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Tuesday, October 29, 2013

Overtorque Epitaph

Bolt: 1/4 x 24 = 23 inch/pounds wet

That's what the maintenance manual said
And there was nothing special about this particular bolt

So with no further thoughtful thinkings
I applied some light oil to the threads
Threaded on the nut until the locking feature gave it's resistance
And applied the torque wrench carefully
Ratcheting the nut down until it mated gracefully with the washer
Pressing into the casting evenly

Sanely

The Snap-On quarter inch torque wrench clicked quietly
Easily audible in the near silent cavernous aircraft hangar

That job done
I turned the page of the manual
Where a further instruction said:

Bolt: 1/4 x 24 = 100 foot/pounds (retorque)

I looked at that for a moment
For it seemed a bit excessive for a fastener of this size
But I don't write the manuals
That's what the pros do, eh?

The stockroom provided a bigger torque wrench
I clicked the proper socket onto the 3/8 lug
Set the rotating handle to 100 ft/lbs
Locked it down and set to torquing the bolt again

I half expected it to snap the shank
But it didn't

And after some light muscle flex on my part
The larger sized Snap-On torque wrench clicked
A little louder than the smaller one
But disturbing nobody in it's clickiness

That done
I read further down the page
Where a further retorque was instructed

Bolt:  1/4 x 24 = 800 foot pounds (retorque)

Now this bothered me
There was just no way that a quarter inch bolt could stand up to that
I mean
We are talking big torque here!
Just about the most that I'd be able to apply without some sort of help

But after double checking the reference and revision
I shook my head and walked back to the stockroom
Trading in my two smaller wrenches for the largest torque wrench we had
Which was a two piece affair
Consisting of two four foot sections
The lower part had the torque wrench guts in it
And I set the dial for 800
Installing the handle extension on it afterwards

Soliciting some help in the form of an able bodied assistant
Who removed her cape
But not her top hat
In a bow to bygone elegance

She held the head of the wrench in place
While I applied all my weight to the bar
Pushing
Pushing
Pushing
Watching the bar assembly flex
Until a loud "SNAP" was heard

Well, that did it
We broke the bolt this time

But when she gently pulled the socket head off the nut
The bolt was still intact
As it should be

So reassured that all was as it should be
I referenced my maintenance manual once again
Looking for the next step in our installation procedure
And wouldn't you know it

Bolt:  1/4 x 24 = 12,000 foot pounds (retorque)

I was astounded
I was perplexed
This just couldn't be

I called over everyone else in the hangar
Who all discussed and quorumed over the issue
The final decision being
That with the help of two others
I would apply the torque while everyone else snacked on popcorn and watched

Griping over their brotherly love
I trudged back to the stockroom
Knowing that there was just no way..............

Only to have the stockroom manager hand me a Sweeney torque multiplier
Which just happened to have as it's highest setting:  Twelve thousand foot pounds

"This is surely doom!"
I cried to my comrades
As I wheeled the unit back to the plane

Who took another sip of their Cokes and waved me on
With reassuring thumbs up and smiles

Hanging the torque multiplier from the crane
My two assistants held the socket in place on the now tiny seeming nut
While I applied the breaker bar to the turning lug

The dial indicated 2000 foot pounds
And I felt my joints start to ache
Metal on the aircraft groaned on my behalf
Strange sounds emanating from the center of the fuselage

The needle inched it's way past 6000 foot pounds
My shoulder felt like it was going to come out of it's socket
The two guys holding the multiplier unit were sweating and shaking with fear
Out of the corner of my eye I saw the left main landing gear strut and tire compressing

Still I pushed the bar onward
Making the tool read 9000 foot pounds
And with a sudden leap of motion the right main landing gear tire rose up off the ground
Causing my peanut gallery of people to rush forward with straps
Which they man handled onto tie down lugs in both the wing and the concrete floor
Tightening them down firmly while I paused for a breath

They retreated back to the cheap seats
And I pushed the bar again
Harder and harder I pushed
Blackness pinched inwards on my vision as my blood pressure boiled
Making it seem like I was looking down a long tunnel
The only light at the end of which
Was the torque multiplier's dial
Moving slowly towards the goal

11,000 foot pounds indicated
And the concrete floor cracked
Sending a thunderclap into the air
Bursting my eardrums

But the floor held in place
So I didn't let up
Looking through the now pinpoint of vision left to me
Feeling blood dripping from my ear lobes
Hearing nothing
Seeing only the dial

The dial

The dial

The needle touched 12,000 foot pounds
My heart gave out

The breaker bar clattered to the floor like a falling sword onto stone
A crowd of onlookers roared it's approval
A stadium shaking sound that pro athletes live for

None of which I heard with my dead deaf ears
As I fell endlessly towards a stone epitaph

"Here Lies Wrench
He Wrenched To Live
He Torqued To Die
Keeping Old Iron
In The Sky"