Imperial Russian Navy Dreadnought Fire Control
The information on this page is the work of Mr. Stephen McLaughlin.[Permission Needed for Publication]
Fire-Control Positions in a Russian Dreadnought
Fire-control Positions in a Russian dreadnought
|Chief Fire-Control Officer||For'd Conning Tower|
|1st Assistant Fire-Control Officer||Central Station|
|2nd Assistant Fire-Control Officer||For'd Conning Tower|
|3rd Assistant Fire-Control Officer||After Conning Tower|
|4th Assistant Fire-Control Officer||Spotter, Fore-Top|
|5th Assistant Fire-Control Officer||Assistant Spotter, Main-Top|
|1st Torpedo Officer||For'd Conning Tower|
|2nd Torpedo Officer||After Conning Tower|
Four range-finders per ship. At present these are 9-foot base Barr & Stroud, and Pollen. They are to be replaced by 15-foot base Pollen range-finders as soon as they can be secured from England.
Range and deflection transmitting instruments
In the central station a range panel on which are mounted three electrically operated dial instruments. A is the master range dial, B the rate of change dial, and C the dial by which spots are applied. Repeater range dials similar to A are installed in all turrets, in officers' booths and at sightsetters' stations, also in both conning towers. The operation is as follows: When the pointer on B, the rate of change dial, is on zero, there is no movement of the hands on dial A. If the pointer on B is set, at eg. 100 yards, which means a decrease in range of 100 yards a minute, the hands on A, the master range dial will show a constantly decreasing range at the rate of 100 yards per minute, and the repeater dials in turrets and conning towers show at all times the same range as the master range dial. On the periphery of the sight setter range dials is a pointer which moves with the sights. The sight setter simply keeps the outer pointer in line with the inner one which is controlled by the master range dial. The range graduations are shown on all dials but the sight setters need not concern themselves with these, although they are trained to set the ranges given by voice tubes and telephones.
There are two pointers on the master range dial in the central station, one red and one black. When a spot is given, for example, up 50, the operator turns the handle of the spot dial to 50. the [sic] red pointer of the master dial also advances 50, but the black one does not. The range indicated by the red pointer is shown on all repeater dials. After the spot is on the master dial, the operator moves the pointer on the spot dial, by hand, back to zero. Both pointers on the master range dial move in accordance with the rate of change so that the interval between these pointers is the net value of spots. All range graduations on Russian fire-control instruments are in cables (200 yards), the smallest graduation being 1/4 cable.
Alongside the range panel in central station is the master deflection dial, which has repeaters alongside all the range repeaters. Zero deflection is marked 100, left deflection being graduated to zero, right deflection to 200.
The only plotting done in the Russian fire-control system is for the purpose of determining the rate of change of range. The Russians do not depend upon their range finders to keep the range after the guns have opened fire, for they have found the accuracy of these instruments to be greatly decreased after firing has begun. The readings are taken, however, and reported to the 3rd Assistant Fire-Control Officer in the After Conning Tower. He plots the position of his own ship and that of the enemy on a large chart, for the purpose of determining the enemy's course and speed, in order to get approximately the rate of change of range.
The following formula is used:
- V = own speed
- G = bearing of enemy
- Ve = speed of enemy
- Ge = angle between enemy course and bearing
- R = rate of change of range
- R = V cos G Ve cos Ge
Complete tables are worked out from the above formula so that R can be quickly obtained from positions plotted on the chart. Plotting is done solely to obtain the two unknown quantities Ve and Ge.
Recognizing the difficulty of obtaining exactly the rate of change, the Russians have devised a scheme in which they do not desire to know the exact rate. At long ranges, if the rate of change is Zero, or if it could be exactly known and applied to the sights, every salvo might straddle the target without obtaining a single hit. If the rate as applied to the sights is slightly in error, the patterns of the successive salvos will move across the target and some hits are bound to result. Before the salvos get entirely off the target a spot is applied to bring it back. If the error in rate is too great the patterns of the salvo splashes will move across the target too rapidly, and require too much spotting. In this case the Chief Fire-Control Officer reduces or increases the change of rate. He does not desire much spotting after getting on, not more than a spot of 50 yards every three or four salvos. The spotters and the plotter report directly to the Chief Fire-Control Officer, and he directs his assistant in central station what spots, and changes in rate to apply to the range. The desired error in rate is such that will cause each successive salvo to fall a trifle shorter than the preceding one. When the shorts become more numerous than about 25%, a plus spot is given.
To illustrate in detail the procedure in the Russian system, the following description is given of fire-control on a dreadnought of the latest type in commission with a main battery of 12 - 12" - 52 calibre guns arranged in 4 triple gun turrets. As soon as the target is visible, ranges are taken and plotting begun to determine initial range and rate of change of range. Corrections in initial range and deflection, worked out from range table table, are applied. When the initial range on the range dials becomes 100 cables (20,000 yds) a ranging shot is fired from № 1, the forward turret. This shot is corrected for deflection only and a second ranging shot is fired from № 3 turret. If necessary, the deflection is again corrected. Two shots are allowed to get on in deflection if necessary, before changes in range are given, for it is believed that at 20,000 yards the range cannot be intelligently changed until the deflection is correct. A third ranging shot is fired from № 2 turret and the range correction applied. A fourth ranging shot is then fired from № 4 turret, and corrected. The spot for the first range correction is made sufficiently large to determine the limits between which is the target. For example, if the 3rd ranging shot is short, the spot is intended to put the 4th one over. When this is corrected, if the Chief Fire-Control Officer thinks he is getting close he will fire a salvo next, of six guns from № 1 and № 3 turrets. Or he may fire more ranging shots or a 3 gun salvo from № 1 turret.
When salvo firing is ordered by the Chief Fire-Control Officer there is a salvo of 6 guns fired every 20 seconds. Turrets 1 and 3 fire together followed by turrets 2 and 4 twenty seconds later. This gives a firing interval of 40 seconds for each turret. The loading of guns is all mechanical and requires 28 seconds, giving the pointer 12 seconds to get on. Turrets are numbered consecutively from forward.
When salvo firing begins the Chief Fire-Control Officer starts "building his ladder" as it is called. With a salvo of six splashes striking every 20 seconds he can tell at once if the error in his rate of change is too great, and he changes it, meanwhile keeping the salvos straddling by spotting. Too much spotting is not believed in, however, after once getting on. When the error in rate is small each successive salvo will move across the target slowly, splashing in almost the same relative position to the target as the preceding salvo. This is the condition desired in "building the ladder."
Fire-control officers become very skillful in determining approximately the rate of change from observing the positions, relative to the target, of successive salvos. They can detect, at once, a change of course of the target and correct their rate, before the officer plotting has obtained sufficient reliable data from the range-finders to enable him to calculate the new rate of change.
The officer in charge of the fire-control desk in the Russian Admiralty stated that the system as outlined above, is the result of years of steady application of the best mathematical brains in Russian to the problem of naval fire-control; that since the naval disaster in the Japanese war, which is claimed to have been due to the very poor system of Russian fire-control, constant experimentation and tests have been going on to determine the best system to adopt. He stated that since the adoption of the present system the average hitting ability of the entire navy had increased to a surprising degree; that in every naval engagement with the Germans in the present war, this system gave excellent results, and although some of the Russian ships had been rather badly shot up in engagements, there had never been any trouble in fire-control. He stated that the superiority of the Russian system over the Germans had been demonstrated repeatedly. One example was the engagement, in the Black Sea, between an old Russian battleship with 4 - 12" - 40 calibre guns, and the German battle cruiser "Goeben" with 8 - 11" - 50 calibre guns. The Germans made four hits, the Russians eleven, and only the superior speed of the "Goeben" enabled her to escape, badly damaged, to Constantinople, where she has since remained. At first, in this fight, the German shooting was very good, but as soon as the Russians began landing their salvos on the "Goeben" her firing became demoralized and inaccurate.
The Russians have not yet installed director firing on any ships in commission, but they are about to do so having had highly favorable reports from Russian naval observers in the British fleet as to the merit of this system. They will retain their own system of fire-control however.
It is interesting to note here that Russian gunnery officers, or fire-control officers as they are called, are all highly trained specialists. To become Chief Fire-Control Officer of a ship, it is essential to complete a three year post graduate course in technical ordnance. Usually the Chief and one or two of his assistants are graduates of this difficult course, and his other assistants are candidates for it.
The Russians consider fire-control the most important branch of the service, and this belief is shown by the fact that the Chief Fire-Control Officer of the ship which stands first in gunnery each year is immediately promoted one grade when the standings are determined.
Fire-control officers have no other duty but ordnance and fire-control until they attain the rank of Captain.