Chapter 13 2.2 Tracking Fleet Exercise

There was such a thing a long time ago: when the navies of a hostile country were conducting exercises on the high seas, they were close to the exercise waters, mainly through radio surveillance to collect information on the composition, process, and troop formation of the exercise.However, before the Second World War, it was done as quietly as possible from a distance and in a cautious way so as not to provoke the opponent.But recently, they have used the principle of freedom of the high seas to act openly. During NATO naval exercises, Soviet trawlers must appear in the exercise waters.At most, forty trawlers entered the waters where 160 ships participated in the exercise.Needless to say, these trawlers are equipped with advanced radio listening equipment.Therefore, in order to avoid this situation in 1963, the NATO authorities stopped announcing information about the exercise in advance.However, when NATO conducted joint naval and air exercises in 1964, the Soviet Union dispatched not only fishing trawlers, but also ships, aircraft and submarines, waiting for the arrival of the NATO fleet.From the beginning of the exercise, almost throughout the entire exercise period, tightly entangled the NATO fleet and issued a report.

In May 1967, during the Japan-U.S. joint exercise in the middle of the Sea of ​​Japan, two collision accidents occurred between U.S. and Soviet destroyers.This is still fresh in our memory. On May 8, when the exercise troops sailed out of the west mouth of the Tsugaru Strait, Soviet ocean-going tugboats were waiting there.On the 11th, four Soviet destroyers followed and approached to a place about 100 meters away from the submarine undergoing anti-submarine training, so the exercise was temporarily suspended.On the 10th and 11th, the destroyers of the United States and the Soviet Union collided again.In addition, from the beginning to the end of the exercise, a total of 30 Soviet military aircraft have been conducting reconnaissance flights at a low altitude of 200 meters of the exercise troops.

Obviously, this action by the Soviet Union was to collect intelligence, such as reconnaissance of the composition of the entire exercise, a summary of the operation, reconnaissance of the communication telegrams of the exercise troops, and acquisition of data from electronic devices such as radars.In addition to this military purpose, there are also political ones. Here are a few examples of the Japanese and American navies tracking each other in a cautious way during exercises: Japanese spy ship Cruiser Yubari When Vice Admiral Toshiro Yohata (later promoted to lieutenant general) visited Pearl Harbor, he inadvertently heard from a U.S. Navy sergeant who was the guide that the U.S. fleet would conduct a large-scale exercise off the coast of Hawaii. Made a report.Therefore, in July 1934, the Japanese Navy sent the cruiser Yubari to the exercise area to collect the communications of the US fleet exercise and collect data for research.This is the first time that our navy has specially sent ships to the waters of the US naval exercise in order to obtain intelligence.

At that time, through the detection of long-wave and medium-wave communications, it was learned that the US Navy had used short-wave communications: sending short-wave signals from the flying spacecraft Shenandoah, investigating its propagation in various places in the Atlantic and Pacific Oceans, and so on.However, the Japanese Navy did not prepare a short-wave receiver at that time, and could not conduct detailed interception directly. Erimo special ship The Manchuria Incident led to a sudden tension in the relationship between Japan and the United States. In January 1932, the Stimson Doctrine of the United States Secretary of State Henry Stimson issued a declaration not to recognize Japan's invasion of Manchuria, which further deteriorated the relationship between the two countries.At that time, the atmosphere in central China like Shanghai was also unusual.

During this period, the United States decided to concentrate its fleet in the Pacific Ocean and conduct large-scale exercises in Hawaii. In order to obtain information on the composition of the intelligence exercise, the formation of the troops, and the entire process of the exercise, and to find out the movement and combat readiness of the US fleet, our navy dispatched the special ship Erimo to the exercise area.Major Kanuki Ogawa of the U.S. Division of the Intelligence Department of the Military Command boarded the ship in the name of the ship's officer, and Major Joe Fukamachi, a communications intelligence expert, was appointed as the chief communications officer. In addition, many talented communications intelligence personnel boarded the ship temporarily.

In late January 1932, the Erimang quietly left the Yokosuka Army Lane.Two or three days later, on January 28, the Shanghai Incident finally occurred.In the book "Secret History of Showa" ("Bessatsu Zhizhi" December 1956 issue), Ogawa, who had a special mission, recalled the situation at that time as follows: The radio broadcasts of Japan and the United States frequently broadcast various situations during this period, and the crew on our oil tanker could not restrain their excitement.The young military officers begged repeatedly: "It's already started in China, why are we still traveling around the mountains and rivers, taking this unarmed oil tanker to watch the US fleet's exercises?"Let's go to the battlefield!It is really a lot of effort to explain the truth to these young people, to comfort and persuade them

Our tanker finally approached the exercise area.This major exercise of the US fleet started with great fanfare in the waters near Hawaii Island. Our communications and intelligence team concentrated on collecting exercise information and mastered the general process of the exercise. However, what particularly unexpectedly aroused our interest and curiosity during this grand exercise was the fact that the aircraft of the United States Army were flying freely in the sea at that time.These are Army aircraft, known as the Staff Air Force, and they are always in close coordination with the Navy aircraft, and they are so free to fly over the oceans that we are shocked.

We clearly observed that under extremely difficult circumstances, Army aircraft effectively and accurately attacked the first-class aircraft carrier of the Saratoga class; Miles, resolutely carried out a surprise attack and succeeded.This is really worth noting. Major Fukamachi's communications intelligence team also collected a large amount of information.After returning to China, Fukamachi sorted out and studied these materials in Section 10 of the Military Command (responsible for communications and intelligence work), successfully deciphered the code used by the US fleet (Hepburn machine code), and learned about the composition of the exercise and the organization of the troops. process etc.

Ship of the Stone Corridor In 1939, our navy learned that the US fleet would hold a large-scale exercise in Hawaii, so it took the following countermeasures to conduct communications intelligence training in a situation similar to actual combat: 1. Properly choose the route of the special ship Shilang, which is bound for the west coast of the United States to load heavy oil, at a place just close to the sea area of ​​the exercise.Let the capable communications intelligence team members temporarily board the ship and take on the task of detecting the medium waves of the US fleet. 2. Send capable communications intelligence team personnel to the Jaluit Islands (Marshall Islands) to detect and collect the radio communications of the US fleet and determine their position.

3. The Owada Reconnaissance Station on the outskirts of Tokyo also shifted the main force of the U.S. communications and intelligence team to the U.S. fleet in the Hawaiian waters. As a result, based on the detection and deciphering of the telegrams sent by the U.S. Fleet Exercise Magistrate as the main data, the structure of the exercise, the formation of troops, and the process of the exercise were grasped in considerable detail. American spy ship cruiser Marblehead In the autumn of 1927, the Japanese training fleet (Asa and Iwate) visited the United States.The United States decided to send the cruiser Marblehead of the Asian Fleet to Kobe Port for a return visit.

The U.S. Navy learned by chance on August 30 that the Japanese navy was scheduled to conduct maneuvers that fall.It is said that the latest aircraft carrier Akagi will participate in the exercise, so the US Naval Intelligence Service is very concerned about this exercise. At that time, Major Zacharias collected Japanese naval intelligence through the radio detection device on the fourth floor of the US Consulate in Shanghai, and found that the number of Japanese naval telegrams received gradually increased. Based on this, he concluded that this year's Japanese naval exercises will be more serious than previous years. important.He believes that the telegrams from the ships participating in this exercise may be used to obtain tactical intelligence and other specialized intelligence of the Japanese Navy.However, the monitoring station on land is too far away from the sea area of ​​​​the exercise, and Zacharias suggested that the Washington Department of the Navy send a US warship to operate near the sea area of ​​​​the Japanese fleet exercise.Washington immediately agreed to his proposal. At this time, because the light cruiser Marblehead of the Asian Fleet was about to visit Japan, Zacharias was ordered to board the ship temporarily.He transferred the Shanghai detection equipment and staff to the Marblehead, planning to pass the Japanese naval exercise area on the way to Kobe. On October 20, the Marblehead arrived in the exercise area and detected many radio telegrams from the Japanese fleet. After research, it obtained important information about the Japanese navy. When the ship arrived at Kobe Port on October 28, Zacharias handed over a brief report to Colonel Cotton, the US Naval Attaché in Tokyo, who came to contact the visit.After Marblehead returned to Shanghai on November 4, she made a detailed report to Washington. The value of this report can be seen from the following passage in the letter from the U.S. Naval Communications Office to Zacharias: Your report is excellent, including Japanese naval intelligence that is extremely important to us. Estimate, really makes us grateful. According to the data from the United States, the radio telegrams of the Japanese naval exercises were detected later because the receivers and bases of the radio communication detection agencies were greatly improved.In 1935, by analyzing and synthesizing the fragmented data collected, valuable information was obtained.