Tuesday 15 May 2018

The Battle of Otranto Barrage May 1917


Since the outbreak of the First World War the surface units of the Austro-Hungarian fleet had seen little action beyond coastal bombardment of the Italian coast and although the force lacked battle cruisers and only had four dreadnoughts it was sizable enough to cause concern. Should the vessels breakout into the Mediterranean they could do damage to trade and troop transports and force a fleet action. The Austro-Hungarian ports at Pola and Cattaro were also home to a small U-boat flotilla that had begun preying on warships and trade vessels alike with the Royal Navy losing several larger vessels including the pre-dreadnoughts HMS Cornwallis and HMS Triumph as well as the hospital ship HMHS Britannic, the Titanic’s sister.  

The Etente powers established a blockade of drifters and trawlers across the mouth of the Adriatic Sea over the forty five miles of the Otranto strait between Brindisi and Corfu. The drifters were armed with 6 pounder guns, depth charges and anti-submarine nets and were supported by torpedo boats, destroyers and a cruiser force based at Brindisi with the aim of interdicting any enemy submarines that should try and break out.
Trawlers leaving Taranto for Barrage duties (IWM  Q 63041)

The Barrage was somewhat ineffective at stopping German and Austro-Hungarian U-boats who were passing through with ease and harassing Allied shipping but things were changing with the U-6 being caught and sunk by HMT Calistoga and the Dulcie Doris with Linenschiffsleutnant von Falkhausen and his crew being taken prisoner.

   Following the loss of U-6 and a further seven intercepted by Motor launces and aircraft patrols Admiral Njegovan decided serious steps had to be taken but that his vessels needed to operate in a manner that would see their safe return. The surface vessels had already begun gently probing with a French submarine reporting a force of four Austrian destroyers observing the drifters at night on the 11 March with a further sortie on the 21 April which saw an Italian steamer sunk outsider Valona. Further sorties were carried out on the 25 April and 5 May.

Mikos Horthy commanded the Austro-Hungarian cruisers
   Njegovan had to plan exceptionally carefully so as to preserve his vessels and escape the superior Allied numbers before they could respond. To this end a two pronged assault designed to confuse and draw off the Allies was implemented. At 8 p.m. on 14 May the Tatra class destroyers SMS Csepel and SMS Balaton under the command of Prinz Johann of Liechtenstein left Cattaro harbour and slipped down the Albanian coast passing Valona just after midnight without being seen by any of the searchlights. The destroyers began searching for a convoy or merchant ship to attack at the allotted hour when the second force would be in position.

   The second force consisted of three light Cruisers of the modified Spauna class, SMS Helgoland under the command of Captain Neyesler, SMS Saida commanded by Captain Pinschka and the SMS Novara acting as Linienschiffeleutnant Nikos Horthy's flag ship. The three cruisers were amongst Austria's newest and most modern ships with a top speed of 27 knots but with a relatively weak battery of nine 3.1" guns. The three cruisers struck out of Cattaro at 10 p.m. and headed south. Admiral Njegovan had also dispatched several U-boats out into the Adriatic to sew confusion and watch for Allied response with the U-4 watching Valona harbour, the UC-35 to mine the main naval base at Brindisi whilst the U-27 patrolled between Brindisi and Cattaro with aerial reconnaissance flights prepared for the morning and a taskforce of torpedo boats led by the armoured Cruiser SMS Sankt Georg to act as support.
 
 Admiral Alfredo Acton, the Italian Naval Commander of the area had either received specific information or was deeply suspicious that the Austrian fleet may try another raid and had deployed a force of French and Italian destroyers led by the light cruiser Mirabello on a patrol with orders to sail south-east until midnight when they should cross the strait before turning north towards Cape Boni and then on to Valona. Orders were also given to ready the dispatch of the cruisers in Brindisi with HMS Bristol and HMS Dartmouth brought to readiness.

   Acton was hit by the dilemma of where the Austrian attack would fall and if he were to deploy his vessels to defend the barrage then he would be leaving Brindisi and the vital rail hub or the Italian coastline undefended. He would have to play a reactionary role.

   At 3:30 a.m. a telegram from Fano arrived: The Austrians had been positively sighted in the strait and orders were issued immediately for the Bristol to be brought to half an hour's readiness, the Dartmouth to three hours and HMS Liverpool to six hours. Acton moved his flag to Dartmouth bringing her to half an hour's readiness at 5 a.m. HMS Bristol steamed out of harbour with two destroyers half an hour later with Dartmouth following with another two destroyers five minutes later with the Italian cruiser Aquilla bringing up the rear but Acton was already reacting to the Austrian's first attack.

   The Italian destroyer Borea and it's charge of three vessels had left Gallipoli at 10 a.m. on the 14 May for Valona and had had such an uneventful journey that they had arrived in good time at the Strade Bianche at 3 a.m. with the destroyer at the head of the formation. It was a calm still night with little wind. The moon hung over the mountains in their starboard quarter but the landward side remained very dark and shadowy. One of the Borea's lookouts reported a lot of smoke off to starboard and Commander Franceschi ordered a challenge flashed to the vessel. The pitch blackness suddenly drowned out by the bright illumination of floodlights from SMS Csepel and SMS Balatan moments before they opened fire.

SMS Csepel
   The action was swift and brutal with the Borea turning to starboard to get between the convoy and the Austrian destroyers but to no avail as the Csepel's first salvo had ruptured her main steam pipe leaving her unable to complete her manoeuvre and at the mercy of the enemy. As the Borea sank beneath the waves the Austrians concentrated on the helpless convoy with the munitions ship, SS Caraccio, exploding spectacularly under their barrage and a second vessel was left sinking whilst the third was badly damaged. Having done enough to distract the Allies the two destroyers put the convoy to their rudder and headed for Cattaro leaving the remnants of the convoy to limp or be towed to port. Both the SS Verita and the Bersaliere  made it into port.

   At the Eastern most point of the Barrage the crews of the drifters heard the gunfire and explosions but continued as if nothing was different casting their anti-submarine nets and maintaining a visual in case any action came close but Acton had not alerted them of any threat so whatever was going on was not their concern. At 3:30 a.m. Horthy's vessels arrived at the Barrage and divided with the Novarro heading east, the Helgoland heading west and the Saida concentrating on the centre. On the receipt of a message from the Csepel that the convoy had been disrupted the operation began. Each Austrian cruiser would approach one of the drifters and signal them to surrender and abandon ship before sinking the vessel and taking the crew prisoner.

   SMS Helgoland approached the trawler Gowan Lea at a thousand yards and signalled her to surrender but Kapitän Neyesler was most surprised when his opposite number, Captain Joseph Watt a Scottish veteran of the action the previous December, ordered his small trawler to engage the cruiser at full speed. The crew quickly manned the tiny 6 pounder guns and fired on their larger opponent which encouraged other trawlers in the area to follow suit. The Austrian Commander now caught in an unexpected action dealt with the situation calmly bringing his guns to bear with the first salvo damaging the Gowan Lea's gun and as the crew struggled to unjam it the Helgoland turned its attention upon the other vessels quickly decimating their attack leaving several vessels sinking and the Gowan Lea heavily damaged. Watt ordered his vessel to pick up any British sailor in the water they could and from the sinking trawlers.

Admiral Mark Kerr, the British Commander of the Adriatic force wrote in his dispatch that:

Undoubtedly the Austro-Hungarian cruisers behaved most chivalrously. Whenever a drifter put up a fight and refused to surrender, it was noticeable the most of the guns of the broadside were directed not to hit the fishing-boat, and the shots went wide and they left their plucky little adversary afloat and passed on. It was keeping up the ancient tradition of chivalry at sea. (1)

   With the Drifter line successfully decimated and distress flares and wireless messages being sent by the tiny vessels Horthy gave the order for his cruisers to withdraw to home waters before they attracted too much Allied attention. In their wake they left fourteen drifters sinking.

   Acton soon received reports of what had been happening at the Barrage and a wireless message from the French destroyer Commandant Bory reported sing the Austrians at 4:30 a.m. but had been unable to shadow or transmit until 5:30 a.m. as she was chasing the U-4. Now his forces had to intercept two separate forces.

   At 6:45 a.m. the Mirabello and her four destroyers (Boutefou, Commandant Rivière, Cimeterre and Bisson) positively sighted Horthy’s cruisers and at 7:00 a.m. at a range of 9300 yards they opened fire with their first salvo but the returning heavy fire from the Austrian ships proved too much for the smaller Allied ships and they fell back into a shadowing position in an action that took no more than seven minutes.

   Acton’s force was sailing at 24 knots towards the gulf of Drin and were approximately 245 miles north west of the Csepel and the Belaton and 46 miles North-north west of Horthy’s retreating vessels. Unsure of the Austrian’s exact position Acton detached the Aquilla and Balston
to reconnoitre towards Cape Mendes heading off at 35 knots. By 8 a.m. the Italian vessels engaged the two Austrian destroyers at 12,500 yards but within half an hour the Aquilla had been disabled with her boilers hit by Csepel. With the enemy disabled the two Austro-Hungarian vessels moved into the relative safety of home waters under the guns of the shore batteries around Cattaro.

   Acton sent a request to Brindisi for assistance from HMS Liverpool the Marsela and Bacchiawhilst he took position around the damaged Aquilla

   In Brindisi harbour Captain G. H. Vivian of HMS Liverpool, the senior British Naval Officer was losing his patients behind a cool exterior. The Liverpool had raised steam and been ready for action for an hour but Admiral Bollo, Commander of the Pisa division informed him it was “not necessary” and on his second petition at 9 a.m. the freshly arrived Admiral Revel refused to allow the Liverpool beyond the harbour’s outer walls.
   Vivian had been receiving regular updates of the fleet action and was well aware of the situation faced by Acton’s vessels.

I had then in my mind the probability of our cruisers getting fairly close to Cattaro, being crippled or damaged after a running fight, and then being attacked by heavy ships from Cattaro. I therefore asked if the ‘Pisa’ Division or any of them were going out. Admiral Revel, who had arrived signalled to Admiral Acton at sea to ask if he wanted ‘Pisa’ Division, but by this time the action was practically finished and the reply was “no”. (2)

   Vivian felt this was a mistake that the three Armoured cruisers ( the Pisa, San Giorgio and the San Marco) under Contrammiraglio Bollo could not only assist in sinking the already damaged light cruisers or provide covering fire against the perceived threat of the SMS Sankt Georg or a Hapsburg class pre-dreadnought which would be moving to cover Horthy’s withdrawal. At 10:38 a signal was received from the Dartmouth calling for vessels to “Rendezvous on Dartmouth” and Vivian argued this was a call for assistance and once more implored Admiral Revel that the Pisa Division, who stood ready to leave port, should leave and that the Dartmouth must be in difficulties but again, to no avail, A fear of submarines waiting for a relief force outside of Brindisis harbour concerned Vivian and his Italian counterparts and with only a few destroyers available to escort and screen the larger vessels even Vivian admitted in his report that it may have been for the best that they did not leave especially in light of what was to come.

   The lookouts on HMS Bristol spotted the smoke of Horthy’s vessels at 9:00 a.m. arriving from the south and at 9:30 fire was exchanged at 13,000 yards with the Dartmouth leading the Allied forces into a parallel course. Acton’s forces were superior to Horthy’s in speed and firepower with the Dartmouth sporting eight 6” gns and the Bristol two 6” and ten 4” guns whilst Horthy’s three cruisers had nine 3.9” guns. In a straight fight the Allied ships would easily be victorious.

   Horthy claims in his memoirs that his position was not as bad as it seemed on paper. As the Allies approached he was already a step a head of them. Prinz Liechtenstein had already sent a message outlining his combat with the Mirabello group and Horthy had made the conscious decision to draw the Allies away from the smaller destroyers. He had also received a message from Cattaro offering support from the warships present which Horthy saw as a great opportunity to catch the Allies out but he needed to play for time.
  
   As the first British shells landed in the Novara’s course Horthy ordered a smoke screen deployed to envelope his vessels from sight in the hope the Allies would get closer and fall within the range of his guns and torpedoes. As the smoke cleared the Austrians headed north firing on the Allied destroyers that had got close and also the Mirabello which had arrived on their port side.

HMS Dartmouth

   The ensuing gun battle at between 5000 and 8400 yards was intense with the Bristol and the Dartmouth
firing accurately at SMS Novara’s chartroom was destroyed, a gun put out of action and fires started on deck. Horthy was struck by shrapnel that shredded his hat, singed his uniform down to his flesh and embedded five chunks into his leg. He was brought back to consciousness by a blast of cold water thrown over him to extinguish his burning clothes and moved to a stretcher on the foredeck to watch proceedings. He was lucky as the ship’s First Officer, Lieutenant Szuborits, was killed and so control of the ship passed to Gunnery Lieutenant Witkowski who commanded from exposed upper bridge directing the vessels guns personally.

   The Allies were not faring well either with the Commandant Rivière  halted by condenser issues and the Mirabello with water in her oil. Both vessels were guarded by the destroyers Cimeterre and the Bisson in case of U-boat attack. HMS Dartmouth was carrying the battle on her own as the Bristol’s filthy bottom slowed her down leaving her unable to keep up but it was a task that the Dartmouth was able to do with ease. With the Novara  disabled by a direct hit on the turbine chamber destroying the condenser pipe line meaning the boilers had to be extinguished the cruiser began to slow and the Dartmouth was free to attack the Saida but soon turned to meet the Italian protected cruiser  Marsale as she approached to assist.

   As the fighting subsided the Saida came along side her wounded sister to take her in tow whilst the Helgoland stood guard over the vulnerable cruisers. Acton ordered the Allied vessels to withdraw at the sight of smoke from Cattaro as the Sankt Georg under Admiral von Nensa supported by the coastal defence ship SMS Budapest. The Austro-Hungarian fleet had escaped.

   The battle was far from over however as one Italian destroyer, Acerbi, attempting a torpedo run only to be dissuaded by the Austro-Hungarian fire. Acton, realising too late that he had missed a golden opportunity, withdrew for Brindisi with his damaged vessels in tow.

   All was not plain sailing however as the force cruised through the Adriatic Kapitänleutnant

KptLt Johannes Feldkirchner
Johannes Feldkirchner’s mine laying SM U-125 fired a torpedo into HMS Dartmouth’s port side. The damage was quite extensive and whilst damage control crews battled to control the flooding two destroyers chased off the predatory U-boat as the other warships moved towards Brindisi.

Following receiving news that the action was over from HMS Dartmouth at midday Vivian would have begun to calm down with the emergency passed although the language of his reports to the Admiralty show that his frustration was not far from the surface. At 2 p.m. news came to Brindisi from HMS Bristol that the Dartmouth had been torpedoed.

  
Vivian's first reaction was to get to the Dartmouth as quickly as possible and to the British vessel as well as save British lives but again he was refused permission to leave port. The French destroyer Boutefeu had been forced to return to Brindisi earlier that morning due to a condenser issue but was now ready to depart. Vivian went to petition his Italian counterparts for permission to accompany the French only to see the destroyer leave port. Vivian's growing frustration must have been tempered by horror and a certain amount of relief as a large explosion filled the air as the Boutefeu struck one of Feldkirchner's mines just beyond the boon defence. The destroyer quickly sank in a matter of seconds.
 
With the situation worsening on the Dartmouth, her captain, Addison, ordered the crew aboard the escorting destroyers but remained with a volunteer party who tried to save the ship. With their attempts successful and with the aid of a tug the cruiser limped into harbour by 3:00 a.m. the following morning. The fore of the cruiser was completely wrecked and only her armoured deck had kept the vessel together and it was sometime before she was operational again costing the Allies one of their more powerful cruisers.
 
Following the battle of Otranto barrage the Allies took stock of the situation and of the losses that had occurred. A very British response came from Admiral Mark Kerr, the Royal Navy's C-in-C of the Adriatic fleet based on HMS Queen in Taranto harbour;
 
It is quite certain that until some British destroyers are attached to the barrage for purposes of defence and 'E' type submarines for purposes of offence; that the Barrage can be raided by the Austrians same manner as here to fore. (3)
 
He went on to criticise the Allied naval forces.
 
The temperament of our Allies, who at present supply the destroyers and submarines for the barrage, is not suited for patrol work. Even their fast cruisers take some time as a rule to get to sea when the alarm is raised. A proper British force under a British Admiral would put n end to these raids (4)
 
Kerr's report acknowledged the bravery of the trawler forces but noted that the Austrian raid was the biggest they had seen so far. Steps were taken to only deploy the drifters by day for their protection and increase the standing patrols but these measures meant the Central Powers were free to move their U-boats and surface ships by night.
 
Another observation came from the frustrated Captain Vivian who pointed out that the Italian Navy had neglected to share codes with their Allies. This in itself was not an issue and to be expected if they did not want their Allies to understand certain aspects but on a shared frequency it is some what problematic. As Vivian stated in his report to Kerr, he head the following Communique:-
 
UX to FU "Ships in sight Otranto strait." - I had no idea who "UX" was nor "FU" was.

One other inconsistency that could easily be rectified was that some of the vessels were using local time an others, like the Liverpool, followed Admiralty directives and set their chronometers to Central European time.

 
A further complication was the use of maps and radio usage with the Mirabello's square map being numbered poorly or her radio signals poorly coded which led to confusion as to her actual position and when the Aquilla reported that she as disabled and in need of a tow they did not give a position so only Acton on the Dartmouth knew what was going on.
 
For the Austro-Hungarians it was a well received victory having suffered no losses and sweeping away enough trawlers to open the barrage at night as well as sinking two destroyers and damaging the Allies' cruisers. The whole operation proved the Austro-Hungarian navy was still a force that needed to be dealt with in the strategic situation in the Mediterranean.

End Notes:

 
1 – Horthy, M. “Memoirs”, Hutchinson & Co, London, 1956 p. 85)
2 -  The Navy Record society, "The War in the Mediterranean1915-1918", Temple Smith, Aldershot, 1987  p.251
3 -  Ibid p.257

4 -  Ibid p.258
5-  Ibid p. 256

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