Difference between revisions of "Concentration"

Revision as of 12:59, 12 November 2012

Concentration is the practice and method of having more than a single ship fire upon the same target. Although the practice offers clear benefit in allowing a superior force to make good its advantage in strength, difficulties each firing ship faces in correcting its fire undercuts the effect.

Innovations in procedure and equipment during the war allowed fire to be joined with ever-diminishing loss of effectiveness due to mutual interference and confusion.

Communication

In early 1913, trials of special "Cruiser Arc Lamps" pattern 1875 to convey range, rate and target signals that had been conducted in the Home Fleets were soon to be concluded.^[1]

Sequence Firing

Basically, there were two methods developed to concentrate fire on the same target without mutual interference. The first (and less complex) was sequence firing, referred to as GIC in the Royal Navy for its three-character signal code. In this method, ships coordinated and fired in a fixed time slot sequence, with one ship firing while the other was reloading. With careful attention to time slots, a ship could spot her salvos while ignoring other ship’s salvos in the “off” time slots. Ships exchanged gunnery data, but each ship spotted and controlled her own fire. It required steady communication for coordination and could be used by ships with different size main batteries. However, the fixed time sequence limited the effective rate of fire and was more appropriate for extended range salvo time of flight. The normal, occasional delays in reloading one or more main battery turrets and temporary visibility obstructions for spray, smoke, etc. could cause a ship to miss her sequence. Further, it prevented the normal process in which a ship would correct salvos until the target was straddled and then fire several salvos as quickly as possible before repeating the spotting process to “get on” again. These limitations meant sequence firing was generally effective only for pairs of ships (additional ships further reduced the effective time slots and accentuated rate of fire limitations) at long range. GIC firing procedures were standardised in the Royal Navy after Jutland for capital ship divisions. Following the November 1917 cruiser clash with the German High Seas Fleet, this practice was extended to light cruisers which had been equipped with centralised director fire control.

Master Ship Firing

The other method was massed firing, referred to as GMS in the Royal Navy. One ship acted as the master ship and controlled the fire for all participating ships, enabling multi-battery salvos and larger ladders to get on target quicker. Since one ship was determining the fire control solution, all participating ships had to have the same type of main battery and robust communications to quickly pass range and azimuth corrections for succeeding salvos to each ship. It had the advantage of rate of fire flexibility and larger salvos and was not limited to long range. But, it required intensive training and frequent practice by the participating ships to be effective and fast, uninterrupted communications to work. This was largely beyond WWI technology. In addition, the increased number of splashes from multi-battery salvos was more difficult to correctly spot. In early 1918, Cdr. H. E. Kimmel, a USN observer with the Grand Fleet, confirmed to the USN General Board that massed firing trials had been practically abandoned, “That was a failure.” He added that sequence firing “...shows promise of considerable development.”

Post War Refinements

After the war, all navies pursued the promise of concentration fire and developed the required W/T communication technology and firing techniques to maximize its application. Range clocks and turret azimuth marks were developed to enhance intercommunication and became prominent in interwar photographs. The Royal Navy’s 1939 Firing Manual noted that GMS was, “…the standard system and is used by all ships armed with similar guns and equipped with similar fire control tables.” GIC was an alternate method for ships with different batteries and ships from different divisions, which had not practiced together.

The USN pursued a slightly divergent course developing dye colored shells to differentiate salvos through the use of different colors for each ship. Practice brought proficiency and confidence in this approach was evident in the USN Battleship Doctrine of the late 1930s. “In concentration fire, when spotting projectiles are being used, ships will proceed without regard to each other, as in the case of single or ship-for-ship fire. When spotting projectiles are not used, ships in concentration will fire in rotation beginning with the concentration leader, but no ship will wait appreciably more than one half-salvo interval for a preceding ship to take its turn. When ships are firing in rotation, a ship must not fire a salvo within five seconds of another ship’s salvo.” Given that anything but “short” splashes were extremely difficult to spot at long range, it would seem color dye shells were planned to be used primarily with aerial spotting.

The Royal Navy also pursued spotting projectiles. The British colored dye mechanism, called a “K device,” was based on a French pre-WW II design that proved defective and had to be redesigned. This delayed the issuance of “K shells” (5.25-in and larger) until mid 1942, by which time there was little opportunity for employment.

By the eve of WWII, all navies had developed concentration fire procedures and practiced them frequently until they were confident their ships were ready to use them should the tactical situation arise. But like most other things, it proved much harder to achieve in the stress and confusion of battle than it had been in the many pre-war training exercises. The Royal Navy quickly noted that the frequent drills and practice needed to ensure effective coordination were hard to maintain with ships continually steaming in anti-air and anti-submarine escort operations. Combining warships into last minute ad-hoc divisions for an operation became the norm, which also hindered ships working together long enough to develop the required teamwork. These trends reached a nadir in June 1944 when Admiral Lee had to decline a potential engagement because his fast battleships had been too busy escorting aircraft carriers to practice their traditional gunnery skills. Further, there were few daylight engagements between forces large enough to create the numerical superiority situations that called for concentration fire. Thus, actual examples of concentration fire were fairly rare.

See Also

• Distribution of Fire
• Concentration Dial
• Consort
• Aid to Spotter
• Interval Firing

Footnotes

Bibliography