44 MINING CONDITIONS UNDER CITY OP SCRANTON, PA.
OBSERVATIONS ON PRESENT MINING CONDITIONS UNDER SCRANTON.
INTRODUCTORY STATEMENT.
As stated in the chapter on the history of anthracite, the mining methods pursued in the earlier days of the industry, not only in Scranton, but everywhere in the anthracite fields, were not conducted with the view of ultimately mining the maximum amount of coal, with the least effect upon the surface, but with a view to immediate profits. Hence, little attention was given to surveying and engineering in the early mines, and great irregularity in the method of mining was the rule rather than the exception. This irregularity makes it exceedingly difficult to columnize pillars now where mining is being done in the solid under worked-over portions of higher coal beds.
To illustrate this particular point reference is made to the tracings that show the mine workings under the various school properties and are in the possession of the board of school control. These tracings are included in the report made by Messrs. Stevenson and Knight. In the more recent mining under the city, the attempt has been made to remedy this defect, and this attempt has been fairly successful.
As the result of our inspection of the mines under Scranton, as given in detail on preceding pages, we have grouped the mine workings into several classes; in each of these classes approximately similar conditions obtain, and to each the same remedies for sustaining the surface might apply, as stated below:
SURFACE BEDS.
WEST SIDE OP LACKAWANNA RIVER.
On the west side of the Lackawanna River, at the Dodge, Hyde Park, Mt. Pleasant, Diamond, Brisbin, Cayuga, Yon Storch, and Leggetts Creek collieries, the surface beds being mined are known as the Eight-foot, Five-foot, and two splits of the Four-foot.
As before stated there is only a small area underlain by the Eight-foot; the areas underlain by the other beds gradually increase in size, as the beds are lower in the measures.
In mining these beds efforts have been made—with a fair degree of success—to columnize the pillars, and about the usual percentage of coal, approximately 33| per cent on first mining, is left in for support of the overburden. In a few places reclamation of pillars, or what is commonly termed “robbing,” is in progress, but only where there are comparatively few surface improvements. The menace to the surface from the mining of these beds, as at present conducted, is comparatively slight. When the time comes, however, for the reclamation of pillars from the greater part of the area mentioned, serious surface disturbance may be expected, unless in the meantime some method of support is introduced. Suggestions on this point are given on subsequent pages.