Telegraph block instrument
Telegraph block instrument; NLR (Tyer's) Station-Bay Indicator. Absolute/sending 4-needle (all red) 2-position/2-indication "Bay Blocked/Bay Clear", each with its brass double-plunger assembly below (LHS originally red?; RHS white) and labelled (L to R): "No. 5-8" on scallopped-cornered (small LNWR-Style) ivorine plates. Ex Broad Street equipment, Skinner Street No 2 line.