Coming full circle...Bell Island: Final preparations...The Crossing

1 With 2 track charts

30th July -1200 10th Aug 1942

1 This column was use for documenting the U-boats position and prevailing weather conditions. Weather reports were entered every 4 hours when surfaced and varied in form according to the CO. Wind force was measured using the Beaufort Wind Scale. The sea state was probably recorded using the ' Douglas Sea Scale ', for example Sea 2 was entered on this particular occasion.

2 Recording the ships position was by means of a secret grid system. The Kriegsmarine used a map of the worlds oceans laid out in squares. Each square characterized by a combination of numbers and letters, which when decoded referred to a given position. In this case the square is AN and the position within it is quadrant 4333.

3 Etmal : indicates the total distance covered in sea miles within a 24 hour period ( high noon to high noon ). Figures recorded below the total sea mileage refer to the portion submerged.

1200 10th Aug - 2000 12th Aug 1942

In 1939 Winston Churchill sanctioned a repeat of the WW1 Northern Mine Barrage, an attempt to contain or at least make difficult passage of German raiders from their home ports into the Atlantic via the North Sea and Northern Atlantic. The German occupation of Norway in 1940 led to it's complete revision; a modified and more costly version code named ' Operation SN' by the Royal Navy. The operation lasted about three years and was conducted by the First Mine Laying Squadron who would also be responsible for operations on the British East Coast and South Western Approaches.

Over 110,000 mines were laid, mostly between the Faroe Islands and Iceland. Other fields were laid between the North of Scotland through to the Orkney Islands and onto the Faroes also from the North West of Iceland through to the Greenland Ice Belt. Navigation channels were left between the fields for allied naval shipping; friendly craft were advised by the Admiralty.

The value of any military operation can only be measured by results and on several occasions the viability and value of this great effort was both questioned by it's critics and examined periodically by the Admiralty. Losses to merchant shipping were indeed eventually reduced, but not necessarily as a result of the Mine Barrage, but as a result of the technological and tactical developments in the relentless war against the U-boat. The hunter became the hunted and lost ascendancy, thus negating the need for the continuance of Operation ''SN''. On the 26th September 1943 the operation was officially ended and the First Mine Laying Squadron disbanded.

If indeed, we measure the results critically it can be said that Operation ''SN'' was unsuccessful in achieving it's operational objectives. The operation constituted 35% of British mining operations in WW2 and far more was expected of the minefields by it's designers and promoters. It did not deter raiders and U-boat attacks, which after the conquest of France originated not necessarily from ports in Germany and the Baltic but from ports on the French Western seaboard. One of the operations only tangible successes was the detection of the Bismark, which having sailed through minefield ''SN 71B '' in the Denmark Straight, was detected and eventually sunk with huge loss of life to both sides.

The Bismark and her escort the Scharnhorst had actually avoided detonation of the mines by sailing over the minefield at high water, which meant that there was at least 10m of water over the mines. it was also reported that the effectiveness of this minefield had been compromised by the movement of ice. One U-boat , U-702 , was confirmed as being sunk as a result of collision with a mine off the South East of Iceland , although it is possible that others may have been lost as a result of operation ''SN''. There were a number of allied tragedies as a result of the mine barrage, including the sinking of the destroyer HMS Achates with the loss of 60 lives in July 1941 and the sinking of five ships from convoy QP13 in July 1942 on it's return from Murmansk to Reykjavik, after delivering valuable war materials and supplies to Russia. The convoy was lead and escorted by HMS Niger. Niger, on mistaking an iceberg for Iceland's North Western Cape lead the convoy into the minefield ''SN 72'' at the entrance to the Denmark Strait and although recognizing his mistake, the Captain could not take avoiding action in time to save either his ship or the other unfortunates in the convoy.

In a statement summarizing Operation ''SN'' , the Commander in Chief of the Home Fleet, Admiral Bruce Fraser, said in 1943, that the laying of the Northern Barrage had been '' the least profitable voluntary major naval undertaking of the war''; one has however to balance these rather harsh words against the vast human effort and sacrifices made in the course of the operation. The laying of the fields was after all successful, and this carried out with grim determination under constant threat of attack by the enemy and in the harsh conditions found in the North Atlantic Ocean.

The mines used in Operation ''SN'' were of the Buoyant Anchored type, which is , simply put, an Explosive Charge Barrel, Booster/Detonator Assembly and Firing Mechanism held within a buoyant welded steel hemisphere. The mines were launched into the ocean complete with a heavy bottom anchor, to which the mine was fixed by a sturdy mine anchor wire. After the mine had sunk to the sea-bed , the mine anchor wire was mechanically released and the mine being buoyant , then floated towards the surface until the operating depth , governed by the length of the anchor wire was reached. Once the operating depth was taken up and the wire taught , the mine armed itself after a short delay by the opening of a safety switch , thus completing the mine electrical firing circuit.

For operational effectiveness and economy the mines were laid to a specific pattern, depth and distance depending on the make of mine. The mines were laid in rows at varying depths relating to whether the intended target was to be surface or submerged. During Operation ''SN'' the mines used were constantly being modified and improved to suit the operational conditions and environment, and by the end of WW2 technical developments both in Britain and the United States led to substantial advances in mine reliability and design. By the end of Operation ''SN'' the majority of mines laid were of magnetic influence type.

Contrary to the Hollywood movie perception U-boats spent as much time as possible on the surface as can be seen by the breakdown of the total mileage records in order to operate more efficiently.