 The trains were put back into service on 13 July . The trains were only allowed to operate at conventional speeds and had to go through a weekly inspection . At the same time , NSB removed the surcharge on the Signatur services . NSB stated that they were considering revocation the purchase of the four trains which were still to be delivered . In addition to problems with axles , there were also issues with the braking and air conditioning systems . In mid @-@ August , the tilting mechanism was disabled on all the trains because of a fault in a bearing in the connection between the bogie and the body which allowed for a movement of several millimetres ( at least 0 @.@ 1 in ) . In late August , problems occurred with the braking system causing the trains to automatically brake even when not receiving such signals from the automatic train stop system . 
