# Convoy SC 100

Convoy SC 100 was a North Atlantic convoy, one of the SC series which ran during the battle of the Atlantic in World War II. It was the 100th of the numbered series of slow convoys of merchant ships from Sydney, Cape Breton Island to Liverpool. It came under attack, one of several convoy battles that occurred during the autumn and winter of 1942, losing five ships.

## Background

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 Campbell, under Cdr. P Heineman. Also in the group was the cutter Spencer and four RCN corvettes. A-3 was joined by the corvette Trillium, escorting ships from Wabana, and by three corvettes travelling in convoy for refit in the UK. 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.
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.

## Action

The convoy departed Halifax on 12 September 1942 and was joined on 16 September 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 U-599, of Lohs. U-599 commenced shadowing, while other U-boats of the group joined; first U-755, which had sunk the USCG weather ship Muskeget the previous week, then U-259 and U-569. 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, U-373 and U-596 joined; the latter attacked and sank the freighter Empire Hartebeeste, but a claim by U-373 to have torpedoed a corvette was not substantiated.
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 U-617, 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; U-432 sank the freighter Penmar, but a claim by U-258 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.

## Assessment

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; but Donitz attributed the failure of the attack on the aggressive handling of the escorts as well as the appalling weather. The U-boats sank five scattered ships before losing contact on 25 September; another was lost in a collision. 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.

## Ships in convoy
### Allied merchant ships

| Name | Flag | Casualties | Tonnage (GRT) | Cargo | Fate | Notes |
| Ary Lensen | United Kingdom | | 3,214 | Sugar | | |
| Athelsultan | United Kingdom | 51 | 8,882 | Molasses, alcohol | Sunk by U-617 on 23 September SE of Cape Farewell, Greenland. | Convoy commodore's ship, Capt N H Gale DSO Rd RNR. Survivors picked up by HMCS Weyburn and HMS Nasturtium and landed at Londonderry Port. |
| Atland | Sweden | | 5,203 | Wabana iron ore | | |
| Atlantic | United Kingdom | | 5,414 | Steel, lumber | | |
| Belgian Fisherman | Belgium | | 4,714 | General cargo | | |
| Boris | Greece | | 5,166 | Wabana iron ore | | |
| Dux | Norway | | 1,590 | Lumber | | |
| Empire Guinevere | United Kingdom | | 7,072 | Steel and tobacco | | |
| Empire Hartebeeste | United Kingdom | 0 | 5,676 | General cargo | Sunk by U-596 on 20 September SE of Cape Farewell, Greenland. | |
| Empire Opal | United Kingdom | | 9,811 | Benzene, paraffin | | |
| Empire Razorbill | United Kingdom | | 5,118 | Steel, tobacco | | |
| Empire Soldier | United Kingdom | | 4,539 | General cargo | Marine accident | Sunk in a collision with tanker F. J. Wolfe |
| Empire Stour | United Kingdom | | 4,696 | General cargo | | |
| Esturia | United Kingdom | | 6,968 | Fuel oil | | |
| Greylock | United States | | 7,460 | General cargo | | |
| Gunvor Maersk | United Kingdom | | 1,977 | Sydney lumber | | |
| Innesmoor | United Kingdom | | 4,392 | General cargo | | |
| Mount Evans | Panama | | 5,598 | General cargo | | |
| Norhauk | Norway | | 6,086 | General cargo | | Rescued crew from Empire Hartebeeste |
| Panama | United Kingdom | | 6,650 | Sugar | | |
| Pennmar | United States | 2 | 5,868 | General cargo | Straggled and was sunk by U-432 on 24 September. | Survivors picked up by USCGC Bibb |
| Rio Verde | Norway | | 3,223 | General cargo | | |
| Roumanie | Belgium | 42 | 3,658 | General cargo | Straggled and was sunk by U-617 on 24 September. | Sole survivor was picked up by U-617 as a PoW and landed at St Nazaire. |
| Spurt | Norway | | 2,061 | Lumber | | Turned back |
| Tennessee | United Kingdom | 15 | 2,342 | Sydney grain | Straggled and sunk by U-617 on 23 September SE of Cape Farewell, Greenland. | Survivors picked up by HMS Nasturtium and USCGC Ingham |
| Tore Jarl | Norway | | 1,514 | Lumber | | |

### Convoy escorts

| Name | Flag | Type | Joined | Left |
| HMCS Bittersweet | Royal Canadian Navy | Flower-class corvette | 16 September 1942 | 28 September 1942 |
| ORP Błyskawica | Polish Navy | Grom-class destroyer | 16 September 1942 | 26 September 1942 |
| USCGC Campbell | United States Coast Guard | Treasury-class cutter | 16 September 1942 | 16 September 1942 |
| HMS Deptford | Royal Navy | Grimsby-class sloop | 25 September 1942 | 25 September 1942 |
| HMCS Kenogami | Royal Canadian Navy | Flower-class corvette | 12 September 1942 | 26 September 1942 |
| HMT Kingston Beryl | Royal Navy | ASW naval trawler | 27 September 1942 | 27 September 1942 |
| HMCS Louisburg | Royal Canadian Navy | Flower-class corvette | 21 September 1942 | 26 September 1942 |
| HMCS Lunenburg | Royal Canadian Navy | Flower-class corvette | 21 September 1942 | 27 September 1942 |
| HMCS Matapedia | Royal Canadian Navy | Flower-class corvette | 12 September 1942 | 16 September 1942 |
| HMCS Mayflower | Royal Canadian Navy | Flower-class corvette | 16 September 1942 | 28 September 1942 |
| HMCS Moose Jaw | Royal Canadian Navy | Flower-class corvette | 12 September 1942 | 16 September 1942 |
| HMT Narvik | Royal Navy | ASW naval trawler | 27 September 1942 | 28 September 1942 |
| HMS Nasturtium | Royal Navy | Flower-class corvette | 16 September 1942 | 27 September 1942 |
| HMCS Niagara | Royal Canadian Navy | Town-class destroyer | 12 September 1942 | 16 September 1942 |
| HMCS Prescott | Royal Canadian Navy | Flower-class corvette | 21 September 1942 | 26 September 1942 |
| HMCS Rosthern | Royal Canadian Navy | Flower-class corvette | 25 September 1942 | 25 September 1942 |
| HMS Rother | Royal Navy | River-class frigate | 25 September 1942 | 25 September 1942 |
| USCGC Spencer | United States Coast Guard | Treasury-class cutter | 16 September 1942 | 16 September 1942 |
| HMCS Trillium | Royal Canadian Navy | Flower-class corvette | 15 September 1942 | 28 September 1942 |
| HMCS Weyburn | Royal Canadian Navy | Flower-class corvette | 16 September 1942 | 27 September 1942 |
| HMCS Woodstock | Royal Canadian Navy | Flower-class corvette | 21 September 1942 | 26 September 1942 |

## U-boats

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

### Wolfpack Lohs

* U-135
* U-176
* U-259
* U-373
* U-410
* U-432
* U-569
* U-599
* U-755

### Wolfpack Pfeil

* U-216
* U-221
* U-258
* U-356
* U-595
* U-607
* U-615
* U-617