The Naval Military and Air Situation up to 12 noon on the 18th January 1940, as reported to the War Cabinet:
The period has again been one of relative quiet at sea, there being only minor incidents to report apart from the loss of H.M. Submarines; Seahorse, Starfish and Undine. In Home Waters operations against German merchant vessels have been carried out out off the Norwegian and Dutch coasts, in the latter case with some success.
Enemy attacks on seaborne trade by air, mine and submarine have continued, and have perhaps been slightly more effective than during last week.
The crisis in connection with the military situation in Belgium and Holland necessitated an increased degree of readiness being maintained by our light forces on the East Coast while it lasted.
The movement of Australian and New Zealand troops continues.
10. A diagrammatic analysis of German submarine activities up to the end of 1939 is attached to this resume. A study of this shows that German submarine activity has been steadily decreasing and suggests that the North Sea is becoming the principle operational area of submarines, whereas for the first few months they were most active on our Western seaboard.
11. A minefield is suspected off Liverpool and there may also be mines in the Bristol Channel, but fog has delayed sweeping operations. Mines have been swept up in the searched channel off Blyth, and here, again, owing to fog it has not been possible to clear the channel properly, so that traffic north of the Tyne has had to be held up, which has caused considerable congestion. Sixty-one mines have been accounted for in the Tyne area during the period. Two magnetic mines have been exploded by aircraft off Folkestone.
Experiments are being carried out in a magnetisation of various classes of ships in order to minimise the danger from magnetic mines. The results up to date are promising.
15. The order placing the B. E. F. on six hours notice to meet any eventuality that might arise out of the crisis of the last few days has now been cancelled.
On the Saar Front, the 8th Infantry Brigade relieved the 4th Infantry Brigade during the night of the 14th – 15th of January without incident. The 48th Division is now assembling in France.
Apart from the usual enemy artillery activity, and minor clashes between German and French patrols, no events of importance have occurred in the Franco German zone of operations.
Extended Night reconnaissance
25. Three Whitley aircraft reconnoitred North-West Germany, Austria and East Germany on the night of the 12th January. The reconnaissance was successful, and all the aircraft returned safely without encountering any opposition from enemy fighters, although weather conditions were good. Opposition from the ground was reported to be negligible. Two of the Whitley crews were in the air for ten and a half hours on this reconnaissance.
The pilots reported that the blackout in South Germany and Austria was indifferent, and made special mention of the poor effort to blackout Vienna.
29. In spite of the bad weather prevailing generally over the North Sea, Coastal Command completed 39 routine and 73 special patrols, in addition to providing air escort for 37 convoys. Six mines were located and reported and four submarines were sighted.
A Hudson aircraft attacked a submarine on the 15th with two 250-lb bombs in a position 116 miles to the north-eastward of Buchan Ness without any visible results, and on the following afternoon two aircraft made four separate attacks on a suspected submarine in Liverpool Bay.
On the 13th a search was made by an aircraft and a high-speed launch for the crew of a Heinkel shot down by our fighters. The launch rescued one member of the crew who was found swimming in an exhausted condition some miles out to sea.
See TNA CAB/66/5/2
Composite of contemporary films about the Hudson from Bomberguy.