Powder and Propellants for the Navy: A History of an Energetics Leader

Indian Head 1The Naval Surface Warfare Center at Indian Head has been at the forefront of energetics production, testing, and research for more than 125 years.

By Josh Phillips

The Naval Surface Warfare Center Indian Head Explosive Ordnance Disposal Technology Division isn’t the easiest place to find on a map. Founded in 1890 as the Naval Proving Ground Indian Head, the command is buried deep in the countryside of Charles County, Maryland, along the Potomac River—a place known for bass tournaments, scenic country lanes, roadside produce stands, and cutting-edge naval technology.

One hundred years ago, however, the Cornwallis Neck Peninsula of Indian Head thundered with cannon fire during weapons proofing, while scientists and chemists focused on developing reliable propellants for the nation’s emerging naval forces. While initially founded to test the Navy’s shipboard armaments because of its proximity to the lower Potomac, that mission would shift and give way to the command becoming the Navy’s leader in energetics research and development.

Black Powder’s Last Hurrah

Black powder was on the way out in the mid-1800s, as dense smoke created after firing left the guns unable to be operated for several minutes afterwards. To shorten the firing delay, navies and industry began experimenting with cordite to develop a smokeless powder with the same firing properties as black powder. Smokeless powder also allowed for quicker reloading and re-firing, an immediate clear shot at the target, and did not require a sponge-out of residue as needed with black powder.

The last hurrah for black powder would come in 1898 during the Spanish-American War, when Commodore George Dewey ordered the protected cruisers USS Olympia, USS Boston, USS Baltimore, and USS Raleigh to navigate into Manila Bay to surprise the remaining Spanish fleet. Dewey’s fleet sank eight Spanish ships without losing any of their own. Most of the damage to the Spanish fleet is believed to be caused by Dashiell 5-inch rapid fire guns developed at Indian Head. According to Lt. C.G. Calkins navigation officer, while the 5-inch guns performed well above expectation, the smoke from the black powder obscured vision and hindered the accuracy of the ship’s main 8-inch batteries.

Three days after the battle, Congress authorized the Navy to construct a smokeless powder factory at Indian Head to serve as a full-time production line to meet the needs of the fleet and to remain level with other global navies that were producing smokeless powders of their own.

A New Era: Smokeless Powder

On 16 June 1900, Indian Head produced its first batch of smokeless powder, ushering in a new century and a new era of capabilities for the U.S. Navy. Because smokeless powder burned slower than black powder, the Navy required a longer barreled gun to ensure the powder released all its energy before the shell left the muzzle.

The results of the combined upgrades were significant. The new powder and longer barrels generated higher muzzle velocities—and hence longer ranges—for shells. In addition, according to Rodney Carlisle in his book, Powder and Propellants: Energetic Materials at Indian Head, Maryland, 1890-2001, the 1890 model 12-inch gun, with the shorter barrel, could only penetrate 13.79 inches of steel, while “a 12-inch gun with a smokeless powder charge could fire an 850 pound uncapped projectile that would penetrate 17.92 of nickel-steel at 3,000 yards.”

Smokeless powder had been experimented on and used for approximately 50 years before Indian Head began its large scale production operation. Swedish chemist, inventor of dynamite, and namesake of the Nobel Prize, Alfred Nobel, developed an early formulation of smokeless powder in 1888, although his version was deemed too unstable for naval usage due to it being 40 percent nitroglycerine.

The Navy experimented with small-scale powder production facilities before 1900, but realized they needed an area of considerable size to meet growing fleet requirements. The Navy’s torpedo factory in Newport, Rhode Island, provided testing and small-batch production of smokeless powder before 1900, but it was deemed untenable for any sustained production because of its small size and potential for disaster due to the proximity of the station’s infrastructure if the powder were to explode.

What Newport did have was a young chemist named Dr. George Patterson. Patterson would leave Newport in 1900 to become the chief chemist at Indian Head, where he tested smokeless powder compounds for more than 40 years and became the nation’s foremost expert on smokeless powder.

With a newfound mission to develop and deliver smokeless powder to meet the Navy’s needs, Indian Head produced more than 250,000 pounds in its first year of operation. That number would grow as the site expanded to accommodate the experimentation and production of smokeless powder. Such experiments dealt with the effects of electric light, salt water, and stabilizing agents in the powder.

In 1911, the French battleship Liberté suffered a magazine explosion while moored in Toulon on the Mediterranean coast. The resulting explosion killed approximately 250 people and destroyed the ship. Because of similarities of the US smokeless powder’s formula with the French version, officials were concerned about a similar occurrence on US naval vessels. Patterson’s research and experimentation with smokeless powder, however, found that adding a diphenylamine stabilizer during manufacturing lessened the volatility of the powder.

“By 1912, the specifications for smokeless powder included the stabilizer,” wrote Carlisle. “Thus, when reports of the Liberté disaster alerted line officers to the danger of unstable smokeless powder stored in shipboard magazines, the Bureau of Ordnance could report that, thanks to Indian Head research, American stabilized powder was far safer in magazine storage.”

By the time the United States entered World War I in 1917, Indian Head had become one of the country’s foremost producer of smokeless powder to the good fortune of the US Navy. Demand for smokeless powder had never been higher and to meet the wartime need, Indian Head produced more than 831,000 pounds of smokeless powder from 1918–1919, compared to 297,000 pounds in 1915.

Indian Head 2

World War II and the Extrusion

The post-World War I years brought significant changes and mission shifts to the staff at Indian Head. The command’s lower station, located at Dahlgren, Virginia, became independent and responsible for gun testing in 1921. Indian Head shifted its full-time focus to the production of smokeless powder and other explosives, such as ammonium picrate. To reflect the changes in these duties, Indian Head formally changed its name from the Naval Proving Ground to the Naval Powder Factory (NPF) in 1923.

Indian Head would also undergo a dramatic pivot shortly before World War II, as the command established a facility to produce rocket propellant grains for experimental air-to-air rocket systems to better engage jet-powered aircraft. This double-base powder was composed of nitrocellulose—a highly flammable material composed of wood pulp used in gunpowder—and nitroglycerine that were rolled into a sheet and passed through a press into the necessary length and diameter, resulting in a product aptly named “extruded grains.” The grains were then shipped to other facilities that would load them into 1.75-inch and 2.75-inch folding fin aircraft rockets. “By mid-1943, the first Indian Head [extrusion] presses were at work,” wrote Carlisle. “Two presses were put in operation by August, with three more ready to go if sufficient staff could be hired to run them.”

By 1944, NPF Indian Head began production of extruded grains for rockets, bazookas, and air-to-ground anti-tank weapons such as the Mighty Mouse folding-fin aircraft rocket. The American-Japanese naval engagements in the Pacific demanded the need for more of these weapons produced at a faster pace. To that extent, Indian Head was asked to step up its production to more than 900,000 pounds of extruded grains per month.

The pivot from smokeless powder production to the manufacture of extruded grains received little attention until after the war. F.C. Thames, the civilian chemist in charge of production and supervisor for extrusion work, was asked to describe what contributions were made by his extrusion division in support of the war.

“In the hectic pace to meet production goals and in the generally classified environment of World War II production, there had been no opportunity to develop a public relations presentation of achievements, and by the time Thames had offered his assessment, the work was no longer news,” said Carlisle. “Like much of the incremental technological work done by Indian Head in the 1920s, the rapid and quiet innovation essential to progress in a new area, got little public attention compared to the more spectacular innovations in armament elsewhere during the war.”

Mission Shift

Following the end of World War II, NPF Indian Head saw the need of smokeless powder dwindle, resulting in a workforce reduction and questions about Indian Head’s future role with the Navy and joint forces community. Work at Indian Head would dramatically pick back up in 1950, however, as the nation’s entry into the Korean War resulted in increased demand for Mk-31 2.75-inch rocket grains. Production of these grains required the expansion of the station’s extrusion plant facility as the then-current limitation of the facility allowed for the production of 25,000 individual rocket grains monthly. Following expansion, the plant’s monthly grain production capability grew to more than 80,000 rocket grains.

“The development of large, cast-propellant rockets, in which the propellant would be cast directly into the casings suggested the need for technical changes,” said Carlisle. “Indian Head’s background in extruded rockets in the 1940s and the addition of a casting plant in the mid-1950s suggested that it could lay claim to a solid role in these new developments.”

Among these changes was Indian Head’s selection to produce propellant for the Polaris missile – the nation’s first surface-to-surface, intermediate-range ballistic missile designed to be launched from submarines—as well as the Terrier surface-to-air missile. The production of the Polaris propellant facility in 1954, as well as a casting plan and the expansion of the command’s research and development program showed that Indian Head could be looked on to lead the way in propellant manufacturing for their new ordnance technologies. By 1958, Indian Head’s role as a propellant plant overcame its previous duties as the Navy’s premier producer of smokeless powder, facilitating the change of designations to the Naval Propellant Plant.

Otto Fuel II

In the late 1960s, Indian Head began its involvement in the developing of a new torpedo fuel to replace a propyl nitrate monopropellant thought to be too unstable and dangerous for continued use. Dr. Otto Reitlinger, a manager with the Bureau of Weapons, visited Indian Head to discuss with personnel the formulation of a new, safer torpedo propellant.

“Even though [Indian Head] was not ‘tasked’ with torpedo work and its evolving mission focused on rocket and gun propellant, he sought advice from the Indian Head chemists,” said Carlisle. “In spelling out the torpedo fuel requirements, Reitlinger made it clear that a torpedo monopropellant had to run clean and not produce a lot of carbon to foul the torpedo engine.”

Through trial and error, what the team eventually designed and produced was a torpedo propellant that met all requirements for torpedo fuel production. The fuel was dubbed “Otto Fuel II” and was quickly brought to production at Indian Head for initial use in Mk-46 airdropped antisubmarine torpedoes and in the antisubmarine rocket-launched shipboard torpedo. By 1967, Otto Fuel was regularly produced at the station’s Biazzi Nitration Facility—a continuous flow facility originally used to produce nitroglycerine, but with small modifications also allowed for the development of Otto Fuel II. Indian Head is the sole manufacturer of this fuel, which is still used by the fleet and other allied countries.

Cook-Offs and the Dawn of Insensitive Munitions

USS Forrestal (CVA 59) was deployed to the Gulf of Tonkin in 1967 when a 5-inch Zuni rocket attached to an F-4 Phantom on the flight deck was accidentally discharged, striking an A-4 Skyhawk and rupturing its fuel tank. The fire caused by the explosion engulfed nearly a dozen other Skyhawks. A domino-effect of explosions occurred as ordnance cooked off, resulting in 134 deaths, 21 aircraft destroyed, and $15 million in damage.

Less than two years later on 14 January 1969, an F-4 Phantom aboard USS Enterprise (CVN 65) had a Zuni rocket explode after being overheated by an aircraft start unit. Again, a domino-effect of cooked-off ordnance across the flight deck resulted in the death of 27 Sailors and the destruction of 15 aircraft.

The Navy had been working to improve insensitive munitions (IMs) characteristics for their shipboard ordnance and to find a safer alternative for TNT. IMs minimize the response of a munition to unplanned stimuli, while ensuring it still functions as intended. With the tragedies aboard Enterprise and Forrestal as motivators, the search for ways to maintain lethality while developing IMs for fleet usage took a more earnest approach in the next several decades.

“Making insensitive munitions that would not detonate from external heat and also stand up under electromagnetic and static electrical environment aboard aircraft carriers and other ships became and even higher priority item in 1992, when the Navy issued IM as a requirement,” said Carlisle.

Scientists and chemists at Indian Head, Dahlgren, and China Lake, California, cooperated under the Navy’s Insensitive Munitions Advanced Development-High Explosives program in 1999 to find applications for plastic bonded explosives (PBXs)—a newly qualified explosive substance with a high mechanical strength and excellent chemical stability and that is impervious to shock. Multiple PBX formulations were developed and tested, including PBXN-109, which eventually replaced older warhead payloads on Mk-84 2,000 pound bombs. Indian Head also served as the lead laboratory in the development on a PBX grenade fill substitute to be used in antipersonnel obstacle breaching systems. “[By 2001,] more than a dozen new explosives with insensitive qualities had been introduced and developed in over 43 new weapons using IM developed at Indian Head,” said Carlisle.

Conclusion

It has been more than 125 year since Ens. Robert Dashiell traveled from the District of Columbia to construct a proving ground on an agrarian parcel of land known by locals as Indian Head. Since then, the command has adapted and evolved to meet the ever-shifting requirements of the fleet and services. While the names and requirements have oft changed, Naval Surface Warfare Center Indian Head Explosive Ordnance Disposal Technology Division has stood tall as the Navy’s true leader in the development of energetics.

About the author: Josh Phillips is a writer with Naval Surface Warfare Center Indian Head Explosive Ordnance Disposal Technology Division corporate communications.

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