A pipe handler (50, 350) for handling pipe in a fingerboard (16, 316), the fingerboard (16, 316) having a plurality of spaced-apart fingers for supporting a plurality of pieces of pipe and a plurality of rows, each row positioned between each pair of adjacent fingers, the pipe handler (50, 350) comprising: a pipe handling head (60, 360); an extension apparatus for moving the pipe handling head (60, 360), the extension apparatus having a first end and a second end; a carriage apparatus (52, 352); wherein the first end of the extension apparatus is connected to the pipe handling head (60, 360) and the second end of the extension apparatus is connected to the carriage apparatus (52, 352); a track structure, the carriage apparatus (52, 352) movable on the track structure so that the pipe handling head (60, 360) can access pipe on the fingerboard (16, 316); and a locking apparatus (70, 370) for selectively locking the carriage apparatus (52, 352) in place on the track structure, wherein the locking apparatus (70, 370) is configured to align the pipe handling head (60, 360) with the rows of the fingerboard (16, 316), characterised in that the locking apparatus (70, 370) includes: a lock structure (24, 324) extending along the track structure, wherein the lock structure (24, 324) includes a plurality of v-shaped wedge members (25, 325) and a plurality of valleys (27, 329), wherein each valley (27, 329) is disposed between each pair of adjacent wedge members (25, 325); an extendable rod or a roller forced into engagement with one of the valleys (27, 329) to lock the carriage apparatus (52, 352) in place on the track structure and align the pipe handling head (60, 360) with one of the rows of the fingerboard (16, 316); and wherein the wedge members (25, 325) are configured to guide the extendable rod or roller to the valleys (27, 329). a pipe handling head (60, 360); an extension apparatus for moving the pipe handling head (60, 360), the extension apparatus having a first end and a second end; a carriage apparatus (52, 352); wherein the first end of the extension apparatus is connected to the pipe handling head (60, 360) and the second end of the extension apparatus is connected to the carriage apparatus (52, 352); a track structure, the carriage apparatus (52, 352) movable on the track structure so that the pipe handling head (60, 360) can access pipe on the fingerboard (16, 316); and a locking apparatus (70, 370) for selectively locking the carriage apparatus (52, 352) in place on the track structure, wherein the locking apparatus (70, 370) is configured to align the pipe handling head (60, 360) with the rows of the fingerboard (16, 316), characterised in that the locking apparatus (70, 370) includes: a lock structure (24, 324) extending along the track structure, wherein the lock structure (24, 324) includes a plurality of v-shaped wedge members (25, 325) and a plurality of valleys (27, 329), wherein each valley (27, 329) is disposed between each pair of adjacent wedge members (25, 325); an extendable rod or a roller forced into engagement with one of the valleys (27, 329) to lock the carriage apparatus (52, 352) in place on the track structure and align the pipe handling head (60, 360) with one of the rows of the fingerboard (16, 316); and wherein the wedge members (25, 325) are configured to guide the extendable rod or roller to the valleys (27, 329). a lock structure (24, 324) extending along the track structure, wherein the lock structure (24, 324) includes a plurality of v-shaped wedge members (25, 325) and a plurality of valleys (27, 329), wherein each valley (27, 329) is disposed between each pair of adjacent wedge members (25, 325); an extendable rod or a roller forced into engagement with one of the valleys (27, 329) to lock the carriage apparatus (52, 352) in place on the track structure and align the pipe handling head (60, 360) with one of the rows of the fingerboard (16, 316); and wherein the wedge members (25, 325) are configured to guide the extendable rod or roller to the valleys (27, 329).