Naval warfare during the Industrial Age was heavily influenced by rapid cycles of technological change and weapon innovation, which led in turn to the development of ever larger warships carrying better armor and more powerful guns. Such vessels, however, were enormously expensive to build and maintain. The Jeune École arose as a response by nations unwilling or unable to invest in an expensive blue-water navy. One of its strongest proponents was French Admiral Théophile Aube. The idea was a variation on the old notion that gunboats with very heavy guns could provide an effective harbor defense against a blockading fleet. Aube believed that swarms of small but fast boats equipped with new Whitehead locomotive torpedoes could attack and overwhelm a fleet of ironclad warships whose slow-firing heavy guns would be unable to respond effectively. Such attacks would be best done under the cover of darkness. Thus, a relatively cheap weapon system could destroy a very capital-intensive one.
It did not take long for the weaponeers to come up with a cost-effective solution to this gunboat threat: rapid-firing small-caliber guns with enough hitting power and range to cripple or destroy an attacking torpedo boat. Somewhat ironically, the French firm Hotchkiss was at the forefront in the design and development of these counter–Jeune École guns, followed by England’s Nordenfeldt Company.
The guns were available in 1-pounder (37-mm), 3-pounder (47-mm), and 6-pounder (57-mm) configurations. The ammunition was of the fixed type—a projectile attached to a brass-alloy rimmed cartridge case with a primer in the base.
The guns comprised a simple built-up rifled barrel attached to the body of the gun and swivel-mounted on a pedestal, offering a large field of fire. A common feature was a vertical sliding-wedge breechblock. (See “The Krupp Horizontal Sliding-Wedge Breechblock,” August 2021, pp. 10–11.) After firing, an operating lever was pulled back, releasing the breechblock, which slid along guides in the body of the breech, causing the spent case to be extracted and ejected and cocking the firing hammer, all in one motion. When a new round was loaded and the handle moved forward, it raised the breechblock, firmly seating it against the back of the cartridge. It was now ready to fire using a simple pistol grip and trigger. Recoil was absorbed by a spring-loaded hydraulic cylinder in the pedestal mount.
These guns were relatively light and easy to use. With a minimum of training, a four-man crew could fire up to 25 rounds per minute. One man stood to the right side of the gun and operated the breech lever. The gun captain stood behind the breech and, with his right hand on the pistol grip, aimed along a tangent sight. Bracing his left shoulder against a padded bar, he moved the gun right or left and up or down. A loader stood to his left, ready to insert a fresh round into the breech. The other man supplied rounds to the loader, cleared away spent casings, and stood by as relief for the others.
The U.S. Navy equipped its first modern steam and steel warships with the Hotchkiss rapid-firing guns, built under license by the Pratt & Whitney Company of Hartford, Connecticut. While the guns were entirely satisfactory, Congress had required that the newest warships be built with designs and material obtained from domestic firms. Two enterprising naval officers working in the Office of Naval Intelligence, Lieutenant William H. Driggs and Commander Seaton Schroeder, undertook to improve the Hotchkiss design so that the Navy’s new guns could meet the congressional mandate. Of note, their design used the same mounting and ammunition as the Hotchkiss guns.
The main design change was in the arrangement of the breech and breechblock. Unlike the Hotchkiss design, the top of the breech was enclosed, which would prevent intake of rain or debris. The block was cast with four raised guides on its top and sides that engaged machined grooves in the breech. This arrangement was more gas-tight and allowed the breechblock to be considerably lighter. The weight savings allowed the barrel to be lengthened, increasing a gun’s range without increasing overall weight.
After firing, the operating lever was pulled back, causing the block to drop a small distance to disengage the grooves and then rotate down. As the block fell back to open the breech, the spent casing was ejected and a rifle-style firing pin in the breechblock was cocked. The new round was inserted and a forward motion of the operating lever rotated the block vertically and raised it to engage the locking grooves, firmly seating the cartridge.
Other important improvements included turning the shoulder bar into a type of gunstock and relocating the operating lever to the left side and the gunstock to the right. And the gunstock now included the trigger assembly, so the gun could be shouldered and aimed just like a rifle. Standing off center to the right, the gunner avoided being hit by the ejected casing. Finally, this allowed the breech operator and loader jobs to be combined. Standing to the left, the loader used his left hand to operate the breech lever and his right to load the new round, reducing the crew size to just three men.
Driggs described the new design in an article—“The Driggs-Schroeder System of Rapid-Fire Guns”—that appeared in the January 1892 Proceedings. He reported test results showing superior accuracy and longer range compared to the Hotchkiss design. The 6-pounder had a theoretical range of more than 8,000 yards, but without telescopic sights, the realistic range was less than 2,000 yards. The rapidity of fire would allow the gunner to “walk” his fire into a target at close ranges, albeit with considerable wasted ammunition. The Driggs-Schroeder guns were built by the American Ordnance Company in Bridgeport, Connecticut, and were part of the armament of nearly every class of U.S. warship built in the 1890s, including the USS Texas (“Old Hoodoo”), Olympia, and Maine.
Hotchkiss, however, was not content to share the market and introduced improvements in its own design to make it “semiautomatic.” A spring mechanism and thrust rod were added to the gun’s right side that used the energy from the recoil to work the operating lever, open the breech, and eject the casing. When a new round was loaded, it acted against the extractors, which caused the extended spring to be released and slam the breechblock closed. Thus, the crew was reduced to only the gunner and the loader. As an added bonus, the existing Hotchkiss guns then in service could be easily converted to add this new feature.
Innovation in ship design soon made this class of weapon obsolete as far as first-line warships were concerned. Improvements in torpedo design greatly increased their size and range. A new class of ship—fast “torpedo boat destroyers”—was developed to manage the threat from the small torpedo boats. The new destroyers were larger, faster, and equipped with multiple torpedo tubes that could fire a salvo at ranges beyond the effective penetration range of the 6-pounders. Henceforth, battleships would need a powerful secondary battery of medium-caliber weapons to fend off torpedo attacks. The old Hotchkiss and Driggs-Schroeder guns were relegated to service with patrol boats and small craft.
The Navy’s new destroyers also were tasked with stopping attacks made by their opposite numbers, and for this they required a light, rapid-firing gun with more hitting power than the old 6-pounders, and a 3-inch gun was chosen. However, the new gun’s interrupted-screw breechblock design did not allow for semiautomatic operation, limiting its rate of fire.
In 1906 Driggs was granted a patent on an improved Hotchkiss sliding-wedge breechblock that incorporated his firing-pin design. This became the basis for the semiautomatic 3-inch 50-caliber Mk V gun that became the Navy’s standard minor-caliber weapon. In World War I, it was used on destroyers, submarines, and antisubmarine patrol boats and found a new use as a rapid-fire antiaircraft weapon. During the interwar period, this gun evolved into the 5-inch 25-caliber antiaircraft gun that was mounted on all major U.S. warships. This gun, too, underwent further development, becoming the famous dual-purpose 5-inch 38-caliber gun. These highly sophisticated guns bore only a passing resemblance to their forebears, but at their heart was the same sliding wedge breechblock introduced by Hotchkiss and improved by Driggs.
Sources:
CDR W. F. Hart and LT T. C. Hart, USN, Text-book of Ordnance and Gunnery, 2nd ed. (Annapolis, MD: Naval Institute Press, 1905), 142–48.
LTs J. F. Meigs and R. R. Ingersoll, USN, Text-book of Ordnance and Gunnery, 2nd ed. (Baltimore, MD: Isaac Friedenwald, 1887), ch. 3.
Officers of the United States Navy, Textbook of Ordnance and Gunnery, 1917 ed. (Annapolis, MD: Naval Institute Press, 1917), 72–80.
NAVPERS-16116-1944: Naval Ordnance and Gunnery (Washington, DC: Headquarters U.S. Navy, 1944), ch. 6.