much larger air conditioning pod on the roof, providing extra cooling to cope with the Thai climate. As with other Class 360 units, the trains were built in Krefeld, Germany - and were delivered from 2007, and testing in Bangkok began in March 2008. On 15 May 2012 the Thai Cabinet approved a budget of 5.2 billion baht for the SRT to order seven new, four car sets of Siemens Desiro rolling stock to be delivered by 2014. However, as of June 2013 no orders for new rolling stock had been placed. Four Express trains—four cars, red colour—were used for the two separate express service between Makkasan and Phaya Thai and Suvarnabhumi Airport. The fourth car is a baggage car with no passenger seating The other five City Line trains—three cars, blue colour—are used for commuter City Line service stopping at all eight stations on the Airport Line. Since the suspension of the Express Services in September 2014, all Express sets have been used as all stop City Line services. In 2017, the SRTET commenced refurbishment of the four Express trains to install seating in the fourth car in order to increase passenger capacity. New rolling stock order Approval was granted by the Transport Ministry (MOT) for the SRT to purchase seven new, four car sets of rolling stock in early 2012 due to overcrowding and the urgent need to provide extra rolling stock. During 2013, the MOT reviewed the purchase intention to consider cheaper Chinese rolling stock. In December 2013, the Thai Cabinet approved 4.9 billion baht for the seven new sets of rolling stock. As of mid-2014, a supplier had not been selected, but the SRT indicated its intention to invite bidders to tender for new rolling stock in September 2014. This was subsequently delayed with the SRT expecting to conduct an e-tender in April 2015 with a schedule to sign the contract by June 2015. However, a subsequent tender was suspended in 2016 after allegations of corruption surrounding the bidding process. In early 2017, the SRT Deputy Director stated that the new rolling stock would be tendered and a contract signed by the end of 2017. However, in January 2018 the SRT stated that the purchase would be delayed until the finalisation of the Eastern high speed line tender as rolling stock for this line would be used on the extended ARL. Stations Extension to Don Mueang