86 THE KANSAS CITY BRIDGE.

The last specimen broke under a strain of 84,032 Ibs. per square inch, and
showed a beautiful fracture entirely fibrous.

The cast-iron used in the details was a gray iron formed of a mixture of
pig, generally adopted by the Keystone. Bridge Company.

Specimens were tested by suspending a weight upon a bar two inches by
one, and placed upon support four feet apart. The specifications required that
this breaking weight should not be less than 2,100 pounds, and in all of the
tests it was found to be much in excess of this amount.

The shore span is a riveted trellis girder of wrought-iron 71 feet long and
8 feet deep. The chords are of T section, composed of two vertical plates, one
horizontal plate and two angle pieces ; in the bottom chord the horizontal plate
does not reach to the ends of the span, and the other parts are continuous for
the whole length. The braces are each formed of two pieces of T iron placed
back to back, and enclosing the ties, which are single bars of flat iron; both
ties and braces are riveted between the. vertical chord plates. The laterals are
of wrought-iron, and the trusses are stiffened by short braces of T iron connect-
ing the floor with the web. The end posts are enclosed in light ornamental
castings. The floor beams are of pine, six inches by eighteen, without trussing,
placed two feet between centres; on this is laid a floor similar to that on the
other fixed spans. The amount of material in this span, exclusive of pavement
and hand rail, is as follows: Lumber, 7,684 feet B. M.; wrought-iron, 32,165
pounds ; cast-iron, 4,328 pounds.

The draw measures 361 feet and 3 inches over all; it is a Pratt truss of
similar plan to the large draws erected by the Keystone Bridge Company at
Cleveland, Dubuque, and other points. The skew is taken out of the truss by
making the end panels of unequal lengths, the difference being 5 feet 6 inches.
The upper and lower chords are of like pattern, formed of two I beams and
two channel bars eight inches deep, placed side by side and united by a plate
riveted to their upper flanges. The posts are of wrought-iron, of the Linville
pattern. The ties are round, with both ends upset for screws ; the main ties
are in pairs, and the counters single, passing through the posts. The washer
plates upon which bear the nuts of the ties are of cast-iron, except the top
centre, which is forged. The floor beams are ten-inch rolled I beams, and rest on