Fallout Wiki
Fallout Wiki

The Switchboard is an unmarked location in the Commonwealth in 2287.


Before the Great War, the bunker was used as a secret base of operation for the Defense Intelligence Agency as can be seen written on the floor in the main hall. It was later discovered by the Railroad, who repurposed it as their headquarters. They also uncovered the Predictive Analytic Machine, a pre-War advanced robot designed to predict the future with extreme precision and accuracy, using the most complex formulas, methods, and algorithms based on the data provided.[Non-canon 1]

It was not long before the Railroad's enemy, the Institute, discovered the location. Synths were later dispatched to wipe out the Railroad, forcing them to relocate to the crypts beneath Old North Church, leaving the bunker in the hands of the Institute.


The entrance is unmarked but can be easily found when looking for a drainpipe, found a short distance from the train wreckage located directly west of the Lexington map marker. Start at the train carriage that sits on its side in the middle of the road and look east, just below the road, for the drainpipe. The exit is an elevator in the basement of a Slocum's Joe, a pre-War doughnut shop west from Super Duper Mart.

Entry can be gained either by hacking a master locked terminal oneself at any time or by having Deacon do it during the Tradecraft quest. It is not necessary to be on the quest in order to obtain the perk magazine.

Clearing the location takes one on a journey through utility tunnels until a hole in the wall provides access to the bunker. All Railroad agents present are dead, but some of their defense systems still function and can be activated to help fight the synths that have invaded. After working through the opposition, one can restore power to the basement elevator to allow an exit through Slocum's Joe.

If Tradecraft is active, Slocum's Joe will be guarded by synths, turrets, and mines.

Railroad members

Exploring the Switchboard's tunnels, one will encounter many deceased Railroad characters:

Notable loot

  • Two fusion cores - One in the lower level generator room, near where the sewer entrance empties into the building, the other right near the end, behind a locked security gate, just before the elevator that leaves the area.
  • U.S. Covert Operations Manual issue #1 - In the central area flanked by two sets of staircases. Go up the stairs, it will be on the right side of the desk. The room overlooks a computer-filled work area.
  • Carrington's prototype - In the vault.
  • Two hazmat suits - Found on a table on the second floor, in the room where Carrington's prototype is located.
  • One mini nuke - On a shelf to the right of Carrington's prototype.
  • Two Stealth Boys - On a metal shelf with the prototype.
  • Deliverer - A silenced pistol obtained during the Tradecraft quest.


  • If one selects "system diagnostics" on the turret section of the elevator control terminal, it says that the turret it is connected to is both online and is 53169116662270134434550000000000000000.00 meters away, or roughly 5.62 * 1021 light years.
  • One of the terminals in this area lists DEFCON reports, and suggests that it may have been the Chinese that was the first to strike during the Great War (terminal specifically states "poss." as in "possibly"). The last entry shows that the system went offline at 09:47 hours, the same time shown on most of the clocks in the Commonwealth and the Capital Wasteland.
  • In the databanks room is a poster which shows mixed and matched robots. These are early prototype designs of P.A.M.
  • The Railroad's casualties that died during the Institute's raid are as follows: Roger, Maven, Ms. Boom , Sly Nicholas, Francis O'Dell, Mr. Mathers, Kelly K., Songbird, Beatrice Bell and Tommy Whispers.
  • When traversing through the former Railroad base, the Railroad theme will still play in the background.
  • When at this location, companions make comments, which are activated at the foyer of the agency.
Location comments
Character Comment
Cait "What the hell is the "Defense Intelligence Agency?""
Codsworth "The Defense Intelligence Agency? I wonder how much they knew before the first bombs fell."
Curie "Oh, it's a secret base. Just like the detective books."
Danse "I don't recall the Brotherhood having any records on this agency. We should investigate further."
Deacon ""
John Hancock "Defense Intelligence Agency, huh? Think they might've dropped the ball."
Nick Valentine "Nothing but a tomb for old spooks."
Piper Wright "Could probably spend a lifetime sorting through all this old intel."
Preston Garvey "Huh. Just like I always imagined a secret spy base would look like."
Robert MacCready ""Defense Intelligence Agency." Heck of a lot of good they did."
X6-88 "This place reminds me of the SRB office."


The Switchboard appears only in Fallout 4.

Behind the scenes

The Switchboard is likely based on "The Notch", a Post-Attack Command and Control System Facility located under Bare Mountain in Hadley, Massachusetts, designed to survive a nuclear war and maintain communications links for the US Military. The interior is very similar, including the glass fronted balcony the player sees when they enter the facility.


Xbox OneXbox One When using the terminal in the main hall underneath the office with the U.S. Covert Operations Manual, it is possible to get stuck in between the chair and the desk. Saving and reloading will fix this.[verified]




  1. Fallout 4 Vault Dweller's Survival Guide Collector's Edition p. 273: "[1.34] SWITCHBOARD ENTRANCE (SEWER)
    You can go into the sewer entrance to the Switchboard—the Railroad's old base of operations—from here, ideally during the quest. Your path soon ends at a terminal (Master). The main entrance—extremely well guarded during the quest—is underneath Slocum Joe's in Lexington (Primary Location 1.22) and connects to here. Consult that location for the interior map of the Switchboard."
    (Fallout 4 Vault Dweller's Survival Guide Map)