disable/enable

[bedbug]

Before the AF took over a missile site, Site had to have many test run. Here is one test our crew
ran. Their was no missile in silo, Umbilical pluged in to box to simulate missile.
test 1: Verify disable with base, Turn keys - nothing happened. ( disable sent by base to site,
site send verification back to base)
test 2: Contractor unhooked antenna, Base verify loss of disable.
test 3: turn keys- nothing happened. enable timer prevented launch.
test 4: take 5 min. break. Turn keys- launch starts, all systems worked,got all the proper lights
with Door opened and lift off light. Test complete.

To over ride this system. set timer to 0:00 and unplug antenna. and away we go. It may
not have been that simple I don't know

Having studied the blue prints (part of the job) I believe I could have started a launch with a
jumper between two test points on the back of the launch sequense cabne. They put a lock
on that door.

In early 1970s they put in a 6 tumbler box on the MCCC console. I do not know how this
was wired into the launch sequense cabnet.

[hockey85]

Base command post could disable the missile? Was that over land lines? What else could they do?

Cory

[bedbug]

When we ran the test they disconected the antenna so disable must have been by radio.

Base of course controled disable and enable and they would resend a message if you requested it.
Radio not always understandable.

[D Preidis]

Base command post could disable the missile? Was that over land lines? What else could they do?

Cory

That system was canned in the early 70's and the Butterfly Valve Lock and Butterfly Valve Lock control was installed after some brite crew dog showed a touring Congressman that they could go to level three of the LCC, turn off one or two breakers and then just turn keys.

The BVL system required the enable codes that were sent inside the messages for the Minuteman, although the enlisted crew had to decode the items from the message into the site-specific unlock value.

Once the BVL system was installed the base had no idea as to the status of any sorite as the entire monitoring system from the old stuff was gutted and the cabinets on level three were empty.

[SAC Killer]

Um, without going into details that might still be classified, the mention of enable code for the Minuteman is not technically accurate. In terms of Minuteman, I mean, since I know next to nothing about the Titan II weapon system.

But I'm interested in the first entry here. It looks like the TII guys would "routinely" turn keys as part of testing to ensure the system has been disabled???

In Minuteman, you NEVER turned keys except (1) in the MPT; (2) for SELM test, and then not until all the warheads were physically removed and other safety features put in place; or, last but certainly not least, (3) for Global Thermonuclear War. Oh yeah, and if you were lucky, at Vandy for an FOT launch.

[njh621]

The system Doug is talking about was called the Launch Enable System, or LES. I don't remember exactly how the bypass worked, but it involved turning off a circuit breaker when the complex was on generator or battery power. That effectively bypassed the system. When the LES was replaced by the CSS (coded switch system )and the BVL (butterfly valve lock), communication equipment that was located on level 3 was moved into the rack that the LES once occupied. For the minuteman people out there, I suppose the LES was similar to launch inhibit switch, but only the wing command post could do the inhibiting.

Once the BVL system was installed the base had no idea as to the status of any sorite as the entire monitoring system from the old stuff was gutted and the cabinets on level three were empty.

The WPC (Wing Command Post) was, however, able to monitor the BVL status encoder. I don't believe the need for a disabling system was needed, because without the proper BVL code, the bird isn't going anywhere. The status encoder would lockout after seven wrong codes, and the MNX would have to come and reprogram it if that happened. If someone tried to disable the actual lock on the stage I engine, an explosive charge would lock it shut (the exception was mentioned earlier in this topic). The BVL could be rendered safe for maintenance via an access word, or, if power was removed from the encoder for more then 30 hours (it had a backup battery).

I believe that first entry has to do with the early Titan II days, before the missiles had arrived, and before the LES was replaced; I don't think turning the keys was a routine thing in those days, and after the CSS and BVL went in, the keys would only be turned in the MPT, or in the event of an actual launch.

[D Preidis]

< SNIP >
The WPC (Wing Command Post) was, however, able to monitor the BVL status encoder. I don't believe the need for a disabling system was needed, because without the proper BVL code, the bird isn't going anywhere. The status encoder would lockout after seven wrong codes, and the MNX would have to come and reprogram it if that happened. If someone tried to disable the actual lock on the stage I engine, an explosive charge would lock it shut (the exception was mentioned earlier in this topic). The BVL could be rendered safe for maintenance via an access word, or, if power was removed from the encoder for more then 30 hours (it had a backup battery).

I believe that first entry has to do with the early Titan II days, before the missiles had arrived, and before the LES was replaced; I don't think turning the keys was a routine thing in those days, and after the CSS and BVL went in, the keys would only be turned in the MPT, or in the event of an actual launch.

Memory fades after 30 years. Why does age make the brain go into neutral sometimes! Thanks for refreshing me on some of the details. The WCP could not interact with the BVLC in any way but maybe they did have monitoring capability. I just can't remember how though as I do not remember any hard lines other than the PAS that fed back to base.

We tested the actual systems a few times per year using the Missile Verification and Launch Verification checklists.

The Launch Verification had the BMAT put the system in test mode and the officers would turn keys. The weapon system would go through a launch sequence without firing any ordnance but testing the entire ground based and airborne components of the system including opening the silo closure door when directed (Door normal or door simulated). A crew member or Pad Chief would go topside to monitor security and safety while the door opened. I went up a few times and rode the door open and closed a couple of times. Put change on the rails and flattened them for the crew to have as keepsakes (still have a couple of quarters that you can almost shave with).

After the Launch Verification was complete the crew would run the Missile Verification checklist and run the missile, including the hydraulics, through a pre-programmed, simulated flight.

[SAC Killer]

Okay, so that was like the Minuteman SELM (simulated electronic launch -- minuteman) test, used to verify weapon system performance. We'd pull the weapons off a flight, (or maybe disconnect them & put a simulator in the loop instead, don't remember now). We'd electrically isolate the flight (with two LCCs from the rest of the squadron), and the crews would enable the birds & turn keys. The missiles would go right thru terminal countdown, except we didn't open the closure (it would have shot off the rails, thru the fence and out into the farmer's field), and obviously the birds did not launch.

If I recall, SELM was done once per year per wing, but memory a bit fuzzy these days.

[bedbug]

I read a report I think from Vandy where the shock absorber didn,t return to the
extended position and next time the door opened it broke several 1inch cables sheared off
several large I beam braces and went about 50 yards.

The door weight 740 tons and it opens about 20 ft. in 20 sec.

[Penson]

>>The door weight 740 tons and it opens about 20 ft. in 20 sec.

The museum has video of a launch ver at 570-3. From door lift to full open is 15 secs flat. Much faster than the spec of 17-21 seconds. I believe total door travel is 36 feet.

[SAC Killer]

I'm interested in the mention above about no missile in the launcher. How did they do that in Titan II? In Minuteman you yank the RS and the can, and then the entire rest of the missile at once. Then the reverse to bring it back up. When it happens a site is off alert for 5 days or so. Fortunately an infrequent procedure. In Titan, presumably you offload the propellant, then what?

Inquiring minds want to know!

[Penson]

In Titan II the removal sequence was:

After a thorough safety check and walk-around...

1) Pull the RV
2) Remove all pyrotechnic and explosive components (there were many)
3) Off-load propellant
4) Pull stage two
5) Pull stage one

All this required several days to accomplish.

A full "recycle" (pulling one missile and installing a new one) required about 30 days.

[hockey85]

Wow. Thats along time.

[SAC Killer]

Of course in MM we also dealt with the pyros. Generally didn't pull them. We safed them in place, before removing the weapon. It took a while to safe all the ordnance in the launch tube before we could start pulling stuff up. Both the missile and the launcher had pyros in there.

[Penson]

Well, now that I think about it they didn't actually removed ALL pyro. The removed the vernier and translation rockets, and safed the rest in place. Removing everything would have taken quite a while. There were an astonishing number of pyrotechnic and explosive devices on Titan II.