Crump weirs are control structures. They are broad-crested weirs. The triangular shape of the weir has several advantages, e.g. only minor siltation occurs upstream of the weir. a part of sediment transport can flow over the weir. In addition, aquatic creatures can often pass this weir upstream.
HM 160.33 is a weir according to E. S. Crump with defined inclinations both upstream and downstream. The Crump weir is preferably used as a sill. Sills are used to decrease the flow velocity to avoid erosion. A sill is well dimensioned for the prevailing discharge when there is no hydraulic jump.