This window has ordinary single light check-rail sash held in position with spring bolts in place of sash pulleys and weights. This is a faithful replication of the original window, and this type of construction was common for cheap work. The frame has a one-piece sill and drip cap with bed moulding. The casing is 1-1/8" thick in order to accomodate screens and storm sash. Note that the sill projects slightly past the width of the casing.