Fog was a constant issue on the east coast at all times of the year. If the fog became too bad, the whole convoy would be ordered to anchor, more or less where they were, waiting for things to improve. More often than not, this would develop into a nightmare for the escorts. Some ships dropped their anchors immediately, some drifted around, waiting to hear if the other ships had really started to drop their chains, some tried to get out of the main line and find a quiet place of their own. Collisions were frequent, and some ships ventured into non-swept areas, risking themselves as well as the escort trying to guide them back to safety.
In harbour, the convoys needed strict and competent handling. The arrival of a large number of laden ships at the same time is a challenge at the best of times, and now the east coast ports themselves constituted primary targets for the Luftwaffe, even before the fall of France. Berthing facilities, cranes, warehouses, yards and docks were all stretched to the limit.
Due to a lack of minesweepers, sweeping was largely done in daytime, focusing on keeping marked channels clear. The convoys moved by night as well, though, and sweeping in and out of port was limited. In general, the sweeping was not coordinated with the convoy movements and new mines were as often as not detected by an unlucky ship, usually sailing independently, hitting one. The loss rate of independent ships to mines was six to seven times that of ships sailing in convoy in the first four months of 1940. The ‘Q’ system of issuing warnings of minefields applied in a strict sense only to warships.10 In most cases the Naval Control Service would also forward the warnings to convoy commodores in the area, keeping them informed and able to discuss the route of the convoy should the escort commander fail to react. Hence, those sailing in convoy had the advantage of their escort being updated on mine danger areas, whereas those sailing independently did not receive this information. One may wonder why the positions of the known minefields were not broadcast publicly, as it could be taken for granted the Germans knew exactly where they had put their own mines and had little to gain from listening in.11
The German U-boats were not comfortable operating too close to the east coast of Britain. Defensive minefields added to dangers of shallows, and difficult currents meant that the trade routes in the east were largely left to the Luftwaffe and, later, after the occupation of France, the S-boats. Except for the very successful mining campaign in 1939, few ships were sunk by U-boats on the British east coast. In the early months, some were sunk in the northern part of the Channel, but these were sailing independently off the coast.
North Sea Convoys
To protect their own and chartered ships from Scandinavia to Britain, including ore freighters from Narvik, the Admiralty introduced a convoy system across the North Sea a few weeks into the war. From the first week of November, fish, butter, meat, timber, pulp, aluminium, ferro-alloys, minerals and other commodities were sent by railway or coastal ships to Narvik, Trondheim, Bergen and Gothenburg and loaded onto British or British-chartered ships. Following neutral sea lanes to collection points in south-western Norway, they were eventually assembled in convoys and escorted across the North Sea.
Most of the convoys, known as ON to Norway and HN back, sailed between Methil and various points of entry to the Inner Leads off Bergen.12 In early February 1940, after initially working on an eight-day schedule, the volume of trade forced an increase to a four-day cycle from convoy ON-10, weather permitting.13 The first convoys were rather small, while during the winter they swelled in size to around thirty to forty ships each, including neutrals. In all, twenty-five convoys sailed from Scotland to Norway and twenty-eight from Norway to Scotland between November 1939 and April 1940, when the German invasion of Denmark and Norway severed the traffic.14
A convoy for Scotland leaving Norway off Frøysjøen north of Bergen. At least two Royal Navy destroyers can be seen. (Riksarkivet Kom-adm-eske 945)
In Norway the convoys were administered by the NCSO in Bergen. The office of Captain Harris-St John was the largest such organisation in Scandinavia and, assisted by British consuls in the smaller ports between Stavanger and Trondheim, organised the convoys in and out, ensuring papers were in order, pilots standing by and so on. The Norwegian government was at first reluctant to consent to the organisation of what was obviously an advantage to one of the belligerent nations from one of their ports. Norwegian ships were sunk in significant numbers by German U-boats and mines though, and in mid-November, the British Legation in Oslo was quietly informed that Norwegian authorities would not object to the practice, ‘provided no British warships entered neutral waters’ and Norwegian ships would be allowed to join the convoys. Officially, the Norwegian naval authorities in Bergen followed a restrictive line towards Captain Harris-St John and his staff. Unofficially, though, Rear Admiral Carsten Tank-Nielsen, Commander of Sea Defence District No. 2 (SDD2) was ‘most helpful’, maintaining very positive relations with the British NCSO, providing advice as to the best routes to take while inside the Leads as well as forwarding signals to the convoy and providing intelligence of German U-boats sighted in the North Sea. He also discreetly afforded Norwegian naval escort of the convoys while inside territorial waters. The incoming convoys were usually met at the territorial limit by a Royal Norwegian Navy (RNN) torpedo boat and taken into the Leads while the British escort picked up another set of ships to be escorted back to Scotland.15
On the British side, the Scandinavian convoys were administered by the C-in-C Rosyth through the Naval Control of Shipping Office at Methil in collaboration with C-in-C Home Fleet. Many neutral ships carrying goods between Britain and Scandinavia would also seek protection in the ON/HN convoys. The minimum speed of 8–9 knots established for other convoys was routinely waived due to the multitude of ships seeking protection. The many neutrals tagging on caused particular problems as they were not in possession of the maps, instructions and signal books the British masters had been provided with. This was to some extent overcome by the NCSOs in Bergen or Methil providing a single-sheet pamphlet with basic instructions and signals, handed out prior to departure. Neutral ships were included in the convoys, provided the ships ‘traded with or for the British Empire or Allied countries’. Neutral ships not carrying what the Germans would consider contraband would, at least into the first months of 1940, feel safe travelling independently, well marked and with lights on at night. The fact that neutral ships were permitted to sail independently in British waters made them vulnerable to mines and added to the policy of restricting the Q-message mine-warning system to the convoys, this resulted in greater losses from mines among the neutrals than necessary.
Contrary to the Atlantic convoys, the Scandinavian convoys were adequately escorted by potent A/S destroyers. Four to seven Home Fleet destroyers and one C-class A/A cruiser and/or a submarine usually made up the local escort for the convoys. Most convoys were also screened by a covering force of cruisers, keeping to the south. Occasionally, capital ships of the Home Fleet would also be at sea, covering the sailing from a distance, usually to the north-west. Air cover was also provided at times over the western part of the crossing. Weather was appalling during the winter, with frequent gales, snow and fog. Progress was slow at times, landfall was hazardous, and many ships lost touch during the nights in crossing.