Part 55 (2/2)

(See page 426.)

Balanced type. Thickness of inclined plate, 14 inches; of side plates, 10 inches. Height of side plates, 7 feet. Largest diameter of turret, 393 inches. Weight of turret, 192.41 tons.

CONNING TOWER AND ENTRANCE s.h.i.+ELD FOR UNITED STATES BATTLEs.h.i.+P ”Ma.s.sACHUSETTS.” (See page 426.)

Conning tower, one piece hollow forging, nickel steel, oil tempered.

Thickness of walls, 10 inches. Inside diameter, 83 inches. Height, 82-1/2 inches. Top plate, nickel steel, oil-tempered, 1-1/2 inches thick. s.h.i.+eld, face-hardened nickel steel, 10 inches thick, 66 inches high.

[Ill.u.s.tration: SAFE DEPOSIT ARMOR PLATE VAULT

Size, 42 feet 6 inches by 24 feet 6 inches by 9 feet 6 inches high; weight, 450 gross tons.

_Courtesy of the Bethlehem Steel Co._]

[Ill.u.s.tration: FRONT DOOR, WITH TIME LOCK, FOR ARMOR PLATE SAFE DEPOSIT VAULT

Thickness of front door plate, 12-1/2 inches; weight of door plate, 12,000 pounds.

_Courtesy of the Bethlehem Steel Co._]

[Ill.u.s.tration: _Reproduced by permission of the Philadelphia Museums._

CASTING PIG IRON

Molten iron from the blast furnace in the rear is allowed to flow out on this molding floor in which the shape of the ”pig” is molded in the sand. After cooling, the pigs are broken apart and stored.]

[Ill.u.s.tration: _Courtesy of Indiana Steel Co._

OPEN-HEARTH FURNACES

Iron is converted into steel by the basic or open-hearth method in the furnaces shown here. The 100-ton ladles are in position at the tapping side of the furnaces to receive the molten steel.]

[Ill.u.s.tration: _Reproduced by permission of the Philadelphia Museums._

POURING STEEL INTO MOLDS

The great ladle in the upper portion of this picture is filled with steel at the furnace. A traveling crane then takes it to the train of flat cars on which the molds stand and the steel is poured. After cooling, the molds are removed and the steel in the form of a ”billet”

is taken to the next process in manufacture.]

[Ill.u.s.tration: GIRDLING THE EARTH WITH STEEL

A steel beam, red-hot, drawn out 90 feet long in a huge steel mill in Pittsburgh. Steel rolled here may find its place as part of a skysc.r.a.per in the Babel of New York, be builded into the framework of a vessel in the s.h.i.+pyards of San Francisco, or help to construct a railroad into the heart of China.

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