The Stourbridge Observer, Cradley Heath, Halesowen & District Chronicle.
Stourbridge, West Midlands, England, 1886-09-11 00:00:00

THE ACCIDENT ON HER MAJESTY'S
SHIP COLLINOWOOD.

The report of the Ordnance Committee on the
bursting of a gun on board the Collingwood on the
of May last has been issued. The committee eimmined
all the evidence obtainable, and tried certain ex-
periments, after which they report as follows :
"From the information laid before them, the com-
mittee have arrived at the fallowing conclusions: 1.
The metal in the chase of 12-inch B.L. gun, Mark 11.,
No. 16, was, as shown by the mechanical tests and
chemical examination, irregular in its character; such
metal would be specially liable to the setting up of
internal strains during the processes of forging or of
oil hardening. 2. The metal had not been subjected to
annealing processes, by which such strains would have
been mitigated; annealing not having been adopted
until a date subsequent to the manufacture of this
gun. 3. The gun had been, before issue, fired with
large charges (3401 b. 0.2) of a slow-burning powder,
the effect of which would be to subject the chase to a
severe stress. [This powder was subsequently with-
drawn from the service owing to its capricious charac-
ter.] 4. After the preliminary firing trial and proof
had been carried out the gun was not fired for IS
months. The fracture of the chase occurred on firing
the first round after this period, tl.e charge used being
a reduced one of 22111 b. Prism. 1, brown. 5. The chase
burst with violence whe.. firing a charge which subjec'ed
it to comparatively low pressure, after having previously
sustained, without apparent injury, a series of high pres-
sures. Taking the above into consideration, the com-
mittee are of opinion that the fracture of the chase
of No. 16 gun, when fired with three-quarters of the
service full charge of powder, was due to a combina-
tion of the following causes: (a) to a want of uni-
formity in tbe metal of which the chase was com-
posed; (b) to the absence of annealing after forging
and oil hardening, which treatment would have miti-
gated any internal strains set up by these processes;
(c) that such strains were probably intensified by the
preliminary and proof rounds, and their effect was
developed during the interval of time between
proof and the accident; and (d) to the
foregoing unfavourable conditions not having be:?n
counteracted by the hooping of the chase,
With reference to the steps to be taken to pre-
vent such an occurrence with the remaining guns of
similar pattern, the committee recommend that the
chase of these guns should be strengthened by booping
them to the muzzle after removing the front coil 3 B.
With reference to point (c), they recommend that these
guns be lined in the chamber to a diameter of 142 in.,
and that after this operation the guns be proved with
two charges, each of Prism. 1 brown powder, to give
not less than 17 tons pressure per square inch in the
chamber with a 7141 b. projectile. These two rounds
to be followed by five rounds of such a charge as may
be determined on for service. The pressure to be
given by this charge not to exceed 15 tons per square
inch in the chamber. With regard also to other guns
the committee recommend similar precautions."