Technical Specifications for Ships

built under the Merchant Marine Act of 1936

Foreword

The following analysis provides a description of all types of vessels designed and built by the United States Maritime Commission under the Merchant Marine Act of 1936. In addition to such basic types as the C1, C2, C3 (Cargo), Victory , Liberty, and T2 (Tanker) types, all specialized designs that were created to serve the diversified war and peacetime transportation needs of the nation, are shown.

Since many designs were modifications or conversions from standard designs, only design characteristics or standard designs are generally shown. Design characteristics are for identification purposes and are not warranted as those of any particular vessel.

A description of the classification system of letters and numbers used to outline characteristics of all Maritime Commission designs will be find next.

In the following pages various terms are mentioned which give the factual data of each vessel. Definitions of these terms will also find next.

(from Vessel Design & Characteristics, Office Chief of Transportation, Washington D.C. 1 June 1948)

Index of Vessel Designs

Classification System for Maritime Commission Designs

The system will be based on three groups of letters and numbers which will endeavor to outline characteristics of the vessel. The first group "prefix" will indicate the type of vessel, such as cargo, passenger , etc., and its approximate size. The second group "intermediate" will indicate the type of machinery, and number of screws and the third group "suffix" will indicate the paticular design of the type of vessel and modifications of the same.

Example : C2-S-AJ1

For the first group (see Table 1) a letter will be used in conjunction with a number. Please note example above as an illustration; the "C2" stands for a cargo ship between 400 and 450 feet ong.

The second group will be outlined in Table 2 with the appropiate symbols with a number. Continuing the classification , our example would now be "C2-S" standing for a single screw cargo ship, steam machinery, of a lenght between 400 and 450 feet.

It can be seen from the above that there may be many variations of length and form in the range 400 and 450 feet and hence it is necessary to have a design letter that will fix the particular vessel under consideration. A third group is, therefore, used and the design letter will remain fixed regardless of any change that may be made. The design letter of our example is, therefore "AJ" in this third group indicates the original arrangement of this particular design . This number can be varied to reflect changes of a major nature such as addition of passengers, conversion  to troopship, etc. An example is as follows: Let us assume that accomodations for 50 passengers were added to this particular vessel. As this would be a major change, the third group would become "AJ2". Since accomodations for more than 12 passengers had been added this second group would become "S1", and as these accomodations were for less than 100 Passengers, the first group would not change. Our complete designation would then be C2-S1-AJ2. Since we already have, and may have many more, "C2" vessels it is important to point out here that any verbal abbrevation (nickname) of this particular design should b2 "AJ" and not "C2".

The Prefix

The first or "prefix" group indicates (a) the general class of vessel (cargo, passenger, refrigerated, tanker, etc.) and (b) the lenght-range within which the design falls. The symbol in this group are assigned in accordance with the folowing table:

Table 1

The following older designs (except the last four) accord with table 1 but they do not accord with table 2, in as much as they were  given their identification before the present scheme of self-descriptive symbols was fully developed:

In the preceding list of older designs the letter or word following the hyphen are simple distinguished characters. All of the remaining and newer designs have more fully self-descriptive designations as shown in the Exampe.

Intermediate Letter or Group

Following the "prefix", the intermediate letter or combination indicates the type of power machinery and pro-pulsion, and whether passenger accomodations, if any, are provided for 12 or more persons, or more than 12. These symbols can be interpreted by references to the following table:

Table 2

The Suffix - - Identification of Design

The third group, or "suffix", supplies the exclusive identification of the particular design, and indicates the approximate time when the design originated. The alphabet letters are assigned in series; therefore, if there is but one letter, this indicates that the design originated earlier than one having two letters. Likewise, a single letter that is near the beginning of the alphabet indicates an earlier date than one near the end of the alphabet. As between two designs, each of which has two letters, the same date relationship obtains between their first letters, than their second letters in relation thereto. (There are occasional irregular designations, of which the date does not accord with the above scheme).

The figure following the letters in the suffix indicates that it is either  (a) the original design of that particular alphabet designation or (b) a modification thereof. The original design is invariable numbered "1". Thereafter modifications, if any, are numbered "2", "3", and so on - - "2" indicating the first modification, and so on.

Definitions