This is a detail of the Tilford, South Dakota's preserved openwire line which used drop bracket transpositions (01-transposition scheme) for voice frequency exchange lines. This shows the typical placement of brackets and associated ties, Hemingray 42 insulators and pin positions evacuated for these transpositions. This is from the last open wire line in Northwestern Bell's five state area (now part of CenturyLink). This line was preserved through the concerted efforts of D. G. Schema over a two and one half year period.