"The objects of SRBP [Short range battle practice] were to test and train gun pointer groups at pointer fire, to test and train loading crews at maximum safe rates of fire to test material, and to stimulate interest in gunnery. It certainly succeeded in increasing speed. In 1919 battleship main batteries averaged about 1.9 Shots Per Gun Per Minute [SPGPM]. By 1930 the average rate had risen to about 2.5 SPGPM, though for a variety of reasons it never got much higher than this. In fact, the obsession with speed in Short Range Battle Practice finally became so great that in 1938, CNO, fearing that some ships were not checking for bore clear with sufficient care, promulgated regulations specifying a minimum twenty-four second loading interval, and imposing a penalty if it was not upheld.34 Navy "E"s in gunnery, predominantly displayed on the sides of turrets between the wars, were primarily awarded for performance in Short Range Battle Practice. Aside from being a fertile source for the study of loading accidents, the results of SRBP are of relatively little historical value, and will not be studied here."
Were did I say spotting APC hits was easy ? I said they were spotting the water columns ! At the same time, Kirishima was illuminated with starshells from 4x5"/L38, which fired 62 shells against her. So it was rather easy to observe the fall of shot.
More into the early war 16"/L45 problems:
"The introduction of the new 16"/45 and the 16"/50 batteries installed in the treaty battleships in the late 1930s and early 1940s was somewhat less than agreeable. New 16-inch range tables used incorrect powder temperature velocity differentials and inaccurate instructions to compensate for the rotation of the earth. Charge assessment problems gave the new 16"/50s an initial velocity about 30 ft/sec higher than expected, so they initially overshot their range tables, especially when the range was long. At the same time, proving ground experiments showed the 'jump" for the new guns to be negative, rather than positive, meaning they undershot their range tables when the range was short. The unfortunate combination caused a vexing problem which took at least two years to solve. Further, although the new 14-inch guns were lighter and more reliable than their predecessors, when equipped with similar fire control systems they proved to be no more accurate than the guns they replaced.26 "
"26 In fairness, the overshooting-undershooting problem would have only been a problem in true blind fire, where no observation of the fall of shot was possible; in most practical cases, of course, the initial salvos could be brought closer to the target by imposing ACTH (Arbitrary Correction To Hit) and successive patterns could be spotted on to a target visually or by radar. Inherent dispersions, of course, couldn't be corrected that way. The Bureau of Ordnance expected the nine-gun patterns given by the 16-inch batteries mounted aboard the Washingtons, South Dakotas and Iowas to be slightly larger than the eight-gun pattern sizes for the old 16-inch guns mounted aboard Colorado, Maryland and West Virginia. Specifically, eight old guns were expected to yield an average range pattern of 1.8% of range while nine new guns would give a 1.9% pattern. These were ideal figures; in practice the old 16-inch guns gave a seven-gun pattern size of about 2.2% of range during their last firings in 1941. The dispersion of the 16"/45 and 16"/50 guns, incidentally, was essentially identical; ranging sheets at Dahlgren often listed dispersions for the two types interchangeably. Today, the 16"/50 yields a 9-gun pattern size of about 1.5% of range at short ranges, slightly less if the range is long. Viz. Bulletin of Ordnance Information, No.3, 1945, FTP 2101, Reports on Gunnery Exercises 1940-41 and Naval Weapons Laboratory Tech. Report No. K-26167. "
"As before, the normal battle target has been replaced by the outline of a 785 foot, 20 knot target. The signal to shift targets came at 1 minute 55 seconds into the firing, but fire was not shifted until after the fourth salvo..."
Dipsersions at 13000 yards:
Note the NUMBER of shells fired in order to obtain several hits.
- dispersions.PNG (216.54 KiB) Viewed 1313 times