A Wartime Assembly Feat
In November 1942, amid the massive shipbuilding effort of World War II, the United States set a ship construction record that stunned even seasoned engineers. The Liberty ship SS Robert E. Peary was assembled and launched in just 4 days, 15 hours, and 29 minutes at the Kaiser Shipyards in Richmond, California. The feat was not a fluke but a demonstration of how far industrial coordination had advanced under wartime pressure.
The Liberty Ship Program
Liberty ships were standardized cargo vessels designed for rapid production to replace losses from German U-boat attacks. The U.S. Maritime Commission aimed to mass-produce them using prefabricated sections, allowing simultaneous work across different shipyards. Between 1941 and 1945, more than 2,700 Liberty ships were built.
The Record-Breaking Build
The Robert E. Peary was named after the Arctic explorer and assembled during a well-publicized demonstration intended to showcase American industrial capability. More than 1,000 workers operated around the clock in shifts. The ship’s prefabricated sections were prepared in advance and assembled using heavy cranes and welding teams.
Construction began on the morning of November 8, 1942, and the ship was launched on November 12, completing the job in just over 4.5 days. The previous record had been around 10 days, making the Peary’s completion time a benchmark that has never been repeated at that scale.
After the Launch
Although the Robert E. Peary needed further fitting out after launching, the demonstration was symbolic of the efficiency the U.S. had achieved. Onlookers, including military officials and journalists, attended the launch to witness the event. The ship later served in the Atlantic and Pacific theaters, fulfilling the exact role it was built for: transporting supplies and cargo to support the war effort.
Legacy of the Liberty Ship Program
The speed of the Peary’s construction was never the norm, but it proved what could be done when resources, labor, and coordination were maximized. While most Liberty ships took around 40–50 days to build by 1943, the Peary remained the standout example of industrial speed and wartime urgency.
In 1942, a U.S. shipyard accomplished what seemed impossible—building an entire cargo ship in under five days.
As World War II raged, the Liberty ship SS Robert E. Peary was assembled and launched in just 4 days, 15 hours, and 29 minutes, setting a world record…🧵👇 pic.twitter.com/Bt1Jirtjga
— Detective Tiger's Stories (@TigerDetective) June 18, 2025