[R-390] Screws bolts and the like

[rbethman]

List,

My major life experience I obtained was after I returned from across the 
"pond".

I received very in-depth Mechanical Maintenance Technician training and 
board certification.  It covered Nuclear Power Production, and 
Conventional Power Production.

We were also trained in the art of being a Machinist.  That was a hard 
part of it too!

I have experience in maintaining large Railroad Engines, and some that 
had there initial use in submarines.

The two specific ones would be the GM EMD 16-567-E4, and the 
Fairbanks-Morse 38 TD 8 1/8.

The very large bolts and nuts had very high torque specifications.  The 
EMD is a 16 Cyl., 567 cu. in. per cylinder displacement, the E4 
designates it as turbo-charged.  (The bloody turbo was the size of a VW 
Beetle!)

The Cylinder crab nuts had NO lock washers at all.  The Torque spec. was 
2000 ft./lbs. +/- 200.  NO this is NOT a typo!  Torque multipliers were 
required!  I can't say that in my 20s that it really saved the body.  
The last one I was involved with installing, I was the "big" mechanic, 
so I got the booby prize. It involved a three engine set that MUST be 
re-torqued after a 72 hour run at full power and load.  I managed to get 
through all three of them, finally tearing a shoulder on the *very* last 
one.

The Fairbanks-Morse are no better.  The crankshaft journals required 
tightening by hand as far as possible, then followed by a slugging 
wrench.  Many a time I swung the 20lb. sledge hammer.

These are a couple of the reasons for later Rotator Cuff surgeries, and 
the degree of Arthritis that I have.

Torque specs, the *real* ones in the Manufacturer's Maintenance manuals 
specify either a dry torque value or a wet torque value.

Dry meaning just that.  No lubricant in that "joint"!  Wet torque means 
that a specific lubricant is to be used in the torquing process.

The old RTFM is imperative.  These specs are NOT arbitrary.  The are 
developed by the engineers, and they fall into the MUST be followed 
category.

I also learned the Electrical Distribution side since we worked in teams 
and cross-trained OJT.  It was the only real method that was available.

I have spent my later years having to watch carefully HOW much force to 
use.  It has been interesting how many sizes, such as 15/16s that I have 
broken the dang wrench on trying to get the electrical connection tight 
enough.  I'm sure the cold weather wasn't any help that one day.  I was 
tightening 500MCM and 750MCM with 12 AWG strands in freezing weather.

One of the cables fought back when I was trying to get it to bend and go 
where it should in the cold.  I distinctly remember getting tossed back 
on my rump at least once, possibly more.  It has been over 3 decades 
since that one day.

Enough posting.  Torque, fasteners, and the methods are indeed a science.

Thankfully our radios are NOT in this realm!  I am no longer up to it.

Regards,
Bob - N0DGN