Description of the Coke Ovens Tower Hill 2 Mine & Coke Ovens, Tower Hill Pennsylvania

Two types of coke ovens are present on the property. The coke ovens are arranged in two roughly parallel banks and are located in what is now a meadow situated to the southeast of the main cluster of mine buildings and structures. A continuous row of approximately 144 beehive ovens comprise the northeastern bank and a row of approximately 250 rectangular ovens arranged in three blocks of 50 and one block of 100 comprise the southwestern bank.

The earliest beehive ovens at the site were installed in 1907. While the specifications for beehive oven construction were never standardized, all ovens conformed to the same general pattern and were built of heat-resistant masonry. The beehive ovens at Tower Hill No. 2 are constructed of irregularly coursed ashlar, fieldstone, and firebrick. The interiors of beehive ovens are generally 8 feet tall and roughly 12 feet in diameter. Beehive ovens have a large side door and a round opening at their crown called a "trunnel head," which acted as both a loading port for the raw coal and a chimney while the oven was in operation. On top of the row of ovens ran a train of "lorries;" steel cars that moved on rails and had a dumping mechanism to charge the oven below by depositing an 8 ton load of coal through the trunnel head. The side door was closed with bricks sealed with mud, leaving just a small opening at the top for ventilation. The remaining heat from the previous charge would ignite the new load of coal. After the coal was ignited, it was cooked in the ovens for forty-eight to seventy-two hours, depending on the size of the charge. After the cooking was completed, a sprinkler hose was inserted through the side door to cool the coke so it could be handled. The bricks were then pulled from the lower door manually, and the coke was loaded onto wheelbarrows, or later, onto an electric trolley called a "Covington Device" that ran on a set of tracks laid parallel to the front of the ovens. The coke was loaded onto trains for shipment to steel mills.

Rectangular ovens were first constructed at the mine ca. 1912. These ovens were also constructed of firebrick and irregularly coursed ashlar and fieldstone. Like the beehive ovens, the rectangular ovens were loaded through trunnel heads by lorries that ran on a track on top of the ovens. Unlike the beehive ovens, the rectangular ovens had two doors, one at either end of the oven. The opposing openings facilitated evacuation of the coke. A pushing device, which ran on a track on the southwest side of the ovens, would push the coke out through the opposite opening and into a waiting rail car. This mechanization cut hours out of the coking process. All metal from the coke ovens-including tracks, doors, and hinges-was removed and sold as scrap when the mine closed. What survives today are the masonry shells of the ovens, the majority in sound condition.

The physical layout of Tower Hill No. 2 differed somewhat from the typical mining/coking operation built in the early twentieth century. Most commonly, coke operators built their ovens in several short parallel blocks of less than 100 ovens. The arrangement allowed workers to recharge the ovens in less time using less power. Tower Hill No. 2 features a single row of 144 beehive ovens and a parallel row of 250 rectangular ovens arranged in blocks. Ovens constructed in long rows would have been easier to expand over time as the operation grew by simply adding ovens to the end of the row and extending the track for the lorries and covington device. Another difference in this mine is the placement of the mine shaft. Operators tended to locate the mine shaft at the center of the oven configuration to facilitate movement of the coal from the mine to the ovens. At Tower Hill No. 2, the shaft is situated 400 feet to the northwest of the western flank of the beehive ovens. This may have been a function of the landscape. The ovens are located in a large, open, fairly flat meadow that easily accommodated the linear arrangement of the ovens.