5.9.4.1. Kennedy’s Gauge Outlet This outlet was developed by RG Kennedy in 1906. It mainly consists of an orifice with bellmouth entry, a long expanding delivery pipe, and an intervening vertical air column above the throat (Fig. 5.5). The air vent pipe permits free circulation of air around the jet. This arrangement makes the discharge through the outlet independent of the water level in the watercourse. The water jet enters the cast iron expanding pipe which is about 3 m long and at the end of which a cement concrete pipe extension is generally provided. Water is then discharged into the watercourse. This outlet can be easily tampered with by the cultivator who blocks the air vent pipe to increase the discharge through the outlet. Because of this drawback and its high cost, Kennedy’s gauge outlet is generally not used.
