a 1941 gun duel between a merchant and U-boat

[sublynx]

From BdU's war diary the 3rd of July, 1941:

"U 69 sank in DH 19 a 5,000 ton ship (4 guns, 6 Flak machine guns) with artillery."

http://www.uboatarchive.net/BDUKTB30292.htm

uboat.net tells us there actually was a gun duel between the merchant and the type VII on a mining mission to Lagos, Africa

http://www.uboat.net/allies/merchants/ships/1028.html

I was under the impression that using guns in a situation where the u-boat could be shot at was a no-no. Apparently the order was not that strict. We of course don't know why the commander of U-69 decided to have a gun duel.

[Sailor Steve]

It would seem that he saw Robert L Holt in the afternoon and shadowed her until night, and made a surprise attack after the moon had set. It is possible that the crew of the Holt never actually had a target to shoot at.
http://www.u-boot-archiv-cuxhaven.de...rt_l_holt.html

I wasn't aware that there was an actual order against engaging with guns. I would think it was a matter of the fact that one hit on a submarine can render it no longer a submarine, but just a slow torpedo boat.

[sublynx]

Thanks for the link! I was not aware that the museum's pages. They seem to have a lot of interesting stuff on them

U-boat commander's handbook has a few sections where it restricts the usage of deck gun.

BdU's war diary in late October 1939 has something on this too:

27.10
In order to lessen our losses and based on the reflections set out in the War Log on 23.10, I have decided to issue the following orders:

1) Boats may not board ships which have been stopped, for examination.
2) Ships are to be sunk by torpedo only, even when they are only attacked after examination (which can now only consist in looking through the papers) or after resistance has been quelled with gunfire.

I don't know what the wording of the order has been, but I suppose it has given the commander's some room to consider how, when and where they will use other armament than torpedoes.

The attack on Robert L. Holt might have been made without knowing how many guns the ship actually had but it seems that I might consider making some deck gun attacks against armed merchants from now on

[MantiBrutalis]

The U-boat may be an unsteady platform to shoot from, but on a very dark night it is also a tiny black target in a huge black ocean. If the captain of a U-boat thinks he can do enough damage and panic before the men can man the guns, a surprise attack could be deadly.

Many U-boat captains did finish off wounded ships even if their guns were still functioning - merchants sailors usually escaped the damaged vessel (or were too inaccurate to hit). The odds of hitting something that small, moving, and under constant fire was very low. One shot could destroy a U-boat, but it was very unlikely to hit one. Still, only the bravest risked it.

[sublynx]

Originally Posted by MantiBrutalis

If the captain of a U-boat thinks he can do enough damage and panic before the men can man the guns, a surprise attack could be deadly.

Well it worked for U-69! They were clearly weaker gunwise, but that did not matter after the surprise attack from close range.

[irish1958]

Originally Posted by MantiBrutalis

The U-boat may be an unsteady platform to shoot from, but on a very dark night it is also a tiny black target in a huge black ocean. If the captain of a U-boat thinks he can do enough damage and panic before the men can man the guns, a surprise attack could be deadly.

Many U-boat captains did finish off wounded ships even if their guns were still functioning - merchants sailors usually escaped the damaged vessel (or were too inaccurate to hit). The odds of hitting something that small, moving, and under constant fire was very low. One shot could destroy a U-boat, but it was very unlikely to hit one. Still, only the bravest risked it.

I may be wrong, but I recall that someone (?Jimbuna) once stated that the merchant gun crews were in fact Royal Navy crews and not merchant sailors.

[Sailor Steve]

Oh, you're very right. If not RN then USN. Merchant gunners were their own division, and if you look through the ship reports at www.uboat.net you'll see many cases in which a u-boat attacked with its deck gun and then dove and ran when fired upon by the merchant. That was the norm, but there were exceptions. On a dark night the merchant as seen from below is a black outline against the sky. The u-boat as seen from above is, well, not seen at all. Suddenly the merchant is being shelled from out of nowhere. The gun crews have to get to their guns and prepare them. The loaders have to form the chain from the magazine to the guns. By that time they've taken several hits, and then they find they don't even have a target to shoot at except for the muzzle flashes in the dark, and when your eyes are looking at black on black a sudden flash is more likely to blind you than give you solid information on the target location.

Yes, a surprise attack at night can be devestating.

[desertstriker]

Very interesting thanks for the links. talk about a ballzy move

[bstanko6]

The uboat commanders handbook did label the uboat as a horrible gun platform and they are right! In the early war the gun was used to fire warning shots at merchants to get them to stop due to prize regulations. There were some commanders like Otto Kretchmer who was awesome at sinking ships with a deck very quickly, but he only attempted this in the dead of night! Outside of that, the handbook had specific ways to use the deck gun.

http://www.subsim.com/radioroom/showthread.php?t=219438

[TorpX]

Well it worked for U-69! They were clearly weaker gunwise, but that did not matter after the surprise attack from close range.

I'm thinking that U-69 was too close for the guns of the Robert L Holtto be brought to bear; that is depressed enough. The U-69 article stated they closed to less than 800m before firing, so it sounds like most/all of the ships guns were useless in this situation.

[Sailor Steve]

I doubt that's the case. If the gun is 40 feet in the air and trained flat the shell is going to hit the water in less than two seconds. The 4.7" DAMS gun had a muzzle velocity of 2330 fps, which means that it will hit the water at about 800 meters. The problem is that the 4.7"/45 could depress 10 degrees, which means that for it not to hit the U-boat is going to have to be right alongside. Most of the different DAMS guns were similar in elevation.

I think they just got surprised, the same as HMAS Sydney.

[TorpX]

Originally Posted by Sailor Steve

The problem is that the 4.7"/45 could depress 10 degrees, which means that for it not to hit the U-boat is going to have to be right alongside. Most of the different DAMS guns were similar in elevation.

I think they just got surprised, the same as HMAS Sydney.

Yes, I didn't know that the gun could depress 10°.

However, just saying they were surprised doesn't really explain the matter. 130 rds. of 8.8 cm shells cannot be fired off that quickly. Possibly they knocked out the rear gun first off, then methodically worked over the ship from the rear?

[Niedowidek]

That reminds me of gun duel between U-123 and Culebra. January 1942, Hardegen was out of torpedoes while returning from Paukenschlag mission.

As tension built in the control room Hardegen continued to watch intently as the target came on in the bright daylight. “One thousand meters … We’ll surface at six hundred … Use E motors and planes, LI… nine hundred … eight hundred … Stand by to surface! … seven hundred … Periscope down! Surface!”

“Turmluk ist frei,” Schulz sang out. “Boot ist raus!” “Hatch is free. Boat is up!” The gathered deck force clambered noisily up the ladder, the Old Man in the lead. Hardegen took in the scene with his glasses while the gun crews took their positions and the two guns received their first shells from the crew chain. What must emotions be like on that steamer? he wondered. No doubt its seamen shuddered inside to see this huge metal shark suddenly break the surface and bare its teeth. “Permission to fire!” Hardegen called fore and aft through the megaphone. The target was now four hundred meters distant. With a sharp clang the 10.5 breach closed, and a second later the muzzle erupted with the first shot, which cleaned the barrel. It fell well aft of the target. The second shot hit below the bridge, the third below the stack. From von Schroeter’s gun dense brown cordite smoke trailed aft across the conning tower. But now the enemy gun crew was training its weapon in 123′ s direction, and an incoming shell plunged into the water to port of the U-boat sending up a large column. “Take out that gun crew!” Hardegen yelled to the 2-cm machine-gun crew behind him, but they yelled back, “Herr Kaleu, the firing pin is broken!” Now four more incoming shells ricocheted off the water sending some fragments banging against the U-boat’s hull and others whistling past Hardegen’s head on the bridge. One puncture of the pressure hull, Hardegen worried, and 123 would not be able to dive anymore. The enemy gun crew had continued to fire while von Schroeter’s gun was pounding away at the hull beneath them— Hardegen would say later: “It must have been awful for that gun crew to feel our explosions just below them. I have to show my respect to the enemy: They stuck to their battle stations.” 12 But finally the U-boat’s aim and range combined to hit squarely on the target’s gun pivot, destroying the gun and killing the crew. Von Schroeter’s 10.5 crew raised their arms and cheered. A few more shots set the bridge on fire and silenced the machine guns. The freighter blew off steam, slowed, and began settling by the stern. The surviving crewmen went into lifeboats while the wireless operator, among the last to leave, put out repeated SSS signals. On 123 the belowdecks crew one after the other were invited to the bridge to see the dramatic picture of a burning, sinking ship.

Gannon, Michael. Operation Drumbeat: Germany's U-Boat Attacks Along the American Coast in World War II

[Aktungbby]

Shortly after moonset the Commanding Officer increased the U-Boat´s speed and closed the distance to the vessel to about 1.000 meters. Carefully, the vessel darkened its lights while the dawn began. Notwithstanding, the vessel´s silhouette was to be seen well as the distance decreased. Without a moment´s hesitation Jost Metzler ordered "Action station for artillery fire!", and following the preparation required he ordered "Open fire!". Metzler increased "U-69"´s speed another time reducing the distance to the vessel to less than 800 meters.
The artillery fire from "U-69" was precise, and initially there was no defensive action by the vessel. The surprise attack seemed to have worked. Alternately, the 8,8 cm gun fired high explosive and incendiary shells in short sequences. Apparently, the vessel´s radio room had been hit by one of the first salvos, as the U-Boat´s radio operator reported "Ship has not sent any emergency signals!"
Meanwhile one recognized at the U-Boat´s conning tower that the vessel was armed considerably after all. There were guns of greater caliber each at the fore-castle and the stern. Now, the vessel started to open fire as well, but none of its shells hit "U-69". Just the opposite, its artillery fire was so un-precise that the bridge crew at the U-Boat assumed all fire control equipment of the vessel must have been destroyed already hindering any directed gun fire at all. After a short fire break Metzler changed the side of the attack. "U-69" moved behind the vessel´s stern to re-attack it from the other side. Soon the vessel was hit several times below the water line, causing damage to the boiler room.
Immediately, the typical blowoff of steam was to be heard, and a large steam cloud could be seen. In the mean-time, the vessel hardly made any way. The vessel´s guns seemed to have been destroyed or could not be used any longer. As a maneuver of last resort the ship´s master attempted to ram the U-Boat, but did not manage to do so because of the vessel´s small speed. "U-69" had closed to the vessel that much to allow identifying the superstructure of the ship in detail, with almost everything completely destroyed. The vessel was burning across its entire length and was dead in the water. Because of the hits at the waterline the vessel started to sink slowly over its stern. There was no sign of any life among its crew. Metzler ordered to seize fire. The freighter showed a scene of destruction: The entire superstructure demolished and flames everywhere, the masts bended and the funnel riddled. "U-69" left the burning vessel in the morning of the 03rd of July 1941 which now was about to sink definitely. Kapitänleutnant Metzler had to be aware of enemy Naval forces or aircraft rushing to the scene at any moment."
The events of the combat engagement were noted in the U-Boat´s war diary. It was not possible at that time to clearly identify the vessel, but it could be described, including its armament. The freighter was equipped with a minimum of four guns, one each at the bow and the stern, two more nearby the bridge, from where at one time rounds were fired against "U-69". Also, there were some light Bofors AA-guns. "U-69" ´s war diary lists the following expenditure of ammunition:

102 rounds of ammunition 8,8 cm high explosive shells
34 rounds of ammunition 8,8 cm incendiary shells 220 rounds of ammunition MG C/30 (2 cm)
400 rounds of ammunition MG 34. http://www.u-boot-archiv-cuxhaven.de...rt_l_holt.html

Besides a captain, retired Vice-Admiral/convoy Commodore Wodehouse, was also aboard the merchant, an outstanding British rugby star, had also been a gunnery officer at Jutland aboard HMS Revenge. He had not been one to stay retired with a war on! The R.L. Holt vessel had 8 gunnery personnel: 2 Lance bombardiers, 4 gunners- of the 4th Maritime Regiment of Royal Artillery and two DEMS gunners essentially Defense Equipped Merchant Able-bodied seamen. No lack of fighting spirit is evident if still attempting to ram! The element of initial surprise must have been paramount, together with a the considerable and unrelenting hail of fire at under 800 yards from U-69's 136 rounds of 8,8 cm ammo ...which killed all 56 aboard before sinking the vessel. FYI: The U-69 had expended all of its 'eels' prior to engaging the R.L. Holt. on The River Lugar and Empire Ability; sinking both. It was homeward bound prior to its encounter with R.L. Holt.