The continuing availability of the train system was thrown into doubt in 2006, with the release of the first 'remote control' train sets, which used battery-powered motors and did not have metal conducting strips in the tracks. For about a year, both systems were available, with the 9-volt system being marketed under a "Hobby Train" brand, available direct from Lego. By the end of 2007, the 9-volt system had been discontinued. RC Trains In 2006, Lego introduced a new line of remote control trains. In an effort to reduce the cost of the track, Lego returned to making track entirely made out of plastic (foregoing the metal rails), and introduced a new train motor powered by batteries and controlled via an infrared remote control. To enable the models to be battery-powered, the powered vehicles had a specific train base, which was 6 studs wide to accommodate a snap-fitting battery pack. The new battery-powered system had some advantages over the 9-volt trains; it allowed more than one train to be controlled independently at once, and track layouts did not have to worry about matching up the polarity of the rails. However, the infrared remote control introduced problems of range, and the use of batteries required them to be replaced or recharged at regular intervals. The lower production costs of the plastic track allowed Lego to introduce a new double crossover track piece (first produced in 2007, now discontinued), and the track itself was available at a cheaper price than the 9-volt track. The Power Functions Era (2007-present) On 1 October 2007 Lego announced that they would discontinue both the 9-volt and the RC train formats in favour of a new system. The announcement cited a lack of sufficient demand for the 9-volt product line to be profitable, caused partly by the need to replace key machinery and place minimum orders for motors and power regulators. The new range was announced as launching in 2009, and would use the new 'Power Functions' system also used in the Technic line, which would allow the company to "amortize the development and on going cost across multiple themes". A new train was introduced in the summer of 2009 called the "Emerald Night", modelled on a steam locomotive. This train was sold without a motor as set number 10194. Necessary part numbers were listed on the rear of the box to convert the Emerald Night to