In November, 1889, off Helder, North Holland, there were competitive tests of compound armor plates, each weighing 12:4 tons and being 11:02 in.
thick. Three of the plates were manufactured on the Wilson system by Caminel, St. Chammid, and Marrel, respectively. and the fourth on the Ellis sys tem by Brown. The gun used was a Krupp, in. caliber, and firing forged steel projectiles weigh ing 556 lbs. The test was a severe one ; the St. Cha mond and Marrel plates were so badly treated that they were out of the contest after the first shot at each the Cannnel plate was perforated with ease, much of the hard steel face separating from the soft hack. The Brown plate stopped the first two projec tiles, but not the third. and is considered to have be haved excellently. (See Fig. 3.) In 1890 there was another test given a Cammel plate, 8 ft. by 6 ft. by 10 in. thick, the projectiles for the 1st, 2d, and 5th shots being 100 lbs. lloltzer, and for the 3d and 4th shots 98 lbs. Palliser. This plate was greatly outmatched by the projectiles : not only was the penetration very deep. but the hard steel face suffered much more. From this it was judged that the improvement in the Caramel compound steel-faced armor-plates had about reached their limit. The lack of uniformity in results obtained under similar conditions, and the fre quent scaling off of the hard steel faces in these and many other trials were thought to be sure indications of imperfect welding. Against brittle projectiles like the Palliser the compound plates acted to greatest advantage.
Of a number of English-made steel plates which were tested in 1888 but two gave results at all comparable with those obtained from the competing compound plates. a decided lack of uniformity in the metal being very apparent. A steel plate made by Vickers gave bet ter results. The equal penetration and the very similar effects on the armor-piercing projectiles gave evidence of great homogeneity of the plate. The elasticity of the metal was well exem plified by the rebounding of the projectiles, and its comparative softness by the effect on the back of the plate. A large order from the English Government followed the satisfactory showing of the Vickers plate.
In 1888 the French tired chilled cast-iron projectiles of 83.8 lbs. against Schneider steel plates 51 in. thick. Each of the projectiles was broken in about the same manner, and their penetrations not being in proportion to the projectile's energies, it was concluded that the metal lacked uniformity. Liter, the same year, a heavier plate, in. thick, was tired at
with chilled cast-iron projectiles weighing; 99.2 lbs. with most excellent results, homogeneity of the plate being clearly demonstrated. The plate, however. greatly outmatched the projec tiles. In May, 1890, a Schneider plate was again fired at, and behaved much better than in either of the preceding trials. In July of the same year plates of time same make were fired at with Finspong armor-piereing cast steel. The similar effects on plate and projectiles indi cated satisfactory uniformity, and the plate was considered superior in resisting power to any Schneider plate previously tried. It also demonstrated the practicability of forming steel into curved plates without detracting from the resisting power of the metal.
We now come to what were considered the most important and conclusive armor trials ever undertaken by governmental officials. These arc interesting, not only on account of the definiteness of the results obtained, but also from the fact that in each case the plate which fairly carried off the honors was neither one of the old-time rivals—English compound and Schneider steel—but was an alloy of nickel with steel. In addition, the projectiles used were so little damaged on impact that time effects on the competing plates can be fairly compared, a matter of considerable difficulty in earlier trials. The trials at Ochta are given first. as the nickel-steel plate tested there was made a year previous to that used in the Annapolis test in this country.
The trial took place at the Ochta naval battery, in Russia, and three plates were submitted. A Brown (Ellis patent) compound plate, a Schneider nickel-steel plate, and it Vickers all-steel plate, each 8 ft. square, about 10 in. thick, and 1P7 tons weight. The gun was a 6-in, 35 caliber, firing a Iloltzer lbs. Five shots were fired at each plate; the first two were not so well tempered as the remaining three. Here the Brown plate was completely outmatched ; in addition to an unexpected degree of penetration, it was also badly fractured, an unusual occurrence when a compound plate of such thickness is attacked by small projectiles, but the slight scaling off of the hard steel face showed that the welding was excellent. Its performance proved that it did not merit classing with its competitors.