HMS Rawalpindi, Magnetic Mines and an unseen ‘raider’

The Naval, Military and Air situation up to 12 noon on November 30, 1939 as reported to the War Cabinet:

Naval Situation.

General review.

1. The search for the German warships that sank H.M.S. Rawalpindi has been the dominant feature of the naval operation in Home Waters. These operations have been hampered by bad weather, and up to the moment of going to press have not been successful.

2. Further German magnetic minelaying in the shallow waters of the east coast has taken place, but on a reduced scale compared with the previous week. Seven merchant ships (six British and one Polish) have been sunk in this area.

3. Nothing further has been heard of the raider reported in the Indian Ocean. The re-disposition of British forces in foreign waters referred to in last week’s resume has proceeded except for certain modifications made as the result of the sinking of H.M.S.Rawalpindi.

Home Waters.

4. From the interrogation of the 10 survivors of H.M.S. Rawalpindi that were picked up by H.M.S. Chitral and later information received, the following brief outline of the action can be deduced: —

Rawalpindi was on a north westerly course when, at 3:30 pm on 23 November, the enemy was sighted to the westward steering north. Chitral was to the northward and the cruisers Newcastle and Delhi were to the southward, the nearest ship being more than 30 miles away. Visibility was good, and after about 10 minutes Rawalpindi altered course to 180° to starboard, which brought the enemy on the starboard quarter. Smoke floats were dropped, but did not give any effective screening. The enemy first sighted close rapidly and signalled “stop” and “what ship,” and a few minutes later fired one round, which fell short. Soon after she opened fire and her second salvo hit somewhere on the boat deck and started a fire, the range then being about 14,000 yards. Rawalpindi replied to the fire, but her guns was soon put out of action; one gun, however, claimed to have scored three or four hits. The first enemy sighted soon crossed the stern and the second enemy ship was now sighted to starboard, and it was this ship which appears to have done most damage. Rawalpindi gradually lost her speed as the range fell to 8000 yards and the fire spread.

7. On receipt of the news of the sinking of H.M.S. Rawalpindi the Home Fleet took up positions in the North Sea calculated to intercept the German warships, should they be attempting to return home. Strong searching forces were ordered towards Icelandic waters and the armed merchant cruisers were temporarily withdrawn from the Northern Patrol. Special submarine patrols were disposed in the North Sea and special air searches and patrols were also arranged to be flown. These operations have continued throughout the week under review.

German Magnetic Mines.

15. During the week under review German aircraft have continued to lay mines off the east coast. Mines were dropped by aircraft in the Thames Estuary on 24 November, and on 25 November trawler’s reported them off the coast of Northumberland. They appear to be two types of minelaying aircraft. One type alights on the water to lay the mine, and the other mines are dropped while in the air with a parachute attached. It is believed each machine can carry two mines. Two magnetic mines were recovered on 23 November, and these have been fully examined. They are designed to lie on the bottom and fired by the magnetic field of the ship passing over them.

16. The following counter measures have been taken: —
(a) on 28 November an air raid was carried out by our long-range fighters on Borkum, which is the base of the mine-laying aircraft. [see para.61]

(b) A balloon barrage of 30 balloons is being installed to the eastward of Southend Pier, and from the end of the barrage to the Edinburgh Channel. A.A.guns and mobile searchlights on self-propelled barges are being provided. A gun area has been arranged in the Edinburgh Channel, to be served at night by three anti-aircraft cruisers and to paddle minesweepers mounting Bofors guns. Further extinctions of navigation lights in the Thames Estuary are being made.

(c) A special magnetic sweep has been prepared based on data obtained from the mines recovered.

Protection of Sea-borne trade.

34. Between the 22nd and 29th of November 12 convoys comprising 452 British, 33 Allied and 6 neutral ships have been sailed, bringing the total number of ships concerned up to 29th November to 3,802. Three ships have been lost while in convoy this week making a total of five since the beginning of the war, which gives a percentage of losses of ships in convoy of one seventh of per cent. The average escort forces employed daily to amount to one cruiser, three armed merchant cruisers, six escort vessels and sixteen destroyers; in addition three French destroyers daily escort between Gibraltar and be Western Approaches.

Military situation

Western Front.

Allied forces.

38. The British Expeditionary Force is to extend its left to take over the front hitherto held by the French 51st Division, which is being withdrawn from Lord Gort’s command on the 1st and 2nd December.

Soviet Russia and Finland.

46. Interest has centred on the Soviet-Finnish dispute, which flared up afresh as the result of an alleged incident on 26th November, when seven Finnish shells were said to have fallen among a party of Soviet troops; a charge which the Finnish authorities deny as they say that’s no Finnish artillery was within 20 km of the frontier. The Soviet Government alleges that the incident took place at 3:45 pm on Sunday, but they had their official protest ready to hand to the Finnish ambassador at 8:30 pm on the same night, and it seems highly probable that the incident had been foreseen. The subsequent breaking off of the diplomatic relations shows that the Soviet is determined to force the pace and at least to subject Finland to the maximum degree of intimidation which she can exert.

Should the Soviet decides to press an attack in strength Finland must be overrun, but she would never be pacified and the task of seizing and holding any considerable portion of the Finnish territory would probably prove a test of the efficiency and morale of the Red Army to which the Soviet government may hesitate to subject it.

Air Situation.

Royal Air Force Operations.

Reconnaissance of German Naval Bases.

59. Six Whitley aircraft carried out a reconnaissance of Wilhelmshaven, Cuxhaven, Heligoland, and Brunsbuttel, on the night of the 24th 25th of November. Leaflets were dropped in the course of this operation. The reconnaissance was repeated on the following day by four Blenheim aircraft. The position of certain warships was reported, but no enemy capital ships were observed. All our aircraft returned.

Fighter Operations.

61. Long range fighter patrols have been arranged with the object of destroying enemy mine-dropping aircraft. Formations of six and eight aircraft engaged on this task swept the area lying between the British and enemy coasts on the 25th and 26 November without sighting any hostile aircraft.

With the same intention, twelve Blenheims of No.s 25 and 601 Fighter Squadrons carried out a low-flying attack on the seaplane base at Borkum at dusk on 28 November. Three seaplanes found on the slipways were attacked with machine guns, and attacks were made on the enemy pom-pom and machine-gun defences which were firing. A number of ships in the channel to the south of the island opened fire as the Blenheims turned away from the attack. No enemy aircraft were intercepted on the return flight. All aicraft landed safety at Debden.

See TNA CAB/66/3/45

Earlier in the war:

Later in the war: