On November 8, 1941, the British battleship HMS Warspite arrived at the U.S. Navy Yard in Bremerton, Seattle, to undergo repair work after being damaged in combat. As part of the repair work the battleship’s main battery of 15-inch guns needed to be replaced. However, the U.S. Navy did not make 15-inch guns since most American battleships at the time carried 14-inch or 16-inch weapons. Consequently, the British had to ship replacement guns across the Atlantic Ocean in multiple transports, transfer them onto trains in Norfolk, Virginia, and then rail them all the way across the United States. Furthermore, the threads on the metal screws used to construct the Warspite were incompatible with American screws and fasteners, creating further difficulties for the shipyard. Similar situations occurred throughout World War II as the U.S. Navy fought the Axis alongside allies whose gun calibers, radio frequencies, electrical power systems, and doctrine often did not align with ones. After the war the U.S. Navy launched a major standardization effort with the British and Canadian navies as part of a larger program to craft common equipment and procedures between all three militaries. The three navies focused on defeating attacks by Soviet submarines against the North Atlantic sea lines of communication in a future conflict with the Soviet Union. However, creating standardized equipment proved extremely difficult due to economic considerations, national pride, and incompatible tactics and methods. In contrast, American officers discovered that standardizing doctrine and procedures could be accomplished far more rapidly which removed one of the stumbling blocks to standardizing equipment. In other words, the U.S. Navy learned to standardize concepts before calibers.
The postwar Navy’s pursuit of standardization highlights issues of contemporary relevance to the U.S. Navy: how to develop and maintain the ability to operate with foreign naval forces with little advance warning. Numerous recent examples demonstrate the importance of pursuing and maintaining interoperability: the French carrier Charles De Gaulle’ s operations against the Islamic State, March 2017 logistics interoperability exercises with the Japanese Maritime Self-Defense Force, and the recent tripartite agreement on carrier and submarine cooperation between French, British, and American navies. As the CNO’s Design for Maintaining Maritime Supremacy calls for the Navy to prioritize “interoperability initiatives” as part of strengthening its partnerships, the Navy could benefit from its history by pursuing conceptual standardization with partners and allies before seeking common weapons systems.
Although the U.S. Navy expressed interest in continuing to exchange technical information with the Royal Navy and the Royal Canadian Navy in the summer of 1945, official action did not begin until after war’s end.  During a meeting with British Field Marshal Bernard Montgomery in September 1946, President Harry Truman approved standardization talks with the British and Canadian services. These talks occurred between 12 and 25 November 1946 at the Pentagon and led to a series of classified agreements calling for standardization of equipment, basic parts such as screws, procedures, doctrine, and communications. The participants in the talks agreed that the ultimate goal was for units from each nation to be able to operate in combined formations. In practice, national identity and diverging technical requirements hindered efforts to standardize equipment. A senior officer in the Admiralty highlighted this fact in a July 1948 report on standardization with the U.S. Navy:
Progress [in standardization] has been made with many items, but over a considerable field standardization is hindered by national character and tradition. A crisis graver than May 1940 would be needed to get our seamen into American caps; a reversal of the War of Independence would be required to get American seamen into ours.
The U.S. Navy introduced sonobuoys in 1942 for use against German submarines. These earliest buoys allowed crews on the aircraft which deployed them to hear the sound created by nearby submarines, but not determine the bearing from the buoy to the source of the sound. As a result these buoys were known as omnidirectional buoys. In contrast, postwar development focused on directional buoys that could provide that bearing. In June 1947, an American team began developing such a buoy, known as the AN/SSQ-1, and shared its progress with Royal Navy researchers. In return, the British also provided the Americans with regular reports on the development of their own directional buoy, called the Mark I. Thus by early 1948 both navies had competing buoy designs in progress.
Despite launching a separate program, the British still sought to eventually standardize their sonobuoys with the Americans. In any future war, British buoy production might be curtailed by Soviet bombing and so the prudent course was to develop one that could be produced in America and used by both navies. In pursuit of this goal, the Royal Navy approached the U.S. Navy in 1948 to discuss forming a combined Anglo-American committee to standardize sonobuoys.
While preliminary discussions about such a committee were underway, in July 1948 the U.S. Navy suggested to the British that they abandon their efforts to develop their Mark I directional sonobuoy and concentrate resources on creating a standardized Anglo-American model. The Sea/Air Warfare Committee, which oversaw British anti-submarine policy for the Admiralty and the Air Ministry, rejected the American proposal. Wary of halting development of their Mark I buoy simply to standardize with the Americans, the Royal Air Force representatives pointed out that the British already had an early working prototype and that stopping the Mark I in favor of a standardized version would impose a delay of 18 months before the common buoy entered production. The committee admitted that “compared with the U.S. our experience of this equipment is limited, but our scientists are confident that they can produce as good a system as America.” In addition, the American proposal reminded the British of their perennial concern regarding standardization: for the U.S. Navy, it meant buying American. The eventual success of the British Mark I buoy and the troubles encountered by the American version would ultimately demonstrate the wisdom of this approach.
Despite the free exchange of research information, the British and Americans proved unable to develop compatible technical standards for their sonobuoys. The failure to standardize technical requirements in 1947 and 1948 laid the foundation for serious setbacks in buoy standardization in 1950 and 1951.
The two sonobuoy programs formally intersected in 1950 when the British and American navies agreed to establish a Sonobuoy Working Party to standardize their equipment. However, differences in production timelines hampered efforts to develop a common, standardized version. In early 1950 the British Mark I directional buoy entered service, leading the Royal Navy to argue for the adoption of its buoy as the standard model. Across the Atlantic, the American program remained in development. Although its effort dated back to 1947, the U.S. Navy did not provide the contractor with research done on directional buoys in the closing months of World War II. Thus, by 1950 the new American buoy, the AN/SSQ-1, was not ready to enter service, though a working prototype was available.
In addition to different acquisition timelines, the operational demands of the Korean War and fundamental technical differences further undermined standardization. The Working Party had no sooner scheduled combined trials of the British Mark I and American AN/SSQ-1 directional buoys when North Korea invaded South Korea in June 1950. The Korean War invoked Norman Friedman’s “iron low of mobilization . . . produce what is on hand – you do not wait for something better.” The U.S. Navy diverted existing buoy stocks to the Western Pacific, withdrew from the planned trials, and began full scale production of their prototype AN/SSQ-1. The comparative trials would have highlighted significant differences in American and British buoy design and concepts of operation.
The British and American directional buoys differed from each other in two fundamental respects: the radio frequencies used to transmit sound and the method used to keep track of buoy locations once they were deployed. Operators on ships and aircraft with equipment designed to receive signals from a British buoy could not pick up signals from an American buoy and vice versa. The American buoy used frequency modulation (FM) while the British buoy used amplitude modulation (AM) and according to Canadian observers, “on both sides scientific thought appears to be unwilling to change.”
Furthermore, each navy had a different approach to using sonobuoys in combat. The American concept called for two aircraft to hunt a single submarine simultaneously with one plane carrying detection equipment including sonobuoys and the other carrying anti-submarine weapons. The British and Canadians rejected this approach which required large numbers of maritime patrol aircraft, a financial burden that they could not afford. The Royal Navy wanted a single aircraft capable of detecting and attacking a submarine. The two navies also used different methods of plotting where buoys had been dropped. In the U.S. Navy all buoys included a small radar responder beacon which allowed aircraft to track their locations using the more advanced aerial radar deployed on U.S. Navy patrol planes. In contrast, British and Canadian aircraft dropped a separate buoy that served as a beacon, marking the location of a pattern of sonobuoys. British and Canadian planes dropped the buoys in one of several pre-set patterns and the beacon would be near the center of the pattern. These basic technical differences between British and American sonobuoys were the result of a failure to standardize requirements. By the end of 1950 both navies were well into production runs of their own directional buoys, filling their stocks with buoys that could not be used by the other nation.
In the midst of these technical differences, the meeting of the Sonobuoy Working Party in May 1951 fell into disarray when the American representatives accused the British of reneging on an earlier commitment regarding sonobuoy radio bands. The Working Party’s talks broke down, requiring a six month cooling off period before they could resume. After the collapse of the talks, U.S. naval officers involved in sonobuoy standardization became increasingly anxious about the lack of progress. The solution adopted by both sides when the Working Party’s talks resumed in October 1951 was to invite the Canadians to join them. Membership in this group allowed the Royal Canadian Navy to lobby for its own goal in naval standardization: creating common designs that would remove the need for Ottawa to choose between American and British equipment. The Canadians also wanted to standardize procedures since the RCAF and RCN used different patterns for aircraft laying sonobuoys. Eventually, the Canadians got their wish. The resumption of Sonobuoy Working Party talks in late 1951 led to agreement on the technical details of a standardized sonobuoy by 1957. The six years between the resumption of talks and the final agreement highlight the challenges of rapidly standardizing equipment, even between navies with close ties.
Sonobuoy standardization made sense in operational terms and could reduce production costs. The ability to draw upon each other’s supplies of buoys in a crisis would provide all three navies with greater flexibility. However, despite the priority accorded to the project, the road to standardized buoys proved to be full of bumps and detours, largely the result of diverging operational concepts.
Common Doctrine and Communications
In contrast to the troubled sonobuoy saga, the Canadian, British, and American navies found that developing a common doctrine for anti-submarine warfare (ASW) and standardizing communications procedures could be accomplished relatively quickly. In the aftermath of the British, American, and Canadian campaign against German U-boats in World War II, naval planners on both sides of the Atlantic wanted to ensure that in a future war with the Soviet Union, all three navies used the same ASW practices. As a result, in December 1948 the British and Americans formed a working group to prepare common ASW doctrine and promptly invited the RCN to join it.
The working group moved rapidly, competing an initial draft of a common ASW doctrine based on existing U.S. Navy and Royal Navy doctrine by late April 1949. The draft declared the goal of anti-submarine operations was “to deny the enemy the effective use of his submarines” a direct quotation from U.S. Navy doctrine. Noticeably, the overall objective was not the Royal Navy’s standard ASW goal: the safe and timely arrival of the convoy, though British influence was evident in specific portions of the document. The draft explained that its overall goal would be achieved through five principles of ASW: restriction of submarine movement, operational control of shipping, convoy and task force anti-submarine defense, torpedo countermeasures, and coastal defenses. The first principle, restricting submarine movement, emphasized preventing them from moving through certain areas through the use of barriers of ships, aircraft, and mines. The second and third principles both prioritized “the safe and timely arrival” of convoys and groups of warships, respectively. The fourth principle, torpedo countermeasures, was more a technical issue of how to divert, confuse, or intercept homing torpedoes. The final principle, coastal defense, focused on making harbors and bases safe havens from enemy submarines. The principles did not go into as much detail as the British desired since the U.S. Navy wanted agreement reached on broad principles before delving into the details of tactics.
Taken together, the five principles represented a subtle, but significant shift away from the wartime British approach to ASW, which strictly emphasized the safe and timely arrival of the convoy at its destination. The U.S. Navy also focused on convoy protection during World War II but at the same time devoted substantial resources to pursuing German submarines through offensive operations, particularly in the last two years of the war. The Americans sent small escort carriers with escorts into the North Atlantic to find German submarines and hunt them to exhaustion. This approach meant remaining in the submarine’s operating area for an extended period and was not well suited to defending a moving convoy. The British approach also sought to destroy submarines but emphasized other tactics such as diverting convoys around known submarine locations and forcing them to retreat from attacks on convoys. These tactics prioritized protecting the convoy over sinking submarines. A U.S. Navy report in 1947 described the difference between the two approaches: “they [the British] place emphasis on convoy protection versus our emphasis on ‘hunter-killer’ group operations.” The combined principles drafted by the working group retained the Royal Navy’s phrasing, “safe and timely arrival,” but this phrase was no longer the overarching principle of ASW.
The draft common ASW doctrine was then sent to each nation for review and comment. The Canadians approved the draft as it stood in May 1949. Within the U.S. Navy, the first principle, restricting submarine movement, received the most attention. The Americans proposed two changes in August, both of which were accepted.  The name of the principle was changed to “offensive action against submarines” and air attacks on submarines and submarine bases were given greater prominence at the request of U.S. naval aviators. With these changes, the revised draft ASW doctrine received approval by all three naval headquarters by early February 1950. In less than 15 months the three navies standardized their anti-submarine warfare doctrine, clearly demonstrating the speed with which concepts could be standardized, in contrast to equipment.
With common doctrine accepted, the question facing naval planners was whether to take the next step in standardization: writing a common tactical book based on this doctrine to be available on warship bridges. Such a book would allow surface ships from each navy to operate together in combined formations. Canadian pressure to write such a book overcame initial British reluctance when the U.S. Navy supported the Canadian position. U.S. Chief of Naval Operations Admiral Forrest Sherman took a personal interest in the project and in March 1950 the three navies agreed to write a new tactical book based on the Royal Navy’s Conduct of the Fleet and a new signal book built on the U.S. Navy’s General Signal Book. Together these two would enable warships from all three fleets to operate together with little advance warning or preparation.
Another working group of British, Canadian, and American naval officers began writing the new tactical book in June 1950. the content came from both existing American and British books, while the format followed the British volume. The authors prioritized clear, concise language that avoided ambiguity. The British members “leaned over backwards,” according to one U.S. Navy report, by accepting American spellings of words such as maneuver, defense, and center and by agreeing to avoid British expressions such as whilst and asdic (the British term for sonar). Furthermore, the Royal Navy accepted American organizational terms such as officer in tactical command (OTC) and Combat Information Center (CIC) instead of the British Action Information Organization. All these choices represented major British concessions.
During the drafting process both the British and Americans frequently gave ground to one another to resolve points of difference in their tactical procedures. For example a group of ships sailing one behind the other was a “column” in Britain but a “line” in America. Line was used over column. The British command for ships to “wheel” (turn) was accepted over the American command “change course.” Reviewers praised the draft book. For example, Vice Admiral Matthias S. Gardner, the Commander of U.S. Second Fleet, concluded the draft instructions “would be entirely adequate for maneuvering combined naval forces” and were “commendably well written in simple, direct style.” The resulting product, Allied Naval Maneuvering Instructions, Allied Tactical Publication I, was published in January 1952 becoming known as ATP 1. While ATP 1 was being drafted, another working group of British, Canadian, and American naval officers were drafting a new signal book, based on the U.S. Navy’s General Signal Book. This volume became known as Allied Communications Publication (ACP) 175 and was completed in March 1951. In less than two years, the British, Canadian, and American navies drafted, revised, and produced common tactical and signals books, building on the shared ASW doctrine established in February 1950.
Standardization as an ideal appealed to officers in all three navies; pursuing this goal revealed that procedures and methods were more easily and rapidly standardized than equipment. Efforts to develop a common sonobuoy initially foundered on technical differences as well as different methods for employing sonobuoys against submarines. Furthermore, industrial base considerations made each nation reluctant to wholly adopt equipment produced in a foreign country. As one Canadian officer commented, standardized equipment “is great so long as it is all manufactured in Toronto.”
The U.S. Navy’s early Cold War standardization program demonstrates that the industrial, technical, and operational challenges of interoperability are not new problems. In fact the Navy has grappled with these issues since at least the 1940s and this body of knowledge can inform the Navy’s response to contemporary concerns.
The doctrinal differences undermining the sonobuoy effort highlighted the need to agree on doctrine and methods before developing common pieces of equipment. A British review of the progress of standardization in 1948, a year after the initial agreement between the three nations, rightly concluded: “It would seem standardization of techniques and tactics will be more important than standardization of equipment.” Representatives from the three navies finalized doctrine, tactical publications, and communications relatively quickly: less than two years for common ASW doctrine, a new tactical book, and a new signals book. Once they shared a more unified way of thinking about anti-submarine warfare, creating requirements for standard equipment and then producing it became easier. Common doctrine can lead to common requirements which leads to common hardware. Or to put it another way, standardize concepts before calibers.
This approach can help the Navy efficiently maintain interoperability with long-standing allies while expanding it with newer partners. The CNO’s charge to prioritize such initiatives underlines the importance of strong partnerships built on shared thinking and procedures. Seventy years ago, three wartime allies faced a rising threat at sea, and mentally prepared to defeat it. Today’s U.S. Navy and its partners and allies can do the same.
 Ian Ballantyne, Warships of the Royal Navy: Warspite (Annapolis, MD: Naval Institute Press, 2001), 138–40; Captain J.H. Breaks, RN, British Advisory Repair Mission, “Report, Engineering, 1941 to 1945” July 1946, 218, ADM 199/1236, National Archives of the UK [hereafter NAUK]. At the time, Britain and the United States both used feet and inches but the threads on British and American screws had difference depths and distances between each thread.
 For background see Jeffrey Barlow, From Hot War to Cold: The U.S. Navy and National Security Affairs, 1945-1955 (Stanford, CA: Stanford University Press, 2009); Michael Palmer, Origins of the Maritime Strategy: The Development of American Naval Strategy, 1945-1955 (Annapolis, MD: Naval Institute Press, 1990).
 Chief of Naval Operations Admiral John Richardson, “A Design for Maintaining Maritime Supremacy,” January 2016, 8, http://www.navy.mil/cno/docs/cno_stg.pdf.
 Michael Simpson, ed., The Somerville Papers (Aldershot, UK: Navy Records Society, 1995), 649, 651.
 Nigel Hamilton, Monty: Final Years of the Field-Marshal, 1944–1976(New York: McGraw-Hill, 1986), 654–59.
 Commander Anthony H.G. Storrs, RCN, Deputy Director of Naval Plans to Director of Naval Plans and Intelligence, “Tripartite Discussions on Standardization and Strategic Problems – Washington, November 1946,” December 7, 1946, File 1272-35, “Tripartite Discussions on Standardization and Strategic Problems – Washington, D.C. November 1946,” Volume 8087, RG24-D-1-c, Library and Archives Canada [hereafter LAC].
 “Appendix B,” enclosure to ibid., 5.
 Director of Plans (Q) to Director of Tactical and Staff Duties Division, “Standardization RN/USN,” June 3, 1948, Appendix C to Director of Tactical and Staff Duties Division to Assistant Chief of Naval Staff, “Standardization RN/USN, T.S.D. 4581/48,” July 14, 1948, 1, ADM 1/22428, NAUK.
 Russell Mason, “The Evolution of Airborne Antisubmarine Warfare” March 9, 1970, 24, Author’s personal collection.
 Ibid., 10.
 “Report of Underwater Sonar,” Enclosure E to Chief of Naval Operations, “Serial 0062P31, Report of Visit of Undersea Warfare Weapons Group to British Isles during August-September 1947,” October 31, 1947, 78, Folder A16-3(1) (6-12/47) (3 of 4), 1947 Secret; Box 168; Entry P 111, CINCLANT Secret and Top Secret Correspondence, 1941-1949; Records of Naval Operating Forces, Record Group 313 [hereafter RG 313], National Archives at College Park, College Park, MD [hereafter NACP].
 Commander James M. Robb, RN and Wing Commander Anthony Gadd, RAF, ASR, “Sonobuoy Development Program, Sub-SAWC I/5/49” April 9, 1949, File 1270-78 Pt. 2, “Committees and Conferences - RN and RAF Sea/Air Warfare Committee and Sub-Committee, 1946-1951,” Volume 8071, RG24-D-1-c, LAC.
 “Joint Sea/Air Warfare Committee, Minutes of the Seventh Meeting of the Tactical and Training Subcommittee,” Enclosure B to ALUSNA London, “300-S-48, Great Britain - Navy ASW Doctrine,” November 1, 1948, 1, Folder A16-3(1) ASW-Jacket #3 (10-12/48) (2 of 3), 1948 Secret; Box 191; Entry P 111, CINCLANT Secret and Top Secret Correspondence, 1941-1949; RG 313, NACP.
 Air Commodore Geoffrey W. Tuttle, RAF, Director of Operational Requirements, “Report on Sonobuoys - British/American Standardization, Sub SAWC II/54/48,” August 4, 1948, File 1270-78 Pt. 1, “Committees and Conferences - RN and RAF Sea/Air Warfare Committee and Sub-Committee, 1946-1951,” Volume 8071, RG24-D-1-c, LAC.
 Rear Admiral Edmund Nicholas Poland, RN (ret), interview by Nigel de Lee, April 8, 1991, Reel 17, Sound Archive, Catalogue 11951, Imperial War Museum, London, United Kingdom.
 Directors, Joint A/S School, Londonderry, “53/2, Progress Report - Summer Term, 1951” August 31, 1951, 11, AIR 20/6833, NAUK.
 Norman Friedman, Naval Anti-Aircraft Guns and Gunnery (Annapolis, MD: Naval Institute Press, 2013), 10.
 Joint Secretaries, “Minutes of the Eighteenth Meeting of the Technical Investigation Subcommittee” October 17, 1950, 1, File 1270-78 Pt. 3, “Committees and Conferences - RN and RAF Sea/Air Warfare Committee and Sub-Committee, 1946-1951,” Volume 8071, RG24-D-1-c, LAC.
 Air Commodore Geoffrey W. Tuttle, RAF, Director of Operational Requirements, “Report on Sonobuoys - British/American Standardization, Sub SAWC II/54/48.”
 Commander James M. Robb, RN and Wing Commander Anthony Gadd, RAF, ASR, “Sonobuoy Development Program, Sub-SAWC I/5/49,” 1; Joint Secretaries, “Minutes of the Eighteenth Meeting of the Technical Investigation Subcommittee,” 3.
“Air,” Appendix 4 to Commodore Horatio N. Lay, RCN, Naval Member, Canadian Joint Staff (Washington) to Naval Secretary, “NMWS 1926-193/139, CANAVUS Report of Proceedings for December 1950,” January 9, 1951, 1, Folder HMCS Niagara (Base) 8000, File 3, HMCS Niagara (Base) Reports of Proceedings, 1950, Box 145, 81-520-8000, Directorate of History and Heritage, Ottawa [hereafter DHH].
 Group Captain Clare L. Annis, RCAF, “RCAF Anti-Submarine Policy” January 20, 1950, 1–3, File 28-1-1 Part 1, “Anti-Submarine Warfare - General Policy, 1942-1951,” Volume 5269, RG24-E-1-b, LAC.
 “Air,” Appendix 4 to Commodore Horatio N. Lay, RCN, Naval Member, Canadian Joint Staff (Washington) to Naval Secretary, “NMWS 1926-193/139, CANAVUS Report of Proceedings for December 1950.”
 “Appendix 4 - Air,” enclosure to ibid., 2.
 Commander Malcolm C. Morris, RN and Wing Commander, “Minutes of the Twenty First Meeting of the Policy and Plans Subcommittee, Sub SAWC 1/21/51” December 14, 1951, File 1270-78 Pt. 4, “Committees and Conferences - RN and RAF Sea/Air Warfare Committee and Sub-Committee, 1946-1951,” Volume 8071, RG24-D-1-c, LAC.
 Squadron Leader Reginald R. Ingrams, RCAF, “Notes Taken During an Informal Discussion of Maritime Warfare Tactics and Equipment with Dr. J.W. Abrams - 21 May 1951” May 23, 1951, 2, File 28-1-1 Part 3, “Anti-Submarine Warfare Generally-Policy, 1951-1952,” Volume 5270, RG24-E-1-b, LAC.
 Commander Malcolm C. Morris, RN and Wing Commander, “Minutes of the Twenty First Meeting of the Policy and Plans Subcommittee, Sub SAWC 1/21/51”; Commodore Horatio N. Lay, RCN, Naval Member, Canadian Joint Staff (Washington) to Naval Secretary, “NMWS 1926-193/139, CANAVUS Report of Proceedings for October 1951,” November 7, 1951, 1, Folder HMCS Niagara (Base) 1951, File 4, HMCS Niagara (Base) Reports of Proceedings, 1951, Box 145, 81-520-8000, DHH.
 Lieutenant P.C.H. Cooke, RCN, Secretary, “Minutes of the First Meeting of the Subcommittee, Tactics and Training, of the Sea/Air Warfare Committee” April 6, 1950, 2, File ACS 8100-1 F.D.1, “Anti-Submarine Warfare, 1949-1951”, Volume 11182, RG24-D-10, LAC.
 Captain Paul R. Heineman, USN, Chairman, Combined Canadian, United Kingdom, United States Anti-Submarine Working Group, “Final Draft of Papers of the Combined Working Group - Forwarding of,” April 21, 1949, File 8100-5, “Anti-Submarine Warfare - Joint Canadian-British-United States Anti-Submarine Warfare (CANUKUS)”, Volume 35135, RG24-D-1-c, LAC.
 “Recommended ‘Common Doctrine for the Conduct of ASW on the High Seas,’” Enclosure A to Chief of Naval Operations, “Serial 00130P31, Common Doctrine for the Conduct of Anti-Submarine Warfare on the High Seas” April 22, 1949, Folder A16-3(1) ASW (1-12/49) (3 of 3), 1949 Secret; Box 216; Entry P 111, CINCLANT Secret and Top Secret Correspondence, 1941-1949; RG 313, NACP; “Command Structure and Relations Involved in the Conduct of Anti-Submarine Warfare” October 9, 1947, Enclosure A to Chief of Naval Operations, “Serial 0079P30, Organization for World-Wide Anti-Submarine Warfare,” October 13, 1947, Folder A16-3(1) (6-12/47) (3 of 4), 1947 Secret; Box 168; Entry P 111, CINCLANT Secret and Top Secret Correspondence, 1941-1949; RG 313, NACP.
 “Common Doctrine for the Conduct of Anti-Submarine Warfare on the High Seas,” Enclosure B to Captain Paul R. Heineman, USN, Chairman, Combined Canadian, United Kingdom, United States Anti-Submarine Working Group to Combined Canadian, United Kingdom, United States Anti-Submarine Warfare Committee, “Final Draft of Papers of the Combined Working Group - Forwarding of,” April 6, 1949, 1–2, File 8100-5, “Anti-Submarine Warfare - Joint Canadian-British-United States Anti-Submarine Warfare (CANUKUS)”, Volume 35135, RG24-D-1-c, LAC.
 “Recommended ‘Common Doctrine for the Conduct of ASW on the High Seas,’” Enclosure A to Chief of Naval Operations, “Serial 00130P31, Common Doctrine for the Conduct of Anti-Submarine Warfare on the High Seas.”
 Rear Admiral Brian B. Schofield, RN, Chief of Staff, British Joint Services Mission to Secretary of the Admiralty, “BNS 1865/48,” June 13, 1949, File 8100-5, “Anti-Submarine Warfare - Joint Canadian-British-United States Anti-Submarine Warfare (CANUKUS)”, Volume 35135, RG24-D-1-c, LAC.
 Eric Grove, ed., The Defeat of the Enemy Attack on Shipping, 1939-1945, vol. 137 (Aldershot, UK: Ashgate, 1957).
 The instructions given to USN escort carriers in 1944 explicitly stated: “Your task is offensive. Your group exists for the sole purpose of locating and destroying enemy submarines.” See Admiral Royal E. Ingersoll, Commander in Chief U.S. Atlantic Fleet, “Carrier Anti-Submarine Operations - Letter of Instructions,” August 24, 1944, 1, File 7-6-2, “Anti-Submarine Warfare Operations - A/C Cooperation, 1942-1944,” Volume 11022, RG24-D-10, LAC.
 “ASW Operational and Tactical Report,” Enclosure A to Chief of Naval Operations, “Serial 0062P31, Report of Visit of Undersea Warfare Weapons Group to British Isles during August-September 1947,” 7.
 The British took every opportunity to impress upon the Americans the importance of convoys and “safe and timely” arrival. In late 1948, the Commander of the Home Fleet, Admiral Rhoderick McGrigor, RN, visited Admiral William Blandy, the Commander in Chief of the Atlantic Fleet. McGrigor found that Blandy believed convoys should not be formed at the start of a war but only when sufficient escorts were available. Over the course of their discussions, McGrigor convinced Blandy that convoys, even with a small escort, gave greater protection than sailing independently. McGrigor expressed surprise in a letter to the First Sea Lord about Blandy’s view that independent sailing was preferable to convoys: “It seems difficult to believe that the USN have not learnt this lesson from their experience on the East Coast in 1942.” See Admiral Rhoderick R. McGrigor, RN, Commander in Chief, Home Fleet to Admiral Bruce Fraser, RN, First Sea Lord, November 24, 1948, 3, ADM 205/70, NAUK.
 RCN-RCAF Representatives to Chairman, Combined Canada, United Kingdom, United States, Anti-Submarine Working Group, May 25, 1949, File 8100-5, “Anti-Submarine Warfare - Joint Canadian-British-United States Anti-Submarine Warfare (CANUKUS)”, Volume 35135, RG24-D-1-c, LAC.
 Lieutenant Commander Thomas C. Mackay, RCN, Staff Officer (Communications) to Commodore Horatio N. Lay, RCN, Naval Member, Canadian Joint Staff (Washington), “0-8530,” August 31, 1949, Folder HMCS Niagara (Base) 8000, File 2, HMCS Niagara (Base) Reports of Proceedings, 1949, Box 145, DHH.
 Rear Admiral Brian B. Schofield, RN, Chief of Staff, British Joint Services Mission to Chairman, Combined Canada, United Kingdom, United States, Anti-Submarine Working Group, “BNS 1865/48/1,” December 27, 1949, File 8100-5, “Anti-Submarine Warfare - Joint Canadian-British-United States Anti-Submarine Warfare (CANUKUS)”, Volume 35135, RG24-D-1-c, LAC; Commodore Horatio N. Lay, RCN, Naval Member, Canadian Joint Staff (Washington) to Chairman, Combined Canada, United Kingdom, United States, Anti-Submarine Working Group, “CANUKUS ASW Working Group Papers,” January 12, 1950, File 8100-5, “Anti-Submarine Warfare - Joint Canadian-British-United States Anti-Submarine Warfare (CANUKUS)”, Volume 35135, RG24-D-1-c, LAC; Rear Admiral Charles B. Momsen, USN, U.S. Member Combined Anti-Submarine Committee to Chief of Naval Operations, “Serial 0028P31, Combined Canadian, United States, United Kingdom, Anti-Submarine Committee Papers, Forwarding of,” February 12, 1950, File 8100-5, “Anti-Submarine Warfare - Joint Canadian-British-United States Anti-Submarine Warfare (CANUKUS)”, Volume 35135, RG24-D-1-c, LAC.
 “Minutes of the 10th Meeting of the Working Group,” Enclosure C to Major R.F. Walker, Secretary, Canadian Joint Staff, Washington, DC to Chiefs of Staff Committee, “CANUKUS Anti-Submarine Warfare Working Group,” November 22, 1949, File 28-6-10, “Anti-Submarine Warfare - Combined Canadian-British-United States (CANUKUS) Anti-Submarine Warfare Working Group, 1949-1950,” Volume 5274, RG24-E-1-b, LAC; ibid., 2.
 Commodore Horatio N. Lay, RCN, Naval Member, Canadian Joint Staff (Washington) to Naval Secretary, “Allied Signal and Tactical Publications,” March 30, 1950, 1–2, File ACS 1300-1, “Flag Officer Atlantic Coast - Communications - General, 1948-1961,” Volume 11146, RG24-D-10, LAC; Captain Jack R. Allfrey, RN, Secretary to First Sea Lord, “Notes on Meeting Between First Sea Lord and Chief of Naval Operations on 24th March 1950 at 1700,” April 1950, 2, Folder F7, A19, Box 72, Records of the Strategic Plans Division, AR/131, Archives Branch, Naval History and Heritage Command, Washington, DC.
 “Memorandum for Reviewers of Subject Draft,” Enclosure A to Chief of Naval Operations, “Serial 0834P31, Original Draft of Chapters 1 through 8 of ‘Allied Naval Maneuvering Instructions,’” September 13, 1950, 1, Folder A4-3-A4-3(1)(d), Confidential, 1950; Box 26; Entry P 80, Confidential & Restricted General Administrative Files, 1946-1956-Commander, 2nd Fleet; RG 313, NACP.
 Commander Second Fleet to Chief of Naval Operations, “Original Draft of Chapters 1 through 8 of ‘Allied Naval Maneuvering Instructions,’” October 6, 1950, 1, Folder A4-3-A4-3(1)(d), Confidential, 1950; Box 26; Entry P 80, Confidential & Restricted General Administrative Files, 1946-1956-Commander, 2nd Fleet; RG 313, NACP.
 “Communications,” Appendix 10 to Commodore Horatio N. Lay, RCN, Naval Member, Canadian Joint Staff (Washington) to Naval Secretary, “NMWS 1926-193/139, CANAVUS Report of Proceedings for March 1951,” April 10, 1951, Folder HMCS Niagara (Base) 1951, File 4, HMCS Niagara (Base) Reports of Proceedings, 1951, Box 145, 81-520-8000, DHH.
Rear Admiral Robert Waught Murdoch, RCN (ret), My Navy Recollections, interview by Chris Main, September 21, 1978, Part 4, SC104_MRW_197, Military History Oral History Collection, Special Collections, University of Victoria Library, British Columbia, http://contentdm.library.uvic.ca/cdm/compoundobject/collection/collection13/id/491/rec/2 accessed Apr 2017.
 “BAD 1687/47, R.N./U.S.N. Standardization,” 28 May 1948, enclosure to Vice Controller to Assistant Chief of Naval Staff, June 9, 1948, 8, ADM 1/26858, NAUK.