Complex sentence: Two Class 16CRs, numbers 813 and 818, were sold to Dunn's Locomotive Works, to be employed at Delmas Colliery, and were at one time seconded to Durban Navigation Collieries (Durnacol) in Natal.
Split into simpler sentences: Two Class 16CRs, numbers 813 and 818, were sold to Dunn's Locomotive Works to be employed at Delmas Colliery. They were at one time seconded to Durban Navigation Collieries (Durnacol) in Natal.