Battle of the Struer Strait

Battle of the Struer Strait
Part of Sundering Sea Campaign of the Siduri War
The HMS Martina Librizzi underneath a sky of flak fire.
Date 7 October 1935 Location Struer Strait Result Inconclusive
Belligerents
Cacertian Empire	Shirvani Dominion Republic of Syara
Commanders and leaders
Licinia Senecio	Umid Xalidli
Units involved
Northern Fleet	Sundering Fleet
Strength
1 carrier 3 battleships 3 heavy cruisers 6 cruisers 15 destroyers	1 carrier 2 battleships 1 battlecruiser 2 heavy cruisers 3 cruisers 4 light cruisers 20 destroyers
Casualties and losses
1 carrier damaged 1 heavy cruiser damaged 1 cruiser sunk 3 destroyers sunk 24 aircraft shot down	1 battleships damaged 1 cruiser sunk 1 light cruiser sunk 2 destroyers sunk 16 aircraft shot down

The Battle of the Struer Strait was a naval engagement between the Inner Sphere and the Cacertian Empire during the Sundering Sea Campaign of the Siduri War. The battle took place on 7 October 1935 and was the first instance of combat between two aircraft carriers in history.

The Sundering Sea was largely closed to the Common Axis owing to the close proximity of the Shirvani Dominion, which the Inner Sphere could use as a staging ground for commerce raids into the Bara Sea in order to disrupt Common Axis shipping. Through the first year of the war, large numbers of merchant raiders—which included submarines, armed merchant marine, and even larger warships such as battlecruisers—had moved from the Sundering into the Bara via the Struer Strait between the neutral states of Serikos and the Venetian Principality. In an effort to block Inner Sphere movements, the Cacertian Royal Navy was tasked with containing Inner Sphere incursions. This task, however, was difficult to accomplish due to the need for Cacertian naval forces elsewhere, especially in the Nuadan Campaign on the opposite side of the Siduri Continent.

Between late 1934 and Fall 1935 there had been a number of indecisive engagements between the Common Axis and Inner Sphere, namely the Battle of the Bara Sea and the Battle of the Seyne Gulf, but neither side had been able to gain the upper hand. The need to close off the Bara Sea from Inner Sphere incursions was heightened in March 1935 when the Syaran battlecruiser Sacred Promise sank attacked six Common Axis convoys. With many of the Cacertian Navy's battleships tied down in the Nuadan, the task was passed off to the Navy's carrier arm. Aircraft carriers were still a relatively new implementation for naval warfare and there remained many uncertainties regarding how to employ carriers and their aircraft. As a result, many in the Cacertian Admiralty remained unconvinced of the capability of aircraft carriers and their ability to decisively influence naval campaigns.

On 7 October 1935 a Cacertian fleet under Admiral Licinia Senecio consisting of the Victor Sarissita-class HMS Martina Librizzi, the battleships Delfina Ballestra, Agnesina Calco, and Lucrezia D’Este, supported by three heavy cruisers, six cruisers, and 15 destroyers entered the Struer Strait. Hopes to avoid detection had been dashed when the force was spotted by the Shirvani sumbarine SQ-57, and was met by the Inner Sphere Sundering Fleet led by Admiral Umid Xalidli and consisting of the Asakumo-class aircraft carrier Sacred Oaths Still Kept, the Shirvani battleships Humbut Gunduzgil and Ibis Ulvih, the Syaran battleship Elegy for Erasmios, the battlecruiser Pious Saint, two heavy cruisers, three cruisers, four light cruisers, and 20 destroyers.

The Cacertians spotted the Inner Sphere fleet first and dispatched its opening waves of aircraft at 0845 to attack from a range of 35 kilometers. Shirvani radar detected the incoming flight, leading the Syarans to launch their aircraft. The Cacertian aircraft reached the Sundering Fleet first and launched attacks with dive bombers and torpedoes, sinking the light cruiser Given Truths. Attacks against the combined Inner Sphere battleships proved costly for the Cacertian aircraft, who suffered 19 shot down out of a wave of 33 aircraft for only superficial damage. By the time the Cacertians had withdrawn the Syarans had launched their own wave of 25 aircraft, which followed the Cacertians back to their fleet and attacked the Martina Librizzi and her battleship support. The Syarans succeeded in hitting the Martina Librizzi twice, but their relatively light payloads failed to do significant damage beyond limiting the Cacertian carrier's launching ability.

After confirming the numerical inferiority of the Cacertian fleet and believing the Martina Librizzi was out of action, Ulvih ordered the Sundering Fleet to pivot north. Senecio, believing the Sundering Fleet was still sailing due east, attempted to swing behind them. At around 0945 the two fleets passed alongside one another, leading to a prolonged exchange of gunfire. The Humbut Gunduzgil was hit thrice by the Agnesina Calco, and Lucrezia D’Este and began listing to port, forcing the Syarans to launch torpedo attacks with their destroyer flotilla; the effort resulted in the loss of three Cacertian destroyers between Syaran torpedoes and shellfire from the Pious Saint and the heavy cruisers. The Shirvani answered back with shellfire that struck the heavy cruiser HMS Colletone and damaged her forward turrets. The two sides broke contact afterwards for two hours.

Recognizing she was facing a superior force and with her carrier effectively unable to provide air cover owing to damage to her flight deck, Senecio opted to abandon the operation and withdraw back to the Bara Sea. She ordered the fleet to pivot hard to starboard then swung around to sail east, hoping that the Sundering Fleet would lose contact. Aircraft from the Sacred Oaths Still Kept however spotted the maneuver and reported back to the fleet, leading Ulvih to turn south-east to intercept the Cacertians. At 1030 the two sides drew within weapons range again, but this time the engagement favored the Cacertians, who had managed to push ahead and effectively crossed the T of the Sundering Fleet. The resulting exchange of shells went poorly for the Inner Sphere. The Humbut Gunduzgil was hit three times more and suffered a total failure of her weapons. The Shirvani cruiser Azad Dadasgil was hit only once, but the 380mm shells tore through the deck and detonated her forward magazines; she sank by the bow with only 16 survivors. The Syaran destroyer pair Lament and Trepidation were sunk by gunfire from the Cacertian heavy cruiser triad, leaving Ulvih to order the fleet to break off the pursuit.

Senecio was able to escape back into the Bara Sea without further incident. The outcome of the battle and the lessons to be learned from it were debated almost as soon as the fleets broke off their engagement. Both carrier wings had seen only limited success. Attacks against major capital ships, especially battleships, had proven extremely dangerous; Cacertian battleships were ringed with large amounts of anti-aircraft guns and Inner Sphere fire control systems were superb and as a result both sides had suffered heavy losses to their aircraft. Combined with a lack of experience on how best to attack enemy warships meant that neither carrier arm lived up to its potential, while the threat of surface combatants remained significant.

The battle nevertheless foreshadowed the eventual rise of aircraft carriers as the principle arm of naval warfare, while also revealing the limitations of early models and their capabilities. Both sides would continue to employ carriers throughout the conflict, but it wouldn't be until the Eracuran War that carriers would emerge as the primary means of naval power. Surface combatants, namely battleships and cruisers, remained the decisive arm of naval engagements for the remainder of the Siduri War.