Drilling rig mast erection system

A drilling rig mast erection system, comprising:

• a mast support shoe fixedly attached to a drilling rig substructure, said mast support shoe comprising a support shoe pinned connection;
• a bottom mast section of a drilling rig mast, said bottom mast section comprising a first mast pinned connection that is adapted to be pivotably connected to said support shoe pinned connection;
• and
• a mast positioning apparatus that is adapted to pivotably position said bottom mast section so that said first mast pinned connection is positioned adjacent to said support shoe pinned connection, said mast positioning apparatus comprising:
• a bottom mast support spreader comprising a first end and a second end, a first spreader end pinned connection positioned on said bottom mast support spreader at said first end, a second spreader end pinned connection positioned on said bottom mast support spreader at said second end, and a first mast erection apparatus pinned connection positioned on said bottom mast support spreader, said first mast erection apparatus pinned connection being positioned on said bottom mast support spreader between said first spreader end pinned connection at said first end and said second spreader end pinned connection at said second end, wherein said first spreader end pinned connection is adapted to be pivotably connected to said bottom mast section at said first spreader end pinned connection;
• and
• a mast erection apparatus having a first end that is adapted to be pivotably connected to said bottom mast support spreader at said first mast erection apparatus pinned connection.