THE DEVELOPMENT OE ARMOUR. 
473 
under the first blow and it must not be perforated by the second. 
Both shot broke up without perforating. The second shot only 
cracked the plate which thus was accepted. Subsequently a 13-in. 
Carpenter shot, weighing 1,100 lbs., struck it with a velocity of 
1,810 f,s., an energy of 2,500 foot tons and a perforation of 26*9 in. of 
iron and was broken up, making a crack or fracture 3 inches wide. 
In March, 1895, an 18-in Carnegie Harveyed plate also for the u.s. rack- 
Oregon belt, had borne cracking and perforating tests nearly as above. in g and 
Owing to difficulty in applying the Harvey process satisfactorily to pei tesTs tmg 
thick armour, “ Double forging” came in. Long exposure to a very Double 
high temperature may cause crystallization in the centre of a large forging, 
mass, and re-forging after the Carburying process is a natural remedy 
for this evil. It had been tried at least as early as 1892, but the 
results had not always been encouraging. The following however is a 
sample of a Carnegie double forged nickel Harveyed steel plate, 8 ft. Carnegie 
x 8 ft. x 10 in., tested at Ochta near the end of 1895. plates at 
The details of the trial are shown in the following table. Ochta. 
Round. 
Projectile. 
Striking 
velocity 
f.s. 
Striking 
energy, 
ft., tons. 
Calculated 
perforation 
of iron, 
inches. 
Estimated 
actual 
penetration. 
Relation of 
calculated 
iron per¬ 
foration to 
thickness of 
plate. 
Reforged 
Striking Carnegie 
energy per plates 1895. 
ton of plate 
foot, tons. 
Calibre, 
inches. 
Weight, 
lbs. 
1 
6 
88 
2589 
4090 
19-2 
7-9 
1-92 
350 
2 
6 
88 
2597 
4116 
19-3 
8-5 
1-93 
351 
3 
6 
87-35 
2391 
5063 
22-6 
10-2 
2-26 
432 
4 
9 
402-7 
1879 
9856 
20-6 
11-75 
2-06 
841 
The projectiles were of Poutiloff make. The interesting feature is 
the high velocities employed. The plate defeated the attack very 
well, although broken by the last round as shown in Fig. 6. 
On September 4th, 1895, a 14-in. Carnegie reforged plate for the j 0M , a i4d». 
side of the Iowa battle-ship was struck by 10-in., 500 lb. Carpenter P la te. 
shot, with velocities of 1,482 and 1,856 f.s. they broke up with 
about 3J and 9 in. penetration, no cracks were made. Having thus 
passed acceptance test, a 12-in. Wheeler, 850 lb. sterling shot was 
fired with a velocity of 1,800 f.s., the point of which got through and 
cracked or broke the plate across (see Fig. 7). Captain Ja< ques wrote 
of this that it was the best record yet obtained. The perforation of 
the last round through iron would be 24’4 inches, so that the plate’s 
figure of merit is just about 1*74. Subsequently a 13-in., 1,100 lb. 
Wheeler Sterling shot was fired with 1,800 f.s. velocity which passed 
clean through unbroken. 
In the summer of 1895, at Indianhead, a reforged Harveyed 
Carnegie 6-in. plate (that is an 8-in. reduced by reforging to 6-in.) 
was attacked by a 6-in. gun firing Wheeler, Sterling and Carpenter plate 1895. 
shots, striking with a velocity of 2,100 f.s. One shot of each make 
welded its head into the plate, slightly cracking the latter. The 
projectiles were thus defeated by a plate 1 calibre thick. The 
calculated perforation in iron is 14’9 or 2*5 times the thickness of the 
6-in. re- 
forgedj 
Carnegie 
