WD56NVBS.DOC

North American Aviation’s

Extreme Temperature Test Facility Downey, CA

built in 1955 and used until 1959

known as

The Bombshelter

used to develop the mach 3

Navaho G-26 & G-38; B-70

plus

GAM-77 Hound Dog and Minuteman I

The Equipment was moved to Autonetics new facilities Anaheim CA

The Facility was taken over by Space Division and used by them for

Moon Shot and Space Shuttle development

In 1966 North American was bought by Rockwell

In 1996 Rockwell facilities were bought by Boeing

Note 1: Read this in conjunction with file NAA-BS57, which is a copy of a presentation made in 1957 seeking further work when the Navaho program came to an end.

Note 2: Due to photos, these files are about 20 meg each, your machine should have at least 32 meg of RAM for convenient viewing.

Fig 1 “The Bombshelter”; Bldg 123 Extreme Temperature Test Facility, Downey CA

An Expanding Secret Operation

When I first reported for work they were so crowded for space that George Keller made room for me in his office along with his secretary Janet Jones. About my second week George Keller took me to a location south of the main building where work was under way to build a “high temperature” test lab. This was needed to develop Navaho G-26 hydraulic equipment. The G-26 was to be an Intercontinental Missile that flew at mach 3 – it’s controls had to operate at elevated temperatures.

This was a secret program, and explained why George Keller told me, while interviewing in the parking lot, that he couldn’t tell me what I’d be doing or working on; but that it would be very interesting with lots of challenges. When I reported for work I was immediately impressed with what I saw about me – this was not an ordinary aerospace complex or program – this place was packed with hi-tech people. To make room for the expanding projects they were spinning off parts to new locations. The rocket engine people had just been moved to their new plant at Canoga Park CA and given the name Rocketdyne and another group of people had just moved out to create a new Atomics International division. The place and organization was repeatedly being modified. Everyone accepted the inconvenience without missing their stride at doing their job – they knew what they were doing was special – they were all young.

Nothing but a Concrete Slab

They had completed a large concrete slab a few days before and someone had left an electronics rack base there, a sturdy square plate with wheels. George, about 220 pounds on a 6 foot frame took a run, jumped on the cart and scooted across the slab as if it were a sled on ice! He was delighted that he did so well. I couldn’t help thinking, how different this is from the KC GM environment inherited from Detroit! This was a kind of hi-tech play that George brought to the job. George was a people person, widely known and respected in his field – he was prominent in the SAE A6 committee for aerospace hydraulic systems.

The plan under way was to bring a WW II bombshelter up Clark Street from it’s prior location near the Douglas Plant in Long Beech. The bombshelter would be the controls center for test cells to be added along the east side. The work began under George Keller, who originally had the X-10 and would be taking on the G-38, and was assigned to Paris Stafford who had the G-26 work. Paris in turn had put Chuck Hamblin in charge of ordering equipment such as Ovens and Instruments for controlling them. At some point George decided to assign me to work on the new test lab.

Flight Control Power Elements

Don Williams, head of Flight Control, signed the papers to hire me, he was the Group Leader and Elliott Buxton his assistant. George Keller, Paris Stafford, Gene Hawkins were among the supervisors under them. The organization was growing fast and when Williams and Buxton moved up, Tom Shuler, from the computer simulation lab, was made head of Flight Control, with George Keller under him in charge of Power Elements with Paris Stafford and Greenlief Sargent Supervisors under George. Later, during a visit at lunch, Paris told me Tom was chosen for the job as he had made the highest score in tests given to all Sr Engineer personnel.

Fig 2 Bombshelter Test Facitity Floor Plan

The Bombshelter

Within days the Bombshelter arrived and the Ovens were put in place. The concrete block test cell wall put up and the expendable blow off corrugated metal roof covered them. See through square ports, figure 4, were cut in the 15” thick bomb shelter walls and thick glass installed – the operator was certainly well protected from an explosion in the test cells. I was assigned to work with Chuck Hamblin who gave me a tour of progress being made. Facilities workmen had just left and we now had to prepare things so we could run tests.

The Bombshelter Control Room dominated the personality of the place and the facility was soon known to all as “The Bombshelter”, though technically it was K-7, Building 123, the Extreme Temperature Test Lab. One did not just walk through the Control Rooms, you had to weave your way through the partitions which had been created to protect people from bomb blasts, figure 2.

Fig 3a & b Remote control schematic

Remote operation of Oven Cooling doors:

Chuck Hamlin had arranged for the ovens to be equipped with doors which could be opened when it came time to cool down the oven, letting the oven blower suck in cool air and let out hot air. My first task was to figure how to remotely operate these doors. I searched through catalogs and found a commercial reversible DC motor, with adjustable limit stops. I then made a sketch of how to mount the motors, with linkages to open and close the doors on command from the control room. Each oven was different and required it’s own special mount. My prior experience as a Process Engineer with GM, made this a relatively easy task.

Our Navaho Machine Shop

I was introduced to the people in the Machine Shop and given an open ended charge number to pay for anything I needed to have built. They were superb craftsmen and wonderful people, this started a long and beneficial relationship. However, I immediately learned there was quite a difference between how these fellows worked compared to those at the Buick-Olds-Pontiac Assembly plant not too far away in South Gate CA, where I’d worked for about a month before going to North American. They were different cultures, different worlds. At the GM plant I’d make my sketch and ask them to “glue some angle iron together that looks like that” and within an hour I’d have the part. I gave similar instructions to the Downey shop and a few days later got back a work of art! They had machined notches in a plate to accept the angle iron legs and had bolted the angles to the plate with recessed hex screws – they “didn’t know how” to do a quick and dirty job, they were expected to be craftsmen. At GM they would have been let go for spending too much effort on a minor task. The Downey shop foreman had assigned it to a machinist, not a welder, and he was proud of what he gave me. I didn’t have the heart to say anything but thanks, I’m sure it will do the job.

Fig 4 Test Cell #4 Window as seen from test cell side. Those protective walls had a purpose.

(I was in that test cell 10 minutes before it blew – never again did anyone enter a cell during a test!)

Multiple kinds of Power

To Chucks credit he had arranged with the facilities people to have multiple kinds of power built into the facility. The near end of figure 1 shows boxes on the north side of the test cell. These are power boxes that control 440 volts of 3 phase power to the test cells. Also included is a heavy duty source of 28V DC and 110V 400 cycle AC plus conventional 110 V 60 cycle AC. Many aerospace systems used 28 vdc and 110v 400 cycle ac, thus it was very handy to have access to these for remote control mechanisms. We often used discarded experimental missile parts as remote control mechanisms. 28V DC is particularly useful for reversible motors with limit switches and indicator lights for position status. It was also very useful for remote controlled solenoid valves to turn fluid flow on or off.

The Fire Department & Safety

Fig 5a Fire and emergency equipment CO2 horn in test cells

From the beginning, Safety was a prime consideration, it was required that we always have a fireman on hand when we were conducting a test. The above shows the movable CO2 bottles on carts, the emergency stretcher on the back wall and the emergency call box with alarms at the center. The floor plan and photos reveal CO2 flooding equipment, as required by the plants safety codes. These were bright red CO2 bottles connected to bright red nozzles in the test cells, figure 5b left. These were strategically placed throughout the facility and connected for emergency release.

Fig 6 Technician Larry Hein at Test Cell #1 Control Panel

After we got underway, Stafford put me in charge of the Bombshelter and we soon had a staff of 5 to 8 technicians and one test engineer who daily reported at the Bombshelter for their work assignment. Smiley Colburn & Andy Lasloffy #1, John Guffy & Bill Green #2, John Hockensmith & Beany Miller #3, Elmer Subky #4. From the inside lab were Larry Hein, Bob Logan, Orvel Stevens, Jim Jordan, Earnie Potch, Leo Hunt, Vic DeCrancica, McReye, ___ Posey

The Salvage Yard and Pauleys Surplus Supply

We had a tremendous need for various kinds of parts. In addition to the Stock Room’s wide variety of parts, we could place special buys through purchasing. We repeatedly ordered stainless steel tubing, stainless fittings and the special silicon based hi-temp OS45 synthetic oil by Monsanto. Many special items we found in the gold mine of parts at our near by salvage yard, and at Pauley’s War Surplus, a huge store in down town LA. We were constantly having to innovate and these abundant supplies of good but discarded items were extremely helpful. The control rooms and test cells were soon festooned with plumbing, wiring and miscellaneous special parts, all needed at some time to perform some test.

Main Control Panels

One of the first things we had to do was set up the control rooms so equipment in the test cells could be operated remotely. Chuck had started this by having panels, with two lift up lids, built and installed below each test cell control room window.

Fig 7a Control Room Control Panel

These were blank when I arrived. We installed the large indicator lights that came with the Oven systems then abandon further use of the large industrial sizes. Our in-house stock room carried a wide variety of switches, terminal strips, indicator lights, etc; which were much smaller and adaptable to our needs. Knowing we would need many signal paths, we set up terminal strips under these control panels and extended wires under the walls through 2x4 sized drainage holes at the bottom of the 15” thick bombshelter wall, to similar strips mounted on the test cell or oven walls.

Fig 7b The other end

In time we expanded these to include even more inter connects. These wire bundles were very helpful once we got underway. It was the panel shown that had the switches and indicator lights used to open and close the oven cooling vent holes. That simple beginning was soon expanded.

CO2 Inert Atmosphere for the Ovens

Chuck had arranged for the Cold Box to be set up in a room on the west side. Figure 2 shows this room and a tank for alcohol refrigerant and a large box of Dry Ice, outside to the south. Chuck had ordered a Dry Ice crusher and two large upright heavy duty vessels in which crushed dry ice would be dropped. Ambient heat was to convert the dry ice to CO2 gas, which in turn could be routed to the ovens where it could be used to create an inert atmosphere. These were standard items in Fire Fighting supply catalogs, the fire dept was all for it, as they could use these to charge their CO2 bottles. It was soon discovered that without a means to heat the dry ice, it would not generate enough CO2 gas.

We shifted to using bottles of CO2 to supply the ovens. We needed lots of bottles with all four ovens going – CO2 had to be constantly fed into the ovens to make up for losses. We had the entire south fence lined with some 100 CO2 bottles manifolded together to generate CO2. Some of these bottles can be seen at the far right of figure 8. In emergency we poured water on the bottles to heat them – plant facilities people said this was unacceptable. The city of Downey had strict rules about water use and drainage.

The Pure Carbonic people, aware of our sudden increased use of CO2, came to our rescue by providing the CO2 generating unit below. When they delivered Dry Ice and bottled CO2 they also send a truck of liquid CO2, which they off loaded into this large storage container. This container was equipped with electrical heaters that converted the liquid to gas. From then on we never had a CO2 supply problem.

Fig 8 CO2 Supply for Creating an Inert Oven Atmosphere

“hot ovens” to become “cold boxes”:

The Pure Carbonic engineer was very helpful and provided a Temperature-Entropy diagram for CO2, so I could pursue an idea I had. (Later he came to work for plant facilities people, with the support of my recommendation.) The idea was to use CO2, as it was used in a refrigeration mechanism, to refrigerate an oven by expanding CO2 under pressure at the oven. We installed it and it worked, but we seldom had occasion to use it.

Union Labor

Our technicians belonged to a union, but accepted, and often welcomed, having engineers work with them building test setups. I was constantly hands on, often figuring out how to do something as we worked. Plant Maintenance people took a dim view of engineers, even our technicians, doing “their” work. Chuck had placed an order to have a closed circuit water sprinkler system installed for heating the crushed dry ice containers. Maintenance people, held up for parts, finally came and set it up. When we tried to use it, it didn’t work. I figured out what was wrong and had just put it back together when the fellows who installed it saw me doing “their work” -- they were all set to “turn me in”. I’d been turned in before by plant electricians – but let off because a work order had been submitted for the job and we were being held up in running a test -- after a three week delay. This time I had no such excuse. I said to the fellows; you have the perfect right to turn me in, but I thought I was doing you a favor. The fact is you didn’t do the job right, and it was easier for me to fix it than to go tell your boss you screwed up. I showed them what they had done wrong -- they decided it was in their interest to not say nothing.

Fig 9 Oxygen Analyzer

Monitoring the Ovens CO2 content

Chuck had ordered Oxygen Analyzers from A.O. Beckman company in Fullerton. These were very clever units. A flow meter on the right was set to regulate the amount of air sampled and a mirror inside projected a light on a display, out of view above left. The scale was 0 to 100% and we reduced the oxygen to 10% during tests. We ran tests with varying oxygen content, to determine when a fire would extinguish. It was a popular hand out to persons in the industry.

Fig 10

Remote Control of 3 phase Power

We used lots of 440V 3 phase AC power to run hydraulic pumps, heat exchangers and special equipment out in the test cells. Facilities provided manually operated switches, placed in the test cells, which controlled power by use of ON and OFF buttons. These were called “mag switches” because they used AC electro magnets to move the main switches. When looking through a catalog for something else, I noticed there was a way they could be rewired for remote control. There were several of these large switches in the near by Salvage Yard. I carried one back, took it apart and found how it worked and made a diagram of how we could rewire them for local and remote control. We soon had all the power switched modified to work this way, including indicator lights to show status.

Fig 11 Test Cell Hydraulic Controls

Remote control of Hydraulic Pressure

We also had the problem of how to remotely control hydraulic pressure. Searching through a Vickers catalog I found they made a special part you could buy to do remote control. The main control valve on the local hydraulic power supplies was manually operated. I found that the valve heads for manual operation could be rotated for various installations and could also be modified for remote control by using an ordinary needle valve. We were soon able to control system pressure locally or remotely.

In the beginning we used home made hydraulic supplies that used missile pumps to obtain the high pressures. Eventually we built a central system on top of the bombshelter as a source for all test cells. The local pressure control valve is at upper left. Below it is a small hydraulic line that goes to a needle valve operated by knob “A”, shown below, in the control room.

Also shown at left is a high pressure oil filter and a emergency Solenoid operated dump valve controlled by a switch on the control panel.

Fig 12 controls to far side valves

Battery of Needle valves for flow control

We were dealing with very high pressures, often 3000 to 4000 psi. To perform on-off and proportional control it was necessary to use high pressure needle valves. The control of system pressure via a shaft through a hole drilled through the wall had proved so handy, I had the facility people drill a family of holes, so we could pass rods, through plates on each side of the wall, to needle valve on the test cell side. These were a practical solution to what had been a difficult problem.

Initially I had designed a mechanism by which a reversible DC motor, with stops, could be used to operate a needle valve. A needle valve abruptly comes to a stop when it closes and is almost impossible to open if driven shut with a motor. I had a mechanism built which would slip over teeth when being closed but have a positive bite to open. The closing force was spring regulated. This worked quite well but was a costly way to operate.

I had occasion to show this mechanism and the replacement rods – and the closed circuit TV and the replacement mirrors – to Lee Atwood Chief Engineer for North American Aviation. He had been told of our facility and asked for a tour.

Fig 13 Oven #2 in Test Cell #2 – Actuator Load Fixture for Seal Testing is to right under door

Closed circuit TV for seeing inside the test cells

Several had anticipated the problem of seeing what was going on inside the test cells, in the area behind the ovens. A closed circuit TV was ordered and I had the task of rigging it up for use.

It was no good unless you could place and move the camera, from inside the control room. Figure 14a shows the TV camera mounted, with left-right and up-down remote controls, on top of a movable electronics console. It was not an easy task to figure how to do this. At Pauley Supply War Surplus store in down town LA we found some Camera Position Control motor mechanisms. I bought several at $10 each. Using a grid pad at my bombshelter desk I designed a means of mounting them so we could aim our TV camera from inside the control room. This is another time I appreciated the craftsmanship of the fellows in our machine shop. Once they knew what it was for, they delighted in doing the job and followed up on it’s installation.

Fig 14a TV camera control in test cell Fig 14b TV monitor in control room

Our mechanism worked better than the TV setup. It was difficult enough to get a test set up ready and checked out, then extra to get the TV setup, focused and lighting right. TV state of the art was not all that good yet. We were wasting at least an hour each time we had to redo the test setup, to refocus and start again. It was not very satisfactory in the first place, plus it was time consuming.

Do It With Mirrors

The stuff really hit the fan when we found we’d sprung a hydraulic leak in cell #4 and lost 20 gallon of OS45 hydraulic fluid, which cost about $8 per quart! We had no idea anything was wrong, until it ran out of fluid. There had to be a way of seeing around those ovens.

Fig 15 Mirror is on right side of view into oven area

As a kid I was fascinated with how WW I soldiers had rigged up a periscope to see across no-mans-land while still in the trench. I thought of this as I stood looking though the control room window into the #4 test cell, there was a gap between the oven and control room wall. I check the view from in the test cell. We could place a mirror on the oven wall which would permit seeing the right near corner of the test cell. From that corner there was a good view of the cell ceiling. From the cell ceiling we had a full view of the other side. I immediately went to a nearby store and bought three mirrors. I had already made the two axis mechanism for the TV camera and knew I could make a thing to move an overhead mirror. I had technicians hold the mirrors while I went inside the control room to have a look – it looked great to me. The fellows mount one mirror on the oven, using a hinge so it could be adjusted, then another in the corner of the test cell so it too could be adjusted. I made a design for moving the overhead mirror and took it to the machine shop. It worked great, soon had all the test cells were equipped with mirrors.

Fig 16 TV position control adapted to moving mirrors

Fig 17 Overhead movable mirrors for seeing the far side of the test cells

Larry Hein checked out a theodilite (sighting instrument for aligning tooling) and used it to magnify the view through the mirror system. He marveled at how you could count the threads on a screw on the far side of the oven – it really was a high quality improvement.

Fig 18 TV observation out

Fig 19 Mirror observation in

Fig 20 Thermocouple Instrument

Measuring Temperatures with Thermocouples

Tests required temperature measurements of many attributes. The technicians became very skilled at making and placing thermocouple ends at an appropriate place. We had spools of thermocouple wire, two wires one iron and one cooper, which were brought together and preferably heiarch welded at the tip. Hydraulic cap fittings were drilled and a small tube welded in place. Thermocouples were inserted through the tubes and welded to the inside end of the tube. With a T fitting in the hydraulic line, the thermocouple could be placed where desired in the flow stream. Thermocouple wires were brought back to the Honeywell controller shown at the left.

The Honeywell controller was equipped with a Wheatstone bridge, with vacuum tube amplification, to show the amount of voltage generated due to heat. Each thermocouple was calibrated before a test run, and the technician would log the temperatures, at appropriate intervals, during a test.

Oven controls operated on a similar principle but equipped with 24 hour recording charts which could be filed with the test report.

Fig 21

Oil Quantity Indicators

It was important to know how much hydraulic oil was in the reservoirs. The oil, OS45 was synthetic Silicon based by Monsanto. If contaminated with water, silica jell crystals would form.

When we were using a separate hydraulic supply in each cell, I solved the quantity problem by buying Toilet Bowel floats and mounting them to rotate an electronic potentiometer as they floated up and down. We applied facility 28 VDC to the pot and read the wiper output with a voltmeter in the test cell. This worked very well. I then added position sensitive switches, mercury activated, to the float arms. When the float dropped too low it would turn on a warning light on the control panel.

Oil Quantity in a Sealed Hot Pressurized Tank

We had the problem of measuring the amount of oil in a hot pressurized container. I came up with the idea of placing a capacitor in the tank and measuring the change of capacitance resulting from the change in oil level. Beany Miller and I searched the salvage yard and found four aluminum tube sizes, where one tube would fit in the other. We used teflon to separate the tubes and mounted the tubes to the lid. We had a hydraulic fitting modified to pot two feed through wires in glass, so it would be electrically insulated and hold pressure at temperature. We made a Wheatstone Bridge circuit with the capacitor being the variable leg and excited the bridge using 110 V 400 cycle plant power. (At that time we didn’t know how to build a high frequency electronic oscillator.)

We were delighted to find it worked -- but the best mili-ammeter we could find would only give us a half scale reading. I said, we only used a half wave rectifier, lets make it a full wave rectifier. That did it, we could get a full meter change, from empty to full. The meter at the top left is the readout used.

Intercom between Control Room & Test Cell

At left is the control room intercom, typical for each cell. These were in frequent use during a test set up and saved a lot of legging it back and forth.

At this time some of the technicians were taking electronics classes sponsored by the company and someone had made a radio. Radios were a no-no inside the plant, but even the Firemen who made periodic checks ignored them as they enjoyed listen to music during their standby for an all night test run.

Someone decided to connect this radio to the test cells using the intercoms. Soon they could listen to the radio from each cell. One day, coming from the cafeteria, – the bombshelter started booming like a giant Juke Box! Someone going through had not only turned on the radio. We quickly ran and shut it off – our secret was out – but no one told us to remove the radio.

Fig 22

Measuring drips in the Oven from the Control Room

We did extensive testing of shaft seals on actuators – from elasomers to metallic seals. The industry was trying to come up with a quality high temperature shaft seal.

Fig 23

A test actuator was placed in the oven and cycled for hours under load, using the above load setup. Drips from the shaft seal were carried outside the oven and dripped into a tall slender graduated beaker. However, the results were not known until the oven could be cooled down so the room could be entered to see the result.

I came up with a U tube method, letting drips that fell on the oven side, lift the level on the control room side. The fellows calibrate before a run and made periodic checks during the run. Thus we knew leak rate, and could terminate the test of a poor seal rather than run the full time.

Tom Dorse and Chuck Hamlin became our metal seal experts. Tom was ever optimistic about his next design going to be the one that worked – non of the metal designs ever worked good enough. Tom and I chain smoked cigars at the time and he was constantly trying to convert me to his special dried up potent brand of stogies. My cheap ones were potent enough.

Fig 24

Heat Exchangers

From the beginning it was recognized that we need a heat exchanger system that permited us to use room temperature pumping systems to provide hot oil under pressure to items being tested in the ovens. George Keller set the conditions by saying we could not over heat as this could cook the oil, and we could not heat the oil by throttling it as this could breakdown the synthetic oil molecule. George defined that the metal in contact with the oil could not exceed 700 deg F. This had been discussed at some length by the SAE A6 committee, of which George was a part. We needed a method we could control.

Fig 25

Electric to Oil Heat Exchanger

My first design used a round aluminum bar with flow passages machined, as if large threads, with heating rods placed in holes drilled from each end. Aluminum does not lend itself to welding so an outer piece of aluminum was shrunk on over the inner threaded portion. This worked but the ends seeped oil. End plates were shrunk on, then the design could hold 4000 psi, heated or cold. I did repeated calculations to determine how much we could shrink the core piece using dry ice, and how hot we could heat and handle the outer part using the oven. The first end plates we used were a cooper alloy, but we didn’t have enough of that material; we found aluminum end plates would do the job. Once we dropped the hot outer part over the cold inner part, it took just moments before they fused as if one. I got the idea from Coast Artillery ROTC where they shrunk outer barrels over inner barrel to gain strength.

We built about 8 of these units and mounted them in a portable cart. A Fenwall thermal switch, set for 700 deg F, was placed at the center of the core on the hottest unit. The heater elements, inserted like sticks of dynamite, were wired to connect to 3 phase 440 volts. The 110 V heaters were connected in sets of four to provide a 440 volt load. The Fenwall sensor switch was set to operate a three phase power switch. These worked but it was a costly way to do the job.

Fig 26

The second design used alternate layers of stainless tubing and heater rods squeezed together into groves milled in aluminum plates. Aluminum bolts were used to squeeze the plates, thus the squeeze was constant for any temperature.

These heater rods were also connected to 440 V 3 phase power. A Fenwall automatic controller, below, was used to maintain the temperature of the aluminum plates at 700 deg F.

Fig 27

Oil to Oil Heat Exchanger

The first design was a tube in a tube in a tube. The high pressure oil flowed in one direction, through the center passage, and the return oil through the inner and outer passage. The end cap was furnace brazed to the tube ends in one operation. Rocketdyne people put me in contact with people in Slauson who had developed methods for doing furnace brazing. I went to see them and they showed me their set up and told me the best tolerances to use between parts before brazing. Their “ovens” were covered pits heated with natural gas. The part to be brazed was lowered into the pit, resting on a sand base. With the lid on and the heat turned up, it was allowed to soak for several hours. The brazing paste melted and flowed into the joints. Their brazing paste, for stainless steel, was a mixture of Boron-Nickle-Chrom. The result was a beautiful “welded” seam. I was acquainted with how a furnace braze looked from cutaway sections of steel propeller blades, it was like a blind weld inside the blade cavity, a neat process.

The inner tube had an extra thick wall – however when proof testing the outer tube the next tube started to crush. The unit still worked but the method was abandon for design #2.

Fig 28

Design #2 was made in the manner of a conventional commercial unit with parallel tubes carrying high pressure and an outer jacket carrying the return through a series of baffles which helped provide turbulent flow with minimum pressure drop.

I was constantly consulting my pre WWII Heat Transfer book by Mc Adams. This was not one of my favorite subject in school, but the text book was excellent; focusing on it’s details it permitted coming up with a very effective design.

I’ve provided in a separate document NA-BSHE.DOC, the tables, data and kinds of calculations made to come up with the designs. Each significant attribute was calculated, often many many times reiterating until the materials, sizes and arrangement performed mathematically before it was built. I made extensive use of work done by others like thermal coefficients for heat transfer in materials and to/from liquids. Consideration was given on how to achieve turbulent flow without excessive pressure drop. Calculations were made on wire sizes, switches and controls for going from 3 phase AC power at 440 volts to 1 phase at 110 volts. These were not complex calculations, they require access to good data tables, and were tedious. All were done with a slide rule, pencil and paper. There were no hand calculators or computers to grind out the trial and error calculations.

Fig 29 Water to Oil heat exchanger. Fig 30 Fenwall Electric and Honneywell water auto controllers

Water to Oil Heat Exchanger

Thankfully, I was able to find an excellent water to oil heat exchanger, fig 29, that had a stainless steel inner tube surrounded by a cooper outer tube.

Auto Temperature Controls

This time I used a Fenwal Auto Controller, fig 30, for the Electric to Oil Exchanger. I used a Honeywell valve and controller to regulate cooling water flow, fig 30.

The Water to Oil units were so cheap that we built them into each of the test cells, placing them on the cell wall out of the way.

Fig 31

Packaging the Heat Exchangers:

We packaged the Oil to Oil and Electric to Oil units in a movable insulated cabinet, left. This worked very well and could be moved from test cell to test cell as needed.

Unexpected Problem -- Bending Tubes:

Fig 31a Fig 31b

When it came time to assemble the units the technicians could not achieve a tight enough bend on the tubes to fit the spacing of the heater plates. The problem was even more difficult on the Oil tubes.

Our tube bender was an excellent one, but the holding mechanism did not adapt itself to such tight bends. I studied the tube bender and began experimenting. Two things had to be done, I had the machine shop make us a special mechanism to replace the one that came with the bender, and I cut about ¼ inch from the sleeve that fit over the tube and under the holding nut for AN standard flaired tube end. These changes permitted making the sharp bends shown in fig 31a & b.

Electrical Connections

It was also a tight fit to make all the electrical connections. I was concerned that the heater tubes would shrink when cooled and slip down from the vertical position and short out. I found special non-conductive material in the salvage yard which I made into supports to hold the heating rods up, they fit like special washers under the heater rod ends at the top. Each heater rod used 110 volts, by connecting two at the top and two at the bottom, the four handled 440 volts. The bottom wires sets were connected to balance a 3 phase load.

Thermal Insulation:

Johns Mansville catalogs showed various options on thermal insulation materials. The above white material, from those catalogs, was called magnesium-oxide, or something like that. It was non-combustible and a good heat insulator. This was to reduce radiant and conductive heat loss to the outside.

Heat Exchangers for Johns Hopkins University

George Keller had invited the people from Johns Hopkins University to use our test facility. They were technical advisors to the Navy and we hoped this might result in Navy work coming our way. They were very impressed with out heat exchanger system, which we used to conduct their tests. They said they were going out for bids and buy such a setup. I said I’d not been able to find anything on the commercial market, that’s why we built our own. They were very nice fellows so I offered to write a specification for them. I said the way to work this is for you to call George with a request for bid, this will provided the excuse for me to write the specification, and provide a design for what you need. You can then use the spec and design to go out for bids, to whomever you wish.

During their stay, the head of their labs came to see our setup and observe their test in progress. After several days conversations and looking things over they asked if I’d be interested in going to work for Johns Hopkins and run their Hydraulics lab. I was flattered but said no, that my family and I had just got settled, liked our new home and the job at hand.

They called George, having discussed it with him before they left, and I started to work on a spec and a design to meet their needs. When submitting it I placed conditions that work would not start until they approved the design, etc. I was completely shocked when Stafford came out to the Bombshelter to say they decided to not to go out for bids but have us build the heat exchangers. I hadn’t expected this turn of events. I told Paris that while we draw up the actual design and they review for approval we can order the long lead time parts. Paris grinned and said, they waived the need to approve the design, they said go ahead and move out. I said but there is no way can we meet the time allotted – this means we have to design, order parts and build it in the same amount of time I’d estimated just to build it. Paris said, don’t worry just move out.

We did, the fellows -- including Bob Parkinson, came in on their our own time on week ends to complete the job. Autonetics had just come into being about two weeks before and when we called Packaging to prepare the thing for shipment they arrived in a scooter with horse hair packing and a cardboard box. They said how in the hell did Autonetics come up with a thing like that for it’s first product! The design we built Johns Hopkins was what is shown as the #2 design – which is the one I did for them, then built more for ourselves.

The Vacuum Chamber

One of our most technically difficult tasks was doing the Vacuum chamber and heater system for testing a hydraulic servo. We were to simulate the conditions in a thin wing segment that would radiate at 450 deg F on a small servo-actuator being cooled by it’s own hydraulic oil supply which in turn would be cooled by the Inter Continental Ram Jets fuel on it’s way to being burned. A vacuum chamber was needed to simulate the very high altitude.

Fig 32 Vacuum Chamber with a simulated wing segment radiating 450 deg F on a servo-actuator.

The servo was to operate, without failure, for a mach 3 flight to the other side of the Earth.

Fig 33

Claud Tibbs had ordered the Vacuum housing and obtained a Vacuum pump. It was left to us to work out the details. Mounting the vacuum chamber on a cart and connecting it to the vacuum pump was the easy part. Claud, or someone, bought the heater element segments, one simulating top and bottom of the wing segment. It was not difficult to mount these and place the servo with it’s hydraulic connections inside and pass hydraulic lines through the chamber lid. By then we knew how to pot wires with glass inside a hydraulic fitting, to conduct electric power and signals through a sealed wall.

The difficulty was how to control power to the heater elements. Stafford, or someone, put me in contact with people who specialized in making industrial controllers. I called them and two relatively young engineers showed up with information catalogs. They were very sharp and knew what was needed and how to do it. They said the best way to do proportional control of AC power for our setup was to use Saturable Reactors. This is a kind of transformer where you regulate what is passed by controlling the flux path. They provided the saturable reactors, associated controllers and sensors. The black boxes under the cart in figure 34, controlled the gray boxes with eye hooks under the table in figure 33, which in turn fed the two heaters in the vacuum chamber. The gray box under the end of the table figure 34, which I obtained from facilities engineering, was needed to convert our 3 phase power to single phase. This was a proven industrial method but new to me. By the time we finished I understood how it worked and could have built our own system had we need to do so later.

Fig 34 Power transformer left and Saturable Reactor Controllers with sensor transformers below right.

Impulse Tests on B-70 flex hoses

Another difficult test setup was for Impulse testing of B-70 flex hoses for the LA division. Wally Yurs of the LA division had arranged for us to do their impulse testing. They provided a test rig and the hoses. We set up a servo to cycle the hoses while they were heated in the oven. We sustain 4000 psi steady state on the hoses, as they were flexed, then applied a 5600 psi impulse spike.

We had to achieve four hydraulic pressure levels from our single pump: 4000, 3000, 500 and a 5600 psi spike. We set the pump to put out 4000 psi and applied this steady state to the flex hoses. With another pressure control valve we dropped this down to 3000 psi to operate a missile servo-actuator used to cycle the test fixture which was designed to bend the flex the hoses under pressure. A third pressure control valve was used to drop down to 500 psi to command a flow control valve.

We used heavy 5/8 dia tubing to flow through a hydraulically switched to “deadend or bypass” flow valve. When set to bypass, the flowing oil would develop momentum, when switched to dead end this momentum created the pressure spike in the hoses. We set up a hydrauliscope, an oscilloscope with special transducer, to measure the pressure spike. We could regulate the amount of the spike by adjusting the 500 psi switching pressure on the deadend-bypass flow control valve.

It was necessary to use some 10 accumulators to absorb the resultant hydraulic shocks, and sustain normal operation of the other parts. This brutal punishment went on for weeks at a time. Though the test paid for our technicians, Autonetics lost money paying for the CO2 consumed.

Fig 35

Frequency Response Tests

Servo actuator performance was measurd by running Frequency Response Tests. All control rooms were set up with test consoles for performing such tests.

At left is a typical servo test console. The oscilloscope at top was a must for almost any test. It’s primary use was to display the servo command and the feed back, one on the X and one on the Y axis. When they produced an X hour glass pattern, the command and feed back were out of phase by the amount set on the Phase Shift dial. This is the large dial on the panel below the Oscilloscope. (It is also th right dial of the third panel from the bottom. These are different panels which can perform the same function.)

The mid panel has multiple kinds of servo drivers.

The second from the bottom panel is a VTVM Vacuum Tube Voltmeter.

The very bottom panel is where square wave power supplies were place when transducer excitation was shifted to square wave from sine wave.

It was a constant challenge to keep test measuring equipment up with the changes in technology.

Fig 36 # 3 Oven with Varidrive to run pumps

The Varidrive

Oven #3, operated by John Hockinsmith was used for testing hydraulic pumps. This required that we have a heavy duty motor to drive the pumps and that we have a means of varying the motors speed.

Searching catalogs I found a unit with a heavy duty motor and a variable speed drive. When it came in I had the fellows mount it on heavy duty rollers so we could move it about from oven to oven if needed.

An opening had been made in the oven wall but we needed to extend the drive shaft output so we could mount a pump to it on the inside of the oven.

I made a sketch of the extension, in effect a pipe housing a bearing supported shaft. I took the sketch, a pump and rolled the varidrive to the Shop. In going over the task to be done, the lead man chuckled saying, “you need all that huge motor to drive that small pump!” I looked at him and smiled saying, “my concern is if that Big Motor is powerful enough to turn that Small pump when it’s delivering at full load.” Initially people did not appreciate the power of those pumps or the force of the actuators they drove. At 3000 to 4000 psi you enter a different world than most know.

John ran pumps as requested by Lou Purpura who was the Engineer in charge of specifying and selecting the pumps. The New York Air Brake Piston Pump was the one selected for use on the Navaho program.

Fig 37 The Iron Bird in the walk in oven

The Iron Bird

The G-26 missile was simulated in the form of an Iron Bird, mounted on the slab on then north side of the bombshelter, inside the fence. The iron pads it rested on can be seen in figure 1.

It could be laid flat to work on and lifted vertical, the take off position, for system tests. Work on this was done by engineers and technician from the main plant. It was always a mystery to me what this was supposed to do for them.

Someone decided that they should move it into the big walk in oven adjacent to the environmental lab, were the large shake tables were located, and run system tests on it at temperature.

Art Greer and Bob McCoy were the lead engineers on this effort. They and the technicians spent many months setting it up.

Instrument Response Time

One day at lunch Art Greer sidled up to me and asked, “do you sometimes just feel plain dumb?” I chuckled and said often, what happened to you?

He said, we spent months setting up to read the dynamic performance of they hydraulics in the Iron Bird when it was at temperature. The technicians plumbed the lines to high quality pressure gauges which could be seen from the oven window. We even set things up so we could record performance by reading the pressure guages with a movie camera, so we could study the results by going over the film.

Remember the other day when I came out and was asking you about the recording speeds of your Sanborn and other high speed recorders, and you spoke of the need to use pressure transducers and oscilloscopes to read transient pressure spike. Well, that’s when it first dawned on us, something we knew but had forgot. Those very accurate pressure guages we set up, have lousy response times, that movie film of their movement is not going to tell us a damn thing we’re wanting to know. We just wasted a lot of time and money – that’s why some of us feel so damn dumb right now.

I said Art join the club – almost none of us have done the kind of thing we are doing before. I learn how dumb I am every day. We’re lucky to be among people where you have a chance of finding the answer to the problem your having. Art and I worked together for another five years or so, then he left for another job and I’ve never heard of him since. I liked Art, he was a perceptive thinker, it was always a pleasure to share thoughts with him – I miss him.

Fig 38 John Hockinsmith at his work bench counting contaminate in filter samples

The John Moore Inspection

John Moore, head of Autonetics, announced he would be making an inspection of all the labs at the facility, no small undertaking as they were wedged in everywhere. We made a considerable effort to clean things up, as if for a military inspection. Since we were funded by the military there was a bit of truth the the comparison.

John Hockinsmiths work bench was located midway and there was no way to go through without seeing it. John was always emmacculate in how he worked and had a Pump he'd tested taken apart and neatly arranged on his bench. It was an impressive display and all persons passing through for the first time would stop and dwell on the intricacies of the pump.

John had also been taking classes, sponsored by the company in after work hours, on electronics. As a part of this they assembled hands on projects which demonstrated how something functioned. John had placed one of these at the back and under the shelf of his work bench. It was a dry cell battery with two small neon bulbs, normally used to indicate AC status. These had been setup to alternately blink on-off as timed by a resistor capacitor circuit. It was an excellent learning project.

John Moore stopped at John’s bench when he came through and all in the inspection party were pleased, feeling Moore was sure to be favorably impressed. We were startled by John saying, "whats that, what's that doing here, is that made with government paid for parts?" I said, "that’s one of the company sponsored, after work training project, to learn the fundamentals of electronics, we are trying to keep abreast in other fields too.” I don't believe John Moore even heard me, he proceeded to lecture and scold all about that we were absolutely not to use any government purchased equipment for personal use.

We were dumbfounded by his reaction! Only later did we learn that he had caught all kinds of hell from the Air Force because some fellows had rigged up a pencil sharpener using military parts to run the sharpener. The pencil sharpener was a clever adaptation, the fellow were proud to show off. But the inspecting military officer chose to come down hard on that – as a waste of government funding – he unloaded all over John Moore. This in fact was why John was making a tour of the facilities, he was personally making sure there were no such things -- and impressed on everyone there were to be none.

Making Movies

When the Navaho program came to an end, George Keller and others decided that we should make a movie of our capabilities. George hit the road with a suitcase of sample servo actuators and a movie showing our capabilities – which included the bombshelter. George wanted something dramatic, like a fire breaking out in the oven. We staged this by setting up an actuator that we could operate using plant air – we were going to ignite oil in the oven and didn’t want the possibility of igniting other oil. We mount the actuator so we could squirt oil on it when hot with 100% oxygen in the oven. We only wanted just enough oil to make a visible fire, but not enough to blow the lid off the oven. We set this up in the #1 1200 deg F oven. But how do you know how much to squirt or make a squirt.

I said we need a squirt gun. One of the fellows said my kid has one, I’ll bring it in the morning. So next morning he arrives with his kid squirt gun and all of us gathered about to experiment with it. We loaded the gun with real oil, and used a fish scale to measure the force on the trigger when we got the right squirt distance. We then measured the diameter of the piston in the gun and using a drill bit determined the size of the hole. One of the fellows drilled the right size hole in a hydraulic fitting, mounted an accumulator set to the proper pressure and placed a solenoid valve to release the squirt. We then needed a way to time the squirt. We had some “clock” motors that rotated at various speeds. I selected a slow one and had it rotate a rotary switch with many switches per rotation. We then experimented with how many switch segments to keep the signal on to get the right squirt. Like kids with a new toy we were impatient for the oven to heat up so we could test the effect. We worked up from a feeble to hefty amount to get the best burst of flame. When we had it working we called in the movie camera crew, which were a very professional outfit. On cue the fellows manually cycled the actuator with air, and another commanded the squirt – it flamed up and the cameraman was delighted. We took three shots with various effects.

George was delighted with the result however he had to admit to the audience that it had been staged – as they thought it was a jerky servo action and wondered if we’d lost the inert atmosphere.

The Fisherman

They had been digging trenches across the black top to the north of us, normally a “staging” area for flat beds bringing supplies into the main plant. It was also the rainy season and for about a week the trenches were full of water. On the spur of the moment one of the fellows rigged up a dummy, under a rain coat, and provided him a fishing pole from tubing with a line dangling a rag fish. This was in plain view of a bus stop for people going to buildings across Imperial Highway. All coming or going would burst out in a big grin when they saw the fisherman undaunted by the rain. Everyone enjoyed a bit of the lighter side once in a while.

Rebuild Facility Power

Whenever we had a heavy rain, water poured into a manhole cover at the SW corner of the Bombshelter. It was a matter of time until the main plant power was knocked out. The electricians would come out intending to go down the manhole to fix the problem – then watching the rain pour in decided to leave it alone. We finally convinced them to build a cover over the area, a benefit to us as well as keep rainwater out of the manhole. Sometimes our ovens would overload the circuits and contribute to loss of main plant power. The electrical people said, yeh, we need a roof and you need a new power setup.

Whoever did the initial power setup for the bombshelter went from one patch job to the other inside the bombshelter. Industrial engineering would send a guy out who would look about and go back, deciding to have nothing to do with the mess. For my own use I had made a drawing of the power circuits – they were a mess. So using another sheet I made a drawing of how it should be done. I took both drawings to the head of Facility engineering saying you can convert this to your own drawings – as I know you also want to get that mess cleaned up so you don’t knock out main plant power. He looked it over and grunted a thanks and I left.

A few days later an outside contractor showed up. They drilled four holes into the west wall concrete for tampins, and mounted a motor driven 12” diameter carbide tipped circular saw and made a hole through the concrete, reinforcing and all. The next day they mounted a large main circuit panel with a main 700 amp 440 volt 3 phase fuse at the top and dropped it down to smaller units from there on. The plant industrial engineer had provided them a copy of my drawing and they were doing it the way I’d laid it out. What I’d drawn was how it would be nice if it was done that way. I had no idea how to go about running conduits through those reinforced 15 inch walls. That didn’t phase these fellow a bit – they’d just mount their motorized hole cutter and go right through. It was refreshing to see how competent people could operate. Some 6 months before a crew from in house facilities had used jack hammers for several days trying to make a hole in those walls and had given up when their jack hammers could not make their way through 2” reinforcing rod.

The Final “Peal Off” Test for Wright Field

When the Navaho program was abruptly canceled, 4000 people were laid off in one day. This included all technicians from the Bombshelter. I was the only one of the Bombshelter crew left!!

Wright Field was interested in sustaining the work we were doing and the “Peal Off” program. This was remaining Navaho program money available at the discretion of Wright Field. We were to continue high temperature testing of G-38 components that might have B-70 applications. We were very lucky to receive this funding and were able to bring most of the technicians back.

Thus followed a six to nine month effort which culminated in running an 8 gpm system at 3000 psi with 600 deg F oil at 600 deg F oven ambient. We had to pool all heat exchanger assets to do this test.

The shift to Minuteman

Once we got the Minuteman contract all except B-70 high temperature testing came to an end. Because of the extensive test equipment in the place we continued using the facility to do work on other vehicles as the Hound Dog and preliminary tests associated with Minuteman.

The military and commercial planners decided not to go ahead with Supersonic aircraft. We had proven the limits of current state of the art and how difficult it was to sustain supersonic speeds. With the new solid missile technology it was much more economical to loft a Minuteman missile to the far side of the Earth than fly there at mach 3 the hot way.

In 1960 the equipment was moved to a new Autonetics facility in Anaheim, and the emptied Bomb Shelter converted to Space Divisions needs for the Moon Shot and the Space Shuttle.

John Guffy went to work for IBM, McReye and Potch retired, Bill Green, Tom Dorse and Chuck Hamlin stayed with Space Division. All others move to the new Autonetics plant in Anaheim. Only the above memories are left of what was.

Leo Hunt, technician, working primarily in the main plant lab, now living in St George Utah, was very excitedly enthusiastic about this story when first read by him about 1995.

__ DeFrancisco Technician, worked in main plant and sometimes at Bomb Shelter – I could remember him but not his name.