HMCo #346p [H-16 / C-1 Seaplane Hull]

"[1918-11-13] Wed 13: Have orders to stop work on flying boats [#347p to #360p?] that are not well advanced. This throws us out of much winter's work." (Source: Herreshoff, Nathanael G. Diary, 1918. Manuscript (excerpts). Diary access courtesy of Halsey C. Herreshoff.)

"... the Naval Aircraft Factory was put into production with the H-16 patrol flying boat. Plans and engineering data for this type of machine were received by the factory October 26, 1917. On March 27, 1918, just 228 days after ground was broken and 151 days from the receipt of drawings, the first H-16 built by the factory was successfully flown and on April 2, 1918, the first and second factory built H-16 flying boats were shipped to Killingholme, England.
...
As sources for hulls seven small yacht building yards were obtained, and for the supply of wings, metal parts, tanks, engine foundation assemblies, tail surfaces, etc., the services of about a dozen plants were enlisted which would have otherwise stood partly idle due to the large decrease of their peace-time business. ... The productive capacity of these outside plants was placed directly under the control of the manager of the Naval Aircraft Factory who maintained a branch office in each and directed them as if they were departments of the factory proper. This novel manufacturing procedure proved highly successful.
...
The Naval Aircraft Factory was initially put in production on the Curtiss H-16 drawings. These drawings were not suitable for progressive assembly manufactured by concerns unfamiliar with aircraft. The Curtiss Co.'s experienced foremen and workmen did not need absolutely clear and complete drawings of every minor part. Also many parts were cut to fit during final assembly. ... It therefore became necessary to redraw, redetail, and standarize the H-16 drawings so that part makers could work independently. The H-16 as thus revised was designated C-1. This work of standardization was carefully and thoroughly done by Mr. George R. Wadsworth.
In the spring of 1918, advices from our naval aviation forces overseas indicated that the British experimental air station at Felixstone had developed a new type of patrol flying boat called the F-5 which was a great improvement over the Curtiss H-16 both as to seaworthiness and bomb-carrying capacity. This presented the problem of whether or not to stop the production of H-16's and change to F-5's. Such a change would mean a long interruption of delivery as the H-16 was by this time in rapid standardized production. However, it also appeared about this time that larger bombs than the H-16 could carry were required to sink German submarines and that the F-5 could carry them. The end of the war was not in sight and looking toward 1919, the decision was made to switch production to F-5's as rapidly as possible without stopping the delivery of H-16's.
The British Admiralty, at the request of Admiral Sims, furnished the Navy Department with the drawings of the F-5. These drawings were a great disappointment and were entirely impossible for quantity manufacture. They required hand cutting and fitting by experienced airplane workers and also materials we did not have in quantity.
The labor of converting H-16 plans to C-1 standard plans was slight compared with the labor involved in the complete redesign of the F-5, preserving external dimensions of course. All metal parts had to be redesigned for machine fabrication by our methods. The hull in particular was considered weak by Commanders Richardson and Hunsaker and the former completely redesigned it on a longitudinal framing system, preserving the outer lines only. The engine installation was designed for Rolls-Royce engines in the British boat and it had to be redesigned to take Libertys. Thus the American F-5-L was created which resembled its British prototype only in essentials.
The output of the Naval Aircraft Factory to November 11, 1918, included 183 twin-engine patrol flying boats, with 50 sets of spares, valued at $5,435,000. Of these 183 boats, the last 33 were F-5-L's. ..." (Source: Sitz, W. H. "A History of U.S. Naval Aviation." United States Navy Department, Bureau Of Aeronautics Technical Note No. 18, Series of 1930, Washington, 1930, p. 15-17.)

"[Item Description:] [Seaplane] barges require 6 instead of 4 weeks building time, #306p [SP-1841] and #308p [SP-2232] away and paid, #322p [SP-2373] to be taken away in a day or so, #321p [SP-2235] having dock trials and hopefully to be turned over next week, #323p [SP-2840] has boilers in, hope to have her almost finished by contract time April 1st, other yards are raising wages and our men are uneasy, hope to have at least one [seaplane] barge in the water by time you are back, gov't wants six by that time, navy dept is probably going to order 42ft flying boat hulls [#346p, #347p, #348p, #349p, #350p, #351p, #352p, #353p, #354p, #355p H-16 / C-1 Seaplane Hulls]." (Source: Swan, James. Letter to N.G. Herreshoff. Halsey C. Herreshoff Collection at the Herreshoff Marine Museum Item MR_51000. Subject Files, Folder [no #]. 1918-03-14.)
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Note: This list of archival documents contains in an unedited form any and all which mention #346p [H-16 / C-1 Seaplane Hull] even if just in a cursory way. Permission to digitize, transcribe and display is gratefully acknowledged.

• H-16 Seaplane Hull (HMCo-made index card)
• Note: The vessel index cards comprise two sets of a total of some 3200 cards about vessels built by HMCo, with dimensions and information regarding drawings, later or former vessel names, and owners. They were compiled from HMCo's early days until 1920 and added to in later decades, apparently by Hart Nautical curator William A. Baker and his successors. While HMCo seems to have used only one set of index cards, all sorted by name and, where no name was available, by number, later users at MIT apparently divided them into two sets of cards, one sorted by vessel name, the other by vessel number and greatly expanded the number of cards. Original HMCo cards are usually lined and almost always punched with a hole at bottom center while later cards usually have no hole, are unlined, and often carry substantially less information. All cards are held by the Francis Russell Hart Nautical Collections of the MIT Museum in Cambridge, Mass.

• H-16 Seaplane Hulls
• Note: The L. Francis Herreshoff index cards comprise a set of some 1200 cards about vessels built by HMCo, with dimensions and / or ownership information. Apparently compiled in the early 1930s, for later HMCo-built boats like the Fishers Island 23s or the Northeast Harbor 30s are not included. Added to in later decades, apparently by L. F. Herreshoff as well as his long-time secretary Muriel Vaughn and others. Also 46 cards of L. F. Herreshoff-designed vessels. The original set of index cards is held by the Herreshoff Marine Museum and permission to display is gratefully acknowledged.

Year: 1918c
E/P/S: P
No.: 346
Name: H-16 Flying Boat Hulls

Source: Vermilya, Peter and Maynard Bray. "Transcription of the HMCo. Construction Record." Unpublished database, ca. 2000.

Note: The transcription of the HMCo Construction Record by Peter Vermilya and Maynard Bray was performed independently (and earlier) than that by Claas van der Linde. A comparison of the two transcriptions can be particularly useful in those many cases where the handwriting in the Construction Record is difficult to decipher.