April 15th, 1940 (MONDAY)
UNITED KINGDOM:
RAF Bomber Command: 4 Group. Bombing - Stavanger Airfield. 102 Sqn. Six aircraft attacked successfully.2 Group. 110 Sqn( Blenheim ). Two aircraft to Heligoland. Reconnaissance. One aircraft attacked a patrol ship encountering heavy fire and was shot down.
On return 110 Sqn. is ordered north to Lossiemouth in Scotland to join 107 Sqn for attacks on Norway.
RAF Coastal Command: No. 22 Squadron's Bristol Beauforts make their first mine-laying sortie in the mouth of the River Jade.
A single Hudson on patrol off the Norwegian coast is attacked by two Bf110s one of which crashes into a mountain while trying to attack the Hudson. Another Hudson FTR from the same area.
Bletchley Park: British Intelligence deciphers the German Enigma code used in Norway.
NORWAY: The Main Body of the British 24th Guards Brigade arrives at Harstad, Norway.
Oslo: The Germans remove Quisling from the government, replacing him with the puppet Ingolf Christensen.
As the Harstad troopships approach the port, escorting destroyers HMS Brazen and HMS Fearless find U-49 and sink her. RAF Bomber Command lays its first mines off the German and Danish coasts.
During an attack on the Vigra radio station mid-way between Bergen and Trondheim a Junkers Ju 87R rams one of the aerials, putting the transmitter out of action.
As the allied landings begin, the commitment of the Luftwaffe to the Norwegian campaign is increased leading to the establishment of Luftlotte 5’s HQ at Hamburg to exercise command over Norway. Milch is the temporary commander of Luftlotte 5.
The main British expeditionary force arrives in the Narvik area.
HMS Furious was detached from the Home Fleet with three escorting destroyers, HMS Isis, HMS Ilex, and HMS Imogen and proceeded to enter a heretofore unnamed fiord which was immediately dubbed "Furious" fjord. At 1050, three Swordfish were flown off. One was assigned to photograph the German positions in the Narvik area, while the other two were to fly an A/S search of Vaagsfjord. In the event, the camera was unserviceable and no pictures were obtained. However, the observer noted an estimated 11 German transport aircraft on a frozen lake North of Narvik.
At 1726 a striking force of nine Swordfish, six from 816 Squadron, led by the OC, Lieutenant-Commander H. H. Gardner, RN, and three from 818 Squadron, were dispatched to bomb grounded German aircraft. The aircraft each carried 8 x 20 lb. Cooper bombs while the commander's aircraft carried two additional 250 lb. bombs for experimental purposes. The aircraft attacked in clear weather and results were good. Several direct hits were obtained. It was noted that the 250s blew large holes in the ice, and it was felt that the "runways" were made unserviceable. Heavy Flak was encountered. Five aircraft were hit, U4B:P4167 in the petrol tank, necessitating a water-landing near the task force, Sub-Lieutenant(A) J. N. Ball, RN (P), Lieutenant A. S. Marshall, RN (O), and Naval Airman first class R. Pike (AG) being rescued by HMS Zulu. (Mark Horan)
GIBRALTAR/ATLANTIC OCEAN: HMS Ark Royal remains at Gibraltar. HMS Glorious, in company with the destroyers HMS Velox and HMS Watchman continue towards the Clyde.
EGYPT: Cairo: Wavell discusses the possibility of war with Italy -
..it was obvious that we had little or no knowledge of the general Allied appreciation and plan for war against Italy, naval, military or air. The essential factors were
a. to what extent air action will be taken against objectives in Italy itself, which will influence Italian reinforcement for Libya.
b. plans for French action, by air and land against Tripoli.
c. whether action against Libya or the Dodecanese would be the primary commitment of any forces that become available for offensive action against Italy.
C-in-C Med. considers that the reduction of Libya is of the greatest importance to enable the route through the Mediterranean to be maintained.
JAPAN: Tokyo: The Foreign Minister, Mr. Arita, warns that if hostilities spread to the Netherlands and thus to the Dutch East Indies, peaceful co-existence in the Pacific will be damaged.
FRANCE: Anticipating an invasion RAF units are dispersed around France. No. 1 Sqn. moves its Hurricanes to Pontavert alongside Battles of 12 and 45 Sqns and places three aircraft on constant patrol.
U.S.A.: The motion picture "Dark Command" is released. Directed by Raoul Walsh, this western about an 1860s renegade stars Claire Trevor, John Wayne, Walter Pidegeon, Roy Rogers, George "Gabby" Hayes and Marjorie Main. The film is nominated for best art direction and best music Academy Awards.
Fort Hancock: A Coast Artillery crew starts the service tests of the US Army's first radar system. This is the SCR-268 (Radars were designated as radio equipment for security reasons. SCR = Signal Corps Radio). It was developed as a searchlight control set for coast artillery AAA units. By great efforts the Signal Corps was able to reach a frequency of 205 MHz -- high for the day, but absurdly low for the purpose. Owing to the very long resulting wavelength of 1.46 m, a very large and cumbersome antenna array was necessary in an attempt to achieve reasonable accuracy. It was the first radar to employ lobe-switching to improve elevation and azimuth accuracy. Even so, the practical precision was no better than +- 1 deg, and multipath reflections made the elevation accuracy much worse within about 10 deg above the horizon, except at very favourable sites. However, it was powerful, rugged, and readily movable, and gave good range indication. Because the beam was relatively fat, it was fairly useful for search over limited sectors, and it gave useful height indication for fighter direction. (Will O'Neil)(157,158,159,160,161 and 162)