three eight-hour shifts." "[A]fterwards you can work it like a machine." The object of these deep diggings was to reach the famous Mammoth Vein, an undulating seam of high-quality anthracite twenty-five feet thick, projected as providing a virtually inexhaustible supply. This indeed was the shared vision and plan of Gowen and Keim from the outset of the Coal & Iron Co. Three years into the project, however, the Mammoth Vein was estimated as still deeper than digging had reached. Even after the colliery became operative in 1875, its production never reached even 1/10 of its projected output 750,000 tons per year. In total, the mine operated only ten years, with a cumulative output of 275,871 tons. Financing the Coal & Iron Co. The aggressively expansive operations of the Coal & Iron Co., including the Twin Shaft project, required vast outlays of money, and the coal and iron operations were not returning a profit on those outlays. Rather, the source of Coal & Iron Co. funding was an increasing load of debt owed by the parent railroad: increased by US$65 million during the first five years of Gowen's presidency—almost twice the railroad's valuation when he took the helm in 1869. Annual interest on this debt, about US$4 million, was a little less than the average profit of the railroad during those years. The public face of the Reading's finances—prospectuses and annual reports—obscured these realities. In 1874, Franklin B. Gowen came under attack again, this time charged before stockholders of accounting sleight of hand—of cloaking continuous losses in the Coal & Iron Co. by infusing into that subsidiary as "capital investment" funds borrowed by the parent railroad, only to mysteriously shuffle large portions of that "investment" back to the parent to cover high dividends paid to railroad shareholders. In light of those consistent high dividends, though, these accusations were sloughed off, and there was no shareholder revolt to derail him. Controlling the anthracite markets The specific destination of coal bound to Philadelphia was that city's Port Richmond area along the Delaware River. In this complex of rail yards and wharves, coal was unloaded for local marketing or for transshipment by boat to other markets such as New York and Boston. In the late 1840s and early 1850s, one of Gowen's predecessors as president of the Philadelphia & Reading, John Tucker, undertook to bolster the railroad's presence and control in Port Richmond with