The S.G.C.'s leading technician and engineer, Master Sergeant "Sly" Siler keeps the Stargate and the base facilities up and running. Frequently encountering mischief, he has been known to be subject to more than a handful of scraps, resulting in his share of scrapes and bruises. He has been electrocuted at least once and knocked out of the way or slammed into the base concrete on several occasions. He's frequently found in the base infirmary, with a bloody nose or broken bone.
Despite his accident-prone nature, Siler has remained a vital aspect of base operations from the very beginning. Always busy, he is often seen clutching a wrench.
Solitudes - When the Stargate breaks down, Siler arrives on the scene to properly recharge each individual chevron to its proper power output.
Upgrades - Siler's arm is broken after a suped-up O'Neill accidentally shoves him over a railing.
Window of Opportunity - Unknowingly stuck in a time loop, Siler stumbles into Dr. Jackson on several loops, showering papers in every direction.
Entity - Siler must help defend the base from an alien life form that takes up residence in the computer.
Redemption, Part 2 - When Jonas and Sam conceive a plan to launch the Stargate into space to save Earth, Siler must help remove the activate gate from the base using an overhead crane.
The Changeling - In Teal'c's dream state, Siler is a fireman, responsible for opening the doors so the trucks can leave the firehouse.
Heroes, Part 1 - Siler becomes the test subject for Dr. Lee's new ceramic polymer vest shield, taking a direct staff blast by Teal'c.
Rising, Part 1 - Siler helps Dr. McKay connect a Zero Point Module to the S.G.C.'s Stargate power systems, in order for the Atlantis expedition to gate to the Pegasus Galaxy.
Zero Hour - Siler helps Dr. Lee fight off an alien plant that spreads wildly throughout the base.