However , because the electrification did not cost much , the branch was only able to have special two - or three-car trains running on it . This was because the power supply was not strong enough to support trains that had more cars . The low-cost nature of the electrification meant that the branch could only support special two - or three-car trains -- the power supply was simply not strong enough to support full-size trains , and the short platforms on the branch line would not have been long enough to support eight-car trains .