- See Sinclair for other articles with titles that contain, either by relationship or by coincidence, this character's surname.
Born in 2234, Sinclair began his Starfleet career as one of many talented engineers of Scottish heritage. In an astronautics class, Sinclair was frequently antagonized by instructor Montgomery Scott, who regarded Midshipman Sinclair as a kindred talent and wanted to inspire the young man to succeed. Because of this pressure, Sinclair has a fervent desire to prove himself as a superior engineer if ever compared to the older Scotsman, including a desire to push a starship to a greater efficiency rating that Scott's eventual assignment, the Constitution-class USS Enterprise.
Sinclair is usually disheveled, wearing regulation coveralls bearing signs of wear, with smudges of grease and mechanical substances on his clothes, face and red hair at most all times he is encountered by crewmates, in or out of the engineering compartments. At one point aboard the USS Lexington, Sinclair even attended a diplomatic function without visiting his quarters to change clothing, wearing greasy coveralls while greeting a distinguished ambassador.
Sinclair is also known to operate a non-regulation still in the engineering areas, which is largely overlooked by other members of the senior staff, reportedly because of the fine alcohol that is created for the ship's crew as a result of this endeavor.
As a Starfleet engineer, Sinclair's 2260s personnel file noted proficiency in using and working with the technology of computers, deflector shields, transporters, warp engines, life support systems, directed energy weapons and other starship weapons, as well as other electronics and damage control procedures. Thonen is fluent in Andorian languages and Federation Standard, and has been schooled in Caitian language at a basic level.
In 2269, Sinclair's USS Hastings and crew were assigned to ferry representatives from the Gorn Alliance to Maltharin II in an attempt to end a dangerous situation, to halt attacks on the Federation by renegade Gorn, who were later encountered by the Hastings. (FASA RPG module: Demand of Honor)
- The exact outcome of the mission is not certain, as it was in the hands of the RPG player whether or not the situation could be satisfactorily resolved.
|location||assignment||dates||rank or rate||assignment insignia||rank insignia|
|Starfleet Academy||student officer||2250s||cadet-midshipman|
|USS Hastings||chief engineer||late 2260s||lieutenant commander|
|USS Lexington personnel|
|USS Lexington (NCC-1709)||J. Baila • Berriman • P. Coss • D.W. Davidson • Garth of Izar • Ito • T. Ivari • L. Kelso • R. Leslie • W.C. Perinal • M. Rousseau • W. Samuels • D. Sinclair • L. Sterling • C. Stuart • N. Uhura • D. Watley • R. Wesley|
|USS Lexington (NCC-14427)||Declan Keogh • Manojlovich • Rosita Pérez|
|USS Lexington (NCC-61832)||T. Allenby • H. Anderson • Antonacci • Audrey • G. Ben Zoma • Bowdren • T. Cadwallader • S. Carson • Cavanaugh • J. Cox • Eberling • Fornnel • Gaines • F. Galloway • Griscom • Halprin • Hasegawa • G. Jenson • P. Joseph • Kumagai • Leff • E. Lense • R. Mithra • Moytulix • Pridemore • Rodgers • Soriano • J. Turner • Twistekey • Man-Fai Wan • Wilhoite|
|USS Lexington (Steamrunner-class)||A. Jago|
|USS Hastings personnel|
|Armand • Cochrane • Collingwood • Immanura • Lanier • Markham • Mitchell • Mueller • Obote • Ortez • Petrovich • Saalik • Sinclair • Stuart • Thanas • Thomas • Thonen • Tracey • Travers • Tremaine • Watanube • Winder • Wolfe|
The time period of the RPG adventure is placed at two years following the Cestus III incident shown in TOS episode: "Arena", established as being in 2267 by most sources. This allows us to extrapolate Sinclair's birthdate (his 35 years of age subtracted from the probable mission date of 2269) and likely dates of Academy education, as well as his service on the Hastings and other assignments.