Eigenbrodt and his production crew also had to simulate the actual wreckage using real railcars placed along a stretch of open track.
Suspecting terrorism, the National Transportation Safety Board (NTSB) calls FBI Special Agents Don Eppes (Rob Morrow), David Sinclair (Alimi Ballard), Colby Granger (Dylan Bruno), and Nikki Betancourt (Sophina Brown) to the scene.
Don leaves David and Colby at the scene to rescue survivors while he and Nikki talk to a conductor who had jumped out of the train before it crashed.
Nikki attempts to tie the conductor's deceased crew-mate, who stayed on the crashing train trying to apply the brakes and has Syrian origin, to a terrorist plot.
At CalSci, Dr. Charlie Eppes (David Krumholtz), Don's younger brother and an FBI math consultant, demonstrates a group of swarmbots, robots which can gather information using infotaxis, the use of information to create a map of the robots' environment, to Don and their father, Alan Eppes (Judd Hirsch).
Don and Nikki question several other people, including a former member of the mob who is now a legitimate businessman, the freighter train's owner, and a rail master.
During the interview, Don learns that the rail master has had a lack of sleep and left his post a couple of minutes before the crash to rouse himself.
Series production designer Bill Eigenbrodt and the crew found a private track about 30 minutes outside of Los Angeles which contained a bowl.
[2] Using a crane, Eigenbrodt and the art crew spent two days arranging the cars to give the appearance of a train wreck.
The site frightened director Rod Holcomb, and he became concerned about the actors' safety inside the cars once filming started.
Eigenbrodt built a set on the Numb3rs soundstage at the LA Center Studio for the actors to climb through.
To maintain a sense of realism, several area firefighters and paramedics assisted with the technical aspects of the rescue.
Later, to simulate the movement of the bots through the crash site, the art department attached candlecams to sticks with wheels.
[1] "Thirty-Six Hours" was originally scheduled to air fourth, placing it in the middle of the storyline about Charlie's security clearance.
In the original script, Charlie volunteered at the scene with his friend and fellow FBI consultant Dr. Larry Fleinhardt (Peter MacNicol).
[4] While Amita attempted to discover the cause of the crash, Alan expressed concern about Charlie being punished for helping investigators without a security clearance.
[2] Jeffrey Robinson of DVD Talk highlighted "Thirty-Six Hours" in his list of "exciting episodes".