GIBRALTAR RUN
This convoy action was fought out as part of play testing DEADLY WATERS © by Mal Wright. Clash of Arms Games.
There was no real OG-90S. This convoy was fictional and arranged for the purpose of the wargame.
Convoy OG-90S departed from EASTOMP, (East Ocean Meeting Point) just north of Londonderry at dawn on December 1st 1941. It was designated (S) for slow and comprised 38 merchant ships with a stronger than usual escort. The merchant ships were mostly of small or medium size headed for Gibraltar at a convoy speed of only 7 knots. Some carried ammunition and military stores, but most were in ballast, being on the outward bound voyages that would bring vital cargoes back to the UK. A few were from neutral countries, but under lease to carry cargo for the British. The majority were British or Norwegian vessels. They were arranged in 14 columns, with three in some. Two in others.
Of them the only new merchant of any reasonable size was the CAM ship SS Empire Faith. Her catapult held an old Hurricane fighter. However it was hoped the pilot might not have to be launched off into potential danger as the new and experimental escort carrier HMS Empire Audacity was attached to the escort. This ship was later re-named simply HMS Audacity. Her limitations were many. There was no hangar and she only operated Martlet fighters, all of which had to be stored and serviced on deck. The Martlets had no capability against submarines other than sheer fright, but of course the Germans were not to know that and a wise U Boat commander would not sit on the surface watching an aircraft approach. So their ability to provide that element of fright would be tested as well as the fire power to intercept and shoot down enemy aircraft.
The escort comprised the Bittern class sloop HMS Stork flying the pennant of the SOE (Senior Escort Commander), with the skipper of the Grimsby class sloop HMS Deptford as deputy SOE. These two ships were in the screen ahead of the columns. On each side of them were flower class corvettes HMS's Gardenia, Samphire, Vetch, Convolvulus, Pentstemon, and Marigold. Three to port and four to starboard. Outboard of them, on either wing stood a Hunt II class destroyer. HMS Blankney to starboard and HMS Exmoor to port. These two ships were only available for the first two days and nights, after which they would have to turn back. Bringing up the rear was the old ex-US destroyer HMS Clare, which had undergone long range escort conversion recently and was fitted with quite a formidable load of depth charges. The flower class corvette HMS Rhododendron was allocated to Audacity as close escort.
First blood was sudden and surprising. The convoy had barely been at sea a few hours when a U Boat was encountered at periscope depth and before any detection took place, it torpedoed the Stork. She sank rapidly along with most of her crew, leaving the skipper of Deptford as SOE. Two escorts quickly picked up ASDIC contact. U 125 was a type IXC U boat on outward passage from Lorient, and which had stumbled across the convoy. Convolvulus was first to detect the intruder and delivered a full patter while the U Boat was diving deeper, but without success. Next the Deptford followed up with another full pattern which shook the boat up but did little damage. The attack had taken place quite close ahead of the convoy, the columns of which were now bearing down on the scene. This forced Deptford and Convolvulus to take extreme care, not only to avoid being rammed by the lumbering herd, but also not to cause damage through dropping charges close aboard.
The player commanding U125 took full advantage of this diving gradually deeper, but at a diagonal angle across the path of the convoy. This shook off Deptford, which was too close to ship 42 and forced to turn away. Convolvulus continued pursuit but now found it had lost contact in the deafening noise produced by the merchant columns. She followed toward the rear and Clare came up the columns in search, but contact was not regained and U 125 made good her escape passing under 32 and then 13 on his way out. He was well astern of Samphire by the time he was clear of the convoy noise.
The afternoon began with another surprise. Two Dornier 217's came in very low from astern and avoided detection until within two miles. There was no time for AA fire before they were over SS Baron Newlands sailing in position 42. The first score a direct hit but the second Do217 missed. The merchant was severely damaged and on fire. The Do217's streaked out over the front of the convoy pursued by ineffective AA fire, but were then pounced on by a pair of Martlets from the Audacity. One was sent into the sea but the other escaped. Meanwhile Baron Newlands had controlled the fires and flooding but was in no condition to continue with the convoy. She was detached back to the UK and moved to our ‘stragglers' list. The vessel was eventually beached in friendly waters.
Daytime having been rather busy, it was expected that the night would bring attacks and these commenced not long after dark. The first was an Italian Submarine Enrico Tazzoli, which approached the starboard column on the surface but was detected by the corvette Marigold, which turned toward her and opened fire. Star shell rounds failed to illuminate her, but the Italian player decided having been detected, was a good reason to break off. He turned port toward the rear of the convoy, but found himself illuminated by Clare, which raced toward him with all her (few) guns blazing. Tazzoli's superior surface speed was too much for Marigold, but not enough to escape Clare, but he persevered a little longer hoping to get so far away that the pursuers would turn back to the convoy. He was partly right. The SOE ordered everyone else to continue, but allowed the two in contact to drive the Italian boat off. After two moves the boat was well to the rear of the convoy, when Marigold and Clare both scored gunnery hits. Neither could penetrate the thick hull with their 4"guns, but one set off the ready use ammunition for the deck guns and AA, killing all the Italian gunners and starting a large fire on the conning tower. A periscope was wrecked, and a fuel leak caused. Our Italian skipper decided it was time to head down and crash dived. That certainly solved the fire, but the noise of the crash dive brought Clare thundering overhead to drop a pattern. That caught the Italian boat at shallow and inflicted damage to her electric motors.
Marigold was now able to reach the scene and also delivered a pattern that caused some flooding, but little else. The ex-Flush decker Clare was hampered by her large turning circle, such that Marigold delivered another pasting before Clare could line up again. But by now the Italian boat was diving deeper and deeper, avoiding all charges dropped. With the convoy well clear of the area the SOE decided that driving the Italian boat off was sufficient and wanted his escorts back in position. They were therefore ordered to break off and catch up with the convoy much to the relief of the Enrico Tazzoli, which gladly slipped away.
It was as well he did recall them, because before they had even resumed their positions a U Boat on the surface ahead of column two, fired a spread of torpedoes. None hit, but the boat was detected by Samphire and the two Hunt class destroyers were ordered to join with Deptford, as the German tried to tough it out and use his speed to race clear of the convoy. It took a while, but eventually the boat was illuminated and far too many 4"rounds crashed into the water for the German player, as the two Hunts in particular gave him a rapid fire pasting. U108 was in trouble. Hits wiped out the bridge crew, started some small leaks and jammed the rudder to starboard. He was forced to crash dive and was caught at shallow as a full pattern was delivered. U108 suffered minor flooding, and things looked pretty grim as the jammed helm forced him to dive in a circular pattern. More depth charge patters were dropped and the boat was severely damaged. However by the time the jammed helm was repaired the action area was being run down by the convoy, forcing the pursuers to take avoiding action lest they became collision casualties. U108 was then lost in among the columns. After a frantic hunt the German boat avoided her hunters and escaped but the serious damage forced her to return to Lorient.
Just as Clare and Marigold were returning another U Boat came in from starboard but was detected on radar by Clare. She fired on it and U434 crash dived to safety. Samphire was now out the rear of the convoy after the pursuit of U108 and briefly joined in, dropping some patterns on the contact. But the German boat was quickly lost and the escorts resumed their stations.
Just after dawn an aircraft was detected on radar and two Martlets sent out to investigate. A Focke Wulf 200 Condor was caught circling the convoy, while transmitting contact reports. The Fw200 was sent crashing into the sea and Audacity's fighters had scored a second kill. During the afternoon a HF/DF intercept was picked up on ground wave, which indicated it was very close. The SOE asked for the duty Martlets to investigate and shortly after they sighted U434 which was transmitting contact reports and acting as a squealer. Not knowing anything about Martlets, the U Boat skipper took her deep and contact was lost.
Dusk fell on what would be the last night before the two Hunt class destroyers would have to detach. It proved a very active night. A U Boat found itself in attack position dead ahead of column 5 and fired a spread of torpedoes at the Tramp Lisbeth, which sank immediately. Another torpedo found the Vanellus, which also sank rapidly. However at this point the SOE ordered all ships to perform Raspberry. In the brilliant illumination that resulted, the type IXB boat U107 was lit up and all escorts within range opened fire. Swamped by a storm of hits the U Boat command crew and gunners were all wiped out in a flash as light guns set off the AA ammunition. Shell after shell hit her and although unable to penetrate her thick hull, the effects were deadly. The boat circled out of control with the fire burning brightly, fuel leaks developed and she suffered damage to her diesel engines from the shock of the Hunt class destroyer Exmoor hitting her repeated. However as soon as Deptford scored hits with her 4.7"the pressure hull was penetrated and U107 could not dive. But she did not seem to be sinking, so the Exmoor turned in and rammed her squarely amidships. U107 sank rapidly and experienced an explosion while still at shallow. Exmoor seemed to have got off lightly with some flooding and her sonar knocked out. But as the U Boat sank in her death throes, flooding on Exmoor increased. There was an effort made to correct the situation but eventually it the struggle was lost and she capsized. Her sister Blankney took off most of her crew, along with Deptford. This was all too much for one of the faster ships and the merchant Spero slipped from the convoy and became a romper, hoping to reach safety on her own. She was transferred to the Events beyond the convoy chart. She did not make it to safety and was lost with all hands.
The rest of the night passed without incident and at dawn Blankney made her farewells and returned to the UK.
Shortly after two more Do217's slipped in very low and delivered a stinging surprise attack on the medium size merchant Alresford in position 142. The ship was soon on fire; her speed reduced to 1 knot and she fell out of the convoy. Amazingly the fire was controlled but a badly damaged ship with one knot speed seemed a poor prospect for the crew which abandoned ship. By then Martlets from Audacity had intercepted the Do217's. Again one was sent into the sea and the other went home damaged. The SOE decided that the chances of Alresford surviving were poor and decided against detaching an escort to tow her home. As she was also well astern the ship was left in expectation she would sink of her own accord. Alresford was moved over to the Events beyond the Convoy chart. But amazingly when the chart was checked at the end of the game, the damaged freighter had been located by a high seas rescue tug and independent escort, after which she was successfully towed back to the UK.
In the afternoon the Martlets investigated another HF/DF report and once again force a submarine to dive, thus breaking contact with the convoy. This one had been the Italian Argo and played no further part in the convoy action.
By evening the escorts were alert and ready for some pretty difficult times, but instead a storm blew up and there were no contacts at all. The weather continued into the next day and the convoy made good progress without enemy interference, but at dusk the storm blew out and trouble was expected.
It came not long after dark when the Rhododendron, providing a screen for the Audacity, sailing independently out on the port side of the convoy, detected a U Boat surfacing a mere half mile ahead of her. She rushed at U574 immediately, all guns firing, while Audacity turned away. The surprised U Boat immediately dived, but Rhododendron collided with her while still going down. The corvette suffered little damage, and the U Boat lost two periscopes as well as suffering some flooding. What was to hurt the most was a full pattern of depth charges set at shallow. U574 was in distress at once and dived out of control. She had no sooner recovered the situation when the angry corvette was back and caught her at medium depth, with another full pattern. The boat was destroyed with a loud boom and the corvette was able to signal Audacity that the danger had passed.
The rest of the night went by without incident and at dawn Marigold reported a small object sighted at long range. The Martlets raced to investigate with Clare making her way to the location at her best speed under orders from the SOE. The contact turned out to be a raft with Luftwaffe survivors, which added to the victory points for the Allied side.
Weather intervened again during the afternoon. No enemy contacts resulted and the storm continued during the night, keeping all the U Boats away. At dawn the weather was clear and air cover provided by a Hudson and a Sunderland, supplemented the Martlets. There were no contacts of any kind and this repeated itself in the afternoon and the first part of the following night. By that time the convoy was getting close to its destination and air support was frequently available.
The latter part of the night was rocked when the freighter Adjutant was torpedoed and after a brief fire, sank.
Samphire gained an ASDIC contact shortly after and moved in on U71 which was seeking the depths. Charges shook her severely and she was still recovering when shaken again and forced to dive several levels deeper. Having reached very deep she was able to stop the plunge and creep away very slowly. The determined Samphire continued to hunt her, achieve another contact and dropped two more patterns before the U Boat managed to eventually escape. Her damage was not fatal but mission ending and U71 was forced to return to Lorient.
By morning the convoy was approaching Gibraltar and had air cover overhead. A distant contact was investigated and U67 was forced under while transmitting a contact report. Although not sunk she could not surface to seek contact and was forced to spend the day deep to avoid aircraft. By dusk the convoy had arrived at its destination. Somewhat battered, but with most of its merchant ships intact. It had been subjected to frequent submarine attacks but had been spared a Wolf pack and the Luftwaffe had proved more a nuisance than anything as both ships they hit survived.
Note re convoy columns and ship numbering. Convoys were usually much wider than deep to avoid having long flanks that would be easy to attack. Columns were numbered from port to starboard. 1 therefore being the first on the port side. The highest numbered column would therefore be the one on the starboard side. In the case of the above convoy this was number 14.
The ships in a column took a number based on their position. This number followed that of the column. Therefore 11 was the first ship of column one and 13 would be the third ship in column one. 132 would be the second ship in column 13. Ship 44 would be the fourth ship in the fourth column and so on.
Flower class corvettes were weakly armed for surface work, but well fitted for ASW duty. Their gun power was only intended to be sufficient to outgun a submarine on the surface. This applied to some other escorts as well. The Hunt class and other ships with twin 4"mountings could put up a formidable amount of AA fire but the 4"gun could not penetrate the pressure hull of a submarine. Although unable to sink a U Boat with gunnery, they could none the less cause some very serious external damage and trough shock of impact, could cause other problems, including mechanical, steering etc, bring on small flooding and cause fuel leaks. The problem was realised soon after the start of the more intensive U Boat war that developed in 1941. Because of this the British developed a 4"round called SHARK. However this was not able to be readied and supplied until very late in the war and it is not known to have been ever used in action. It was tested against captured U Boats at the end of the war and could penetrate the pressure hull of even the Type XXI.
However the British 4.7"using SAP was able to penetrate a U Boat hull and cause fatal damage. For this reason these guns were retained on destroyers modified for escort duty even though their directors were removed to save weight for extra AA and radar sets. It was very hard to hit a target low in the water, such as a U Boat would be, but as actions took place at very close ranges even local control could hope to score some. In addition escorts swept the U Boat with all guns that could bear, especially light AA. These too could not penetrate but the storm of fire would sweep gun and command crews away, while their tracer rounds provided other ships with visual location of the target.
In the game described the only ship with 4.7"guns was the sloop Deptford.
