This museum is unique–there’s only one in the world.

From the 1950s to the 1980s, the US had a force of 54 Titan II intercontinental ballistic missiles based in silos in the southwest. Each missile was armed with a 9-megaton W-53 nuclear warhead.

In the 1980s, as part of the strategic arms agreement with the Soviets, the Titan II silos were dismantled. Only one, near Tucson AZ, was allowed to remain, as a museum. Today it is the Titan Missile National Historic Site.

Here are some photos.

The museum

A diagram of the site. On the left is the control room and crew quarters. In the middle is a storage and maintenance center, and on the right is the silo. In the Titan stations, each missile had its own control room. On the later Minuteman sites, one control center would handle ten different missiles.

When the site was operational, all you would have seen was a barbed-wire fence surrounding the heavy silo cover

There would have been this warning sign, but no armed guards

The site was surrounded by these small radar antenna, known as “tipsies”. They detected moving objects, such as intruders, and sent an alarm to the control room. The control room would then radio the nearby airbase to send armed security personnel to check it out.

Normally, the 750-ton silo cover would close off the opening to the missile, protecting it. It slid open moments before launch.

To go on duty inside the missile control center, you entered the site through this gate. To get in, you had to use the dedicated phone to call the control center, identify yourself, give a special code, and have them unlock the entrance. It was the first of four such phone calls you needed to get inside.

Communications antennae. Most of these would normally be retracted underground and protected by a steel door, and extended only for use

This was the entrance to the underground control complex. Unlocking the steel door required another phone call and code to the control center.

Upon entering the control complex, you descended 60 feet on metal steps

The first blast door. You had to call the control center and have them unlock the door automatically.

The blast door weighs several tons, but it is so finely balanced that this nine-year old girl can move it

Immediately there is another blast door and another phone call. The hinges were held by heavy steel pins. There were cameras located here so the control room could make sure you were not being coerced or followed by any potential enemy. If all was well, the pins were retracted and the door could be opened.

This corridor leads to the control room

The control room. There were two teams of two in the control center at any one time, each doing a 24-hour “alert”. One crew was on duty for 12 hours while the other was sleeping in the crew quarters upstairs.

Air Force policy required everyone in the control room to be accompanied by somebody else at all times, as a security precaution

The air intake. Air from outside was filtered to remove any potential chemical agents or radioactive particles.

All of the structural elements of the complex were shock-isolated—they sat on big steel springs to absorb the shock wave caused by any nearby nuclear explosions from incoming weapons

If a launch order were to come, it would take the form of a coded message that each of the two-man crew copied down. If they both agreed that the code was valid, they would find the appropriate orders on these printed cards. The order told them what time to launch their missile (missile launches were timed so that the explosion of one warhead would not affect the flight path of other warheads).

As a security precaution, one of the valves that fed fuel to the Titan II’s engine was locked into place. To ready the missile for launch, the crew commander had to enter a security code into the computer which unlocked the valve. (The docent here demonstrating how the valve worked is Marge, who served as a crew commander here at this particular silo back when it was operational.)

At the indicated Zulu Time for launch, each crew member unlocked one of these padlocks to open the cabinet where the launch keys were stored.

Launch key inserted

There were two key stations, far enough apart that one person could not reach both—it took two people to launch. The keys had to be turned within two seconds of each other and held for four seconds.

Missile enabled. At this point, the launch process happens automatically and cannot be stopped.

Missile away. It takes 58 seconds to go from launch key turn to take-off. The missile would then take about 30 minutes to reach its target in the Soviet Union.

This corridor leads from the control room to the missile silo. The launch crew had no reason to enter this area, and most of them never even saw the missile they were operating. But the missile was serviced regularly by technicians and maintenance people.

Like the rest of the complex, the access corridor was shock-proof. The slack in these cables allowed them to bounce around and stretch without breaking.

At the end of the corridor was the missile silo. Retractable metal decks gave access to various parts of the missile.

The missile in its silo

The missile in its silo, seen from above