585 
THE DEVELOPMENT OF ARMOUR 
DURING THE YEARS 1893-98. 
BY 
CAPTAIN C. OKDE BROWNE, late R.A. 
Continued from No. 11, page 557. 
Progress of Manufacture from 1893 to 1898. 
The chief new feature in armour is the Krupp process, the results of Krupp > s 
which have appeared in the trials above noticed. The process is process, 
sufficiently peculiar and the details still treated so far as manufactur¬ 
ing secrets that little can be written with advantage. The effect is to 
impart extraordinary toughness to armour in conjunction with a very 
hard face, and as above noticed- this tells chiefly in thick plates 
because when severely attacked they are subject to a rending strain 
which seldom falls on a thin plate. This often arises from the fact 
that the width of a thick plate is not very much greater than of a 
thin one, so that shot whose powers of perforation may be fairly 
matched against thick and thin plates will impose a much greater 
shock and rending strain on the former. For example in the attack 
of 6-in. and ll^-in. Vickers* plates (see pages 510 to 512) the 6-in. 
plate was attacked by 6-in. shot whose perforation was equal to 13’45 
of iron, or 2’24 times the thickness of the plate. The llj^-in. plate 
was attacked by 12-in. shot with 23’5-in. perforation through iron, or 
2*05 times the thickness of the plate ; that is slightly less proportion¬ 
ately than the 6-in. plate, but on the other hand, the area of the thick 
plate not increasing at all in proportion to its thickness, the striking 
energy per ton of the 6-in. plate is only 505 ft.-tons, while that of the 
thicker one is 1,146 ft.-tons; and the 6-in. shot in the 6-iu: plate, 
which is only 6 feet wide, constitutes a wedge of t L- of its width, while 
the 12-in. shot in the 11 H -in. plate 7 feet wide is a wedge of \ of its 
width. It is easy to see then that toughness is specially called for in 
thick armour. The succession of manufacturing processes by which 
this toughness is imparted is very curious. Steel which would be 
thought brittle and very unsuitable for the purpose, is subjected to 
processes which would in past days have been thought likely to make 
matters worse, great toughness being the result. The hard face is 
sometimes, but not always, obtained by the action of gas instead of 
solid carbon. Undoubtedly in each factory modifications may be 
introduced and each has its own method of treatment based on 
experience. The Krupp process is one calling for special skill and 
perseverance and could not fail to present difficulties at first which 
might be overcome by each establishment in its own way. 
12. VOL. XXV. 
