[ExI] next satellite, was: RE: next county

Keith Henson hkeithhenson at gmail.com
Thu Aug 6 04:59:29 UTC 2020

<spike at rainier66.com> wrote:


> Another fun aside: this accident coulda been a hell of a lot worse.  It
coulda fallen on some hapless prole.

It would have reduced the shock of the satellite hitting the
floor--slightly.  :-)

That's really some story, kind of thing to pass on to kids, especially
how they recovered.

I am reminded of the first day I was working at the Electro-Motive
Division of GN, perhaps around 1974.  The coordinate measuring machine
(CMM) was in an air-conditioned room to the side of a machine bay
which was perhaps 200 feet across.

The first time I am in the room, one wall (a wide garage door
installed upside down) rolls down and the roof rolls back.  A gantry
crane goes hoot-hoot and a 20,000 pound freshly machined engine block
sails into the room.  It was gently sat on the 22-foot long CMM table
and I backed up to one of the walls as far as I could go.

In a strained voice, I asked the guy who ran the CMM if they ever
dropped one.  He pointed to a divot in the 2-foot thick granite table
about the size of a large dinner plate and said "Yep."

The divot had been filled with some hard yellow patching compound and
ground flat.  Because there was only one, I figured they didn't drop
engine blocks or traction motors very often.

It was a strange place to work.  The square mile shop was built in the
late 1930s.  The floor was wooden blocks set end grain up.  This
protected dropped parts from being damaged.

Right outside the CMM room, there was a huge turntable where an engine
block could be loaded and unloaded while a block was being machined.
The third station held the machines that drilled out the cylinder
bores and did the other machining.  The CMM was there largely to be
sure this machine was making engine blocks and not junk.

I was there a few times a year over three years or so.  Getting in or
out to the CMM room I walked by the exhaust valve line.  Never saw it
running.  I think it made a year's supply of valves in an hour or two.
It was perhaps 100 feet long.

It took segments of high-temperature steel and forged them into a
valve shape,  It then sheared off about 5-inch pieces of 5/8 inch rod,
chucked both the valve end and the rod and friction welded them.  The
final step was to grind off the flash from the friction weld.

The two-stroke engines used 4 valves per cylinder.  The engines were
made from 8 cylinders (which looked like a way oversized car engine up
to 20 cylinder monsters that were mostly for marine use.  The 20
cylinder version just barely fit on the CMM table.

The engines were weldments rather than castings.  I never got to the
welding shop where they made 2 inch deep welds with 5/8th welding rod.
People who talked about it usually referred to Dante's Inferno.

There is plenty of data about these engines here:

And I could say more, for example about the 50kW CO2 laser they used
to harden the inside of the cylinder bores.  But this is enough for
one day.


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