 The southern tunnel has a plaque on its west face "Dated in 1848", but as the tunnel is shown on earlier tithe maps, that is believed to be a rebuilding date.Workshops and a weighbridge were built near New Line Farm to the east of the road and weathering beds were also located here; these were dumps of newly dug clay which had to weather for up to a year to allow the clay to break down to make it workable.In about 1881 new pits were opened up at Norden to the south east of the New Line Farm works.