SAPHEADS.
Diagram 1.Diagram 2.
T-shapedIsland Saphead
Diagram 1.
(a) Bombs can only be thrown from narrow trenches in the direction to which the trench is running. In order to have complete command of foreground with this type of Sap. it is necessary to make the cross-head too wide.
(b) The total area of Sap. may become effective zone from the fire of one bomb.
(c) Only two men can be employed at one time in constructing this type of Sap.