Tony,
Your questions are very provocative of fresh thoughts as I mull over how to answer each. It is a bit like you are stirring the mud that lies at the bottom of a stillwater pond! But, I digress – – – –
Autonetics signed up in 1958 to develop an IMU system that would support the U.S. Government’s Mutually Assured Destruction policy, known as MAD for short. I believe the US had by then stated the US would not launch a first strike against anyone, including the USSR. MAD, in effect, meant we would absorb a first strike launched by the USSR. Assuming our early warning radars worked as planned, the US would have about 30 minutes in which to launch a retaliatory strike. This is the genesis scenario that lay behind the Minuteman proposal. The only way to ensure that the IMU was ready to support such a short reaction time was to have the IMU ready to go to work at all times, ie, the gyros had run continuously for three years. There was no time for platform leveling and alignment. It is part of the DNA of the history of Autonetics that we were awarded the contract largely because of the attributes of the gyro gas bearing. Of course, it helped that we had a lot of data from the development from the G6A gyro. (The G6A was the gyro which preceded the G6B. The G6A was very similar in design to the G6B except it was made of Aluminum and the fill gas was Helium. The G6B was filled with Hydrogen, with a small amount Helium for leak detection. The G6B was made of beryllium, which was by its self a huge leap of faith on the part of Autonetics and the USAF. Be is very expensive, impossible to cast, and toxic to the machinist.) I am reminded of the difficulty of sealing any container containing Helium. If I remember correctly, the diffusion rate of Helium is the largest of any of the gases. It was the difficulty associated with sealing against Helium that drove the decision enclose the G6B in a welded mu-metal cover. I believe we never had a leak failure and we passed the magnetic field tests easily.
All of the Autonetics designed gas bearings were started and stopped without any special concern and that included the gas bearing of the G6B gyro. Not much was known the about thin films on metal surfaces, but it was generally accepted practice to apply what was thought to be a mono-layer of “something” to the surface of the stationary part of a gas bearing. In our case it was the ball to which STP-7 was applied. Engineering folklore of the time held that a monolayer of “something” would mitigate the damage potential of a clean metal to clean metal start and stop cycle.
The STP-7 was slopped onto the ball surface, the ball was then spun in a fixture for that purpose and the technician then tried to remove all traces of the STP-7 by vigorous application of a piece of chamois skin. The ball was deemed ready when the the technician became convinced that all the STP-7 had been removed. My friend, the cleanroom Manager, went to great lengths to protect from layoff the best of the STP-7 application technicians. By the way, STP-7 was selected through the Employee Suggestion Program. The employee is said to have been inspired by an ad he saw on television. So much for science.
You asked what happened when a gyro motor burned up, etc, etc. I have to imagine the aftermath of such a disaster because the record will show there were NO in-silo failures of the G6B4 gyro in, to my knowledge, the first three years of alert status of the missiles. It maybe a longer time. I have vague recollection of some kind of hoopla when we passed a million hours of failure free operation. In fact, I presented a paper on our actual infinite MTBF for the G6B4 gyro at the Honeywell plant in St. Petersburg.
Because Be metal particles and gas were toxic, all Be machining operations had to be done in a very special shop dedicated to the machining of Be metal. I remember that our shop was one of only two in the US at that time. The machines in our shop tended to be not very old and were well maintained. Most of the machine operations were of the manual kind. You are right, most of the machinists were very good at what they did for a living. It took a special kind of artisan to manufacture gyro parts to tolerances of several microinches.
The attachment does not look like anything I am familiar with. No, I do not have the book.
Mel
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