Site Penetration: Getting In
 While you have been opening and inspecting the Launcher Equipment Building, your SET guards have opened the first lock to allow access to the silo. Here one of the guards stands to the side of the 2000lb Personnel Access Hatch (PAH), which lies behind the blue "A-circuit" lock he has opened and removed. Your Team Member has erected the safety barrier poles and cranked open the Personnel Access Hatch using the manual screwjack - a 5 to 15 minute job, depending on how rusty the jack is, and great aerobic exercise. This hatch could not be opened without first opening the A-circuit, and cranking a huge lock pin out of the way - another job that can cost minutes and sweat if it is seized up with cold or corrosion (usually the case). Once the hatch is opened, the access ladder is set up, and then everyone waits for you to open the next lock. |
 You climb the 10 foot distance down the ladder to access the locks on the "B-plug", and dial in the combinations. Then you climb back out, and wait. The waiting is because even after the locks are opened, a timer starts only once everything is opened and all lockpins are extracted. Then the timer must count down before it will activated the motor which lowers the "B-plug" down the PAH tube, and allows access into the Lower Equipment Rooms (LER 1&2). |
After a lengthy wait, used to unload and stage your equipment for lowering underground, the "B-plug" begins lowering itself down the tube. As you look down the ladder, you can see it is nearly at the LER floor level. Your Team Member hooks up a lowering rope and a block & tackle, to lower the several hundred pounds of equipment, tools, and safety gear you will be using, down "the hole". |
 The first thing you do after descending the ladder into the underground Launcher Equipment Rooms is to "safe" the site. The area below ground in the silo is known as a "No-Lone-Zone", an area where on one can be alone with the equipment, except for a very brief time. Since you have only a few seconds that you can break visual contact with your team above ground, you hurry over and install a Digital Safety Control Switch (DSCS) "Safing Key" in its receptacle mounted in the D-Box, which essentially disarms all explosive devices on the site. You then hurry back to the base of the ladder, to regain visual contact with your team. Many of the more experienced Team Chiefs carried their own, unauthorized, safing key, to speed up penetration into the silo LER's. And they often personalized them - this one has themed buttons, one of which states, "Why yes, I am a Rocket Scientist!" |
Back at the bottom of the ladder in Launcher Equipment Room (LER) #1, your team member lowers the equipment to you, so you can unhook each item and free the rope for the next load. Once everything is down, he joins you downstairs, and together you begin a mandatory safety inspection of the 2 LER's before beginning work, to ensure all is in good order.
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 First you inspect LER#1, the upper level. This level contains all of the racks of equipment that contain power supplies, communications gear, digital and computer controls, and a "D-box", a massive metal box with dozens of connector plugs on it - some as thick as a man's leg. The D-Box is a common junction of virtually every signal in the silo, a sort of nervous system for the site. From left to right in the photo, the racks seen are a liquid chiller cooling unit for the missile computer and guidance system, a power supply and security system rack, the Computer Control & Signal Data Converter Rack, and the Medium Frequency Radio rack. These and other equipment racks are mounted on a "shock isolated" floor, which hangs from the ceiling of LER#1 by enormous shock absorbers, to protect equipment from blast shocks during a near-hit from a bomb. You can also see there is not much working space between the racks and the side of the launch tube wall on the left. On this level are also the access doors to the Launch Tube that houses the missile, and the entrance to the PAH and B-Plug. Opposite the area of the equipment racks is the huge piston and pulley system that slingshots the silo door off the site during a missile launch. |
With the upper equipment room inspected, you move to the lower room, LER #2. Where everything in LER1 was technical, everything down here is fairly simple - and massive. Down here are a huge Motor-Generator, used to convert power from outside electricity sources, a standby generator, or emergency backup batteries, into the correct voltages used by the site equipment. This way, no matter what the power source, or if the power falters, it automatically switches to another source and keeps everything running without a glitch. There are also over a dozen huge emergency backup batteries suspended from the shock isolated floor, next to the Motor Generator. There are rechargeable Lead-Acid batteries wieghing 1600 lbs, and several high output, one time use Lithium Batteries, which are seen in the picture here. The lithium units are stacked 2 high, and are lightweight, at a mere 1200 lbs. Opposite the batteries are a small room containing devices that act like lightining arresters to stop electrical energy bursts from damaging equipment, and the Ballistic Gas Generators (BGG's), which are explosive cartridges that pressurizes and forces down the huge piston & cable assembly hooked to the Launcher Closure (silo door) and the giant lock pin that secures it in place. This takes place in milliseconds when the BGG's are fired, launching the silo door out into the farm field.
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Here is a diagram of the big picture - a cutaway view of Launcher Equipment Rooms #1 (upper) and #2 (lower). this will give you a better perspective of what you've been seeing. Some key items are:
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Well now that the inspections are complete, you can finally begin work. Better get a move on - several hours have already passed since your day began, and you have yet to even begin your assigned tasks!
