Another of the Denison plants of great importance is that of the Mason City Sewer Pipe Co., the products of which are 90 per cent drain tile, although a small quantity of common brick and hollow building block are also produced.  The buildings are of excellent construction, consisting of a machine room 160x50 ft., power house 100x50 ft., shop 40x50 ft., and a two-story drier 100x160 ft.

The blue shale used at this plant is very fat and free from sand.  It is dug from the bank to a depth of 40 ft. and hauled to the works in cars by a wire cable.  The material is prepared by a granulator, conical rolls and pugmill.  The dry pan is 9 ft. in diameter and of the Eagle pattern.  The crusher rolls are the product of the Drake Standard Machine Co., Chicago, and the horizontal pugmill is of Madden make.  Water is used for tempering the clay.
The machinery equipment consists of a Madden No. 6 brick machine, with a daily capacity of 160,000 brick or 30,000 4-in. tile; also a Brewer brick cutter and a Bensing automatic tile table, the latter manufactured by the J. D. Fate Co.  For transferring the ware to the drier 400 double-decked all-steel cars of 550 capacity each are used, these being the product of the Vulcan Iron Works, Mason City.  Two double transfers and three single transfers are also required.

The drier is of the waste-heat type, 100x160 ft. in size, two stories high, and of fireproof construction.  The second story is used for drying large-sized drain tile.  This drier is of Denison-Stephenson design, and contains 8 tunnels and 24 tracks.  It is heated by hot air from the kilns and by exhaust steam from the engine, circulated through 10,000 ft. of pipe.  The waste heat is drawn to the drier with a 16-in. fan, and another fan is used at the exhaust end of the drier, both made by Wm. Bayley & Co., of Milwaukee.  Twenty-four hours are required for drying in the tunnels.

The 18 down-draft kilns are 28 ft. in diameter and have 10 furnaces each.  They are connected to 100 ft. stacks, 6 kilns to the stack.  The tile are set in 16’s, 12 benches high.  The kiln flues are open at the sides and closed in the center over the main flue.

For power two corliss engines are provide, one of 100 h. p. and the other of 250 h. p., both made by the Murray Iron Works, Burlington, Ia., which firm also supplied the two horizontal tubular boilers.  This plant is in operation the entire year and employs 75 men.  The factory was erected in 1905 and the same officers control as are in charge of the other Denison factories.  One of the features of this plant is its complete electric-lighting outfit.  (Brick and Clay Record, Kenfield-Leach Company, Chicago, January 1909, Volume XXX, Number 1, Page 14)