480 
THE DEVELOPMENT OE ARMOUR. 
Nickel adopted 
in Sheffield, 
1896. 
Krupp process 
purchased by 
Sheffield ' 
makers, 1896. 
Increase in 
stringency of 
tests in supply 
of armour, 
1896. 
6*10 in., weighing 5 tons 6*1 cwt. It was subjected to the attack 
shown in the table below. Fig. 13 shows the plate after the attack. 
No. of 
round. 
Calibre in 
Weight of 
shot. 
Striking 
velocity. 
Perforation 
through iron 
Perforation 
achieved. 
c.m. 
inches. 
lbs. 
f.s. 
inches. 
inches. 
1 
1641 
8-8 
7-0 
2 
3 
} 12 
472 
57-32 j 
1690 
1894 
9-2 
10-9 
7-2 
9-6 
4 
( 
1950 
11-4 
9-4 
5 
17 
6-69 
169-8 
1408 
10-5 
Through 
6 
12 
472 
57-3 
2)48 
13-1 
Through 
7 
r 
1338 
8-1 
6 7 
8 
9 
} 15 
5-91 
112-4 \ 
1516 
1566 
9-7 
10-2 
10-8 
9-5 
10 
) 
( 
1636 
10-9 
Through 
Effect. 
Projectile set up 0'35 in. 
« » 0-43 „ 
n broken. 
a set up 0*08 in. 
n broken. 
I Projectile unbroken, 
>but set up amounts 
) not exceeding 0'81 in. 
This plate had thus borne, it is observed, blows whose total energy 
amounted to 5,109*9 m.t. (16,590 foot tons). The report concludes 
by noting that the plate had shown striking qualities, having great 
toughness combined with an amount of hardness which offered great 
resistance to penetration. 
This verdict is well supported, for it may be seen that shot whose 
calculated perforation exceeds 10 in. of wrought iron or 8 in. of 
ordinary steel and in one case 11*4 in. of iron or 9*1 of ordinary steel 
and which should therefore have easily perforated this unhardened 
plate, whose thickness was only 6*1 in. were stopped by it, although 
their points got through. The three projectiles striking with a 
velocity 1,894 f.s. or over, broke up, while the whole of the remainder 
set up more or less, the maximum amount being 0*81 in. This plate 
appears to be the beau ideal of what is required for an inland shield 
intended to bear the long continued attack of siege guns of medium 
power. In the latter part of 1896 nickel was employed by our 
Sheffield makers in their Harveyed plates and not long afterwards the 
Krupp patent was purchased by them. Messrs. Cammell considered 
however that as good results were to be obtained by the Harvey 
process, nickel being employed; but at Vickers and Brownes the 
Krupp process was said to offer the special advantage of producing 
thick armour plates of such toughness that it is impossible to break 
them through. In hardness, all the Sheffield makers considered that 
Harveyed armour rivalled that of Krupp. The writer thinks that no 
unprejudiced person can fail to conclude that the results already given 
establish the great toughness. Unquestionably, however, the introduc¬ 
tion of the Krupp process was very costly and troublesome and consider¬ 
able experience is needed to prevent disappointment and to secure the 
high qualities which are attainable under certain conditions. 
In support of this it may be noticed how very few of these admir¬ 
able thick plates have yet been brought forward. 
About the same time, that is the latter part of 1896, the service test 
for British armour was made more stringent, a 6-inch plate being 
called upon to defeat the attack of five six-inch Holtzer shot, striking 
