Freightmaster "Big Freight 13" DVD. Signal boxes and Freight trains: Barnetby is regarded as THE freight hot spot in the UK but how do the trains get there?. Big Freight 13 looks at the various freight flows on the three approach lines from Lincoln, Gainsborough and Scunthorpe and with large-scale resignalling planned for this part of Lincolnshire, all eight signal boxes located on these lines are also shown.