From the sign at the posted coordinates:
"The cement columns on the side of the trail used to support a pair of 40 inch diameter pipes that carried gas from the USS Clairton Coke Works to the former USS Homestead Steel Works, the current site of the Waterfront Shopping Center. There are close to 100 of these cement columns still standing along this just over 1-mile stretch of trail. Some of the columns are now buried under slide material.
This section of trail that you are riding on is not a "rails-to-trails" trail but rather the former gas line service road that was used to service the gas lines. As the trail approaches the Whitaker Flyover, there are three rolling hills which is obviously not a feature of a rail line. This section of the gas lines and service road was abandoned in the late 1980's when the Homestead Steel Works closed. This service road was a vital link in connecting the trail from Duquesne to the Waterfront.
The gas is a by-product of the USS Clairton Coke Works, which is about 9 miles up the Monongahela River. The coke oven gas is created in the coke-making process when coal is baked without oxygen to drive out gases and impurities, and consists mainly of carbon and hydrogen. The gas has half the energy content of natural gas.
The gas lines are still in use in the USS Edgar Thomson Works (directly across the river) as a fuel injectant in the blast furnace. It is used as a reheat furnace fuel at USS Irvin Steel Mill. As you travel southeast on the trail, you can see the pair of green gas lines running across the river to the USS Edgar Thompson Works. If the gas by-product wasn't recaptured and used as a fuel, it would be flared off into the atmosphere."
To complete this cache, you will visit 6 locations where you can see these cement columns (under waypoints). At each location, you will count how many columns there are and plug it into the formula below to get the final coords.
N 40° 23.A(B-6)(C+4)′ W 79° 52.(D-1)(E+3)(F+5)′
I strongly recommend you use the checker below to check your answers. It will give you a generous hint for the final as the coords are very jumpy. Final is not recommended in winter.
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