Captain Callahan, a native of North Carolina reported for active duty in June 1983 where he subsequently completed basic training at Recruit Training Command in San Diego, California. He then attended Basic Electronics School and Radioman “A” School at Naval Training Command San Diego, before transferring to Basic Enlisted Submarine School in Groton, Connecticut.
In February 1985, Callahan reported onboard USS HENRY L. STIMSON (SSBN 655) (GOLD) where he advanced through Radioman First Class, earned his Enlisted Submarine Warfare and completed eight strategic deterrent patrols. He reported to the staff of Commander, Submarine Squadron EIGHTEEN in August 1989 as part of the squadron communications department and advanced to Chief Petty Officer in September 1991.
In March 1992, Callahan returned to sea duty onboard USS JOHN C. CALHOUN (SSBN 630) (BLUE) and following decommissioning, reported onboard USS MARIANO G. VALLEJO (SSBN 658) (GOLD) completing another three strategic deterrent patrols. Callahan reported to the staff of Fleet Technical Support Center, Kings Bay Detachment in March 1994 and subsequently selected to the Limited Duty Officer program. He commissioned as an Ensign in July 1996.
In September 1996, Callahan reported to the USS SIMON LAKE (AS 33) forwarded deployed in La Maddalena, Italy, serving as Communications and Electronics Material Officer until his transfer in November 1998. He reported to Trident Refit Facility (TRF) in Kings Bay, Georgia, serving as the Command and Control Systems Digital Repair Officer from March 1999 until April 2001.
Callahan returned to sea duty in May 2001 as the Weapon’s Officer onboard USS TOPEKA (SSN 754) homeported in Pearl Harbor, Hawaii. Following successful completion of his department head tour, he reported to the staff of Commander, Submarine Force, US Pacific Fleet as the Electronic Material Officer. Callahan reported to Millington, TN to be the junior LDO/CWO Officer Detailer at the Bureau of Naval Personnel (PERS 42) from May 2006 until December 2009.
Callahan next assumed duties as the TRF Weapons Repair Officer in January 2010 until fleeting up to Executive Officer in July 2011. In June 2013, he assumed duties as the Executive Officer of Naval Submarine Base Kings Bay. In June 2015, he assumed duties as Executive Officer of USS FRANK CABLE (AS 40) homeported out of Guam. He became the Officer of Community Management for the LDO/CWO Community in Millington, Tennessee May 2017 – May 2020 and promoted to CAPT 1 September 2018. July 17, 2020 he assumed duties as Commanding Officer, Naval Weapons Station Earle.
CAPT Callahan holds a bachelor’s degree in Business Management from Grantham University (Summa Cum Laude).
Callahan is authorized to wear the Meritorious Service Medal (five awards) Navy & Marine Corps Commendation Medal (five awards), Navy & Marine Corps Achievement Medal (eight awards), Navy Good Conduct Medal (three awards), Global War on Terrorism Service Medal, National Defense Service Medal (two awards), and Military Outstanding Volunteer Service Medal along with numerous campaign and service ribbons. In addition, he earned his Enlisted Submarine Warfare and Strategic Deterrent Patrol Insignia with two silver stars. He is qualified to wear the Officer Submarine and Surface Warfare Insignias.