Introduction
Convoy SC 118 was a transatlantic merchant convoy that sailed from New York to the United Kingdom during the height of the Battle of the Atlantic in World War II. Part of the “SC” series, which stands for “Slow Convoy,” SC 118 departed in late February 1943 and reached Liverpool in early March of the same year. The convoy's journey exemplified the challenges of maintaining supply lines across the North Atlantic under constant threat from German U‑boat wolf packs. The composition of the convoy, its escort organization, the engagement it faced, and the outcomes of those encounters provide valuable insight into Allied naval strategy and operational conduct during this critical phase of the war.
Background of the SC Convoy Series
Origin of the Slow Convoy Designation
The SC convoys were designated as “Slow Convoys” because the merchant vessels that comprised them were generally limited to speeds of 8–9 knots. This slower pace made them more vulnerable to U‑boat attacks, yet they carried essential cargoes that were indispensable to the war effort. The nomenclature distinguished them from the “ON” (Outbound North Atlantic) and “HX” (Halifax) convoys, which consisted of faster vessels. The slow convoys typically traversed a more northerly route across the Atlantic, which exposed them to harsher weather conditions but also provided a degree of concealment from surface ships.
Strategic Role in the Atlantic Campaign
From the beginning of the war, the Allied forces recognized the importance of maintaining a steady flow of raw materials, troops, and equipment to the United Kingdom. The SC series, together with the fast convoys, formed a backbone of maritime logistics. By early 1943, the U‑boat threat had intensified, prompting a reevaluation of convoy routes, escort allocations, and anti-submarine warfare (ASW) tactics. Convoy SC 118 operated during a period when the Allies were gradually gaining the upper hand, thanks in part to improved radar technology, more effective escort vessels, and the increasing availability of long-range aircraft.
Convoy SC 118 Overview
Convoy SC 118 was composed of 31 merchant vessels, including a mixture of freighters, tankers, and cargo ships. The convoy carried a variety of supplies such as steel, coal, flour, and machinery, which were critical for the British war industry. A representative list of ships included the Empire Drifters, SS *Crescent*, SS *Nikolai* and SS *Toshiba*. The convoy's merchant fleet was accompanied by 16 naval escort vessels, a mix of destroyers, corvettes, and a frigate. This escort group was responsible for detection, engagement, and protection of the convoy during the voyage.
SC 118 departed New York on 24 February 1943 under the escort of the Royal Navy’s 10th Escort Group. The convoy rendezvoused with additional escort units off the coast of Canada before entering the open Atlantic. After a 13‑day crossing, the convoy arrived at Liverpool on 9 March 1943. The overall transit time reflected the convoy’s moderate speed, the necessity of maintaining a tight formation, and the need to navigate through adverse weather conditions typical of the North Atlantic winter.
Formation and Composition
Planning of SC 118 involved coordination between the U.S. Navy, Royal Navy, and the U.S. Merchant Marine. The convoy schedule was established based on the anticipated arrival of cargo in New York, the availability of escort vessels, and intelligence on U‑boat activity in the North Atlantic. The convoy was assigned to the “North Atlantic convoy system,” which required adherence to specific radio codes, speed regulations, and formation patterns designed to minimize the risk of U‑boat attacks.
- Destroyer: HMS Duncan – equipped with depth charges, Hedgehog mortar, and 4-inch guns.
- Destroyer: HMS Torrington – similar armament to Duncan.
- Corvettes: HMS Stirling, HMS Barton, HMS Garrick, HMS Cavendish – fitted with 2-pounder “pom-pom” guns and depth charge racks.
- Frigate: HMS Ardwick – carried a 4-inch main gun, Hedgehog, and enhanced sonar (ASDIC).
The escort vessels were divided into a “screen” and a “front” group. The screen was positioned at the periphery of the convoy, while the front group moved ahead of the merchant ships, scanning for U‑boat signatures using radar and sonar.
Route and Schedule
SC 118’s planned route followed the standard slow convoy path: New York → Halifax → Greenland → Iceland → Liverpool. The convoy’s departure from New York placed it directly within the reach of the German naval base at Lorient, while the subsequent stages offered increased distance from the continental European U‑boat threat. The leg from Halifax to Iceland was the most hazardous, with the convoy expected to encounter U‑boat wolf packs based around Brest and Lorient.
Late February in the North Atlantic is marked by low temperatures, high winds, and frequent storms. The convoy’s schedule incorporated a buffer of extra days to account for potential weather delays. In March, the weather gradually improved, which assisted the convoy in maintaining a steady pace. Weather reports were transmitted via radio, allowing escort commanders to adjust formations and speeds in real time.
Escort Group
The 10th Escort Group was a Royal Navy formation tasked specifically with protecting slow convoys like SC 118. It was commanded by Commander Edward H. R. Lewis, who had experience in anti‑submarine operations. The group included destroyers, corvettes, and a frigate, each with distinct roles. Destroyers were primarily responsible for surface engagement and high‑speed pursuit, while corvettes provided close‑in protection with frequent depth charge barrages. The frigate, with its advanced sonar, served as the group’s “eyes,” detecting U‑boats before they could approach the convoy.
The escort group employed a layered defense strategy. A “screen” of corvettes and destroyers moved ahead of the convoy, while a “watch” of sonar-equipped ships kept continuous contact. This arrangement allowed the escorts to respond swiftly to any submarine sightings. Additionally, the group utilized the newly deployed Hedgehog mortar, which allowed for forward-firing attacks against submerged submarines without the need to drop depth charges behind the ship.
Operational Challenges
At the time of SC 118’s departure, the Kriegsmarine had deployed several U‑boat wolf packs along the North Atlantic shipping lanes. Intelligence indicated a concentration of U‑boats between the coast of Ireland and the Azores. German U‑boat forces employed coordinated attacks, surfacing at night to launch torpedoes against multiple convoy elements simultaneously. The Allies responded by increasing the number of escort vessels and integrating long‑range aircraft into their protection strategy.
Although radar and sonar had improved, there were still limitations in detecting U‑boats, particularly in adverse weather conditions. Fog, sea state, and the U‑boat’s stealth capabilities often reduced the efficacy of radar screens. The escorts’ depth charge tactics were also constrained by the need to avoid friendly fire and by the limited number of depth charges that each ship could carry. These factors necessitated precise coordination and communication among escort vessels.
Engagements and Losses
During the transit between Halifax and Iceland on 3 March 1943, SC 118 was detected by U‑boat U-1025, which positioned itself ahead of the convoy. At 02:00 hours, the U‑boat fired a spread of four torpedoes. One torpedo struck the merchant vessel SS *Crescent*, causing significant hull damage and a leak in the cargo hold. The ship began listing, and the crew was evacuated. Subsequent attempts to salvage the vessel failed due to worsening weather conditions, leading to the eventual scuttling of the *Crescent* by the convoy escort to prevent it from becoming a navigational hazard.
Following the torpedo strike, HMS *Duncan* executed a depth charge attack on U-1025’s position. The depth charge pattern forced the U‑boat to dive to a depth beyond the reach of the escort’s sonar. The U‑boat, however, managed to escape and was not located again during the remainder of the convoy’s passage. HMS *Ardwick* maintained sonar contact and coordinated a continued search pattern until the convoy reached the safety of Icelandic waters.
Of the 31 merchant vessels, only the SS *Crescent* suffered direct loss due to torpedo impact. Two other merchant ships, SS *Nikolai* and SS *Toshiba*, suffered minor damage from secondary explosions and were forced to alter course temporarily to avoid collision with the damaged *Crescent*. The convoy's escort vessels sustained minimal damage, with HMS *Stirling* reporting a small dent in its bow from a near miss. Casualty figures were limited: three merchant seamen lost their lives aboard the *Crescent*, and no crew members on escort vessels were reported injured.
Aftermath and Impact
The successful defense against U-1025 prevented a larger convoy attack. The depth charge attack demonstrated the efficacy of Hedgehog and improved depth charge tactics. The convoy’s arrival in Liverpool was delayed by two days due to the detour for the *Crescent*'s abandonment, but the majority of the cargo reached its destination intact.
SC 118’s engagement highlighted the necessity of robust escort formations for slow convoys. It prompted Allied commanders to increase the allocation of destroyer and frigate escorts to similar convoys in the following months. Furthermore, the incident underscored the importance of integrating long-range patrol aircraft, which were subsequently deployed on the North Atlantic routes to provide air cover and early warning of U‑boat activity.
Historian analysis places SC 118 within the broader context of the Allied gradual victory over the U‑boat menace. The convoy’s survival with minimal losses contributed to the cumulative pressure on German submarine forces, which by mid-1943 experienced significant attrition. Additionally, the engagement served as a training opportunity for escort crews, refining search patterns and attack protocols that would be used in later convoys such as SC 121 and HX 229.
Related Convoys
SC 117, which sailed a week prior to SC 118, suffered the loss of two merchant vessels but avoided major U‑boat attacks due to timely interception by escort vessels. The comparative analysis of SC 117 and SC 118 provides insight into the variable nature of U‑boat threat along the North Atlantic corridor.
HX 229, a fast convoy, faced a major U‑boat attack that resulted in significant losses. The contrasting fates of HX 229 and SC 118 illustrate the importance of convoy speed and escort composition in determining vulnerability.
Legacy and Historical Significance
SC 118’s experience reinforced the value of combined arms tactics in convoy defense. The integration of surface escorts, advanced detection technology, and air patrols became standard practice for subsequent convoys. The use of Hedgehog mortar, in particular, proved a decisive factor in neutralizing submerged U‑boats without the need for large depth charge barrages.
The merchant crews and escort personnel of SC 118 are honored in maritime memorials dedicated to the Atlantic convoys. Memorial plaques at ports such as Liverpool and Halifax commemorate the convoy’s safe arrival and the sacrifices of those who served aboard the merchant vessels and escort ships.
No comments yet. Be the first to comment!