20170 and 20143 haul a loaded class 9 unfitted coal train from one of the Leen Valley collieries round the curve from Lenton North Junction to join the “main line” at Lenton South Junction on its way to either one of the older Trent Valley power stations or Toton yard. The train is made up of a mixture of 21 ton and 24 ton coal hoppers and 16 ton and 21 ton mineral wagons. Although a couple of the 16 ton wagons could be vacuum fitted (bauxite painted) the majority of the train is running unfitted and therefore the only braking available to stop this train of at least thirty two wagons (at least 650 tons) would be that of the two locomotives and the 20 ton brake van that would be bringing up the rear. 20170 was originally D8170 and was built in 1966. It was allocated to Toton from new and was withdrawn in September 1991 still allocated to Toton. 20143 was originally D8143 and was also built in 1966. It was allocated to Toton from new, survived a period in store in 1986 and was finally withdrawn in January 1992 also still allocated to Toton. As far as I can tell neither of these two locomotives were ever transferred and spent there whole life at Toton. They were broken up by MC Metals, Glasgow in June 1993 and August 1993 respectively.