(covers information from several alternate timelines)
The Starfleet Corps of Engineers (also known as Starfleet Engineering or Starfleet Engineering Corps) was an agency in Starfleet tasked with solving specialized engineering problems. This agency was one of the oldest, with its origins dating back to the United Earth Starfleet. The agency was located at Fleet Operations Center in San Francisco, Earth, Sol Sector. They had a galaxy-wide reputation, including among the United Federation of Planets' enemies like the Dominion, as the undisputed masters of technological adaptation and modification. (DS9: "Rocks and Shoals")
After the USS Enterprise was damaged during their five-year mission, the Engineering Corps informed Captain Christopher Pike they had no idea when the Enterprise would be back online. (DIS: "Brother")
The Corps of Engineers was responsible for the construction of an underground laboratory complex on the Regula asteroid, where the second phase of the Genesis Project was conducted. (Star Trek II: The Wrath of Khan)
In an alternate timeline experienced by Harry Kim in 2372, he was approved a transfer to Starfleet Engineering Corps, where he worked as a starship design specialist, and was awarded the Cochrane Medal of Excellence for outstanding advances in warp theory. (VOY: "Non Sequitur")
In 2375, during the Dominion War, Klingon starships could be made immune to the Breen energy dampening weapon by adjusting the tritium intermix of their ships' warp cores. This "fix" would not work on Federation ships and Starfleet Chief Miles O'Brien forwarded his findings to Starfleet Engineering for more in-depth analyses. (DS9: "When It Rains...")
Fleet Operations Center, Sol Sector
In January of 2155, Starfleet officer C. Trinneer was a notable member of this agency. He was listed on one of the directory placards at Starfleet Command's Fleet Operations Center, Sol Sector. His office was located in room #5550. (ENT: "Demons", United Earth directory)
USS Enterprise (NCC-1701-B)
USS Enterprise (NCC-1701-D)
- Captain Andrew Probert
- Captain Herman Zimmerman
- Captain Richard James
- Captain John M. Dwyer
- Captain James Mees
- Captain Cari L. Thomas
- Captain Richard McKenzie
USS Pasteur (NCC-58925)
- Captain Richard James (previously worked on the Enterprise-D)
- Andrew Neskoromny
- Gary Speckman
- Louise Nielsen
- Captain James Mees (previously worked on the Enterprise-D)
- Alex Smutko
- Tom Purser
In the first draft script of Star Trek Generations, Geordi La Forge mentioned this organization in a remark he voiced about the Enterprise-D, after the ship's saucer section crashed on Veridian III. He stated, "The entire Starfleet Engineering Corps couldn't get her off the ground."
In the non-canon Star Trek novels, the Starfleet Corps of Engineers has its own series, Star Trek: SCE. The novels follow Captain David Gold and his SCE team aboard a Saber-class starship, the USS da Vinci, in the late 2370s. A temporally transplanted Scotty is the head of SCE.
The eBook The Future Begins states that the Starfleet Corps of Engineers was headed by the Starfleet Corps of Engineers Command Liaison, and its headquarters was based in the Tucker Memorial Building located on the grounds of Starfleet Headquarters.
The eBook Grand Designs states that the chain of command on SCE ships differed from other Starfleet vessels in that, while the head of the SCE team served also as the ship's first officer, this person also reported directly to the Starfleet Corps of Engineers Command Liaison.
In the second issue of the Doctor Who crossover comic Star Trek: The Next Generation - Doctor Who: Assimilation², an SCE team commanded by Captain Ochoa worked on the planet Naia VII mining materials vital to rebuilding Starfleet's defenses following the Battle of Wolf 359. They were ordered to meet specific quotas and to maintain those quotas despite the dangers, which led to reduced safety standards. Though an engineering achievement, the mining operation was difficult and dangerous, and the personnel particularly stressed. In 2368, a mine flooded, killing eight officers and injuring twenty-two.
In the reference book Star Trek: Federation - The First 150 Years, the corps was founded in 2156, as part of the United Earth Starfleet. They were originally an assortment of Starfleet engineers sent to build Starbase 1 in the Algeron system. The group informally called themselves the Starfleet Corps of Engineers. Once the base was completed, Admiral Samuel Gardner made the title official, as he wanted to keep the efficient crew together and move them to a new project.
The Pocket DS9 series novel Avatar, Book One states a team of thirty-five SCE engineers were usually assigned to Deep Space 9. However, following the Dominion War, only half of that contingent remained on the station, resulting in any qualified engineering personnel being put to work on a major refit of the station in 2376.