The Locomotive - Lighthouse Survival Blog

1898.] THE LOCOMOTIVE 141
be takt'ii into account, and tlio brace made correspondingly larger. It is partly on
acconut of this ol)li(iuity of the braces that a lar;Lfer factor of safety (vva., a factor of at
least 6) is recomnieiidcul for them. No brace should be shorter than three feet ami a
half, and braces of this length should only be allowed for the outer course of braces,
nearest the shell. If shorter braces than this were used, the angte between them and
the shell would be greater than it should be.
The attachment of braces to the heads of boilers should receive careful attention
Fig. 13. — Showing the Usual Wat of Arranging Angle Irons.
for a brace may be utterly useless, no matter how well it is made, if it is not properlr
fastened. Fig. 16 shows the method we recommend for the attachment of braces to the
ordinary crow-foot, tee, or angle iron. The holes through the crow-foot and the jaw of
brace are drilled, not punched, and a turned pin or bolt, preferably a bolt, is fitted to
the jaw. The nut is screwed up into contact with the jaw of the brace, and prevents
any spreading of the jaw which might otherwise occur. Fig. 17 shows the jaw of a
brace fastened to a crow-foot by a split pin, and illustrates the careless way in which
braces are sometimes secured. The drawing is not an imaginary sketch, but was made
from an actual brace, as accurately as we could measure it. We have seen much worse
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