Page:Popular Science Monthly Volume 91.djvu/843

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Steel Castings for Modern Dreadnoughts

��How are they made — these giant one-piece sections weigh- ing enough to sink a ship?

���The stern post here shown was made for the new superdreadnought "Missis- sippi," and its weight is 44,540 pounds

��The casting in which the man is standing forms a portion of the rudder of the superdreadnought "California"

��THE extent to which steel enters into the construction of the modern battle- ship is realized by very few'. Besides the tons of steel plates which form the hull or hold of the ship itself there are some very large steel castings. The two illustrations here shown are excellent examples.

In the two castings illustrated there are over 90,000 pounds of steel and both of them enter into the stern or rear part of the ship. It would seem almost as though these would cause the vessel to stand on its end or sink it.

One of these is the stern frame or stern post, and the other is the rudder frame. The rudder frame is attached to the stern frame, which of itself constitutes the back- bone of the vessel's stern. The stern post here shown was made for the new super-

��dreadnought "Mississippi," and its weight is 44,540 pounds. The other casting, the rudder, was made for the new superdread- nought "California," and its weight is 50,500 pounds.

The part of the casting in which the man is standing forms a portion of the rudder proper while the large lugs above fit on to the corresponding lugs shown on the stern post in the car.

How were these castings made ? A large sand mold of several sections had to be made for each one, and each part was dried out completely before the molten steel was poured in. The actual amount of metal poured in each case was over sixty-seven thousand pounds for the rudder frame, and over fifty-nine thousand pounds for the construction of the stern frame.

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