Merchant Ship Conversions to Wartime Use

It is no secret that the Navy has nowhere near enough amphibious and logistic support ships to prosecute a sustained war with China.  New construction of sufficient numbers and types of ships when war comes will be impossible given the state of US commercial shipbuilding.  An alternative to new construction is to acquire and convert commercial ships as was done routinely during WWII, especially at the start of the war.

 

Consider the case of troop transports.  At the start of WWII, we had nowhere near enough Attack Transports which were the backbone of the entire Pacific campaign.  Instead, we converted commercial ships to troop transports until we were able to ramp up our wartime shipbuilding.  Here’s a few examples:

 

McCawley Class - The McCawley class consisted of two converted commercial ships built for the American shipping company, Grace Lines, by Furness Shipbuilding Company.  The ships were completed in 1928 as Santa Barbara and Santa Maria. They were bought by the Navy in 1940 and converted to troop transports as the USS McCawley (AP-10) and USS Barnett (AP-11).

 

USS Harry Lee (AP-17) - The Harry Lee was built as the passenger ship SS Exochorda by New York Shipbuilding Co. in 1931 before being acquired by the Navy in Oct-1940 and converted to the Harry Lee (AP-17) in Dec-1940.

 

USS John Penn (AP-51/APA-23) - The John Penn was built as Excambion in 1931 by the New York Shipbuilding Company as one of American Export Lines's original "Four Aces."  She was acquired by the Navy 8-Jan-1942 and converted to a troop transport in Apr-1942.

 

 

Even prior to WWI, the US recognized the need for vastly increased numbers of commercial ships that could be converted to wartime use.  With the 1916 Shipping Act, Congress established an organization to do just that – the United States Shipping Board which, in turn, founded a business, the Emergency Fleet Corporation whose mission was to acquire merchant ships for war needs.

 

Paraphrased from various Wikipedia entries,

 

The Shipping Board had been established while the United States was at peace, with the intent to restore the nation's Merchant Marine.

 

Ten days after declaration of war, on 16 April 1917, the Board created the Emergency Fleet Corporation (EFC) in the District of Columbia with a capital stock of $50,000,000.  The EFC’s purpose was to acquire, maintain, and operate merchant ships to meet national defense, foreign and domestic commerce during World War I.

 

When the United States declared war against Germany the purpose and policy of the Shipping Board and the Fleet Corporation changed from a body established to restore the American Merchant Marine to a military organization tasked with providing transport of war materials to Europe. 

 

The EFC was renamed the U.S. Shipping Board Merchant Fleet Corporation in February 1927, then abolished entirely in October 1936. Its functions were transferred to the United States Maritime Commission.

 

The EFC operated together with some 80 shipyards throughout the country to design commercial ships suitable for conversion to war use.  For example, the Design 1029 ship (full name Emergency Fleet Corporation Design 1029) was a steel-hulled passenger/cargo ship designed to be converted in times of war to a troopship.

 

Today, China does something along these lines with their commercial ships being designed for rapid conversion to wartime vessels.

 

We see, then, that acquisition and conversion of merchant ships to wartime use has been a common practice throughout history.

 

Given our appalling shortage of transport and logistic ships, we will definitely need to acquire and convert merchant ships.  Unfortunately, the US flagged merchant fleet is lacking in numbers.  The U.S. Department of Transportation, Maritime Administration, lists only 180 US flagged, privately owned, oceangoing ships of 1,000 tons or greater, as of 2021.[1]  The breakdown by type is shown in the table below.

 

 

Ship Type	Qty.
Containership	63
Dry Bulk	4
General Cargo	20
Ro-Ro	26
Vehicles Carrier	3
Tanker	64
Total	180

 

 

Of the 180 vessels, 157 were deemed militarily useful.[1]

 

We don’t need to attempt to build more amphibious or logistics ships but we do need to ‘change the landscape’, so to speak, with the following actions:

 

• Need to require merchant ships to include military conversion features in their design.
• Need to increase the number of US flagged merchant ships by modifying the applicable laws.
• Need to plan for acquisition and conversion of merchant ships.
• Need to have conversion plans for each individual ship in hand and ready to go.
• Need to assess shipyard capacity to accomplish conversions.

 

Most of all, we need some kind of organization tasked with the described acquisition and conversion.  It is unclear to me whether such an organization exists within the government/military.  The ‘s responsibilities have, over the decades, been diluted and distributed among various organizations such as the United States Maritime Administration (MARAD) but none seem to have the charter to produce/ensure that commercial ships are designed for easy and rapid conversion to wartime configurations.

 

Of course, converted merchant ships won’t be perfect fits for wartime uses since they are, after all, merchant ships at heart.  For example, we can easily convert a merchant ship to a troop transport, like we did in WWII, but we can’t convert it to a big deck, aviation ship of the type the Navy currently procures.  However, this fits well with the blog’s overall ship design philosophy of single function, cheaper, smaller ships.  The Navy needs to institutionally come to grips with this reality – and desirability!  We then need to revise our doctrine and operations to include these types of ships instead of the big deck, aviation ships we have today.

 

One final consideration is the cost of naval amphibious or logistic ships – they’re expensive to buy and operate!  By having a fleet of merchant ships capable of being usefully converted to wartime work, the Navy largely avoids the cost of procuring and operating the ships while still having access to the numbers and capabilities the ships represent.  Thus, the cost of administering such a program would easily pay for itself.

 

 

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Related Note:  Following is an example of a commercial ship, the SS United States, designed for conversion to wartime needs.  The ship was designed and acquired under the direction of the United States Maritime Commission (MARCOM) which succeeded the United States Shipping Board.  From Wikipedia entries,

 

… the US government sponsored the construction of a large and fast merchant vessel that would be capable of transporting large numbers of soldiers. Designed by American naval architect and marine engineer William Francis Gibbs (1886–1967), the liner's construction was a joint effort by the United States Navy and United States Lines. The US government underwrote $50 million of the $78 million construction cost, with the ship's prospective operators, United States Lines, contributing the remaining $28 million. In exchange, the ship was designed to be easily converted in times of war to a troopship. The ship has a capacity of 15,000 troops, and could also be converted to a hospital ship.

 

The vessel was constructed from 1950 to 1952 at the Newport News Shipbuilding and Drydock Company in Newport News, Virginia. The hull was constructed in a dry dock. United States was built to exacting Navy specifications, which required that the ship be heavily compartmentalized, and have separate engine rooms to optimize wartime survival.[2]

 

SS United States

 

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[1]https://www.maritime.dot.gov/sites/marad.dot.gov/files/2021-04/DS_USFlag-Fleet_2021_0316_Bundle.pdf

 

[2]https://en.wikipedia.org/wiki/SS_United_States