Federal Railway Authority
In July, September and October 2012 trains derailed on the exit towards Feuerbach, which had been rebuilt in the course of the Stuttgart 21 project. Following the latest derailment, platform tracks 8, 9 and 10 were blockaded. In January 2013, Deutsche Bahn justified the derailments as being the result of "malfunctioning carriage buffers". A short-term technical solution developed by DB was rejected by the Federal Railway Authority. The suspension also led to far-reaching delays of S-Bahn and regional services. On 22 January 2013, track 10 was conditionally released for service. Only multiple units and hauled trains could use it. According to Federal Railway Authority data, the unrestricted clearance of the track was not possible on the basis of documents that had been submitted. According to Deutsche Bahn in December 2014, an end to these restrictions was not foreseeable.