the station has 17 platforms, numbered 1 to 17, and arranged in two groups. platform 1, the northernmost platform. the station's main entrance is from st. john's hill, into a foot tunnel which is 15 ft (4.6 m) wide. it runs under the eastern end of the 17 platforms, and to a northern exit, which has restricted opening hours. the foot tunnel becomes very crowded during the morning and evening rush hours, and ticket barriers at the end of the tunnel are a particular pinch point.