The contractor for the Shrewsbury–Chester line died in what year?
Shrewsbury–Chester line:  The engineer for the line was Henry Robertson, a partner in locomotive builders Beyer Peacock, while the contractor was Thomas Brassey in partnership with William Mackenzie and Robert Stephenson. Thomas Brassey: Thomas Brassey (7 November 1805 – 8 December 1870) was an English civil engineering contractor and manufacturer of building materials who was responsible for building much of the world's railways in the 19th century.
1870