The Coastal defence ship is a stranger among warships. A monitor ship (named after the famous warship USS Monitor, a first of its kind in many ways) would be a close equivalent, but on quite, as CDS's typically are – to an extent – more versatile than monitors, which usually mount only one or two disproportionately large guns. Coastal defence ships carry also a secondary battery and light AA guns, but are otherwise similar to monitor ships both tactically and strategically: both types of ship carry a small number of very heavy guns in proportion to their size, which is achieved by sacrificing armor, speed and especially range. As both types of ships are designed for either coastal defence or artillery support in confined waters, these sacrifices were considered acceptable as the ships would on the other hand provide the ability challenge much larger warships with only a fraction of their cost.
Coastal defence ships typically are between a monitor and a cruiser in their size, but carry main guns at least as large and often larger than even a heavy cruiser, which provided the defending navy with significant advantage in firepower. Limited operational range is acceptable in this purpose as the ships could easily resupply from nearby ports, and longer range of heavy guns would – again, to an extent – compensate for lighter armor compared to a cruiser, as the defender could fire several salvos from outside of the reach of their oppressor. Light armor decreased both the cost and draft of the ships, making this type of ship attractive to small nations with tight defence budgets. Thus the coastal defence ship became popular in the Nordic countries and the Netherlands.
Aother type of naval vessel popular to small nations was the motor torpedo boat, which was another cost-effective way to threat much larger enemy ships as even a few torpedo hits could cripple even a battleship, but torpedoes can be fired from a relatively light and affordable platform. The attacker could repel torpedo boat attacks with another relatively cheap warship, the destroyer (the name is shortened from torpedo boat destroyer), which by WW2 had evolved to a very versatile and popular type of ship, but coastal defence ships had to be knocked out by the firepower of heavy cruisers or battleships, and thus the attacker had to invest in a large battle group thi fulfill their mission.
The third popular possibility was the submarine, which also relied in their torpedoes in defeating heavy enemy warships, and by approaching underwater could achieve a devastating surprise attack of 3 to 6 torpedoes in one salvo. The submarines of the interwar era were limited in their other capabilities though: they were more submersibles that "true" submarines, as they could spend only 24 to 72 hours submerged at a time before their oxygen and batteries ran out. Thus the submarines of the era usually patrolled on the surface and only submerged when enemy was detected – and after submerging, the submarine had much limited mobility, as their top speed underwater was usually 7 knots, and at best 10. Therefore the submarine had to move into attacking position well in advanced, either on surface where it was vunerable, or by ambushing the enemy by lurking in their suspected path. The defensive navy usually has the advantage of such defensive position.
For these reasons, the Finnish Navy decided to acquire all these 3 types of warships into their inventory, which was approved by the Parliament in the Navy Bill of 1927. Of these vessels, the coastal defence ship was a stranger in a strange land.
The Väinämöinen class of coastal defence ships were relatively small ships, only 3 900 tons of displacement or just larger than destroyers (which by this time were typically approacing 2 000 tons), but significantly smaller than even light cruiser (which were a type of ship of about 10 000 tons). For ships of this size, the class carried very heavy main guns, four 254 mm (10-inch) Bofors guns in two twin turrets, one fore and one aft. The secondary battery was 8 guns of 105 mm (4,1 in) Bofors dual-purpose guns (both air and surface targets could be fired at) in four twin turrets, one superfiring the fore main turret, the amidships both port and starboard, and the fourth superfiring the aft main turret. As for AA guns, the ships carries four 40 mm Vickers and two 20 mm Madsen autocannons. The anti-aircraft artillery was quickly deemed underpowered, thus the 40 mm guns were replaced with superior 40 mm Bofors type in 1940, and at least six Madsen autocannons were added. This was not uncommon during this era, as the aircraft was evolving in a very rapid pace and most ships were designed a decade earlier, when the air threat was given little priority and in naval warfare were considired mostly as scouts. This was generally reconsidered only after the Spanish Civil War of 1936-39.
Coastan defence ship Ilmarinen. Photo: Reddit |
The 254 mm main guns were the purpose of the Väinämöinen class. The guns fired a 225 kg shell at 850 m/s muzzle velocity to maximum range of 31 km (16,7 NM). The propellant was 70 kg of nitrocellulose gunpowder loaded in brass casings. The calibre length of L/45 was in par of most guns on this size at the time. Larger calibre length, e.g. longer barrel of the calibre, is typically preferred, as the shell has mode travel in the barrel, and thus more time to gather kinetic energy from the propellant and thus achieve greater muzzle velocity, improving armor penetration and flying with flatter trajectory, which improves the chance to hit.
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Coastal battleship Ilmarinen. The profile of the class is distinctive. Photo: Naval Encyclopedia |
Due to the compact design and high conning towers the ships veered slow and hard. This made open sea operations uncomfortable but the ships were safe to run even at rough seas. The small size and distinctive silhouette of the class was fuel for many jokes, such as that Finland has to be a great naval powers as even their lighthouse ships have 10-inch guns.
The lead ship Väinämöinen was launched on 29 April 1932, but ironically the sister ship Ilmarinen had been launched on 9 July 1931. The fitting of the ships took time, though, and Väinämöinen was commissioned on 28 December 1932 and Ilmarinen on 17 April 1934. The Navy had plenty of time to process any teething problems and train the crews before the Second World War, which bursted into flame on 1939.
Blaze of the Century
Operation Sail Race
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Northern Baltic Sea in 1939. Aland Islands and Hanko highlighted. |
During the intermediate peace, the Finnish submarine and coastal battleship forces made any surprise invasion of the Aland Islands very vunerable. The Soviet fleet had anyway access to ports of the occupied Baltics, and these ports had a safe railway access to Soviet inventory. The Soviets thus had no need to make a surprise attack, unless another war with Finland would emerge. And the main advantage for Finland was that the Finns knew when it would take place.
Already on 5 December 1940 had Nazi Germany given information to Finland, that a surprise invasion of the Soviet Union, Operation Barbarossa, was being prepared. Nazi Germany had invaded and occupied Norway and Denmark in May 1940, and Germany was granted a travel permit of troops through Finland to their garrisons in Norway. Finland was not allied with Germany, but the terms were friendly even at their coldest, as there was no alternatives. In May of 1940, a German officer delivered a letter to Finish Navy headquarters. The letter was sealed and labeled "not to be opened until 0300 HRS 22 June 1941". This left no room for guessing.
ANd thus the neext great sail race for Aland was to begin. The Väinämöinen class ships were set on 20-minute alert on 19 June, and the diesels were ignited at 0430 on 22 July 1941. The boilers for the triple expansion steam engines on accompanying cargo ships were already lit, and the mighty Maybach V12 engines of the motor torpedo boats soon followed.
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The initial design of 1929. The main conning tower is further fore than in the actual ships. Photo: Naval Encyclopedia |
The Soviets detected the convoy soon and reacted. Finland and the Soviet Union were not at war yet, and the Finnish convoy was within Finnish coastal waters, heading to Finnish territory and away from Soviet territory, but this was not considered. Soviet bombers attacked at 0600. The attack was repelled by intense fire from the coastal battleship's now upgraded AA batteries; small cargo vessel Sylvia strayed from her course by a blast of a nearby bomb hit and ran aground when the scared crew thought the cargo of ammunition was lit and hastly evacuated the ship, but returned embarrassed when the ship and her cargo was found to be unharmed. Sylvia was towed off the rocks and the convoy resumed the mission. Soon the ships arrived at the demilitarized Aland Islands, which were relimilitarized by a regiment of infantry. The Navy secured the landing until it was complete with artillery.
Operation Nordwind
The Baltic Sea and the Gulf of Finland especially was the most densely mined body of water during the Second World War. For this reason both coastal battleships of the operation were equipped with minesweeping equipment called paravanes. Sea mines are lighter than water and attached to the sea floor by an anchoring cable, to float at a fixed depth both out of sight and in a perfect position to breach the bottom of a ship or even break its keel. A paravane or a water kite is an underwater floating device , a sort of a pontoon with wings to both sides, towed by long arms at the bow of a ship. Steel cables are strung between the paravane and the ship, and any encountered sea mine would snag into the cable by their own anchoring cables. The tension of the cable will pull the mine toward the paravane and cutting jaws on its leading edge, thus cutting the mine free to float to the surface where it can be detected and cleared by shooting, or the mine is will detonated relatively harmlessly when hitting the paravane itself.
The paravane is analogous to mine-clearing plows of a tank in land warfare: it is more of a self-defence for a single vehicle against mines rather than an attempt to clear the minefield itself. Proper mine-clearing is a task for specialized mine-clearing vehicles and crews, which in naval warfare are minesweeper ships. A typical minesweeper of the WW2 era was a small wood-hulled ship of only a few hundred tons of displacement, and many minesweepers were in fact militarized trawlers. They usually operated in pairs, towing a long underwater cable between them to cut the anchoring cables of mines. The minesweepers are usually so small and shallow on draft, that they will not hit the contact fuzes of naval mines, as they are usually set deep enough to hit only major vessels instead of small boats, and the wooden hulls are inert to magnetic fuzes.
There were no fast minesweepers available for operaton Nordwind, as they were assigned to another operation, as were also the German Kriegsmarine R boats. Only slower rudimentary equipped minesweeping tugboats were available to escort the coastal battleships. They had earlier the same day detected an underwater obstacle 20 NM south of Utö, which was believed to be a shipwreck and potentially dangerous if it was close enough to the surface to sang into a minesweeping cable. For this reason, operation Nordwind changed to a different course southwest to the finding.
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Naval mines, an artist's impression. The plugs are contact fuzes to set off the mines, and anchoring chains will keep the mines at a desired depth to hit large vessels, but to stay undetected by small boats not worth destouying and revealing the posion of the entire minefield. Photo: Strategy Bridge |
It was early evening on 13 September 1941. The coastal battleship Ilmarinen was leading the line of ships, with her sister ship Väinämöinen following some 800 meters aft, and a VMV type motor torpedo boat at both sides, armed with depth charges for anti-submarine duty. It is unclear why the Väinämöinen class ships were at the front instead of minesweepers, but this was presumably done in order to lure the enemy's attention towards the force, whose mission was to be a decoy. If the ships were detected, the Soviet forces defending the islands would probably be redeployed towards the northern beaches, and the air forces would also be lured away from the narrow channels to the east. For this reason all radio messages were sent uncrypted and with great emission power, and all men were at battle stations. Mess boys were busy making coffee and sandwiches for the sentries and gunners, but ran to their assigned light guns every time the intercom rang. All alarms turned out to be false, and the young men returned to their former tasks at cabooses time and time again. The diesel engines made only barely visible smoke trail, contrasted by the following escorts' thick smoke columns from their piston steam engines, and the soot pillars were obscured only by the thickening dark clouds as the Sun was setting.
The formation leaves the Utö channel, which had been secured earlier by the minesweepers. All eyes look into the darkening night, but in vain. Nothing is detected. The paravanes are lowered into the sea, as the ships enter a marine no-mans-land. Soon the portside paravane of the leading ship Ilmarinen is seen hung along the hull amidships. It is lifted and inspected, but there is no damage. The misplacement is deducted to be caused by too much tension in the guiding cables, so the paravane is re-floated in the sea.
30 minutes later the paravane is again against the hull. The formation is nearly at the tip of it's move, and the turn will be done to starboard side, so the paravane is deemed harmless even if it had actually snagged a mine. There will be plenty of time to inspect it after the turn.
At 2030 HRS the formation has reached it's turning point and the ship captain, Commander Ragnar Göransson and the Fleet commander, Commodore E. Rahola decide to execute the turn. Commander Göransson gives his order by intercom: 15 to the right, slow speed. The clumsy-looking ship begins its turn surprisingly fast: 10 degrees, then 20, 30, 40, and 50 degrees. Soon the ship will be turned around and the paravane may be inspected.
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A paravane. Photo: Reserviläinen |
Then, for a heartbeat, the night is no more night and the sea is no more a sea. Vast pillar of flame cuts the sea and the sky in half from the portside of the ship. The time is standing still as the flame reaches the top of the main conning tower, and then it is all over in a similar sudden. The men jump from their seats and most believe they have ran into an ambush and the main guns have suddenly opened fire.
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Artificial Intelligence image of a drowning man. Photo: Freepik |
Able Seaman Lyttinen has a longer path in front of him. He evacuates from the fire control room to the AA control room, and further to the shaft leading to cabin 6. Sergeant Pusa and Seaman Klingenberg follow him. When Lyttinen reaches the cabin, the list is steep enough for the furniture to fall onto him. He clears his way with force and seeks his path by hand in complete darkness. Soon he finds a familiar object, the loudspeaker of the cabin. Now he knows his orientation and the door next to the loudspeaker, and proceeds into cabin 5. This is a very familiar place to hom and even in the dark he knows the location of the emergency porthole. He lights a match which helps the men to find the locking latch. Lyttinen opens the latch, but the porthole cover won't budge. It opens inward, but the compressing air forces it shut. Lyttinen utilizes all his strength to pull the cover open, and Klingenberg rushes to aid him, as soon do a couple more of men. They pull for their lives.
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Able Seaman Lyttinen after the loss of Ilmarinen, in a group photo of the survivors. Photo: Lauri Pekkarinen. |
Able Seaman Pätäri is resting at the crew cabin behind the 105 mm turret when the ship bas blown open. He also believes the main guns had hastily opened fire, until the ship rapidly begins to list. He hurries to the weather deck. Only a handful of men are wearing a cork vest, a modern safety device. Pätäri has his vest with him, but he was not wearing it then the mine detonated. He is holding it and tries to put it on, but the ship lists more and he falls into the sea. The listing continues, and the ship is literally falling on top of him - and he has one of his arms pinned behind him by the sling of his life vest. 105 mm ordnance roll out of their racks and several shells hit him as he struggles to swim away from the falling ship. His instinct guides him further out from the ship, until he suddenly is at open sea. He tries to swim further, away from the pull of the sinking ship. Men in the sea cry for help, but he is horrored by the voices of the men still trapped inside. They bang the hull with anything they get in their hands. Only a fraction them even has a chance. The cold water soon exhausts the escaped men, and they fall more and more silent one by one. Many of them are still wearing their weather coats and boots, which pull them under the sea. Pätäri watches in horror as the ship turns completely over, and then the bow rises from the sea for a moment, only to be pulled under by the already sunken aft section. This all happened in only seven minutes.
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. Drawing of the wreck . Photo: MTV3 |
The partially worn cork vest manages to keep Able Seaman Pätäri on the surface. The explosion had ruptured the fuel tanks, and the sea is covered in fuel oil. Many men inhale the fuel to their mouths, lungs and bellies. Pätäri is one of them. He notices himself thinking: This is it. This is the end of the line. This is war, and for me, it ends this way. He feels no fear, and doesn't understand why.
Four VMV boats patrol the wreck, and one of them (VMV 1) dares the devil's tail by pulling 50 men from the sea onto her deck, which is a daring load for a boat of only 30 tons. 1200 hp Maybach V12 engines and 520 hp marine diesels growl softly into the night at idle power as the VMV boats search for survivor (VMV 1 to 7 had Maybach engines, VMV 8 to 17 were diesel-powered). 132 men had escaped the doomed ship, many of them so exhausted that they cannot even produce their name. The last of the rescued had already sank under the surface, but a vigilant sentry noticed him and got a grip form his hair, and managed to pull him onto the boat.
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Motor torpedo boat VMV 9. The VMV class was a very cost-effective and versatile type of naval vessel, and they saw much action during the war. Photo: Wikipedia |
Ilmarinen had ran into a Soviet naval mine. As the Soviet fleet had been for two decades stranded into the confines of Leningrad, so it was forced into a defensive position and consequently mining warfare had been developed to a relatively high level of sophistication. For example, several types of mines were anchored with chains instead of cables, and were too thick for the paravanes' jaws to cut. Ilmarinen's portside paravane had probably snagged into this type of mine and possibly towed it for some time, until it's inertia pulled it under the ship as it made its turn.
In a cruel twist of fate, even as the mission of operation Nordwind was a decoy, the Soviets never detected the force. They never reacted to it, and it was never mentioned. The Soviets only learned of the loss of the coastal battleship Ilmarinen from their diplomats and spies in Sweden, who took notice that suddenly a large amount of obituaries were printed in Finnish newspapers, dated at 13 September with remarks such as "KIA at sea". Due to wartime censorship, the loss of Ilmarinen was not released to the Finnish public until after the war.
Ilmarinen took 271 men with her to the bottom of the Baltic sea. They had now boarded the largest battleship of them all, and they shalt not ever feel hunger or freeze any more
The wreck of Ilmarinen lies upside down 25 NM south of Utö 70 meters deep. Neither ship of the class never engaged in a naval battle. Her sister ship Väinämöinen was given to Soviet Union as war reparations in 1947, and she served the Soviet Navy as Vyborg until scrapped in 1966.
15 kilometers to the northeast from the resting place of Ilmarinen lies another accursed garden of bones, the cruise ferry Estonia, which was similarily taken by the September Baltic sea, in 1994.
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Estimate locations of the wrecks and the Utö guard station. Map: Google Maps. |
References:
IL Historia: Jatkosota merellä. Alma Media, Helsinki 2022.
Pukkila, Eino: Taisteluhälytys – Suomen laivasto jatkosodassa. WSOY, Porvoo 1961
Heinämies, Wilho: Seitsemän minuuttia merellä. WSOY, Porvoo 1945
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