Lean-to rigging apparatus for shaft installation

A lean-to rigging apparatus comprising:

• a spanning beam having a first end, a second end, and a length measured from the first end to the second end;
• a sill support structure rigidly attached to the first end of the spanning beam and configured to abut a first surface in a plurality of positions;
• a wall support member attached to the second end of the spanning beam and configured to abut against a second surface that is opposite the first surface;
• and
• at least one hoist connector arranged on the spanning beam, wherein the hoist connector is configured to allow a connection to a hoist device;
• wherein:
• the length of the spanning beam is longer than a horizontal distance measured from the first surface to the second surface along a direction substantially perpendicular to the first surface,
• the apparatus is configured to define an angle measured from the spanning beam to the direction when the sill support structure abuts the first surface and the wall support member abuts the second surface, and
• the angle is one of a plurality of angles at which the spanning beam is configured to be oriented with respect to the direction, the plurality of angles corresponding to the plurality of positions of the sill support structure.