'Bridford' was a British series of six naval operations to collect important war supplies (ball bearings, rare metals etc.) from Sweden by the use of specially adapted motor gun boats (26/31 October 1943 and five other dates up to March 1944).

The decision to use small British vessels, each adapted to carry 45 tons of freight, was taken in the light of the diplomatic furore which had followed the disappointing result of 'Performance', and was again organised by the Special Operations Executive. The Swedes were informed that the British intended to use the first operation to collect cargo from the two Norwegian ships which had returned to Gothenburg in 'Performance', and agreed that the operation could proceed if the cargo was collected from the shore rather than the interned ships.

Just before the start of World War II, the Turkish navy had placed an order for eight motor gun boats from Camper and Nicholson. Larger than the contemporary motor gun boats built by Vosper and the British Power Boat Company for the Royal Navy, the craft for Turkey were also unusual in having a propulsion arrangement based on three 16-cylinder Paxman VRB Diesel engines, each delivering 1,000 hp (746 kW), rather than the petrol engines of the British craft: the Diesel engines were more fuel-efficient than the petrol engines, and burned less flammable fuel. After the start of the war the vessels ordered by the Turks were taken over by the Royal Navy. The first two and the last of the class were completed with gun and torpedo armament as the 86.5-ton MGB-502, MGB-503 and MGB-509, the last of these with Packard petrol engines as not enough Paxman Diesel engines were available.

Before completion, the other five were allocated to 'Bridford'. This operation resulted from the fact that the UK was to a degree dependent on Swedish ball bearings and also needed other specialist equipment to keep production plants running. In the first part of 1943 these were being flown out of Sweden in small quantities, but far greater supplies were needed and Sir George Binney, who had arranged to bring out a number of Norwegian vessels interned in Sweden in 1940, suggested the use of fast motor boats.

After some deliberation by the Admiralty and Foreign Office, the five uncompleted motor gun boats being built by Camper and Nicholson boats were taken in hand for a major alteration. Forward and aft of the engine room, each of the hulls was gutted to create holds for 45 tons of cargo, and a new bridge structure, of the merchant vessel type, was constructed aft of amidships. This contained accommodation, galley, radio room etc., and was topped by a small open wheelhouse. A lightweight mast/derrick arrangement was rigged forward, and limited protective armament was installed. For political reasons, the vessels were run under the red ensign with Ellerman Wilson officers and Hull trawlermen providing many of the crew as all operations were run out of the Humber estuary.

As converted, the boats' speeds were reduced from 28 to 23 kt maximum and 20 kt cruising, and their range was 1,350 miles (2175 km) at 17 kt. All five of what were now blockade runners were completed in 1943: three conversions were effected by Camper and Nicholson and two by Amos and Smith of Hull, and the craft were named Hopewell, Nonsuch, Gay Viking, Gay Corsair and Master Standfast.

Operations did not start until September 1943 when adequate hours of darkness were available, and the basic plan called for the boats to depart late in the afternoon and reached Sweden early in the morning two days later having transited the Skagerrak during the previous night’s darkness. This was the most dangerous part of the voyage as German naval forces maintained a constant patrol of the area from their bases in Norway and Denmark. The loading port in Sweden was Lysekil, and it was hoped to depart from here during the evening after arrival and be back in the Humber two days later during the morning. In practice such a schedule was rarely achieved for a variety of problems arose.

The first run was scheduled to start on 23 September but was postponed one month because of engine bearing problems, and and all five of the craft finally got under way together during the evening of 26 October. Only Gay Viking reached Sweden, the other craft turning back because of bad weather and mechanical problems. By 31 October Gay Viking had returned with 40 tons of cargo, the normal load. During the next five months, eight further successful round trips were completed, bringing the total cargo carried over the period to 347.5 tons against the planned total of 400 tons.

Over the same period of time, flights by aircraft carried 88 tons to the UK.

The operations were not completed without loss, Master Standfast being captured by the Germans on 2 November before she had completed any round trip, while Nonsuch completed only one round trip as a result of breaking two crankshafts (centre engine on 24 December and port engine on 2 February 1944). Hopewell completed two trips but suffered the breaking of her centreline engine’s crankshaft on 6 March, while Gay Viking and Gay Corsair carried out three voyages but also suffered crankshaft problems: Gay Corsair damaged her central unit on 8 March and Gay Viking her port unit on 17 March.

'Bridford' ended in March 1944 as the nights started to shorten. Despite the problems, though, 'Bridford' had met its objectives as most of the required cargo was shipped. In overall terms the blockade runners proved to be successful with their low silhouette and relatively high speed.