Indiana Army Ammunition Plant

Indiana Army Ammunition Plant

The Indiana Army Ammunition Plant (INAAP) is a former military ammunition and ordinance factory in Charlestown, Indiana. It was the largest gunpowder and ordinance facility of its type in the United States. INAAP was constructed after the passage of the first National Defense Appropriations Act. Four days after the enactment of the Act, the Munitions Program was passed in which the U.S. Ordinance Department sponsored private manufacturing corporations to design and produce ammunition factories, producing smokeless gunpowder and other ordinances.


The development of INAAP was mired in speculation during the lead up to World War II. Rumors began to spread when C.V. Artwell, a real estate operator from Delaware, was taking options on large tracts of land between Charlestown and the Ohio River. 30 In July 1940, the Courier-Journal announced that the world’s largest smokeless powder plant would be constructed near Charlestown on the site of historic homesteads, churches, and pioneer cemeteries, as well as the former Rose Island Amusement Park. 1 The facility would be the largest plant in the Industrial Operations Command, containing 1,401 structures on 19,200 acres, 1 10 11 with a cost of $50 million. 30

When it was announced that the plant would be constructed adjacent to Charlestown, 13,000 workers from across the country descended upon the small town. 30

The rural farming village was transferred within a few months. Street corner markets popped up, schools became overcrowded, and rental prices became astronomically high. Rooms in the town were rented per shift for sleeping purposes, and garages and chicken huts were converted into bedrooms. Seventeen mobile home parks were constructed that contained more units than the city’s 250 homes. 30 The post office went from one clerk to nine to handle the 300% increase in mail volume and surging money order requests that were related to INAAP’s $400,000 per week payroll. 30

Construction & World War II

A contract was let for a government-owned, contractor-operated ammunition plant to the E.I. du Pont de Nemours Company (DuPont) for the production of a smokeless powder plant at the Indiana Ordnance Works. 10 The Quartermaster Corps would oversee construction.

The assembly of the smokeless powder plant was one of three separate manufacture facilities that encompassed the Indiana Army Ammunition Plant (INAAP). INAAP included Indiana Ordnance Works Plant 1 (IOW1) for smokeless powder, the Hoosier Ordnance Plant (HOP) for bagging powder, and the Indiana Ordnance Works Plant 2 (IOW2). 10 11 The three facilities were consolidated into the Indiana Arsenal on November 30, 1945, as designated under the WD Circular No. 329. 9 11

Construction on IOW1 began on August 26, 1940, 11 and by November, E.I. du Pont de Nemours employed over 10,000 laborers. 10 At the height of construction in May 1941, there were 27,520 workers employed in the building of the facility. IOW1 was completed in May 1942 at the cost of $74,956,394. 11

IOW1 contained 800 buildings that were divided into four primary areas: 9 10 11

  • Administration, which included an administration building, telephone exchange, hospital, repair shop, cafeteria, and guard headquarters.
  • Smokeless Powder Manufacturing Area, which featured six parallel, nearly identical manufacturing lines that included two ammonium oxidation plants, two nitrocellulose manufacturing and purification areas, two nitric and sulfuric acid concentration plants, and two propellant manufacturing and finishing areas. Major support areas included an aniline manufacturing area, two coal-fired power plants, and 450 above-ground storage tanks.
  • Storage and Shipping Area, which included 100 above ground magazines, and storage and shipping houses.
  • River Ridge, a residential neighborhood for high ranking officials. It boasted 17 two-story wood-frame houses, and amenities such as a baseball diamond, basketball court, community center, horseshoe pits, playgrounds, a swimming pool, and volleyball court.

Construction began on HOP on January 10, 1941, 11 was partially in operation by September, 10 and finished on February 2, 1942, at the cost of $27,851,660.65. 11 Contractors for HOP included Winston Brothers, C.F. Haglin & Sons, Missouri Valley Bridge & Iron, and Sollitt Construction. The load, assembly, and pack facility was used to prepare cannon, artillery and mortar projectiles and integrated five distinct areas: 9 10

  • Administration, which included an administration building, change house, and hospital.
  • Production, Maintenance, and Storage Area, which contained a bag manufacturing building, an inert stores warehouse, a repair shop, a fire station, and a heating plant.
  • Charging Area, which featured eight load lines for bag loading smokeless powder, and four igniter lines for bag loading black powder.
  • Powder Magazine Area, which contained 177 earth-covered, steel-reinforced concrete igloos.
  • River Ridge, which boasted an additional 17 two-story wood-frame houses.

Construction on IOW2, a rocket propellant plant, did not begin until December 8, 1944. 11 Although sub-production did take place for approximately five weeks, IOW was never completed before the surrender of Japan in August 1945. 10 Construction stopped on August 13. 11

Due to the presence of black powder and other highly volatile materials, safety was one of the utmost concerns. Buildings were spread far from one another to diminish the chance of a mass explosion, and copper-lined transfer chutes were utilized that reduced airborne powder movement. 10 In addition, conductive shoes were issued to reduce static electricity, and employees were searched daily for matches and other hazardous materials. In addition, emergency slides were installed in some buildings to provide a quick escape.

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  • Buildings: 1,700 10 30
    • Hospital Building 719 served as a hospital and laboratory. The 12,563 square-foot building in HOP included male and female wards, a laboratory, X-Ray equipment, and a whirlpool. 9 (It later became Employment Building 2601, and a laboratory from 1987 to 1990.)
  • Cost: $133.4 million
  • Fence: 30 miles
  • Land: 19,200 acres
  • Peak personnel: 11,492 employees (August 16, 1970) 11
  • Power:  68,750 KVA turbogenerators in two coal-fired power plants, using only 5,570 KVA of electric from the Public Service Company of Indiana
  • Railroads: 84 miles of track
  • Roads: 190 miles


Initial Production

IOW1 began producing smokeless powder and black powder for HOP and other load, assembly and pack operations on April 11, 1941. 10 11 Single-base smokeless powder, or nitrocellulose, was used as a propellant for a projectile, while black powder was used to ignite the smokeless powder. By July, IOW1 had produced twice as much powder as the entire nation had in 1940. 10 30

Peak employment occurred on May 1, 1941, when 27,250 contractors and 366 government officials oversaw production at IOW1 at the height of World War II. Production at IOW1 ceased on September 7, 1945, upon the conclusion of the war. 11

HOP began operations on September 2, 1941, which involved bag manufacturing and the load, assembly and pack process. Smokeless powder was weighed, placed in a bag, and sewn shut. Each charge consisted of up to seven bags of powder secured together. The increments were placed in an outer charge bag and then packed in containers and shipped or warehoused.

Nitrocellulose from IOW1 was loaded into bags made at HOP. 30 The hallmark product was a 16-inch diameter bag of powder that when loaded six deep in the breach of a battleship’s turret, could propel a 2,750-pound bullet 25 miles.

HOP employed 8,902 contractors and 87 government officials by March 20, 1945, which rapidly shrank by the time production ceased on August 18. 11

IOW2 was in operation from July 20, 1945, to August 31, 11 and was designed to manufacture double-base rocket powder. The double-base powder was unlike single-base in that it consisted of a 60 to 40 ratio of nitrocellulose and nitroglycerin and used to power bazookas and other rocket-based weapons. IOW2 produced 292,700 lbs. of rocket powder during its short operation. 10 Employment at IOW2 peaked at 17,585 contractors and 36 government officials on June 30, 1945. IOW2 was placed into standby status on February 11, 1946and was never reactivated. 11

Most of the labor force at INAAP were men, although a number of women were employed. At IOW1, approximately 25% of the employees were women, while at HOP, women composed 65% of the workforce. 10 Approximately 10% of INAAP workers were also black, although segregation was in effect and black people were not given office positions.

German prisoners-of-war were used as unskilled labor and were housed in the IOW2 area neighboring the Charlestown Landing Row. The first German prisoners-of-war arrived in May 1945 but were repatriated three months later as World War II ended. 10

Post-World War II

Between June 24, 1946, and March 31, 1950, DuPont activated and operated facilities for the production of ammonium nitrate aqueous solution for agricultural purposes at IOW1 under a CPFF contract. At employment peak on February 1, 1947, DuPont employed 156 and had a monthly production peak of 20,241 tons of ammonium in August 1949. 11

At IOW2, the 44 above-ground magazines were used for propellant storage from January 1946 to August 1952. 11

Korean War

INAAP was partially reactivated in 1948 but did not return to full-scale production of ammunition until 1952 when the Korean War began escalating. 1 10 IOW1 was reactivated on April 28, 1952, by DuPont, and reached peak personnel on August 1953 with 8,067. 11 HOW was reactivated on September 17, 1951, by the Goodyear Engineering, with peak personnel of 8,067 by August 1953. During the war, 50 new storage and maintenance buildings were constructed on-site.

Production at HOW ended on September 20, 1957, followed by IOW1 on September 30. 11 INAAP was once again placed into standby status, and Goodyear and DuPont were listed as the caretakers of the complex until 1959 when that was taken over by the Liberty Powder Defense Corporation, a subsidiary of the Olin Mathieson Chemical. 1 10

Vietnam War

On November 1, 1960, 11 Liberty Powder Defense reactivated HOW’s Bag Manufacturing Building to produce cloth bags for 105mm artillery charges for the Vietnam War. 10 In January 1961, Olin Mathieson dissolved Liberty Powder and took over direct control of the plant’s operations. It coincided with the reactivation of the HOW igniter and propellant loading lines and were supplied black powder and smokeless powder from other ammunition factories. In 1969, Olin reactivated part of INAAP’s smokeless powder manufacturing.

INAAP was not officially reactivated until August 23, 1961, 11 and was designated the Indiana Ordnance Plant by DAGO No. 40 on November 1. On August 1, 1963, the facility was re-designated as the Indiana Army Ammunition Plant by DAGO No. 35. 9 11

In 1966, Igloo 5185 was destroyed in an unplanned explosion, the only one to ever occur at INAAP. 9

Olin continued to manage INAAP until 1972, when ICI America, a subsidiary of Imperial Chemical Industries, took control. 10

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  • Peak personnel: 11,492 employees (August 16, 1970) 11
  • Power:  68,750 KVA turbogenerators in two coal-fired power plants, using only 5,570 KVA of electric from the Public Service Company of Indiana
  • Railroads: 49 miles of 100-pound track and 35 miles of 40-pound track, equally served by the Baltimore & Ohio and Pennsylvania railroads
  • Railroad Yards:
    • Bethany that could hold 60 cars with explosive materials in HOW
    • Ridley that could hold 425 cars in IOW1
    • Watson that could hold 200 cars with inert materials in HOW
  • Roads: 161.2 miles paved and 5 miles unpaved
  • Sewage: Several sanitary surge disposal units could handle 1,048,000 gallons per day
  • Water: Numerous deepwater wells along the Ohio River that supplied 50,200 GPM of water


  • Administrative buildings: 34 total at 186,583 square-feet
  • Hospitals: 2 total
  • Igloos: 176 total at 646,887 square-feet
  • Production buildings: 576 total at 2,052,521 square-feet
  • Research and design buildings: 3 total at 3,992 square-feet
  • Standard Magazines: 114 total at 299,311 square-feet
  • Utility buildings: 21 total at 279,681 square-feet
  • Warehouses: 149 total at 617,019 square-feet
  • Miscellaneous buildings: 566 total at 3,302,029 square-feet


Electrostatic precipitators to remove dust, ash and other participles in smokestack emissions were installed in the power plants in February 1971. 14 Additionally, the Ammonia Oxidation Plant was replaced with a modern, pollution free facility, removing a source of nitrogen oxide fumes that produced a yellowish cloud over the plant at times.

Cold War

After the United States withdrew from Vietnam, the federal government began a modernization project of the ammunition manufacturing facilities. 10 ICI America began construction of three new facilities, including a fully automated Black Powder Manufacturing Facility (INAAP-074) to limit personnel exposure to black powder.

Construction of an entirely new, fully-automated Black Powder Manufacturing Facility (INAAP-074) encompassed the first of three new projects that began in December 1974, 18 with contracts awarded to Sante Fe Engineering. ICI America completed process equipment sub-contract awards.

Construction and equipment installation was completed in December 1978, 10 18 with debugging sustained through 1979. 9 Debugging determined that additional engineering was required to correct major problems in the black powder fines recycling system, electrical grid grounding system, process humidity control, and black powder conveyance systems. 18 In 1980, inert material was processed through the plant during prove-out. 9 The deficiency correcting process was completed on schedule and within cost in February 1982. Small modifications were made until August, and in February and March 1983, 2,200 pounds of black powder was produced.

The Black Powder Manufacturing Facility, occupying nearly 30 acres, included a raw materials building, a process building, four glaze houses, a screen house, and a pack house. Several auxiliary buildings built included a boiler house, maintenance shop, and a change house. the plant had the capacity to produce 500,000 pounds of black powder per month 16 and could be operated by remote control using state-of-the-art technology and computerized systems with only ten employees. 18

The new plant concluded its live explosive prove-out on April 15, 1983. 18 The new $40 million 10 black powder facility was formally dedicated on April 22 after nine years of development. 18 INAAP’s facility was one of two in the nation, the other at the Scranton Army Ammunition Plant in Moosic, Pennsylvania.

The plant was deactivated immediately following prove-out and was not reactivated as it would not be able to meet production quotas; it also had an outdated circa 1974 computer system and design flaws. In 1988, INAAP sought a corporation with $15 million in funding to operate the black powder plant for 20 to 25 years. 23

Two separate but integral buildings were also on site. The Black Powder Sanitary Sewage Treatment Plant (INAAP-014) was constructed in 1977, 9 and featured a rapid mix chamber, flocculation chamber, settling chamber, filter sludge holding tank, final aeration, and chlorination. It was rarely used and was essentially non-operational. The Black Powder Industrial Wastewater Treatment Plant (INAAP-015) was also constructed in 1977 and was non-operational for its lifespan. 9

The two other modernization projects for INAAP undertaken in the 1980s included a semi-automated loading line for 105mm charges and a similar assembly line for 8 inch and 155mm charges. 10 The 105mm charge structure was completed in 1980 and the facility for the 8 inch and 155mm charge line was completed in 1981. Both lines were placed into standby status.


Employment levels at INAAP wildly fluctuated as the Cold War waned by the late 1980s. Employment levels throughout the Vietnam War were sustained around 19,600 but dropped to 700 by 1976. 10 The numbers increased to 1,500 for most of the 1980s, but by 1987, major layoffs were announced for the plant due to a decline in military contracts.

INAAP officials were hoping to land a new production facility for the next generation of booster rockets for the NASA space shuttle. 17 In 1987, 20 the Atlantic Research Corporation of Arlington, Virginia considered IOW2 and the unused Black Powder Manufacturing Facility for the production site of Advanced Solid Rocket Motors. The company ultimately chose Yellow Creek, Mississippi’s abandoned Tennessee Valley Authority’s nuclear power plant. 10 17

There was also hope that INAAP would be a forerunner for a $350 million 22 research explosives production plant to supplement the sole RDX facility at Holston Army Ammunition Plant in Kingsport, Tennessee, and an industrial waste-treatment facility. 13 The other contenders were Iowa Ammunition Plant site in Middletown, Iowa, the Joliet Army Ammunition Plant in Joliet, Illinois, and the Louisiana Army Ammunition Plant in Shreveport, Louisiana.

In the event of a military attack, sabotage or accident, it was feared that the production capability of RDX would be immobilized if production efforts remained solely at Holston. In addition, the Holston plant had insufficient space for the construction of additional production facilities and had been operating beyond its design capabilities for years. 13

The RDX plant would be approximately 3,200 feet from Indiana Route 62, cover 25 to 50 acres, employ 300, and be capable of producing 2½ million pounds of RDX per month.10 22 Congress allotted $75,000 for an environmental impact study for the RDX plant at INAAP. 22 In the end, INAAP never received the RDX production facility.

In February 1989, the Army sought a private firm to operate the automated Black Powder Manufacturing Facility. 16 Three companies, GOEX of Moosic, Pennsylvania, Ensign-Bickford Industries and ICI America toured the facility, however, no decision was made to utilize the plant.

The failure to land the booster rocket plant and the RDX factory, and a reduction of production orders after nearly a decade of stockpiling charges over the Cold War, convinced the Army to consider the closure of INAAP. The facility had become outdated and replaced with more modern plants that used a fraction of the space and people. Technology and progress had simply passed INAAP. 32 On March 10, 1989, approximately one-third of the workforce at INAAP were laid off, including 388 production and maintenance jobs, 51 technical positions, 39 clerical and secretarial jobs, 86 management and supervisory positions, and one guard. 15

The Army decided to cease production at the INAAP in August 1991 and prepared to lay off 1,003 employees. 12 U.S. Representative Lee Hamilton and U.S. Senator Dan Coats, however, helped INAAP obtain two munitions orders, one to prepare a line of propellant charges for other Army depots, and the other for a large quantity of 155mm propellant charges, which extended the closure date to October 1992. When INAAP was closed, only 750 were employed. 10

INAAP, during its tenure, had produced 3.2 billion pounds of black powder. 30

INAAP was placed into modified caretaker status and maintained by ICI America. 1 Under the Armament Retooling and Manufacturing Support (ARMS) legislation, ICI America was permitted to seek long-term adaptive reuse of INAAP in hopes that the property holding costs would be reduced while ownership stayed with the military. 29 When ICI America executives approached the county about sharing reuse proceeds and made a down payment to have a study done in regards to the issue, the county used the funds to start lobbying for total control of INAAP.

The Army plant commander’s office closed its post in 1994 and INAAP was transferred to civilian patrol. 2 The facility’s maintenance was later transferred to Tecumseh Professional Services who sought to construct an industrial park on part of INAAP’s sprawling grounds. On May 9, 1995, INAAP was renamed Facility One. 1

Several lawsuits filed by local municipalities and the county over attempts by several communities to annex parts of INAAP. 10 In 1997, special legislation sponsored by the 9th District Congressman Lee Hamilton attempted to transfer 6,000 acres of the plant to the Clark County Reuse Authority, then known as the INAAP Reuse Authority, under a long-term lease. The remaining 4,000 acres would go to the formation of Charlestown State Park. 29 On November 30, 2000, the Army signed an interim lease agreement with the Clark County Reuse Authority.


INAAP featured immense environmental problems from 50 years of black powder and explosive material manufacturing. 10 A 1995 study found 87 areas that were identified as contaminated, with another 53 areas cited as potential problems. A follow-up study in 1998 estimated that it would take more than $250 million to remedy to the environmental issues. Another study by the Army Corps of Engineers pegged the cost at $33 million. 6 Over 1,000 buildings would require remediation and demolition. 26

By 2000, Facility One, which was renamed to River Ridge Commerce Center, boasted 80 tenants that employed over 800 over 5,370 acres. 2 10

A master plan was released on June 18, 2001, that included a short-range plan excluding 40% of INAAP due to environmental issues. 8 Targeted industries include manufacturing, distribution, and retail covering about one-fifth of the total land area. Included in the guide was the demolition of most of INAAP, as most of the existing structures were single-use related to ammunition production. The plan called for 3,800 workers to be working at River Ridge by 2011. 28

Demolition began on the Igniter Lines on February 6, 2004. 24 Because the buildings contained gunpowder dust and other explosive residues, demolition via machinery and human intervention was not possible. Instead, the buildings were set ablaze — only when the wind was predominately out of the west or southwest. 25 The burns left elevated levels of lead present in the local atmosphere for a brief period of time. 27 A total of 64 buildings were burned.

On June 1, 2005, the Army granted title to 2,308 acres of INAAP to River Ridge in four deeds at the cost of $1,131 per acre. 31 Twenty-four additional acres in the administration complex were transferred in April 2008 and was converted into the Charlestown Business Center and Wilson Education Center. 28

The two coal power plants, unused since 1992, were demolished from October 2011 until late 2012 at a cost of $1.1 million. 33 The contract, awarded to ADS Trinity, involved scrapping 335 tons of salvageable materials from the site and the demolition of the 120,000 and 145,000 square-foot structures and their 180-foot smokestacks.


Administration Area

Igniter Lines

The Igniter Lines in IOW2 were to bag black powder.

Propellant & Explosives Area

Storage & Shipping Area



Air Test House

After packing the powder into shipping containers, the powder is taken to the Air Test House where each container is checked to ensure that it is air tight. This is done to prevent the powder from collecting moisture which can modify its ballistic nature.

Blending & Wringler House Building 113

The Blending and Wringer House was part of the nitration process. In order to obtain a uniform propellant and ballistic characteristic, portions of batches that have a high nitrogen content are mixed with portions that have a low nitrogen content. Slurry from the poaching tubs in the Poaching House was fed onto vibrating screens where nitrocellulose was blended, which passed into collecting boxes. The boxes were then emptied into tubs where guncotton and pyrocellulose were blended. If the sample from the tub had satisfactory nitrogen and solubility content, the slurry was pumped into the Wringer House. At the Wringer House, the large amounts of water that were used throughout the process to move the nitrocellulose is removed. The containers of partially dry nitrocellulose are transported to the Dehydration/Press House via lag cars.

Building 6017

Change House Building 707

Comfort Station Building 727

Control Circulation Dry House Building 220

The Control Circulation Dry House dried the remaining solvent out of the powder before it went to the blending tower, where it would be blended to achieve a set burn rate.

Cotton Dry House Building 104

The Cotton Dry House is where cotton linters, or short fibers that cling to cottonseeds after the first ginning was delivered in 150-pound bales or wood pulp delivered in rolls of 700 pounds, where they were shredded. They were then pretreated in large ovens to reduce the moisture to less than 1% before being blown in ducts to the Nitrating House.

Debagging Building 218-1A

Dehy Press House Building 202

The Dehy Press Houses (Building 202) pressed the cake of nitrocellulose into a powder form.

Ether-Mix House Building 206

Horizontal Press House Building 211

Knife Grinding & Die Shop Building 217-2

Laboratory Building 706-3

Main Laboratory Building 706-1

Mixer House Building 208

The Mixer Houses (Building 208) mixed and kneaded powder. A Baker-Perkins mixer and kneading machine had a 100-gallon capacity.

NC Lag Storage Building 201

Nitrating House Building 105

With shredded cotton being blown in from the Cotton Dry House, 32 pounds of cellulose fiber were mixed in stainless steel nitrators that contained 1,500 pounds of nitric and sulfuric acids that were blended together. The treated nitrocellulose and spent acids were then discharged from the bottom into centrifugal wringers that removed most of the acid through the exterior of the wringer. The acid was used in the production of pyrocellulose or fortified for reuse. Wet nitrated cotton was then immersed in water and the slurry transferred to the Boiling Tub Houses.