(Akv-151 prototype image). It all started in 1949 when the Kungliga Arméförvaltningen (KAF), (Royal Swedish Army Material Administration) requested a new 155mm self-propelled gun from AB Bofors. This vehicle was to be completed and ready for mass production in the mid-1950s, but a series of modifications and new requirements delayed the program and delivery times. This situation led to the program taking a totally different direction in 1953 when the secret “Emil heavy tank project” was definitively canceled when the Swedish Army acquired a good number of Centurion Mk.3 main battle tanks. In 1953, work on the new self-propelled gun/howitzer passed to the firm AB Landsverk, which was commissioned to develop the new vehicle from one of the two prototype chassis of the Emil tank project (KRV). Landsverk prepared a prototype and in 1960 presented it under the designation “Artillerikanonvagn (Akv) 151”.(Akv-151 prototype image). The Akv-151 self-propelled howitzer was a massive vehicle with an undercarriage made up of 6 roadweels with the sprocket at the front and the idler aft. It had an air-cooled V12 gasoline engine, a 150mm howitzer and was operated by 7 crew members. The Emil tank chassis was used, but it was reversed, so that the previous front part became the rear part of the new vehicle. The fighting compartment was completely new and the oscillating turret built by Bofors was installed in the rear of the huge chassis. The prototype was finished and seemed to meet the initial requirements, so the acquisition of 96 units was proposed.(Bandkanon 1A image). Although the Akv-151 was on the right track, in the late 1950s Bofors had been tasked with developing new self-propelled howitzer based on the S-tank MBT chassis and using the same engine, which was actually a combination of diesel engine and gas turbine. This order arose from the idea of using certain parts of the S-tank MBT, such as the engine, transmission and tracks to create a family of vehicles, as was done with the Pbv-302APC, and thus reduce the cost of manufacturing and facilitate logistics on the battlefield. Finally, the Swedish Army did not accept the Akv-151 for service and the program was canceled. Instead, in 1963 after evaluating the tests of the Bofors prototype, they decided to mass-produce it under designation “Bofors Vagnkanon 155 mm L/50 (VK 155 L/50)”, although it would be popularly known as “Bandkanon 1”.(Bandkanon 1A image). The Bandkanon 1A, as it was designated upon entering service, was made of all-welded steel. The engine and the transmission was located at the front of the hull and the crew was made up of 5 members: driver, commander, gunner/radio operator and two loaders. The driver was located on the left, in the central part of the hull between the engine compartment and the turret and had a hatch cover with a day periscope in front. The other 4 members were inside the turret, that was made up of two halves (cabins) located one on each side of the howitzer. The commander and the gunner/radio operator were in the left cabin while the two loaders were in the right cabin. Both cabins had an access door in the front and 3 vision blocks, (2 in the front and 1 on the side) as well as a hatch cover on the roof.(Bandkanon 1A image). The undercarriage was based on that of the S-tank MBT, but had to be enlarged to accommodate the huge turret. It was made up of 6 dual rubber-tyred roadwheels with the sprocket at the front and the sixth roadwheel acting as idler. It had no return rollers and the 670mm wide track rested on the rear roadwheels. The suspension was of the hydropneumatic type and could be locked when in the firing position to provide a more stable firing platform. The Bandkanon 1A was initially equipped with a Ra-421 radio which was later replaced by a Ra-422 radio.(Bandkanon 1A image). The power pack was the same as that of the S-tank MBT and was initially formed by a Rolls-Royce K60 diesel engine and a Boeing Model 502/10MA gas turbine. The power developed was 240 + 300 hp respectively, which due to the huge weight of the Bandkanon 1A, was well below the power required for a 52-ton mass. The diesel engine was constantly running, while the gas turbine was only engaged when driving off-road. Maximum speeds were very poor, being 28 km/h on road and 9 km/h off-road, and the range was only 230 km despite carrying 1,445 liters of fuel. The transmission consists of a Volvo torque converter coupled to a manual gearbox with two forward and two reverse gears, 1 direct gear for road and 1 cross country gear. The power pack and the transmission formed a complete unit and could be easily removed from the vehicle on the battlefield.(Bandkanon 1A image). Although the dynamic capabilities of the Bandkanon 1A were very limited, even for a self-propelled howitzer that is supposed to be far from the front line, where it did shine prominently was in its artillery effectiveness. It carried a 155/50mm m/60 riffled howitzer 7.75 meters long and 4,800 kg in total weight, including the muzzle brake and the replaceable liner weighing 1,340 kg. The howitzer barrel had a semi-automatic wedge-shaped breech block that opens downwards and during movement, the barrel was secured by a lock located at the front of the hull. The maximum range was 25,600 meters and it had an automatic loader that allowed an exceptional rate of fire of 14 rounds in 45 seconds!!(Bandkanon 1A clip image). The howitzer was fed by a recoil-operated automatic loader that received projectiles from a replaceable 14-round clip that was inside the magazine. The loading device consisted of a loading tray which was located beneath the magazine. The loading tray carried the ammunition from the clip to the ramming position and then it was pushed to the barrel. The 155mm rounds were placed in a clip with seven drop compartments, with 2 rounds each. This clip was changed when empty in just 2 minutes, thanks to a built-in electric hoist mounted between the two crew cabins above the howitzer barrel.(Bandkanon 1A image). To change the magazine, the barrel had to be raised to an elevation angle of +38º where the covers on the top of the magazine opened and allowed the extraction of the spent clip and the insertion of a loaded one. Once the clip was loaded into the magazine, one round was loaded by hand on the chamber, but subsequent rounds were loaded automatically. This system was what allowed the high rate of fire and allowed to fire 15 rounds, (1 in the chamber plus 14 in the magazine), in just 48 seconds. The fire capacity was such that it was possible for all 14 projectiles to be in flight towards the target before the first one had hit, meaning that it had an exceptional “shoot-and-scoot” capability, according to the modern definition. This capacity has not yet been surpassed by more modern models, which indicates the advance of its design.(Bandkanon 1A image). The howitzer was raised by an electric motor between +2º and 38º at 5º per second, but if it was raised manually the elevation angle was from -3º to +40º. The turret had a traverse of 15º left and 15º right at an elevation of above 0º, but if the barrel was below 0º, the traverse was only 15º left and 4º right. The Bandkanon 1A aimed the howitzer using a 4x sight with a field of view of 10º. This howitzer fired a high explosive fragmentation (HE-frag) round weighing 47 kg with 3 different charges depending on the distance of the target. The muzzle velocity was 600m/s with charge 1 and 865 m/s with charge 3.(Bandkanon 1A image). There is no doubt that the Bandkanon 1A had outstanding capabilities, but it was not all advantages on the battlefield. It was very heavy, (the heaviest in the world when entered service), slow and huge vehicle, which made it very difficult to pass over unprepared bridges. Furthermore, unlike other Swedish vehicles of its time such as the Pbv-302APC, Ikv-91 tank destroyer or Strv 103 (S-tank) MBT, it was not amphibious, which limited its progress if necessary. Regarding its ammunition, it had the disadvantage of not being able to be used flexibly, since once loaded in the magazine, it could not be exchanged with another type of ammunition, and the range of the rounds had to be calculated before inserting them into the clip, to place the corresponding charges before.(Bandkanon 1A image). As self-defense weapon, the Bandkanon 1A carried a 7.62mm KSP 58 machine gun on a pintle mount on the turret roof but they did not have smoke grenade dischargers or illuminating mortars like other Swedish vehicles of the time. The vehicle was fully protected against impacts from 12.7mm ammunition and shell splinters and its armor was composed of steel between 10 and 20mm thick. It also had NBC protection in the driver’s compartment and in the crew cabins but it lacked night vision elements, although the driver could exchange his daytime periscope by a passive periscope for night driving.(Bandkanon 1A image). In 1963, an order was placed for 70 Bandkanon 1A, which were to be delivered in several series until the end of the 1960s. The first series was made up of 26 vehicles, the first of which was delivered in December 1965 and the last in 1969. However, the first unit equipped with Bandkanon 1A was not operational until 1967. Initially they were framed as divisional artillery in the Norrland area within the Boden Artillery Regiment A8, which had two battalions with 12 vehicles each plus 2 in reserve. Later, no more Bandkanon 1As were delivered due to budget cuts, so these first 26 vehicles of the first series were actually the only ones that were built.(Bandkanon 1C image). In 1988, the Swedish Army decided to modernize and improve the Bandkanon 1A fleet, taking advantage of the fact that the same was being done with the fleet of Strv 103 S-tank MBTs. A contract was signed with Bofors Defense and among the most important actions it was decided to replace the Rolls-Royce K60 diesel engine with a new Detroit Diesel 6V53T diesel engine that developed 290 hp instead of the previous 240 hp. The Volvo manual transmission was also changed for a Bofors automatic, so the modernized Bandkanon 1A would have the same power pack as the Strv 103B MBT. The prototype equipped with this new engine would have to undergo a 1-year testing period before such modifications would be carried out in the rest of the fleet. These tests were successfully passed and the modernization could be applied to the other 25 vehicles without problems, receiving the new designation “Bandkanon 1C”.(Bandkanon 1C image). At the same time that the modernization was being carried out, it was decided to reorganize the deployment of the Bandkanon 1C within the Boden Artillery Regiment A8, forming 3 battalions of 8 vehicles each plus 2 vehicles in reserve. In April 1993, Bofors was commissioned to modify 2 Bandkanon 1Cs by installing a Honeywell MAPS (Modular Azimuth Positioning System) inertial navigation system, which was an independent system from GPS but showed the position of the vehicle and the elevation and orientation of the barrel. In addition, the SKER system was partially adapted, which was an electronic fire control system with a ballistic computer and a radar muzzle velocity meter. After the corresponding testing period, these devices were installed in all Bandkanon 1C.(Bandkanon 1C image). Another important modification was the elimination of the built-in ammunition crane to reduce the weight of the vehicle, but this decision was later proven to be wrong, since having to move the ammunition clips with an external crane was much more complicated and slow than the original maneuver, which basically consisted of pressing a few buttons. It seems that the SKER fire control system was not very popular with the crew either, since in practice they received the direction and firing orders through the same channel as the voice communication, which caused them to have to endure beeps and buzzes in the headphones with the resulting confusion and inconvenience. The muzzle brake was also modified and the four supports for the previous muzzle velocity meter were removed.(Bandkanon 1C image). Although some of these modifications may not have been as effective as expected, the truth is that the Bandkanon 1A self-propelled howitzers needed updating to improve their operability and flexibility of use. At the end of the 90s they received new Ra-480 radio equipment and some vehicles received the experimental “FUM SLB” battalion-type battle management system. In 1998, the Boden Artillery Regiment A8 changed its name to the “Norrland Artillery Regiment”, a name it maintained until 2000 when it was disbanded. In its place the Norrlands Artillery Battalion was created as part of the Norrbotten Regiment I 19.(Bandkanon 1C image). The Bandkanon 1C were in service until April 2003 when they were retired after performing their last shooting exhibition at the Norrbotten Regiment I 19 shooting range on March 31, 2003. On that occasion 5 Bandkanon 1C fired 52 rounds with the same speed and efficiency than usual, showing that they could still be useful. However, the difficulty of finding certain spare parts, which were out of stock and had to be manufactured expressly for this vehicle, together with the scarcity of practice rounds, and above all, the short range of the HE shell compared to the most modern ammunitions, led to the decision to decommission them despite their excellent performance in some areas such as rate of fire, an aspect that remains unbeaten more than 20 years after their retirement.(Bandkanon 1C image). For years it was rumored that the Bandkanon 1A had the secondary, but vital, mission of acting as an “atomic gun”, that is, firing shells with a small nuclear warhead. However, the secret documentation on the “Swedish nuclear weapons program” carried out from 1945 to 1972 clearly specifies that the priority was to manufacture aerial bombs with a yield of between 20 and 50 kilotons. It is true that Sweden showed interest in acquiring North American 155mm W-48 nucler shells with a yield of 0.072 kilotons (equivalent to 72 tons of TNT), but the United States rejected the proposal. However, the option of using the Bandkanon 1A to fire chemical munitions against a hypothetical Soviet attack in the Upper Norrland is much more credible thanks to its very high rate of fire and NBC protection.
