USS Wasp - Small Carrier Experiment

The large carrier versus small carrier debate has raged, literally, since the first carrier was built.  However, every study ever conducted and every experiment attempted has demonstrated the superiority of the large carrier.  Let’s take a look at the first attempt by the Navy to build a small carrier, the USS Wasp, CV-7.

As a brief reminder, Wasp was laid down in 1936 and commissioned in 1940.  She initially served in the Atlantic, often performing ferry duty for Spitfires and, in fact, landed one Spitfire aboard without a tailhook during an aircraft emergency! 

USS Wasp

Wasp transferred to the Pacific in mid-1942 where she supported the Guadalcanal operation.  In late August 1942, Wasp’s air group consisted of 26 Grumman F4F Wildcats, 25 Douglas SBD Dauntlesses, and 11 Grumman TBF Avengers for a total of 62 aircraft, according to Wiki. 

Wasp was sunk on 15-Sep-1942 as the result of a spread of six torpedoes launched from a Japanese submarine, three of which hit the carrier.  Subsequent gasoline fires and internal explosions caused the ship to be abandoned.  She was eventually sunk by three additional torpedoes from a US destroyer.

Here some comparative size specs for the Wasp and her larger cousin the USS Enterprise, CV-6

                                  Wasp   Enterprise

Displacement, tons full load    19,000     25,000

Length, ft overall                 741        825

Beam, ft overall                   109        109

Air Group                     62(a)–71(b)      87(c)

Crew                             2,167      2,217

(a)     August 1942, Wiki

(b)     Time of sinking, Wiki

(c)     July 1942 – May 1943, (1)

We see, then, that Wasp was 76% the displacement of the Yorktown and 90% of the length.

In order to “fit” within the weight/size range, many aspects of construction and performance were compromised.  From Wiki,

“To save weight and space, Wasp was constructed with low-power machinery (compare Wasp's 75,000 shp (56,000 kW) machinery with Yorktown's 120,000 shp (89,000 kW), Essex-class's 150,000 shp (110,000 kW), and the Independence-class's 100,000 shp (75,000 kW)).

Additionally, Wasp was launched with almost no armor, modest speed, and more significantly, no protection from torpedoes. Absence of side protection of the boilers and internal aviation fuel stores "doomed her to a blazing demise". These were inherent design flaws that were recognized when constructed, but could not be remedied within the allowed tonnage.”

Let’s look at a few more specific aspects of the smaller design.

Flight Operations.  The purpose of a carrier is, of course, aviation and the Wasp’s small size impacted its aviation function.  Carriers of that time required sufficient wind over the flight deck to enable aircraft to take off and land and Wasp’s small power plant provided insufficient speed without the benefit of natural wind.  Further, the Wasp required a long period of time to attain maximum speed for take off and landing flight operations – a severe inconvenience in combat!

“… the combination of speed and flight deck size was critical.  The Wasp was deficient in both respects.” (2, p.114)

Crew Size – Despite being only 76% of the size of the Yorktown class (based on displacement), the Wasp required 98% of the crew size – almost no savings!  This would be a key consideration today given the Navy’s single-minded pursuit of the Holy Grail of reduced manning.

Air Group Size – The design scheme for Wasp envisioned an air group of 70 aircraft versus 90 for the Yorktown class. (2, p.89)  That would have given the Wasp an air group 78% the size of the Yorktown.  In practice, the Wasp’s air group was 71% - 82% of the Yorktown’s – a fairly linear reduction proportional to the displacement reduction.

Gasoline and Ammunition Protection – As it turned out, Wasp’s smaller size resulted in increased risk due to explosive aviation gasoline and ammunition.

“Both gas and ordnance allowances were proportional to the size of the air group, and hence to deck area rather than to displacement: a smaller carrier, which could not be so well protected, would actually have to carry a larger proportional tonnage of gasoline and ammunition than would one of her larger sisters.” (2, p.108)

So, the smaller size actually increased the risk due to stored flammable and explosive materials!

Wasp Sinking

On the plus side, the smaller carrier was able to operate an air group of sufficient size as to be operationally useful.  In addition, the smaller carrier did increase the overall carrier numbers.  However, in order to achieve these pluses, the ship was forced to incorporate many compromises and omissions when compared to the larger Yorktown class.  These shortcomings negatively impacted survivability and function and resulted in a ship that was operationally inefficient and combat fragile and, in the event, did not last long in combat.

Despite recognition of Wasp’s shortcomings, interest in small carriers did not die.

“Although the Wasp was acknowledged to be unsatisfactory from birth, interest in smaller carriers did not die off completely.  In 1938 Congress approved another 40,000 tons of carrier construction, tonnage eventually expended in the Hornet and the Essex.  There were, however, some who suggested that some of it go into 10,000-ton light carriers.  In November 1938 Admiral R.L. Ghormley of the War Plans Division wrote that a larger number of such smaller carriers might yet have its advantages, even though unquestionably the larger carriers would provide a greater economy of effort in tons of ship and number of ship personnel per plane carried.” (2, p.114)

Thus, even while unanimously recognized as inferior, the concept of small carriers continued to prove alluring and this allure continues through today, despite every study and experiment ever conducted.  Truly baffling.

______________________________________

(1)http://www.cv6.org/company/airgroups.htm

(2)”US Aircraft Carriers – An Illustrated Design History”, Norman Friedman, Naval Institute Press, Annapolis, MD, 1983, ISBN 0-87021-739-9