Report on the mission of the Combined Fleet Exploration Unit in the South Sea
Kuching, April 24th, 1942 (document established by the staff of the Special Unit)
On the evening of December 31st, 1941, urgent orders were received from the Combined Fleet to prepare and send a suitably equipped ship to search for documents and technical systems in wrecks of enemy ships after the victories won by the Fleet in southern waters. It was soon known that this was a British battleship of the King George V class. The Combined Fleet had already chosen the modern minelayer Yaeyama (1,380 tons, 20 knots) for this task. The Kure shipyard was given the task to prepare the ship to sail within 36 hours. The ship was immediately dry-docked to rectify any defects. Its normal boats were replaced by personnel boats of the type carried by the cruisers and a five-ton crane (taken from a seaplane workshop ship under construction) was added to the stern. The Diving School was ordered to prepare six teams of two divers who would go to work with the two already installed in Kuching. Four very experienced divers from the School's management joined them. A large quantity of equipment was taken on board, as well as spare parts and maintenance personnel.
On January 1st, 1942, again on the express orders of the 2nd Fleet, the Tambelan Islands were occupied. In the afternoon of that day, covered by Admiral Kondo's force, the 3rd Surprise Attack Force of Rear Admiral Hirose (DD Yamagumo, TB Chidori, Hatsukari, Manazuru, Tomozuru, two minesweepers, nine submarine hunters) landed Imperial Navy infantry groups in the islands of Natuna, Selatan and Tambelan. These landings met virtually no opposition.
On January 2nd, the Yaeyama was able to sail.
On January 15th, the Yaeyama arrived in Kuching Bay.
During this time, the 2nd Fleet had done a lot. A chain of lookout posts had been established, seaplanes kept a constant watch against enemy submarines and fighter planes were constantly monitoring the area. Covering minefields had been laid. They had been carefully positioned so that a submarine could not attempt to torpedo the Yaeyama without first passing through a minefield. Above all, thanks to numerous boats requisitioned on the spot, the enemy battleship had been located with precision, marked by buoys, monitored, and a plan of the wreck had been drawn up. It was obvious that this wreck was of incalculable value, despite the fact that it was on its side and almost overturned.
Submarine hunters, torpedo boats and various small vessels were put at the disposal of the Exploration Unit to bring to Kuching the recovered material and documents.
On January 16th, the Yaeyama arrived in the area and the dives began immediately. From that moment, all the recovered objects were progressively sent on board a torpedo boat to Kuching.
The exploration allowed the recovery of many documents. A great number of manuals on the anti-aircraft fire director "Type 285" were thus discovered in the front. In the rear, the teams recovered several heavy four-drawer cabinets. This was a long and complicated operation, as they had to be unbolted from the wall, passed through a door and then through a hatch, despite the almost upside down condition of the ship, before being reassembled. One of these pieces of furniture contained transmission logs (mostly administrative), but the other one must have contained secret books ("Classified Books"). Unfortunately, it was empty or almost empty, most of its contents having probably been destroyed in one way or another when the ship appeared doomed (probably at the beginning of the day on December 31st).
We also tried to recover all the materials related to the radio detectors and especially the detectors themselves.
In the rear, seven other four-drawer cabinets were recovered from the staff offices.
They too were almost empty. One of the most experienced divers managed to penetrate into the Admiral's quarters late in the day. He came back with the fascinating news that a heavy, closed, red-painted steel safe was there. He retrieved from the desk a large number of papers and documents, including what appeared to be Admiral Phillips' personal diary. He estimated the weight of the chest at about one ton. Given the situation of the ship, it was impossible to raise the chest itself. It was decided to break into the chest, after cleaning of the staff offices, with loads of 1 kg.
On January 20th, the dives continued despite rough seas and windy weather. The divers were not intimidated by the danger (one of them had a hand crushed), but the Yaeyama anchored two more mooring toads. At the rear, in the staff quarters, eight drawer cabinets were recovered, for a total of 17. They had obviously been emptied in a hurry, and it was possible to recover some scattered documents.
As usual, this material was immediately sent to Kuching by an escorted torpedo boat.
In the afternoon of the 20th, an enemy aircraft flew over the Yaeyama during a clear day. No radio message could be received, but the plane flew away in the direction of Singapore. It was impossible to intercept it. It was decided to continue working in the night, only on the Admiral's office and the headquarters, using the lighting devices already installed.
All the divers demanded to participate in this very dangerous activity. Four of them were forbidden to participate, in order to continue the work the next day with tired, but not exhausted men. All the divers were indeed close to exhaustion when that night's work began. They nevertheless insisted on doing their work, despite the high risk, because the significance of what they were recovering had been explained to them.
On January 21st, shortly after daybreak, the Admiral's red box was broken into and its contents recovered. Two divers were lost, both due to elementary errors, caused by exhaustion and overwork. At the end of the day, the Yaeyama left the site for the Tambelan Islands.
The volume of documents delivered to Kuching was not far from overwhelming the teams in charge of taking care of them. The furniture and boxes were immersed in fresh water circulating tanks until all the salt was purged and this was verified by a silver nitrate test.
Out of the tanks, cabinets and drawers were numbered and opened. The secret books and other important documents had withstood the immersion very well, as they were closed and stacked. Their pages were carefully turned one by one, each one being photographed as they went along by Kodak process. One sheet of blotting paper, one of celluloid and another sheet of blotting paper were slipped between each page to remove most of the moisture. The blotters were then removed (not the celluloid sheet) to be dried andreused, each page being dried separately with hot air by a sailor. This work normally took 24 hours. The transmission papers were the most fragile and had begun to disintegrate. Their pages had to be painfully detached from each other and processed individually. It is unfortunate that all these efforts yielded almost nothing of interest, most of the secret documents having obviously been destroyed, in application with security instructions, of which we have found a copy!
The contents of the red box were treated in the same way, but were only handled by officers above the rank of
officers above the rank of lieutenant. Photographic copies were also made. This time, the documents recovered proved to be of the utmost importance, and often completely unexpected. The originals were sent directly to Admiral Yamamoto, carried by two armed officers.
On January 22nd, the Yaeyama stayed in the Tambelan Islands to rest the divers.
On January 23rd, the Yaeyama returned to the area, with rested divers.
From January 24th to 27th, the work of recovering the documents resumed. Many documents were recovered from the Admiral's office, including his personal documents. On the 27th, this area had been cleaned. From then on, work continued at a more measured pace, in a meticulous and systematic way. Strict orders were received from Admiral Yamamoto himself to reward the divers with promotions to the rank of officer for non-commissioned officers, and higher ranks for officers. The admiral sent to each diver a bottle of sake from his personal reserve, in recognition of their achievements, and for the feats accomplished, and stated that the name of each man would be brought to the attention oof His Majesty the Emperor. He sent instructions not to risk the lives of the divers again, and that the enemy flagship should be carefully stripped of all accessible equipment, which was done.
On February 3rd, the first diver was able to access the main signal station. This station was located in the heart of the ship; its access, and even more so its entrance, was very dangerous.
The innumerable corpses rotting in this area were a real danger, attracting hordes of fish and posing real physical and psychological problems for the divers in the darkness of the ship's corridors. Some divers could not bear these working conditions and most of them caught serious skin infections, because the slightest scratch was infected, the water being soiled by the decomposing flesh. The efforts to enter the room were temporarily abandoned until the more accessible areas had been cleared of anything of interest.
On February 28th, the recovery of the documentation of most of the radiation detection rooms was completed, allowing us to see that a surprising quantity of documents were available in several copies, but their exploitation, in the absence of the main documents, may prove extremely difficult, if not impossible.
From March 1st to 28th, while work continued elsewhere, an access shaft was opened above the main signal station. In the last two weeks of the month, this post was explored and emptied. Most of the paper had deteriorated, but the coding machines, the manuals for these machines and a large volume of archives were recovered, as well as another red box that contained a large number of codes.
Unfortunately, all these documents were printed with an ink that dilutes very easily at the slightest contact with sea water, and they were practically illegible, except for the title pages, leaving us all the more regretful.
From March 29th to April 22nd, operations continued. Finally, the ship not containing more secrets, the Yaeyama returned on April 23rd to Kuching Bay, where a special rest camp was set up for the divers and their support staff. These now very experienced teams must indeed rest and their equipment must be maintained, as their intervention will soon be necessary in Singapore, whose fall is expected in the next few days.
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Note - It is very fortunate that the British have kept in the Admiral's office a large quantity of material which they should have destroyed. This can probably only be explained because Admiral Phillips was killed, his staff was decimated, and nobody gave the order in time to destroy his secret documents. This is an extraordinary opportunity.
