Naval Aviation
Experiments prior to and during the Great War period showed the potentiality to launch and to land aircrafts on ships or to use small flying boats or planes with floats that operate directly from the water but were maintained on the ship in question. The potential of seaborne aviation was seen in the capability of the aircraft to scout beyond the visual range of the warship equipped with such aircraft and, later, to deliver bombs or torpedoes. Although the capabilities of naval aviation where yet not fully understood, there was some kind of euphoria and several navies began to convert or to design ships meant to operate aircraft at sea. To control these developments, the aircraft carrier was added to the Cleito Treaty as an individual category, another proof of the importance given to the new technology. For some reason, this did not include floatplane tenders or carriers below a certain size, leading to a completely different development of such vessels.
The Royal South African Navy also tested seaborne aviation, beginning with some non-permanent installations in 1915. Finally a liner was converted, then known as CVX Wim Kraash and tests were promising. However, different to other navies, the Admiralty was quite reluctant to immediately free budgets for a purpose build design and waited for results of the Cleito Treaty conference and what other navies would make of it. So it took until 1922 when a first series of design studies was appointed. For two more years no decision was taken, while more and more became known about foreign developments. Finally, a dedicated carrier was added to the building plan when funds for the financial year 1925 were under revision. The ship became the RSAN Hammer, a large design not only meant to operate as carrier but also as a cruiser, thus featuring a cruisers armament and armor. A second unit soon followed in 1926, the Forge, build to a slightly modified design. A building pause afterwards allowed intensive testing and development of doctrine for three years until decision was taken to build a new class of carriers. Tonnage constraints because of the Cleito Treaty did not permit to build large hulls again, so following international tendencies, two smaller units the size of a heavy cruiser were laid down, the Anvils. These two units commissioned in 1931 and 1932 respectively. Later, in 1934, two more full-size fleet carriers were laid down but these did not commission until 1936/37 so it was the formerly mentioned group of four carriers, which represented the RSANs carrier force during the conflict with Argentina and Brazil.
According to the then effective doctrine, our carriers were mainly used to scout for the battle fleet or to operate with the cruisers in blockading Argentine and Brazilian ports. Their enlarged scouting range was used to good results in several occasions but it also became clear, that naval aviation was heavily weather dependent and when weather prohibited the extended use of aircraft, the carriers became little more than large light cruisers. It was this inability to operate planes in bad weather that doomed the Hammer on July 13th. Under great risk her air crews had tried to keep up scouting over the course of the day but finally had to return to the ship when the weather worsened. The last crews to return reported almost no visual range and it must be rated great fortune they even found their way back again. They cannot be blamed for not reporting the approach of an Argentine battlecruiser force and when it was too late for the Hammer to escape, her light armor and armament was no match for a capital ship. The result was inevitable
As a result of this loss, our doctrine had to be changed. Until aircraft technology has reached a point, where operations can be maintained under all weather conditions, carriers have to be permanently escorted by a force allowing successful defense against large warships. Future carrier design also was influenced in that the capability to operate like a cruiser was given up. The weight and space dedicated to medium size guns, magazines, fire control equipment and gun crews was freed and could be used to improve the carrier’s capabilities to operate aircraft.
Late in the war the first long range duel between aircraft carriers again revealed the problems of finding and fighting enemy ships over a distance of several hundred miles. Aircraft development still sets a natural limit to the usefulness of carriers but with advanced technologies reaching frontline units, i.e. more powerful engines, larger airframes, better radio and navigation devices, aiming sights, better results can be expected in the future. It is our designers, manufacturers and yards responsibility and goal to provide these means to the air crews, so our carriers can be used as a reliable platform to project power beyond visual range. And we are making good progress five years after hostilities ended. While the Thomas von Deen class is a design of the pre-war era, the ships large size will allow operating the latest fashion aircrafts and permits the installation of the most modern electronic equipment. The RSAN also commissioned a purpose-built training carrier, increasing quality and quantity of our training program. Finally, a new large fleet carrier was laid down in 1937 to compensate the loss of the Hammer. With 27000 tons standard the Asgard represents a large, modern state-of-the-art design, incorporating all the lessons learnt during the war of 1934/35. She is about to enter service in summer 1940, then raising the total number of active carriers to 7. With so many hulls, the RSAN is well prepared to support operations with four units, while one unit is dedicated to training, one in reserve and one undergoing maintenance.
To keep pace with the development of new technologies and with the increased number of aircraft carrying vessels in service with the navies of the world, another large fleet carrier has been added to the building program in 1940.
As explained, the development of aircraft carriers was quite linear and the way forward is well prepared now that this kind of warship is about to grow out of childhood. Things are a little bit different for our floatplane carrier force. The main purpose of a floatplane carrier is quite similar to an aircraft carrier: to transport, maintain and operate planes. However, the use of floatplanes does not require the ship in question to have a large landing deck and in general installations are less complex, the ship much smaller. In the RSAN a clear borderline was never drawn between a floatplane tender and a floatplane carrier. In service floatplane tenders often were freighters equipped to raise and lower floatplanes from the water and provide some maintenance like a small floatplane base. This definition fits to almost all floatplane operating vessels in service with the RSAN when the Cleito Treaty was put in place and early shipborne catapults became operational, allowing the start of an aircraft while the so equipped vessel is underway. Articles G Ib and Ic of the Cleito Treaty allowed an unlimited number of floatplane operating vessels within their respective limits. Together with the new technical developments this lead to the introduction of two new ship categories: a small patrol/scout vessel of less than 2000 tons and a large ship operating with the main fleet and providing means to maintain and operate numerous aircrafts of different kind for the purpose of scouting and attacking enemy vessels or bases. In autumn 1934 the RSAN had six small and two large floatplane carriers in service.
The Mimir class of 1922 represented the first purpose build design and they served in the Indian Ocean throughout the war, forming the 3rd Scout Squadron in Victoria. Over ten years old and known to be the result of naval designers too eager to put too much on a small hull, they were never detached to South America. However, close to the wars end one of Mimirs finally had to face an enemy surface raider, the AMC Guadeloupe. Again the short comings of the cramped design were revealed. None of her aircraft had been in the air to inspect the suspicious freighter from a distance, because none of her small complement of four floatplanes was operational that day. The limited space and weight dedicated to the aircraft facilities had not allowed storing more aircraft or more spare parts aboard, so at the end of a long patrol loop the Gymir had to face her enemy like any other patrol craft. However, the aircrafts and fuel aboard still meant a potential hazard to the ship as they would easily burn once hit. And this is exactly what happened when one of the initial salvos from the Guadeloupe hit her amidship. In consequence, the erupting flames made it impossible for Gymir´s crew to make full use of her relatively heavy armament and she was sunk by an auxiliary warship she should have been able to dominate. Although the damage she dealt to the Argentine AMC finally sealed that ships fate too, the Mimir class had been proven a bad compromise of being a floatplane carrier and dedicated warship.
Likewise small but of completely different design, the Bölthorn class proofed to be more balanced. Her aircraft complement was increased by 50% compared to the Mimir while her armament was cut down to what was deemed a minimum for successful self defense. Her designers also took care she features an enclosed hangar where planes could be more easily prepared for their next mission, while on the Mimirs aircrafts could only be stored below deck but had to be readied for action on deck without weather protection. Further more, the Bölthorns were not used for independent patrol duties but served in Coast-Guard flotillas where they provided scouting and spotting for Coastal Defense Ships. In that role both units of the class proofed successful and the loss of the Bölthorn to bombs while on such a mission cannot be tracked back to a design failure.
The two large floatplane carriers in service at the beginning of the war were the Thjazi and the Ymir. Thjazi served with the 9th Scouting Squadron based in Mar del Plata and was mainly used for blockade duties. Her aircraft were of good use to extend the area covered by the 9th Scouting or to provide anti-submarine protection in confined waters closer to the shore. In a completely different role, her sistership Ymir was used with 4th Coast-Guard Flotilla to provide support during convoy and bombardment missions. She also participated in the naval sea battle of Porto Alegre where she was badly damaged by a torpedo hit forward.
The different use of the large floatplane carriers allowed a detailed post-war analysis of their capabilities. Both were built to operate with the fleet and to fulfill the role of an aircraft carrier where no such carrier is available. This doctrine also included independent operations with cruiser-like profile for which the units got a light cruiser armament. The Thjazi was used according to this doctrine. Despite several short comings like a deck hangar too small or a lack of automatic short range anti-aircraft guns she succeeded in her role. The Ymir on the other hand was less often used for blue water operations. Instead she stayed closer to the shore, supporting bombardment missions, putting her in much more danger than the Thajzi. Providing a relatively large and widely unarmored target, she was always in danger to be hit by coastal batteries or attacking aircrafts. And also she was intentionally built to be able to stand her own against enemy AMCs or similar vessels while on patrol mission; she was never designed to be part of a battle line fighting enemy capital ships or cruisers. The heavy damage she took from a forward torpedo hit clearly showed how vulnerable she was without having an armored torpedo bulkhead.
Today the lessons learnt from the war have been addressed. The small floatplane carriers have been proven too cramped and limited in capability to be further supported. Two Mimir class vessels have been sold while the remaining third was transformed into a landing ship. Only the Egdir of the Bölthorn class remains in active service, deployed to support our Costal Forces. No future projects are planned. On the other hand, the large floatplane carriers were successful when deployed and used properly. They offer a cheap and capable alternative to standard aircraft carriers when a full scale air group is not required. Accordingly the RSAN commissioned three units of the Unicorn class and laid down two more of the improved Wyvern class in 1939. The new floatplane carriers are larger and address several short comings of the earlier Thjazi design. Their larger hull makes it easier for them to operate a higher number of modern floatplanes, which have become heavier and larger, and also allowed light armor to be applied. The vessels main armament is now composed of a heavy dual purpose battery and an increased number of light guns. Further more, provisions have been taken to allow the conversion of the floatplane carriers to light escort carriers, increasing the Navy´s strategic options. Doctrines have also been modified to correspond to the vessels full capabilities. Hence the new ships are deployed in similar fashion to light fleet carriers today, with a focus on the Indian Ocean.
Cruiser Fleet
When war erupted the Empire featured one of the largest and most modern cruiser forces in the world. Numbers and quality of design had been in focus of naval designers for the past decades, clearly favouring the RSAN over the joint navies of Brazil and Argentina. About forty units stood ready for numerous tasks such as blockade, escort, scouting, power projection and bombardment. Yet the large area to cover and the vast number of duties forced a dispersion of the cruiser fleet that stretched our capabilities to extremes when losses became inevitable and had to be compensated. But the challenge was mastered and in general the cruisers proofed up to their tasks and the rebuilds of old units worthwhile. However, the stunning success of the Arion class light cruisers, which became known as “Pony Express” [1], came completely unexpected. The offensive use of fast surface units for short and dangerous hit and run tactics had not been part of the RSAN pre-war doctrines where the Arions were planned to operate as destroyer flagships. The pressure that could be built up forced our enemies to respond and spend resources that would have been available otherwise. The relatively high losses during those daring high risk missions were overcompensated by achieved results. Efforts to build a similar unit of the 1st Cruiser Squadron and 10th Destroyer Flotilla to fight the Brazilians proofed successful too, albeit less effective in binding enemy forces owing to the more desolate situation of the Brazilian Navy in general.
In all cases where cruisers were lost they succumbed to superior enemy firepower, either in number or quality. Despite all improvements in cruiser design, the old rule was proven right again that cruisers cannot tackle capital ships when gallant Ladon fought her fight to save the carrier Hammer or when the Port Elizabeth lured the Brazilian battlecruisers under the guns of 1st Scouting.
A new development in cruiser design, the use of heavy dual purpose guns as main armament to increase the cruisers capabilities to fight aircraft, came too late to be tested. The first such design, the Dione class, was still under construction and reached active status only post war. However, some first experience from cruiser operations during the war could be used and the follow-on design, the Danae class, was increased in size and firepower, also featuring a new generation of fire control systems. All tests and results from life firing and fleet exercise over the past month are proof of the capabilities of the new designs.
To compensate our losses of six light cruisers total, four units have been built aside the new anti-aircraft cruisers. The two units of the 37er Nampula II class are built as fast and powerful, albeit lightly armoured vessels and will replace the lost Arions. The Charybdis class of 1938 on the other hand is an improved Douala II design, featuring twelve 15cm guns of the latest model on a standard cruiser hull [2].
For future designs further evolution of the multi-role standard type is strongly recommended. These ships represent the work horses of the fleet and cannot be ignored in future building plans.
The situation regarding former Type A cruisers, generally referred to as heavy cruisers, is not that easy. Due to international tendencies to introduce super-cruisers, ships smaller than what is usually considered a capital ship but larger than 13000 tons and armed with guns of more than 21cm calibre, the value of the heavy cruiser has to be carefully examined. The low number of super-cruisers yet present among the navies of our most likely opponents might make a fight between Type A cruisers and a super-cruiser unlikely. However, the question needs to be answered if it is worthwhile to build ships larger and more expensive than the standard type cruiser but not capable to battle super-cruisers or light battlecruisers on even terms.
Our own experience with the new category of super-cruisers or light battlecruisers based on the Radiance and Vengeance classes allows a differentiated point of view. The Radiance is internationally accepted as one of the best designs in this category; her heavy main armament not only capable to defeat the armour of all other designs of her kind but also powerful enough to endanger true capital ships while her armour is thick enough to protect her against the weapons usually installed on foreign super-cruisers. However, as a result the Radiance has grown to a size where the individual unit has become quite large, expensive and indispensable. Building numerous vessels of her kind is impossible due to budget constrains and so her value as a multi-role ship is limited. The Vengeance class on the other hand grew only 2000 tons beyond the former limit of the Type A cruiser but this increase in size was suffice to allow the installation of a 25cm main gun battery quite similar to what foreign designs field. However, neither her speed nor her protection is outstanding or could be enhanced much compared to the original heavy cruiser. So while her main gun calibre allows superiority over most cruisers afloat today, it is not powerful enough to guarantee success at all times or promote operations against foreign super-cruisers or capital ships. To accept an increase in costs and maintenance over the former Type A cruiser remains questionable as a result.
Instead it might be wise to increase - within the constraint of budget and the number of hulls required - the size and power of the standard type cruiser, to merge the former Type A and B categories. However, this might leave us with no adversary to foreign designs. Doubtless foreign developments have to be carefully tracked and evaluated, so our navy will always be prepared and superiorly equipped. If this requires building more super-cruisers or light battlecruisers cannot be answered today. Therefore I recommend installation of a committee to evaluate the future of the former Type A cruiser.