Convoy SC 100

SC 100, comprised twenty six merchant ships and departed Halifax for the UK under local escort on 12 September 1942. The Convoy Commodore was Capt. NH Gale in Athelsultan.

SC 100 was met by its Ocean Escort, Group A-3, led by US Coast Guard cutter {{USCGC|Campbell|WPG-32|2}}, under Cdr. P Heineman. Also in the group was the cutter {{USCGC|Spencer|WPG-36|2}} and four RCN corvettes. A-3 was joined by the corvette {{HMCS|Trillium|K172|2}}, escorting ships from Wabana, and by three corvettes travelling in convoy for refit in the UK.Blair p.32

During the action SC 100 was joined by several units as reinforcement, including the newly formed convoy support group, 20EG, led by Comm. FJ Walker.Roskill p. 201

SC 100 was attacked by units of two U-boat patrol lines, Lohs, of 18 boats, and Pfiel, of 11 Uboats, under the guidance of U-boat Commander (BdU) Adm K Dönitz.

The convoy departed Halifax on 12 September 1942 and was joined on 16 September{{cite web |url=http://www.convoyweb.org.uk/sc/index.html?sc.php?convoy=100!~scmain|title=Convoy SC.100 |publisher=Arnold Hague Convoy Database |access-date=2 December 2022}} by Mid-Ocean Escort Force Group A-3. Ahead of the convoy were three U-boat patrol lines; Vorwarts, of 18 boats, off the east of North America; Lohs, of 19 boats, south of Greenland, and Pfeil, 11 boats, moving west from bases in Occupied France.

SC 100 passed through the Vorwarts patrol line without being detected, and these boats took no further part in the action, but on 18 September the convoy was found and reported by {{GS|U-599||2}}, of Lohs. U-599 commenced shadowing, while other U-boats of the group joined; first {{GS|U-755||2}}, which had sunk the USCG weather ship Muskeget the previous week, then {{GS|U-259||2}} and {{GS|U-569||2}}. These boats began their attack, but U-259 collided with a merchant ship and was forced to break off. Both boats were vigorously attacked by escort ships, but suffered no damage. Two more Lohs boats, {{GS|U-373||2}} and {{GS|U-596||2}} joined; the latter attacked and sank the freighter Empire Hartebeeste, but a claim by U-373 to have torpedoed a corvette was not substantiated.Blair p.33

At this point a massive storm blew up (described by U-boat reports as "a hurricane"), making further attempts impossible. Faced with this BdU called off the operation, but several boats remained in contact and on the third day {{GS|U-617||2}}, of Pfeil made contact and torpedoed Athelsultan, the commodores ship. U-617 also sank the stragglers Tennessee and Roumanie, which had become separated in the storm.

Meanwhile, SC 100 had been re-inforced by ships from nearby convoys, and from 20 EG, bringing the total number of warships to 15.

On 24 September two more U-boats made contact; {{GS|U-432||2}} sank the freighter Penmar, but a claim by {{GS|U-258||2}} of two freighters sunk was mistaken.

The next day, as the weather cleared, aircraft of RAF Coastal Command were able to give saturation cover, forcing all U-boats still in contact to break off contact. With this BdU dropped plans to re-engage with SC 100 and moved the U-boats present to other tasks.

With no further attacks SC 100 arrived safely at Liverpool on 28 September.Hague p. 135

Despite the number of U-boats called to this action few were able to make contact, due to the storm. Those that did were driven off by the escorts; of the five ships sunk by enemy action only two were in convoy at the time. It has been suggested that

the ships of Group A-3 were not fast enough to catch surfaced U-boats;Willoughby, p.198 but Donitz attributed the failure of the attack on the aggressive handling of the escorts as well as the appalling weather.Blair p. 34

The U-boats sank five scattered ships before losing contact on 25 September;Rohwer & Hummelchen, pp.144&162 another was lost in a collision.Hague p. 137 Twenty ships arrived safely.

SC 100 was one of three North Atlantic convoys attacked during September; in the same period the Allies sailed nineteen convoys comprising some 580 ships. Total losses were 19 ships and two escorts, (some 3% of ships involved); the cost to the U-Boat Arm was five boats lost, and another four damaged sufficiently to be returned to base.Blair p.36

The convoy was attacked by both Wolfpack Lohs comprising 9 U-boats, and 8 U-boats from Wolfpack Pfeil, namely

• {{GS|U-135|1941|2}}
• {{GS|U-176||2}}
• {{GS|U-259||2}}
• {{GS|U-373||2}}
• {{GS|U-410||2}}
• {{GS|U-432||2}}
• {{GS|U-569||2}}
• {{GS|U-599||2}}
• {{GS|U-755||2}}

• {{GS|U-216||2}}
• {{GS|U-221||2}}
• {{GS|U-258||2}}
• {{GS|U-356||2}}
• {{GS|U-595||2}}
• {{GS|U-607||2}}
• {{GS|U-615||2}}
• {{GS|U-617||2}}

{{reflist}}

• Clay Blair : Hitler's U-Boat War Vol II:The Hunted 1942-1945 (1998). {{ISBN|0-304-35261-6}}
• {{cite book

| last = Hague

| first = Arnold

| title = The Allied Convoy System 1939–1945

| year = 2000

| isbn = 1-86176-147-3

}}

• {{cite book |title=Chronology of the War at Sea 1939–1945 |author1=Rohwer, J. |author2=Hummelchen, G. |publisher=Naval Institute Press |year=1992 |isbn=1-55750-105-X}}
• Willoughby, Malcolm F. The U.S. Coast Guard in World War II (1957) United States Naval Institute

• [http://www.convoyweb.org.uk/sc/index.html?sc.php?convoy=100!~scmain SC 100 at convoyweb]
• [https://uboat.net/ops/convoys/convoys.php?convoy=SC-100  SC 100 at uboat.net]

SC100

Category:Naval battles of World War II involving Canada

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