The Locomotive - Lighthouse Survival Blog

PUBLISHED BY THE HARTFORD STEAM BOILER INSPECTION AND INSURANCE COMPANY.
New Seuu:s— Vol. XIV. HAKTFORD. CONN., APRIL, 1893. No. 4.
An Accident Due to Bad Workmanship.
Readers of The Locomotive may l)e interested in an accident that came to our
attention a short time ago, and which is fortunately no longer a common one. The
circumstances of the accident were as follows : — The boiler in question was 60 inches
in diameter, and live years old, and had seven tubes in the lowest row. Of these seven
tubes all but the right-hand one had developed leaks just inside the front head, and
had been thirabled. It had been recommended that the six leaky tubes be removed
and replaced by new ones; but before this was done the seventh tube (that is, the right
hand one in the lowest row) suddenlj' failed when tlie boiler was running under fifteen
pounds of steam, the ordinary running pressure being from 75 to 80 pounds. The end of
Fig. 1.— A Fragment of the Tube-End.
the tube pulled off, and the tube was drawn back through the head, and deflected towards
the right, so that two-thirds of the diameter of the tube-hole was uncovered. The con-
tents of the boiler blew out through this opening, filling the boiler-room with steam
and scalding water, and making it impossible to approach the boiler to haul the fire;
the result being that it was badly burned.
Part of the detached tube-end is shown in Fig. 1, and an examination of the frac-
tured area of it showed that for a considerable time the tube had been held together
only by the merest skin of metal along the inner surface; so that although it had been
on the point of giving out for a long time, it had every appearance of being sound
and good. When the thimbled tubes were removed, they were found to be in a similar
condition, the leaks that had developed in them being caused by pin-holes that had
corroded through from the groove that encircled them just along the inner surface of
the boiler head.
The head of the boiler was calipered and found to be a trifle less than -^\ of an inch