Abstract: For the installation of an anchor member at a location below a water level through a retaining wall into a soil formation for supporting the wall, a drill mount is pivotally mounted about a horizontal axis on a retaining member secured to the wall. The drill mount can be pivoted between a drilling position inclined downwardly toward the wall and an upwardly extending loading position where the drill mount is accessible above the water level. A cable line secured to the drill mount pivots it between the drilling and loading positions. A drilling machine is displaceable on a sliding carriage along the drill mount. A drilling tool inserted into the drilling machine is used to drill an opening through the wall. Subsequently the drilling tool is replaced by a borehole pipe and the pipe is driven through the wall opening into the soil formation.