Title graphic

Fleet Oiler Design, 1934-1936

After issuing the tentative characteristics for oilers, the General Board solicited comments from the various bureaus. This procedure, wherein the proposed characteristics for a new ship were circulated among the bureau chiefs, was used by the board as a method of obtaining a balanced design suitable to each of the bureaus (navigation, ordnance, supplies and accounting, engineering, and construction and repair). Each bureau would respond by way of an "endorsement" taking exception to any provisions that were unacceptable to that bureau and furnishing a recommended alternative.

Neither the 15-knot speed nor the 6,000-mile endurance originally proposed by the board (see table 4] were considered acceptable to the Bureau of Construction and Repair, headed by Rear Adm. Emory S. Land. Land was considered by some to be one of the most politically astute officers in the navy.1 The bureau's response to the board's request for comments on characteristics of oilers was transmitted via the "Fifth Endorsement" dated 18 June 1934. Signed by Land, the three-page document recommended that fleet oilers have a sustained sea speed of 161/2 knots (fully loaded), an endurance of 10,000 miles at 161/2 knots, and a cargo capacity of 12,000 tons.2 If adopted, these suggestions would result in a much larger, faster vessel than had been originally contemplated by the General Board.

Land's recommendations concerning the speed, endurance, and cargo capacity of the proposed design, given below, summarized the functions and purpose of a wartime fleet oiler while explaining the relationship between cargo capacity, speed, and length.

Cargo Capacity

In the event of war the ability to provide a maximum amount of oil at a given place in the shortest time may be vital. Such vessels as are intended for this service under emergency conditions should be of as large a capacity as practical. . . . Accordingly, it is suggested that the 10,000 ton cargo capacity now included in the tentative


characteristics, be considered a minimum, and that the present requirement be modified to read "At least 10,000 tons cargo, preferably 12,000 tons  . . ."


The most suitable speed for a naval oil tanker is intimately associated with the amount of oil to be transported and with the cargo oil capacity of the individual vessel. Other things being equal, the greater the capacity, the greater will be the length of ship adopted. Great length is favorable to maximum speed. Recent investigations indicate that a sea speed as high as 161/2 knots, ship in deep load condition, is obtainable in large tankers of proper design without resort to machinery installations of excessive power. The ability to make such a speed would increase the oil handling capacity and might make for safety in a war zone. When not necessitated by special conditions such a ship could be operated at a lesser speed determined by considerations of economy. Accordingly, it is suggested that the speed requirements read "sustained sea speed, ship loaded, to be 161/2 knots."


In the studies referred to in the previous paragraph it was found practicable to provide bunker oil capacity for a much greater radius than that included in the tentative characteristics. It is suggested that the endurance requirement in the tentative characteristics be changed to read "At least 10,000 miles at 161/2 knots, ship loaded, on fuel carried in ship's bunker."3

The expertise demonstrated here shows that Admiral Land, in addition to his political acumen, was also a highly competent naval constructor well versed in technical and strategic matters. Not surprisingly his recommendations were adopted by the General Board and incorporated into "Characteristics for Oilers," which was finalized during July 1934.4

By this date the design study of the 15-knot tanker proposed by the Joint Board for the Standardization of Merchant Vessels was well under way. The progress of the proposed design was closely followed by the Bureau of Construction and Repair, which was intimately involved in the design of the hull form. The bureau even provided additional funds for extended testing at its experimental model basin to insure that all variants (of hull form) could be adequately tested.5Undoubtedly, Admiral Land, as chief of the bureau, would have had to have personally approved any expenditure of this nature and would have followed its outcome with interest. It seems likely that Cdr. Howard L. Vickery kept him advised as to the status of the design being formulated by the standardization board and the general nature of the discussions held during each session.6 As the board's work


Rear Adm. Emory S. Land in full dress uniform while chief of the Bureau of Construction and Repair
Rear Adm. Emory S. Land in full dress uniform while chief of the Bureau of Construction and Repair. Admiral Land played a key role in securing funds for the navy's rebuilding program in the early 1930s and prepared the original design criteria of the Cimarron-class oilers. (National Archives)

progressed, it must have become evident to Land that the 15-knot tanker design would not meet the speed requirements stipulated in the revised characteristics for fleet oilers issued by the General Board. Records show that Land was very well informed about current developments in naval architecture and marine engineering and was intent


on making sure that the auxiliaries designed under his auspices would not limit the future speed of the fleet Train.7 It seems plausible that Admiral Land would have decided to initiate the bureau's own studies on tanker speed after reading the minutes of the board's sixth meeting of 21 November, although there are not records to this effect.8

The Price of Speed

The difference between a speed of 15 knots and 161/2 knots may not seem large, but speed is a highly critical factor in the design of a vessel. It determines the size of the propulsion system, and to some extent, the amount of fuel that must be carried on long voyages, since fuel consumption varies directly with horsepower. These factors become more acute as speed is increased. As can be seen from table 5, a relatively small increase in ship speed affects the cargo capacity since a greater proportion of the ship's load carry capability--its deadweight tonnage--has to be allocated for storage of more bunker fuel. The modest reduction in cargo capacity that accompanies the addition of bunker capacity increases the direct operating costs of a vessel since less cargo can be carried on a given voyage.

Normally, a warship's designer would not be greatly concerned with the operating costs associated with continuous steaming, but Admiral Land was intimately involved in the procurement of funds for the various construction programs and was acutely aware of the budget problems facing the navy. Perhaps Land foresaw the need to finance the construction of naval oilers via the Department of Commerce's loan program. For this to occur, the needed tankers would have to be acceptable for use by commercial operators. In any case, Land queried the industry regarding current design practices concerning the best speed for commercial oilers. He wrote to James E. Moss of the Atlantic Refining Company in January 1935, requesting a copy of its recent study concerning the "operating expenses of large tank ships at various speeds from 12 to 18 knots."9 Moss responded by preparing a separate report for the navy that "shed considerable light on the problem of designing tankers for both Naval and Merchant Service."10 His comments concerning the critical issues of a combined design for commercial/naval use provide a useful summary of the problems involved. An abbreviated version of the key points appears below.

  1. No particular problem is involved in designing a tanker for universal service [designed to carry any petrochemical product, i.e., crude oil, gasoline, etc.].

  2. Additional boiler capacity required for higher speed by a navy tanker would not be an entirely extra expense on a fast turnaround merchant tanker since the extra boiler might permit cleaning and repair under way.

  3. Unless main engines were designed for maximum efficiency at the most economic "merchant ship" speed, the additional fuel cost of operating such a vessel commercially would be very great.


The Effect of Speed on Ship Design

Ship name[1] Mobiloil Chiwawa Kennebec[2]
Length (h.p.) 487'6" 487'6" 487'6"
Beam 68'0" 68'0" 68'0"
Size (d.w.t.) 15,515 16,100 15,850
Sea speed (knots) 13 15 161/2
Engine size (s.h.p.) 4,400 7,000 12,000
Fuel[3] consumption (approximate tons/day) 32.7 52.1 89.3
Fuel consumed[4] (tons) 1,048 1,447 2,257
Bunker size (% of d.w.t.) 6.8 9.0 14.2
[1] These vessels had nearly identical hull forms.
[2] Formerly Corsicana
[3] At .62 lb/s.h.p./hr
[4] Based on theoretical voyage of ten thousand miles

  1. Steaming radius and bunker capacity offer no problem.

  2. Tank ship operators generally prefer single screw even on relatively large vessels, principally because of great propeller damage with twin screws in restricted waters. [Twin screws were generally required where more power was needed.]

  3. The main difference between the merchant tanker and the higher speed naval tanker is hull form. If the only difference between the two types was machinery, fuel consumption, or such, the designing of a combined type would be relatively simple. The great problem is the sacrificing of cargo capacity of the merchant tanker in order that in an emergency she may operate economically at higher speed as a naval tanker.11

The analysis to justify the above conclusions was not based on maintaining a constant displacement, as was the case in table 5. Instead, Moss (or his staff) chose to limit the increase in required horsepower by assuming that a finer lines form would be incorporated in the higher speed design. But this would also result in a reduction of the cargo capacity of the vessel (finer lines would lead to a smaller displacement), which would not be acceptable to commercial operators.

The Auxiliary Building Program

Although it is generally acknowledged that a well-rounded fleet requires an adequate number of naval auxiliaries, Congress has always been reluctant to provide funding for such vessels in peacetime. Several newly designed auxiliaries were added to the fleet in the early 1920s, but most of the rest were rapidly approaching the end of their useful life. Buoyed by the passage of the Vinson-Trammell Act--the


second major naval program in as many years--CNO Standley resolved to obtain an auxiliary building program legislatively similar to the Vinson-Trammell Act (i.e., one that would provide blanket authority to bring the number of auxiliaries up to strength).

In an apparent effort to elicit support for constructing these ships, Standley requested that the General Board "study the Navy's needs in auxiliaries . . . and present a program for [the] yearly procurement including replacement, which [would] bring the Navy to proper strength in [these classes]."12 The board's report, issued on 16 June 1934, was not particularly helpful. It recommended against building any new auxiliaries at that time, fearing that funds for such ships would be diverted from the construction of major combatants. The General Board believed "that all money available for new construction should be devoted entirely to the construction of the Treaty limited classes." In the board's opinion, the number of auxiliaries in the navy was sufficient "to meet the needs of a treaty navy operated on a peacetime basis." Although it agreed that the navy needed these ships, the General Board opposed the diversion of funds to "minor Combatant vessels" until quotas in the treaty classes had been obtained. The board was reluctant to add the cost of auxiliaries to the treaty building program already authorized since the extra expenditures would only provide ammunition for those in Congress opposed to "preparedness" spending. If the schedule proposed by the General Board in reply to Standley's request was followed, no new auxiliaries would be laid down until 1940!13 As for the aging oilers, construction of the first replacements would not begin until 1942!

The board's influence on policy matters had greatly declined since its inception and it had lost much of its prestige during Admiral Pratt's reign as CNO.14 Not surprisingly, Standley chose to disregard the board's recommendations, and pushed ahead with plans to establish a continual program of auxiliary construction to supplement the combatant tonnage authorized by the Vinson-Trammell Act. In retrospect, Standley, who later characterized his concerns for "continual construction" as a "pet hobby," was misled by the ease with which the navy had obtained authorization and funding for its shipbuilding programs of FY 1934 and FY 1935.15

Both Standley and Claude Swanson, the ailing secretary of the navy, underestimated the political pressures that were mounting on the administration to adopt a balanced budget.16 Although Swanson shared the board's apprehensions concerning Congress's reluctance to spend more money on the navy, he disagreed with the board's recommendation to delay the construction of auxiliaries. He wrote President Roosevelt in November stressing the "need of ships which are outside of the treaty categories--these being those auxiliaries which must go with the Fleet to care for the logistic requirements."17


Included in Swanson's letter was a tentative schedule for laying down or acquiring twenty-three auxiliary ships over a three-year period. In his letter, Swanson proposed that they be financed with a grant from the Public Works Administration (as had been used to fund the treaty building programs of FY 1934 and 1935), rather than through the navy's regular budget.18 Swanson believed that another allocation from the Public Works Administration would preserve "the desired balance" in the navy's building program and would further increase employment within the shipbuilding industry.

Unfortunately for the navy, the anticipated rate of reemployment had fallen far short of the pace initially forecast by the department to justify the inclusion of ships in the NIRA's public works program. The design staffs within the bureaus had been unprepared for the large volume of work that was suddenly thrust upon them after the bill's passage in June 1933. Of the six different ship types authorized by the president, only the heavy cruiser plans were completed. Destroyer designs were only partially finished and no plans were available for the newly authorized aircraft carriers, light cruisers, or submarines. No work could be started without a set of approved drawings. The lack of plans quickly became a construction bottleneck, causing delays in material orders and yard activity, which slowed reemployment in the shipbuilding industry. Although the department attempted to rectify these problems, the slow pace of job growth within the industry further aggravated Harold Ickes, Roosevelt's secretary of the interior. Ickes, one of the navy's foremost antagonists, was opposed to financing any naval program with PWA funds. Heeding his advice, the president chose to remove all naval shipbuilding funds from the relief budget for FY 1936.19

After PWA funds were denied, Swanson asked the department (Standley was in London for the second session of preliminary discussions prior to the forthcoming naval conference) to draft an authorization bill along with a list of auxiliaries that were intended for inclusion as part of the navy's regular budget for fiscal year 1936 (calendar year 1 July 1935 through 30 June 1936).20 Drafted on 25 March 1935, it consisted of fifty-four vessels, but for some unknown reason not a single oiler was included in the proposed program.21 Swanson's bill was not enthusiastically received by the Bureau of the Budget's director, Daniel Bell. The navy's regular budget already contained an allotment for treaty construction and Bell was reluctant to approve additional shipbuilding expenditures. He counseled the president against including it in the administration's financial package for the coming year, believing that it was an inopportune time to present such a measure before Congress.22 Roosevelt agreed with this recommendation and the auxiliary bill was quietly dropped from the 1936 budget.

With no chance of obtaining funds to build an oiler, the Bureau of Construction and Repair's efforts on tanker design all but stopped.


Except for additional testing at the experimental basin to determine effective horsepower requirements at various speeds, little or no additional work was done on the design throughout the remainder of the year.23 In the meantime, the lack of modern auxiliaries had become the most serious deficiency in the fleet.24 The inadequacy of the fleet's oilers was so acute that Adm. Joseph M. Reeves, commander in chief, U.S. Fleet, felt obligated to inform Standley of the need for new oilers. Writing to the chief of naval operations he reported: "The four oilers now assigned to the Base Force are barely adequate for normal operations of the Fleet, and early provision of at least two additional oilers is desirable."25

Reeves's remarks must have hit home. Early in 1936, the Navy Department resubmitted a revised auxiliary building program to Congress. Although the program had been reduced to forty-eight vessels, it now included a single oiler.26 With the prospect for funds to build a new oiler in the 1937 budget, the Bureau of Construction and Repair was able to renew its efforts on the design of a high-speed tanker.

Drafting Plans for a New Fleet Oiler

By February 1936, the Bureau of Construction and Repair had prepared a preliminary set of drawings showing the general arrangement of the proposed oiler along with the layout of the cargo tanks.27 This information, along with plans of the fastest Japanese tankers then under construction, was sent by Admiral Land to the commandant of the Central Drafting Office (CDO) in New York (Brooklyn) with instructions to prepare the required lines plan.28 The Central Drafting Office completed this task by June and submitted its design for a 16,000-ton (deadweight) tanker, 524 ft along the waterline, with a single screw, powered by the standard 8,000 s.h.p. power plant developed by the Joint Board for the Standardization of Merchant Vessels.29The underwater lines for the CDO design were influenced by the excellent tank performance of the T-2 design developed by the joint board for standardization.30 By increasing the length along the waterline and providing a finer block coefficient, the Central Drafting Office believed that it had increased the design speed of the new tanker by at least one knot.31

The Bureau of Construction and Repair questioned the accuracy of the calculations used by the Central Drafting Office to determine the power requirements specified in its design. In order to meet the sustained speed directive of 161/2 knots, the bureau (C&R) was planning to specify a power plant 25 percent in excess of that required to drive the ship at that speed. Calculations showed that with this amount of power a trial speed of 171/2 knots would be expected.32 The extra power was added in order to insure that the vessel would be capable of keeping up with the fleet in the worst of conditions, such as caused by a foul bottom. Based on the model tests previously conducted, the


bureau estimated that a twin-screw installation of 13,000 s.h.p. would be necessary to meet these requirements.33 The Bureau of Construction and Repair, however, could not proceed with the design until the Bureau of Engineering provided details on the engine and power plant that would be selected to fulfill the machinery requirements needed to meet design characteristics. Unfortunately, the Bureau of Engineering was slow getting started. It had done little if any work on the oiler's power plant and did not begin serious design efforts until the middle of December 1936.34 The demise of the auxiliary construction bill for the fiscal year 1937 discouraged the bureau from continuing further work on the design of the new tanker. Additional efforts on the bureau's part would not occur until Congress agreed to authorize construction of a replacement oiler for the fleet. By the time this happened, the U.S. Maritime Commission would be actively lobbying both Congress and the navy in an attempt to take over responsibility for building the tankers desired by the navy. How and why this came about requires an understanding of the Merchant Marine Act of 1936 and the activities of the U.S. Maritime Commission.


Previous Chapter (5) ** Next Chapter (7)

Transcribed and formatted for HTML by Larry Jewell & Patrick Clancey, HyperWar Foundation