 In 1993 , NSB test @-@ ran an X2 train on the Randsfjord Line , and between 29 September and 21 December 1996 , ran a unit in regular service on the Sørland Line . On 23 February 1995 , NSB signed a contract to purchase 16 Class 71 trains for use on the Airport Express Train on the Gardermoen Line . The contract included two options , one for 16 trains for intercity traffic and one for 6 trains for regional traffic . The reason for using the same type of train as the Airport Express Train , was to reduce maintenance and operation costs through having a unified fleet . The options would only modify the trains slightly ; they were primarily designed for the airport service and any optimization for intercity and tilting technology was secondary in the design process . The first option was taken out on 5 March 1997 . 
