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CONFIDENTIAL ISSUED BY THE INTELLIGENCE DIVISION
OFFICE OF CHIEF OF NAVAL OPERATIONS
NAVY DEPARTMENT
INTELLIGENCE REPORT
 

The successful continuance of the Axis war effort is so closely linked with the German-Japanese exchange of strategics, that even" the most extreme measures may be encountered in the furtherance of this hazardous traffic. This serial is concerned with tactics which have been used, or may be used, by the enemy.


      1.      Nine runners have been intercepted on the high seas (eight of which were destroyed) since the publication of Op-l6-F-8 Serial 36-42, AXIS BLOCKADE RUNNING, on December 2, 1942. From survivors and operational reports, a considerable amount of material has been obtained relative to enemy methods. Of interest is the fact that most of the "tactical tricks" thus far brought to light were anticipated in the above-mentioned serial.

GERMAN NAVAL CONTROL

      2.      As formerly believed, Axis blockade running is now known to be entirely under German naval direction. Although manned by mixed naval and merchant marine crews (sometimes Italians as well as Germans), blockade runners are classed as Hilfsbeischiffe der Kriegsmarine Or naval auxiliaries. The central control is by the German Naval Directorate in Berlin. This means that - with Gross Admiral DONITZ, leading exponent of under-sea craft, in strategic command - even more operational cooperation between blockade runners and U-boats can now be expected than has been experienced to date. On top of this, we may logically expect to see still further coordination between the activities of runners, aircraft, and surface naval vessels. (NOTE: The importance of such teamwork has been strongly emphasized in public statements by Admiral DONITZ.)

TACTICS ALREADY ENCOUNTERED

      3.      Bay of Biscay Escorts. Blockade runners are practically always accompanied when entering or leaving the Bay of Biscay. Usually surface vessels and planes accompany outbound runners the first two days. These are relieved by submarine escorts which may remain with the runner several days. U-boats have been known to pick up incoming ships as far out as 43.00 North, 38 West. In some instances, U-boats have met and escorted runners on portions of their mid-Atlantic run.

Distribution by Originator________________________________________
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Op-l6
Op-16-1
Op-16-l-F
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C.O.T.C.Lant
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(See page 5 for rest of distribution)

CONFIDENTIAL


Op-16-FT
Serial 46-43
CONFIDENTIAL
- 2 -


      4.      Disguises. Runners masquerade either as United Nations or neutral vessels. In some cases the disguises are carried out with grert detail and skill, as in the case of the DOGGERBANK. This ship had a dummy cargo on deck labelled "General Motors, New York" when it was laying mines within three miles of Capetown. A reconnaissance plane was fooled by the cargo and departed. Later an auxiliary cruiser challenged the DOGGERBANK, and apparently received a correct reply, for it signalled "Good Voyage". Therefore, patrols should guard well against being deceived by clever masquerades and may check a suspicious ship's intercepted position with the Cominch merchant plot.

      5.      Routes. The Indian Ocean route from the Far East is approximately 16,000 miles (about 1,000 miles shorter than the Pacific route). Since the united States - Japanese entry into the war, this shorter route has generally been the one followed. While the Pacific route may avoid the China Sea submarine area, it is a dangerous traverse of our Pacific convoy lanes and it is therefore unlikely that this route will be used unless the enemy is particularly well-informed regarding our convoy movements. The Bay of Biscay continues to be the No. 1 danger spot for runners. Both incoming and outgoing runners tend to hold to the approximate latitude of Bordeaux while East of Ferrol, although the protection of Spanish territorial waters has sometimes been sought. The home-bound PIETRO ORSEOLO, it will be remembered, was torpedoed by a U. S. submarine at 44.37 North 02.18 West while escorted by four DD's. The runner made port after losing quite a bit of its rubber cargo.

      6.      Avoiding other ships. It is standard, practice for a runner to assume a misleading course when it is under observation. Survivors of the REGENSBURG reported that this ship changed course 130° when it believed itself sighted by an aircraft. Runners also take particular pains to keep out of the way of all other ships. The master of the ill-frted RAMSES was specifically instructed to take a course away from any merchant vessel and, on being sighted by a warship, to scuttle promptly without regard to loss of life or property.

      7.      Lookouts. Runners are reported to maintain a sharp lookout for other ships. The RAMSES had a continuous watch of 6 lookouts, while the RHAKOTIS had from 12 to 16 always on watch with high-powered binoculars.

      8.      When escape is possible. Runners may be expected to make full use of local squalls, fog banks, approaching darkness and smoke pots to elude pursuing vessels. (Tho PORTLAND, REGENSBURG and DOGGERBANK are all known to havo been equipped with special smoke-producing apparatus. In addition to smoke canisters aft, the KOTA NOPAN had twenty smoke bombs.)

      9.      Delaying tactics. When intercepted near a U-boat patrol area, a runner can be expected to employ a variety of deleying tactics to gain as much time as possible. Slowness in answering challenges, in heaving to - and replies with unintelligible flag hoists and blinker signals are the usual devices.

      10.     Armament. All blockade runners may be assumed to be armed. Although the RAMSES mounted a "dummy" aft and was armed only with machine guns, rifles and grenades, other runners have carried quite a bit more fire-power. The Italian runner CORTELLAZO claimed to have repelled three aircraft attacks while leaving Biscay. It carried the "usual armament" of one 4" gun aft, plus four 20 mm. machine guns. A number of runners are equipped also with 37 mm. A/A.

      11.     Cargo submarines. Cargo submarines may now be used, or may soon be used, in the exchange of high-value strategics of limited bulk. One large Japanese submarine is known to have visited Biscay ports and other submarines are reported to have been fitted out for cargo carrying.

      12.     Use of ships' radios. Blockade runners are well equipped with radios and search receivers. They maintain a continuous watch on Norddeich from which they receive all their instructions. One runner reported that a Japanese station was tuned in and a different code used when the ship was in the Indian Ocean. Radio silence is maintained unless the ship has some urgent reason for breaking it. The G.S.R. aboard the GERMANIA was reported to have a useful service range of from 80 to 97 miles.

 


Op-16-FT
Serial 46-43
CONFIDENTIAL
- 3 -


TACTICS NOT PREVIOUSLY ANTICIPATED

      13.     A surprise route. One blockade runner, the REGENSBURG, was intercepted in Denmark Strait. Rescued seamen stated that this and other runners were ordered to proceed to German ports via this route and the Norwegian coast because of the high percentage of casualties in the Biscay approaches (It was not believed such a highly hazardous routing would be employed because of the extreme dangers involved in crossing the Northern convoy lanes and Iceland patrol zone.)

      14.     False starts. In order to confuse observers and divert Allied patrols, several blockade runners have made false starts from Biscay ports. Sometimes they return to the same port. At other times they proceed up or dowm the French coast, returning perhaps a month or two later completely re-camouflaged.

POSSIBLE FUTURE TACTICS

      l5.     Operational cooperation with U-boats. More of this is to be expected. For example, when ordered by the Directorate in Berlin, "wolf packs" of U-boats may concentrate on United Nations shipping at points which would tend to draw off Allied patrols from shipping lanes useful to runners. By such a ruse, the Axis may attempt to obtain safe passage for its vital cargoes through the equatorial Atlantic and even into the Bay of Biscay.

      16.     Japanese escorts. With increased U. S. submarine activity in the South China Sea, warship escorts may be furnished runners navigating between Japanese ports and the Dutch East Indies. Such escorts would probably accompany the runners to and from a point well South of Sunda Strait.

      17.     Submarine decoys. When pursued a runner may flee in the direction of U-boat assistance. While no cases have yet been reported of runners acting as submarine decoys, this possibility always exists.

      18.     Under-water armament. The defensive use by intercepted raiders or blockade runners of "trackless" electric torpedoes is a possibility worth remembering when making any approach other than "bow-on".

      19.     Mid-Ocean cargo transfer. The continued urgent need for the German-Japanese exchange of strategics may bring about a wholesale use of cargo submarines. A plan may be worked out whereby these U-boats would not be required to make the full l6,000 mile trip to the Far East, but instead meet with surface runners in African waters. According to such a scheme, by pre-arrangement, several submarines would make rendezvous with a surface runner. From the submarines, the cargo vessel would take aboard optical goods, ball bearings, prototypes of weapons and chemicals destined for Japan, as well as crew replacements and deliver to the U-boats such vitally needed strategics as tungsten, quinine, opium and edible oils.

      20.     Use of reconnaissance planes. Possible, though not particularly likely, is the equipping of future runners with small scouting seaplanes to give warning of merchant ships and patrols on the runner's line of advance.

MISCELLANEOUS

      21.     Scuttling procedure. The KOTA NOPAN, intercepted by the USS EBERLE, March 10, 1943, used four scuttling charges - three were 50 kg. and one was 25 kg. They had a fuse delay of 7 to 9 minutes. Recovered from this runner was the following order signed by Rear Admiral MENCHE, the German "ComBiscaySeaFron":

 


Op-16-FT
Serial 46-43
CONFIDENTIAL
- 4 -


"All important measures, such as sinkings, setting on fire, or destruction of ship through explosive charges, are to be prepared for. Two depth charges will be issued, which are to be placed in the after and midships section of the vessel near the ship's bottom under the engine platform. Confidential papers are not to be thrown overboard, but are to be burned. Kerosene, gasoline or other inflamnable material is to be kept handy for this purpose. The master is responsible for the complete destruction of the documents,"

      22.     Scuttling charges furnished by the Japanese. These are about 16" in diameter, 20" high end drum-shaped. The detonators screw into their domed tops and have fuses with a delay of about 8 minutes. Wooden boxes which are placed around the charges are packed with sand so that only the tops of the detonator plugs are left showing.

      23.     Conditions of alert in port. Captured documents reveal that the words PRESSBURG, SIEGBURG and LANGUSTSN FANG (lobster catch) denote alerts. On the first alert signal, an officer is to go aboard every ship in port. Larger vessels will have not only a deck officer, but also an engineer officer and at least two men. In every case the officer watch is charged with maintaining a sharp lookout for paratroops and any other form of enemy approach and, if necessary, to prepare the ship for action. All other members of the crew are forbidden to leave the ship during air alerts, but are to distribute themselves about the ship in the least dangerous pieces, so that actions stations can be quickly reached at any time.

      24.     Cruising speeds. Survivors of the REGENSBURG disclosed that this runner cruised most of the time "under 10 knots" in order to save fuel and increase its cargo capacity. Although its top speed was 16 knots, it seldom exceeded 9 knots except when in danger areas. This is said to be standard cruising practice for blockade runners.

      25.     Recognition signals. Blockade runners have been reported as having white topmasts and light-colored topmasts. The KOTA NOPAN had spirally-painted topmasts. Recognition signals are said to change with the date and time of day. The DOGGERBANK identified itself to an Axis submarine by hoisting red fire hoses, square pieces of sail cloth and square flags colored green, blue, and yellow. It also fired three Very lights - white, white, and red - to which the submarine replied with a white Very light. (2½ hours later the DOGGERBANK was struck by 3 torpedoes and sunk, probably by another Axis submarine.)

      26.     Refuelling at sea. Some blockade runners carry fuel, provisions, and torpedoes for submarines. Such ships are given rendezvous points at which they are to meet submarines. Usually two different hours of the day are specified at which the rendezvous is to be made. (In the case of the EGERLAND and ALSTERTOR, it was 0800 and 1600 - and it is possible, though not admitted, that all supply ships may be allotted the same two hours. If this is true, it then would be necessary only to radio the date of the rendezvous and the hours would be known both by the U-boat and supply ship.) Should either the ship or the submarine fail to arrive at the first rendezvous hour, the instructions are to put about and not return until the second rendezvous hour. It is stated that U-boats or raiders, in need of amunition, fuel or stores, make their request to Berlin and the nearest suitable supply ship is ordered (via Norddeich radio) to make the contact.

      27.     Falling in with United Nations convoy. According to a former crew member, the German SANTA FE was sunk near Dakar (DNI records indicate this ship was captured by the French November 29, 1939) but subsequently raised and brought with a mixed German and French crew through the Straits of Gibraltar to Naples where she arrived in May, l94l. The ship is said to have attached itself to a scattered British convoy until it got to the Straits where it slipped through under cover of darkness.

 


Op-16-FT
Serial 46-43
CONFIDENTIAL
- 5 -


      28.     Navigating in Japanese waters. According to Norwegian ex-prisoners, the navigational lights in Japanese waters have been considerably dimmed and the main coastal lights in Japan and the Netherlands Erst Indies have been extinguished. Dan buoys mark the edges of mine fields. The lightship outside Balik Papan has been sunk and is marked with a wreck buoy. All ships travel completely blacked out. No navigational lights are used. One runner, the RAMSES, had her ports painted black and automatic light switches on all doors leading to the deck. Runners are instructed to follow the coast and make as much use as possible of shallow water as a defense against submarines. On entering or leaving ports in the Fsr East, apparently no signals are made other than the hoisting of the ship's call letters and no permission is obtained from any shore station to make entry.

COMMENTS

      29.     Multiple missons. Blockade runners have also acted as supply ships for U-boats and raiders. The DOGGERBANK, for example, not only supplied torpedoes and provisions to five submarines while it was en route to the Far East, but laid 100 mines off Capetown as well. Blockade runners in the future may be especially fitted out for the performance of such "multiple missions" - and these missions may include hit-and-run commerce raiding. Even for their own self-protection, there is a decided possibility thst Axis runners may now be given more fire-power - perhaps enough to cope with any intercepting vessel less formidable than a light cruiser. In any event, an unidentified merchant ship should be approached with due caution and circumspection - it may be a raider!

      30.     Time, season and weather factors. Blockade runners may be expected to time their passage through high-risk areas to take full advantage of darkness and low-visibi3dty weather. This has made the winter, with its long nights, the most favorable season for entering and leaving the Bay of Biscay. This past winter, however, the many Allied interceptions have badly disrupted the Axis timetable and there is a strong possibility that blockade running may be attempted during the coming summer months.

      31.     Meteorological aid. U-boats, scattered over the Atlantic, doubtless furnish fairly useful weather date. In summer months, therefore, the departures of blockade runners will probably be timed with anticipated squalls and thick weather.

NOTE: Attention is invited to the tactical information contained in the following Op-16-F-8 Serials: 36-42 (AXIS BLOCKADE RUNNING), 2-43 (BLOCKADE RUNNER SUMMARY for 1942), and l4-43 (RAIDERS AND ARMED BLOCKADE RUNNERS). Also 42-43 (BLOCKADE RUNNER SUMMARY-May 15, 1943).

DISTRIBUTION (continued from 1st page)

B.A.D. (2)
M.I.S. (5)
B.E.W. (2)
U.S.J.I.C.
Archives

Naval War College (2)

Alusna:
  London
  Capetown
  Rio de-Janeiro
  Melbourne

Alusnob:
  Bahia
  Recife (3)

Aluslo:
  Dakar (10)
  Durban
  Kilindini
  Colombo
  Freetown
  Punta Arenas
  Gibraltar
  Sydney (Aust.)

NOB: Bermuda
     Iceland (C) (5)
     Trinidad

DIO: 1, 3, 5(2), 6, 7, 8, 10(3), 11,
     12, 13, l4, 15.

Port Director, N. Y. for distribution
   to escorts of UGF, UGS & UGL
   convoys. (60 copies)

Army Air Force Anti-Submarine
   Warfare Command


SOURCE:
Record Group 313, Commander of Battleships & Cruisers, Pacific Fleet, Blue 361
National Archives & Records Administration, College Park

Transcribed by RESEARCHER @ LARGE. Formatting & Comments Copyright R@L.

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