Signalling
The present Kilmarnock signal box is located north of the station, in the vee of the junction. Opened on 12 April 1976, it is a plain brick building containing an NX (entrance-exit) panel on the upper storey. It replaced four mechanical signal boxes in a scheme that saw the track layout greatly simplified. Originally, the box worked Track Circuit Block to Hurlford signal box and Scottish Region Tokenless Block over the single lines to Barassie Junction and Lugton signal boxes. Kilmarnock signal box was severely damaged in a suspected arson attack on 25 December 2006 but was repaired and returned to full operation within weeks.
The train service to Glasgow is partly limited by the single track northwards as far as Lochridge Junction (near Stewarton). This formerly extended all the way as far as Barrhead (with just one loop at Lugton) following track rationalisation in the early 1970s and restricted the frequency of services that could be operated. A "dynamic passing loop" (in effect a redoubling of the section between Lugton and Stewarton) was installed to help rectify this in 2009. The service frequency was increased to half-hourly from the 13 December 2009 timetable change.
New sidings were installed in 2009-2010 along a short section of the trackbed of the old route to Dalry to facilitate the increased coal train traffic.
Read more about this topic: Kilmarnock Railway Station