Key point: The metal P-38 was easy to use and lightweight, making ideal for a wide variety of tasks beyond just being a can opener.
Far down on the list of important inventions essential to victory in World War II is a modest gadget built of stamped metal called the GI Pocket Can Opener—commonly known as the P-38—which was used by American troops in the field to sever the lids off combat rations. Despite its small stature and relative obscurity, many consider it to be the most perfect tool ever developed by the U.S. Army.
Simple in design, efficient in use, and diverse in application, the P-38 was an ideal complement to the canned meat and bread components contained in C-Rations, a staple of military feeding for more than four decades. The little two-piece hinged device constructed of hardened steel never seemed to break, never lost its edge, and its rugged versatility always provided a quick solution in situations other than its original intent. Soldiers regarded the P-38 as their personal, government-issued Jack-of-all-trades.
“When we had C-Rations, the P-38 was your access to food, making it the hierarchy of needs,” retired Army Colonel Paul Baerman told the Army Times. “Then soldiers discovered it was an extremely simple, lightweight, multipurpose tool. I think in warfare the simpler something is and the easier access it has, the more you’re going to use it. The P-38 had all of those things going for it.”
The official Department of Defense nomenclature for the cutting utensil is Opener, Can, Hand, Folding, Type I, jargon longer in print than its actual 11/2-inch length. Sealed in a paper wrapper to ensure cleanliness and packed inside combat rations, GIs soon realized the small opener with the long-winded title could do much more than open C-Rats. In a pinch it might be used as a screwdriver to help field strip a weapon, cut seams on a uniform, or scrape mess kits clean. To accomplish a mission it could strike flint, measure inches, strip wire, deflate tires, adjust a carburetor, or pick inside a wound. Need a box cutter, marking tool, or decorations on a makeshift Christmas tree? The usefulness of the P-38 seemed boundless, and like many great inventions its origin was humble.
Limited financially because of the Great Depression, the U.S. War Department in 1936 allocated a minimal amount of funding through the Quartermaster Corps and opened a facility on Pershing Road in Chicago called the Subsistence Research and Development Laboratory (SRDL). The lab’s function was to test new foods for the Army and design modern methods of food packaging. By 1942, the original three-man staff had increased to 22 when commanding officer Colonel Rohland A. Isker sought out area metal fabricators to mass produce an inexpensive hand-held can opener with a sharpened and curved cutting blade that could be carried in a soldier’s pocket.
Isker, a forward-thinking career officer who harbored an interest in cookery and the science of food technology, was a chemistry major at the University of Minnesota when he joined the National Guard in 1915, served on the Mexican border in 1916, and trained U.S. officers during World War I. He remained on active duty between wars as a cavalry officer in the Philippines, China, Siberia, and Japan, critical learning experiences that proved useful when he assembled his team at the SRDL.
Under Isker’s command, a small cadre of talented chemists, bacteriologists, home economists, food acceptance specialists, and packaging engineers developed the first logical, comprehensive, and effective ration system ever used for operational feeding in U.S. military history. The lab also created emergency Ration D, assault Ration K, the 5-in-1 and 10-in-1 mess packs, all necessary for the well-being of 16 million American troops serving in all climates and conditions across the globe.
The amalgamation of government with nearly every aspect of American industry was common during World War II, and three firms quickly responded to Isker’s can opener challenge—Washburn Company of Rock- ford, Illinois, Bloomfield Co. located in Chicago, and Speaker Corp. of Milwaukee, Wisconsin—the only makers of wartime P- 38s. Their production was based on a number of U.S. patents awarded for a handheld opener, the first in 1913, a second in 1922, and two others in 1924 and 1928. But new patents do not require improvements, only design changes, and the opener supplied to the Army during the war lacked one key operation for military liking: a locking mechanism that kept the cutting edge in place when the P-38 was not in use. Without such a feature, the blade was prone to open and cause cuts or rip holes in pockets.
Isker explained the problem to John W. Speaker, a native of Austria who since 1935 operated a metal shop in Milwaukee that man- ufactured automobile accessories. Born in 1903, Speaker studied engineering at the University of Vienna, immigrated to the U.S. in the 1920s, and eventually served on the Industrial Committee of the War Production Board during World War II. He worked closely with SRDL personnel and developed a means by which the blade of the P- 38 remained in a closed position. Speaker called the improvement a “detent” in which two small lugs or protrusions on the opposite side of the hinge connection kept the cutting edge shut with spring-like tension. Motivated by patriotism for his adopted country and abhorrence of Hitler’s Germany, Speaker signed a royalty-free, non- exclusive contract for his design with the U.S. Office of Patents in full knowledge that other makers would profit from his detent innovation.
The Army first used the opener in 1942 taped to emergency parachute or “bailout” rations that were supplied to air force crews. The C- Ration, which began large-scale production a year earlier, was initially manufactured with an opening key soldered to the bottom of each tin, which made for its own easy access. The key pulled off, threaded a metal strip built into the can, and opened with clockwise turns, a contrivance familiar to civilian consumers of SPAM and canned sardines. But the method was costly with the millions of combat rations being made and was slowly phased out in favor of the less expensive P-38.
John A. Speaker, who took over the family business after his father’s death in 1960, said making can openers for the government was competitive. “Shortly after I became president of J.W. Speaker, the first contract I bid on was a Department of Defense solicitation for 10 million P-38s, with a rider for 10 million more,” he said. “The bid was about $12 per thousand. We were the low bidder and we beat the competition by one cent per thousand pieces. After the bid opening, my competitor called to congratulate me. We were not the only suppliers of the can opener to the government.”
At least 12 companies made the P-38 in its 40 years of production for the Army. Speaker estimated his company produced some 50 million from 1942 through the 1970s and has tried to learn from the Defense Supply Center Richmond under the Freedom of Information Act how many can openers contractors made for the government. “Unfortunately, they don’t seem to have the information,” explained the 85-year-old Speaker.
Manufacturing numbers for the P-38 soared following World War II to meet the Army’s increasing demand. Luther Hanson, curator of the U.S. Army Quartermaster Museum at Fort Lee, Virginia, estimated 750 million P-38s were produced during World War II and the Korean War and over one billion since. The more that were made, the less expensive they became. Dur- ing its peak years of production, the cost to manufacture one P-38 in quantities of 10 million or more, envelope included, was approximately one cent. In times when other military items con- tracted by the government were purchased at ridiculously high prices, the penny pocket can opener holds the distinct honor of being the most massed produced and least expensive tool ever created by the Army.
Millions of GIs learned early in basic training how to use the P-38 or else go hungry. First a puncture is made with the point of the blade along the top rim of a can. In a rocking motion the cut is advanced forward, toward the user, with a downward shearing action. The opener is held in place along the can’s underneath rim by a notch built into the handle just below the cutting edge and “walked” around the can until opened.
Military specifications were exact and clear as to manufacturing guidelines. The opener had to be made of heat-treated carbon steel and tin plated to prevent corrosion. It was marked “U.S.,” stamped with the manufacturers name or trademark, and to facilitate cleaning, a hole was put in the handle. The P-38 was folded flat, heat sealed inside a small envelope of unbleached Kraft paper, and printed with a diagram and written directions for proper use. Directions also advised that to sterilize the opener, tie a string through the hole and immerse it in boiling water or heat it with a match before reuse. The unassuming hole in the handle turned out to be a special feature allowing GIs to secure the P- 38 to their key ring or hang it around their necks from a dog tag chain.