During World War II, Denver’s war production industry expanded to include the production of ship parts bound for assembly on the West Coast. Known colloquially as “the Rocky Mountain Fleet,” dozens of ships would eventually see production at the Colorado works. Today, the Rocky Mountain Fleet serves as a historical example of Colorado’s contribution to the war effort as well as how national industry operated during “total war”—before World War II, it was unheard of for prefabricated ship parts to be produced in a landlocked state.

War Production in Colorado

On August 22, 1942, the destroyer escort Bentinck launched at the Mare Island Navy Yard in Vallejo, California. The occasion might have been ordinary, had it not been for the fact that the Bentinck and twenty-three sister warships were largely constructed in landlocked Denver, Colorado—more than 1,000 miles from the ocean and a mile above it. The unusual consortium of Denver steel fabrication companies, working in cooperation with Mare Island, began in the Washington office of Democratic Congressman Lawrence Lewis when he met with G. H. Garrett, general manager of Denver’s Thompson Pipe and Steel Company, in July 1941. The Great Depression had damaged Denver’s economy, and city leaders were anxious to attract defense contracts to help restore the city. Denver successfully lured large defense-related employers such as Remington Arms and the Rocky Mountain Arsenal, but smaller local companies such as Thompson Pipe and Steel were in danger of going out of business because of their low priority for critical war materials—in this case, steel.

Lewis arranged an appointment with Commander M. L. Ring, a navy purchasing agent, who put aside the pressures of his job to spend time with Garrett to discuss the navy’s shipbuilding requirements. Garrett spent three days in Washington discussing the navy’s construction priorities and how Thompson Pipe and Steel could help meet them. His final appointment in Washington proved instrumental in Denver’s involvement with Mare Island; before he boarded the train home to Denver, he met with Lieutenant Commander E. P. Simpson, who had just arrived in Washington from Mare Island. Simpson suggested that Garrett contact Captain F. G. Crisp, the industrial manager of the Mare Island Navy Yard, who Simpson knew required additional manufacturing facilities outside the Bay Area.

Ship Production Begins

The clincher for Denver’s manufacturing interest came in November 1941, when the navy designated Mare Island the site for the construction of destroyer escorts. The yard was already working at full capacity, and the navy wanted the ships completed by summer 1943. Denver’s manufacturing consortium helped provide the answer. The subsections of twenty-four ships were to be prefabricated in the Mile High City, shipped to Mare Island via railroad, and assembled there for launching. On December 2, 1941, in conjunction with Director Hartzell, Commander Antonio Pitre and a delegation from Mare Island formally announced the signing of contracts for building ship hull sections, bulkheads, decks, and other parts by the following Denver firms:

• Ajax Iron Works
• E. Burkhardt and Sons Steel and Iron Works
• Denver Steel and Iron Works
• Midwest Steel and Iron Works
• Silver Engineering Works
• Thompson Pipe and Steel
• R. Hardesty Manufacturing
• Eaton Metal Products

Weicker Transfer and Storage was to receive and handle all steel when it arrived in Denver by rail, and reload the finished pieces for shipment to Mare Island. The terms of the contracts called for the Denver consortium to fabricate parts for twenty-four destroyer escorts with a total estimated value of $56 million, to be delivered by June 1943. Construction was scheduled to begin in January 1942.

Though secret, the agreement between Denver and Mare Island marked the navy’s first foray into “farming-out” work and would be watched closely. The success or failure of the Denver program would help determine whether other navy yards would be allowed to use outside facilities to help fulfill contracts.

The scope of the navy work meant that the Denver contractors needed to hire additional workers. The Emily Griffith Opportunity School assisted by providing welding training sessions around the clock. In addition to handling and storage facilities in Denver, the steelyard producing the ship parts needed space for two tanks fifty feet long by five feet wide and ten feet deep, plus a 25,000-gallon acid storage tank, all to be built by the navy. The tanks were to be sunk into the ground to form acid baths into which raw steel would be dipped to remove scale and dirt. The Denver program experienced an early problem with these tanks, colloquially known as “pickling tanks,” when the navy failed to specify that Weicker Transfer and Storage use corrosion-resistant steel bolts: the tanks collapsed after two weeks when the acid ate through the bolts.

The railroad delivered the first 3,000-ton shipment of steel from Mare Island in December 1941, and fabrication began the following month. All subsequent shipments of steel came from US Steel’s eastern mills. Under normal circumstances, the navy would have relied upon the principal trunk lines—the Northern Pacific, Union Pacific, or the Southern Pacific—to transport the completed sections from Denver to California. However, these lines were already running at capacity, carrying war materials across the country. The rail route through and under Colorado’s 14,000-foot mountain ranges imposed limitations upon the size of the ship pieces to be shipped. The Moffat Tunnel, on the line linking Denver and Craig, was the principal bottleneck. The tunnel’s narrow dimensions meant that ship pieces had to be reduced in size to fit through it. None could exceed seventeen feet from the rails in height, nine feet, six inches in width, and fifty feet in length.

August 18, 1942, a delegation of forty Denver manufacturers and War Production Board officials, headed by Governor Ralph Carr, left Denver for Vallejo, California, to officially launch the first destroyer escort built in Colorado. Cynthia Carr, the governor’s daughter, was selected to christen the first such vessel almost entirely prefabricated in an inland city. Originally slated to join the US Navy as the USS Bull, the ship was given to the Royal Navy as the HMS Bentinck and launched on August 22, 1942, amid much fanfare.

Shipbuilding Expands

The destroyer escort program was so successful that on February 26, 1942, the navy named Denver as one of the major steel-fabricating points in the country for naval vessels. With this designation came an agreement to build more ships, resulting in a major expansion of shipbuilding operations in Denver. By being named a major shipbuilding center, Denver was also awarded new contracts to help build fifteen more destroyer escorts worth an estimated $3 million. Mare Island had been ordered to build the ships in 1942, with delivery for early 1944. However, the Allies won the Battle of the Atlantic by the summer of 1943, before all of the ordered ships could be delivered. Thus, five contracts were canceled, and the ships were ordered scrapped on March 13, 1944. Three others were canceled in September 1944.

By late 1943, the tide of war was beginning to turn against the Axis. Allied defeats of the Germans in the Battle of the Atlantic and in North Africa initiated a shift in ship construction priorities. Destroyer escorts and other ships designed to combat the U-Boat menace were no longer the focus of Allied shipbuilding. On July 6, 1943, the navy ordered Mare Island to build eighty-seven LCT-6s (Landing Craft, Tank) for delivery in October. In spite of the limited time the navy allowed for the LCTs’ construction, production in Denver was ahead of schedule. The first vessel was ready for shipment to Mare Island in September. As with the first destroyer escort “launching,” Denver prepared an elaborate ceremony to commemorate the occasion.

War’s End

Denver’s contractors continued working on army barges and navy pontoons until the Japanese surrender in August 1945. The end of the war saw the end of “the Shipyard of the Rockies,” as defense contracts were cancelled and the companies were on their own again. Eaton Metals returned to peacetime work within twenty-four hours of Victory in Japan Day. On August 15, 1945, the workers who had previously built warships for service around the world returned to fabricating sheet and steel products such as storage tanks and farm equipment. Thus ended a unique and successful venture in which a Navy Yard in California and the Mile High City of Colorado not only made a substantial contribution to the war effort but also served as a role model for other “farm-out” efforts throughout the country. This was the program’s true significance, for were it not successful in Denver, it probably would not have been tried in other inland cities.

Adapted from Tom Lytle, “Shipbuilding on a ‘Mountaintop’: World War II’s Rocky Mountain Fleet,” Colorado Heritage Magazine 18, no. 3 (1998).