Embankment protection by pitching (hand placed rip rap) consists of large stones placed by hand on the batter. Smaller rock fragments are placed in the voids between the larger rocks.
The pitching may also be cement grouted, in which case a sand cement grout (usually 3:1) is broomed or rodded into the voids between the stone. The finished product is rigid but has very little strength. Pitching requires adequate, firm support from the embankment and must be protected from undermining at the toe and ends. Some joints should be left ungrouted to prevent uplift from water pressure.
The quality of stone used should be similar to that used for rip rap except that the stone needs to be selected to obtain more uniformly sized and cubically shaped pieces to facilitate hand placing.
During construction the shape of the batter is controlled from string lines stretched between timber profile boards set to the batter profile.
Pitching has been used extensively in the past as a form of embankment protection, however its construction is labor intense. It is more rigid than dumped rip rap and consequently does not have an equal capacity to adjust to any movement of the supporting material, or to arrest an undermining scour.