The daily morning journal and courier., 1904-03-24
TESTS OF ARMoRED TURRETs.
Conclusions of French Experts on the
 Results of the Firing.


 The tests of the tnrret of the French battleship suffren by firing heavy pro- jectiles against it was described in The Sun some time ago. and in the mean time, in spite of the secrecy with which the experiments were conducted. more data of the firing have become avail- able and artillery experts have been able to arrive at some interesting con- clusions which will be of use to the worlds navies.
 It is a remarkable fact that the civil ian Minister of Marine (Secretary of the Navy. We would say) should be the first to attempt a practical solution of the question as to whether the pres- ent armored turrets of battleships would or would not suffer seriously from the shock of projectiles striking them. Up to the present time it has heen the custom in all navies to limit the test to determining the degree of resistance os the armor plates which are to compose the turrets. and not to submit the entire turret, mounted and in position, to a firing test, as was done in this case.
 It was therefore impossible to de- termine with any certainty, under the old method, whether the rotating mec- hanism of the turrets of the types test ed would function properly or not af- ter having been hit by one or more pro- jeetiies.
 However. turrets designed for forti- fcation works on shore 0ike the so- txrifh wounded toa) had been submitted to trial as a whole by firing not only on the separate parts, but also on the completed struc- ture, and then firing from the guns en- closed in these turrets to determine the effect of the previous firing on the tur- rets as to accuracy of fire of the guns mounted in them, as well as the rotat- ing power of the turrets themselves. A humber of such tests have been made and gave very satisfactory results.
 There is, consequently no difficulty whatever in constructing turrets (cu- polas) which will resist armor- piercing shells of 6-inch or explosive shell Of |9 1-2-inch calibre. five calibres long, land these turrets, after having been hit @ number of times. could still turn without any difficulty and would still admit of accurate fire from the enclosed guns.
 These trials proved that when the exposed surfaces Of armor plate were inclined about 45 degrees to the line Of fire it was sufficient to have the weight os the rotating mass os the turret ap- proxinately 250 times the weight of the projectile, in order that, even after hav- ing been hit fifty times by 6-inch steel projectiles. neither the facility of rota- tion nor the accuracy Of fire from the turret guns shall suffer in the least.
 But the turrets of warships had nev- CT before been submitted to tests of this kind. It was usually deemed suf- ficient to test the separate plates of which the turret was to be composed, and if these resisted several shots it was concluded that the turret would offer the necessary resistance.
 Modern ships turrets are cylindrical, with the exposed face slightly inclined. With such turfets the factor 250 given above as sufficient for the weight of armoured turrets of land forts is not sufficient. Since the energy of the pro- Jectile increases with the square of the sine of the angle of impact, and since ships guns nowadays have very high muzzle velocities. 1t is necessary to adopt for armored ships turrets a weight 700 times that of the projectiles striking them.
 The firing against the Suffren was di- rected against 8 cylindrical turret arn- ed with two guns The turret was con- structed of steel plates nearly F inches thick, the diameter of the turret being about 26 feet and it's height about 8 feet. It's weight, including the two guns, was therefore about 44O,00O pounds. The projectile fired against it was a steel 12-inch shot, weighing about GAP 1-2 pounds; hence, the turret weighed approximately 70 times the weight of the Drojectile.
 According to the published reports the rotating mechanism suffered in no wise from the shock of the projectiles Pieces of armor were thrown to right and to left, but these only affected the protecting plates used to cover the tur- ret and prevent penetration into the latter As the weight of the protecting plates was only 1-2 per cent. of the total weight os the turret, it did not affect the result.
 Therefore the test may be regarded as absolutely conclusive, and to M. Pelletan, the French Minister, is due the credi. of having thus elucidated in Ia radical way most important ques- ton. and one never examined into be- fore. Moreover. the French Navy was thus able to prove Contrary to the doubts which had frequently been ex- pressed) that it could count absolutely on the resisting power of it's armoured turretS in actual war.