summer will replace the traditional contact line in the Oslo tunnel between Oslo Central Station and Skøyen. This technology is completely new to Norway. A power supply plant with no moving parts reduces the need for maintenance.
Experience from both Germany and Switzerland would suggest that sections of track containing conductor rails are problem-free, although this new development will require the establishment of revised maintenance and supervision routines, explains Guttorm Moss. All plants require overhaul and inspection, he emphasises.
Construction Manager, Ernst David Øvrebø, of Norsk Jernbanedrift AS installed the new conductor rail in the Oslo tunnel between Oslo Central Station and Skøyen. Copper wire, which will provide power to the trains, is securely affixed to a solidly anchored aluminium profile mounted to the ceiling.
Axle counters
– In the ‘funnel’, at the tunnel entrance from Oslo Central Station towards Nationaltheatret station, where renovation work started in 2009, there have been very few stopping faults. Once we start utilising a new system that identifies a train’s location at any given time (train detection), we will have taken a major step forward. We are installing axle counters in the Oslo tunnel and on sections of track into Oslo Central Station, thereby spreading the inter-dependency across three disciplines and reducing the risk of any faults occurring that could result in a total shutdown.
Axle counters will replace track circuits, which depend on the track being well maintained, with no damage or wear and tear to the insulation between track and sleeper, and between adjacent track circuits. Guttorm Moss now sees an end in sight to this grey period, in which every available human resource has been utilised to rectify faults in order to permit trains to start running normally again. He looks forward to the day when railway workers can focus on preventive maintenance, thus channelling their energies towards the prevention of faults.
