The Billinghurst Requa Battery Gun
The multiple barrels Requa (named for Dr. Josephus Requa) design was first suggested in the Renaissance, and Leonardo DaVinci developed plans for a weapon that rotated a new platform of loaded barrels to provide three devastating rounds of fire without reloading. However, it was the invention of the self-contained metal cartridge, which allowed the weapon to be reloaded quickly that made the idea practical. The cleverly arranged breech, which closed on a piano hinge, allowed for the ammunition strips to be loaded, fired, extracted, and reloaded quickly. It was also possible to adjust the spread of the guns to make them more useful at close range. If spray was important, the barrels spread out a few degrees. Only three gunners were needed to service the Requa volley gun. A three-man crew at an 1861 demonstration of the “Requa Battery” in New York City fired the weapons at the rate of seven volleys, or 175 shots, per minute. In one Army test the gun’s rate of fire reached 225 shots in one minute and 15 seconds. Prominent gun maker William Billinghurst, the proprietary builder of the Requa claimed an “effective range of 1,200 yards,” and Army and Navy records appear to have verified that claim. The government ordnance department generally dismissed the Requa, however, with the argument that such a weapon would consume expensive ammunition at such a rate that it would cause logistical problems.
Nonetheless, the Federal army may have had as many as one hundred volley guns, but most were placed in the static defenses around Washington, DC. Private production of the Requa volley gun began in 1862. The first Federal "Requa Battery," a component of the 108th Regiment of New York Volunteers, was formed in Rochester, New York in 1862. Mack's Rifled Battery was outfitted with the Requa Batteries and recruited to be part of Rochester's 108th New York Infantry. Instead they were added to the 140th as the 26th New York Independent Battery when the 108th left before Mack's unit was at full strength.
There are records of the Federals using volley guns at the siege of Charleston, SC in 1863. Elements of the 39th Illinois Infantry, the 3rd New Hampshire Artillery, and the 48th New York Volunteer Infantry used Requa batteries in the attack on Fort Wagner. They trained their volley guns on the Confederate works in support of an infantry attack. After the initial abortive attempt, General Terry led the 3rd New Hampshire and the 24th Massachusetts on a successful charge against the Confederate rifle pits protecting Battery Wagner. Most of the eighty-six defenders, unwilling to risk retreating over ground seeded with torpedoes quickly surrender. The pits were quickly fortified with Requa batteries and 8-inch mortars allowing Brigadier Q. A. Gilmore to begin his final approach against a stubborn Rebel battery. During an attack on Morris Island, Lieutenant Nichols of the 48th Regiment New York State Volunteers was detached from his regiment and was placed in charge of the Requa Batteries. Men of the 39th Illinois Infantry also served these Requa guns. The Confederate government purchased at least twenty volley guns prior to the opening of hostilities and may have purchased more thereafter. Incomplete southern records have obscured any exact record of their number or deployment.
Although designs for more barrels existed, Requa Volley guns with 25 rifle barrels set in parallel were most common. A trained crew could fire the weapon at the rate of seven strips per minute. This gave a rate of fire of 175 rounds per minute. The several barrels helped to prevent overheating. The prepared strips were pre-loaded and carried in an ammunition case on a limber. The limber and gun could be pulled by as few as two horses. When the side mounted loading levers were up, the breech was open. A powder train was laid behind the ammunition strip. Pushing the levers forward and down secured the breech. A musket cap was placed on the centrally located priming nipple and activated with a simple flip-over hammer mechanism. The barrels, each 24 inches long, fired sequentially from the center out with a characteristic rippling effect. There was an elevating screw below the breech mechanism. [Source --
Civil War Tech: How Simple It Is After All (2018)]