10.5.3. Inclined-impact Cisterns For such cisterns, the glacis is carried straight down into the cistern and reliance is placed upon the effectiveness of the jump forming on the glacis for dissipation of surplus energy. However, the vertical component of the supercritical jet is not affected by the impact and, hence, energy dissipation is inefficient.
The dimensions of such cisterns are also decided in the same way as in the case of horizontal-impact cisterns. But, because of imperfect energy dissipation, the cistern has to accommodate the roughening devices and, hence, the cistern length for this class of cisterns is more than that for the preceding classes of cisterns.