Bowsaw
From DT Online
Bowsaws are a type of framesaw. Modern Bowsaws have a metal tube frame with very coarse blades about 600mm long. They are used mainly for rough cutting of logs and shrubbery with few applications within a D&T workshop,
Traditional Bowsaws consist of a wooden frame and were used for cutting curved shapes in thicker materials than for a Coping saw and Fretsaw but their use in D&T workshops has been much replaced by a Bandsaw or Jigsaw.
Typically, blades are about 250 to 300mm long and from 10 to 24 Teeth per Inch (TPI). The blade is kept in tension by twisting a loop of cord by means of a length of wood passing through it to create a tourniquet or turnbuckle type action.
They are normally used as shown with both hands gripping one of the handles - two handles are provided to allow the blade to be turned and cut in different directions.