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This
past winter I had the privilege of restoring a working model of
a wooden oil field derrick using the old cable tool method of drilling
for oil. During the project for the White Deer Land Museum in Pampa,
I was forced to research and learn why and how each component part
worked in order to restore the equipment to working condition. By
the time I finished, I became fascinated with the simplicity of
this crude equipment and how man had created and operated it under
trying times and in extremely remote locations.
First of all, most wooden derricks were built and used during the
"horse-power era" when teams pulling wagons were the only conveyances
available. Loads were strictly limited in size and weight. This
meant that anything heavy or bulky had to be broken down into lesser
weights that horses and mules could haul. Labor was plentiful and
cheap so most drilling equipment was built on location using only
critical manufactured parts ordered from catalogs. Further economy
was utilized if the well was a producer using the same original
drilling equipment to pump and produce the oil.
Most people think an oil derrick is built like a windmill tower
with bracing nailed to long leg timbers. Not so, as derricks are
much taller, the bases wider and the tower must withstand much heavier
weights than windmill towers. The process of construction is much
more critical.
To withstand
this use, derricks do not use corner timbers, but instead use L-shaped
cornices for legs. All bracing including "bands," and X bracing
is fitted and butted together inside the cornice. Nails are used
only to hold the bracing in place. The strength comes from the jointing
and butting. Also remember, during the time of wooden oil derricks,
concrete use was limited. The entire derrick and equipment were
mounted on heavy timbered "mud sills" laid on the ground and covered
with a wooden plank floor. The derricks were free-standing and built
on location. Most wooden derricks were powered by steam engines
as the internal combustion engine had not been produced yet. This
required a steam boiler, water tank and boiler fuel of some source.
This was also before geared, reversible transmissions, clutches
and V-belts, so flat belts and ropes were used to provide power
to the winches and band wheel. Interestingly, all equipment ran
the same direction and reversing could be accomplished only by twisting
belts or ropes. Later, reversing winches speeded up the drilling
process.
Since all equipment operated at slow revolutions, many bearings
were wooden requiring frequent lubrication. Braking of the winches
was accomplished by heavy metal bands clamped around the wooden
flywheels of the equipment.
The actual digging of the hole was judged by feeling the jar on
the cable as it raised and dropped the bit against the formation
in the bottom of the hole. For this reason, the cable tool drilling
crews were called "Jarheads."
Today's rotary
drilling crews would laugh at the old-time crude equipment but somehow
it got the job done. The crews were a tough, hardy lot who continually
improved their equipment as they gained experience in the always-changing
oil formations. We salute the old "Jarhead Crews" of the wooden
derrick and cable tool drilling days.
© Delbert Trew
"It's All Trew" February 28, 2008
Column
E-mail: trewblue@centramedia.net.
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