Complex sentence: Originally Springside had a siding and a signal box, operated by a signalman who came down fron Crosshouse on the shunt and once the day's work had been completed the signalman would catch the next available train back to Crosshouse.
Split into simpler sentences: Originally Springside had a siding and a signal box, operated by a signalman who came down fron Crosshouse on the shunt. Once the work had been completed the signalman would catch the next available train back to Crosshouse.