8 May 1944

8 May 1944 Channel Islands Sea Defence diary

Weather: wind from 90°, 7 metres per second. 01:40: sea-target alert for Batterie Strassburg following sighting of two enemy motor torpedo boats in BF 2696, lower right. 02:20: British motor torpedo boats attacked a German convoy comprising minesweepers M 4601, M 4602 and M 4606 and steamers Rena Marguerite, Klaus, Paul et Janine, Tonkin and Bizon in BF 3574, upper left.

02:23: Bizon torpedoed and sank in BF 3574, upper left. Missing: four crew and two shipboard anti-aircraft personnel. Wounded: two crew and one shipboard anti-aircraft man. All other persons aboard rescued.

02:55: Batterie Strassburg fired one salvo at two enemy motor torpedo boats in BF 2698, upper right, bearing 225°, range 200 hectometres [20,000 metres]. No hits observed. 04:09: Strassburg again fired one salvo at two enemy motor torpedo boats in BF 2696, centre left, bearing 217°, range 113 hectometres [11,300 metres]. No hits observed. Ammunition expenditure: eight 22-cm high-explosive shells.

The following observations concern the employment of coastal artillery. The motor torpedo boats were sighted from Strassburg's fire-control post at approximately 180 hectometres [18 kilometres]. This exceptionally long night-time visibility resulted from an extraordinarily bright night: moonlight lit the sector south of Strassburg almost as brightly as daylight. The boats were first seen in that sector. By the time the battery had been immediately alerted—a process taking five to six minutes—the boats were so close to the convoy, also clearly visible at that distance, that opening fire would initially have endangered it. The Sea Commandant's operations room therefore informed the convoy by wireless of the sighting. The British boats attacked shortly after the signal was sent.

In the ensuing action Strassburg could intervene only twice, and only when the boats, attacking in two pairs, withdrew westward from the convoy. After Strassburg's shelling, neither pair renewed its attack; both continued west. The battery's intervention was exceptional because of that night's particular illumination. It could not have intervened on a dark night. The lesson is that in bright moonlight motor torpedo boats can be seen and engaged at up to twenty kilometres in the moonlit sector.

Timely artillery engagement, possibly preventing the attack on the convoy, would have been possible only if the boats had been detected in time. As repeatedly reported, the naval radar sets employed here cannot detect motor torpedo boats. The Luftwaffe sets on Guernsey were unavailable that night, unlike usual, because they were being used against air targets. Motor torpedo boats can therefore still attack German convoys immediately beside the islands, within artillery range, without being detected and engaged beforehand. This will change only when the three promised Würzburg sets are installed on Guernsey, Jersey and Alderney. Installation has begun in part. [These assessments and claims are those of the diary.]

Between 29 April and 7 May, land mountings for 2-cm anti-aircraft weapons: artillery arsenal command, four complete and one under construction; island arsenal workshop, three complete and ten under construction. In the harbour area four concrete plinths complete and one under construction.

Construction, Naval Artillery Battalion 604, Batterie Mirus: Würzburg set, Epa–Seipa, road at No. 2 gun and Düsseldorf anti-aircraft position continued. Anti-aircraft-landing stakes driven in near the airfield; 150 anti-tank shelter holes in the battery complete. A 150-cm searchlight erected at Rötenstein strongpoint [source spelling retained]. Transformer-station foundation excavated; barrack at the farmhouse demolished; camouflage begun at Rebeplatz [place-name reading uncertain]. Work on two 7.5-cm embrasured positions suspended for lack of cement.

Batterie Steinbruch: doors and rail track for searchlight B complete; wire obstacles and infantry positions continued. Three cable junctions exposed; cable trenches excavated; telephone cabling for anti-aircraft positions continued. Work on 7.62-cm positions, shelter for searchlight B and anti-aircraft positions 5 and 6 suspended for lack of cement.

Batterie Lothringen: earth removal before the old fire-control post, excavation of cable trench from E-bunker to fire-control post, battery camouflage and repairs to machine-gun positions and rifle pits continued. Shelter holes roofed. Outside workers continued heating installation in the new fire-control post. Work on the 7.5-cm position suspended for lack of cement.

Batterie Strassburg: splinter-proof ammunition shed complete. Work on the second 7.5-cm position, Brown House demolition and development and camouflage of infantry positions continued. Shelter holes begun. Camouflage firm continued battery camouflage. Embrasured positions for two 7.5-cm guns and two searchlight shelters remain suspended for lack of cement.

Naval Artillery Battalion 605, Batterie Annes, Organisation Todt: earth banking at the ammunition bunker complete; the OT work detachment left on 27 April. Painting of gun bunkers III and IV complete and painting detachment withdrawn. Levelling and camouflage continued, but the Fortress Engineer Staff withdrew the detachment for other employment before work was finished. Battery work: searchlights continued; entrances to Nos. 2 and 4 gun bunkers and accommodation bunkers 2 and 4 camouflaged. Position for the charge projector (Ladungswerfer) begun; position trench continued; wire obstacles at the battery entrance strengthened; levelling and camouflage continued.

Batterie Elsass: Organisation Todt built the fire-control post. Battery erected anti-aircraft-landing stakes; developed machine-gun and anti-aircraft positions; constructed searchlight Bruno position, J.'burg, and a firing range.

Harbour barrier battery, Organisation Todt: wall to prevent firing underneath at gun bunker 1; protective wall at gun bunker 3. Nos. 2 and 4 guns set in concrete; screed laid in bunkers 2 and 4; Nos. 1 and 2 guns installed. Painting in gun bunkers 2, 3 and 4; telephone installation at No. 4 gun; levelling and excavation for cable and drainage. Preparations for a barrack between Nos. 1 and 2 guns. Battery work: makeshift fitting-out of existing bunkers; painting and installation work in three bunker rooms; excavation for an accommodation room; latrine and water pipe constructed.

Artillery command post: situation room fitted out; twenty-pair indoor cable laid and connected. Naval radar: splinter protection for generating sets and a cable trench. Battalion headquarters: infantry-defence installations and makeshift air-raid bunker developed.

Roll 2422, scans 0831–0834, original pages 44–47.