Transporter chief Pitcairn was a male Human Starfleet crewmember in the 23rd century. He served in the operations division aboard the USS Enterprise in 2254 under the command of Captain Christopher Pike. Pitcairn was one of the ship's transporter chiefs.
That same year, Pitcairn operated the transporter console for the landing parties beaming to and from Talos IV. (TOS: "The Cage")
The part of Pitcairn was played by Clegg Hoyt, but his voice was supplied by Robert C. Johnson.  "The Cage" Director Robert Butler approved of casting Hoyt as Pitcairn, commenting in retrospect, "
That was a good move, I think, because he always brought a reality to anything he did." (The Star Trek Interview Book, p. 99)
The utility jumpsuit
Pitcairn wore had no indication of rank and was worn by both non-commissioned and commissioned officers; therefore, his rank cannot be determined from his uniform.