The construction of the USS Wasp (CV-7) was a direct result of the Washington Naval Treaty (1922) and its successor, the London Naval Treaty (1930). These treaties placed strict limits on naval tonnage for signatory nations, including aircraft carriers.
When Japan announced its intention to withdraw from the treaty on December 29, 1934, the United States was already far along in its naval planning process, which had been shaped by the treaty's constraints. This explains why the USS Wasp was smaller than later carriers, even as Japan prepared to rearm unrestricted by treaty obligations.
1. The Treaty Limits on Aircraft Carriers
Under the Washington Naval Treaty, the United States, Great Britain, and Japan agreed to limit their fleets to specific tonnage caps for warships. Aircraft carriers were restricted to a combined total of 135,000 tons for the U.S. Navy. By the mid-1930s:
The Lexington-class carriers (Lexington and Saratoga) accounted for 66,000 tons.
The Ranger (CV-4) and Yorktown-class carriers (Yorktown and Enterprise) accounted for an additional 43,500 tons.
This left the United States with roughly 15,000 tons of unused carrier tonnage under the treaty, which was earmarked for a final carrier—the USS Wasp.
The U.S. Navy prioritized using all available tonnage allowed under the treaty rather than leaving any of it unutilized, leading to the design of the Wasp within this limited tonnage.
2. The Design Compromises of USS Wasp
To fit within the remaining tonnage allowed by the treaty, the USS Wasp was built with significant compromises compared to the Yorktown-class carriers:
Smaller Size:
At 14,700 tons, the Wasp was considerably smaller than her predecessors. This limited her ability to carry as many aircraft, fuel, and armaments.
Reduced Armor Protection:
To save weight, the Wasp was constructed with less armor, making her more vulnerable to enemy attacks.
No Torpedo Protection:
Unlike the Yorktown-class carriers, the Wasp lacked torpedo bulges or advanced underwater protection, a significant vulnerability.
Smaller Air Wing:
The Wasp could carry approximately 76 aircraft, compared to the Yorktown-class's complement of over 90 aircraft.
These compromises were seen as acceptable at the time because the Wasp was intended to be an experimental design, filling the gap in carrier numbers within treaty limitations.
3. Japan’s Withdrawal from the Treaty
When Japan announced its withdrawal from the Washington Naval Treaty in 1934, it was too late to significantly alter the USS Wasp's design. The ship was already in the planning and early construction stages, and the U.S. Navy was operating under the assumption that treaty restrictions would remain in place for the foreseeable future.
The Japanese withdrawal marked the beginning of a naval arms race in the late 1930s, but it would take time for the United States to respond effectively with larger and more capable carrier designs, such as the Essex-class carriers, which were built after the treaty system collapsed completely.
4. Lessons Learned and the Role of USS Wasp
The limitations of the USS Wasp became evident during her service in World War II. Despite her vulnerabilities, she played a significant role in early Pacific and Atlantic operations, including:
Escorting convoys to Malta during Operation Pedestal.
Participating in early amphibious campaigns in the Pacific.
However, her lack of protection and smaller size proved fatal when she was torpedoed by the Japanese submarine I-19 on September 15, 1942, and subsequently sank.