12 cm tornautomatpjäs m / 70 The 12 cm tornautomatpjäs m / 70 ( " 12 cm automatic turret gun model 1970 " ) , also known as ERSTA ( " Ersättning Tungt Artilleri " or " Replacement Heavy Artillery " ) was developed to defend vital points like seaports from enemy landing ships , as well as area denial and fire support , even on a nuclear battlefield . Due to political cost - cutting requirements , the number of 12 / 70 batteries built in Sweden was limited to 6 . For the same reason , some protection aspects were abandoned . History . In the 1960s , the Swedish coastal artillery sought to replace several older heavy artillery systems . A study called ERSTA ( " Ersättning Tungt Artilleri " - " Replacement Heavy Artillery " ) was initiated to ascertain which alternative ( conventional artillery , rocket artillery or missiles ) would be best for heavy coastal defense . The ERSTA study . The ERSTA study was a 1960s Swedish coastal defense study aimed at determining what would become the next heavy coastal defense system . A 120 mm automatic gun system was eventually selected . < BR > Originally , Rb 08 anti - ship missile installations were seriously considered but abandoned , possibly because much of that project may have been exposed to the Soviet Union by Stig Wennerström , the spy who also leaked vital information about the air defense system STRIL 60 . Deployment . Several locations were studied and suggested for 12 / 70 batteries , and 10 locations were eventually selected and constructed in 2 series . In the end , due to funding issues , only the first series of 6 batteries was built starting in 1971 . Additional cost - cutting measures had to be taken so EMP protection was severely reduced and the supporting installation of each gun was made smaller by replacing the full featured kitchen with a less capable galley and reducing the overall size of the crew quarters . System description . Each 12 / 70 battery consists of 3 fully independent gun emplacements , a command center , ranging stations and a close - in defense system with AA guns , mortar positions and troop shelters . There were 2 different kinds of 12 / 70 installation , known by their Bofors designations " TAPJ 9101 " and " TAPJ 9102 " ( TAPJ is an acronym for " TornAutomatPJäs " ) . The 9101 system was designed to be installed in a large hole blasted in the bedrock , while 9102 was a variant which did not require such a deep hole and would be installed in a large hole dug in soil , i . e . where no stable rock was available . On both variants the hole is plugged with several meters of densely reinforced special concrete . Turret and gun system . The 12 / 70 gun is a fully automatic , water - cooled vertical sliding wedge design mounted in an armored turret which is electrically traversed under computer control while the elevation motor is controlled manually ( presumably a cost - cutting measure ) . It is fed from a magazine several meters below ground where the crew uses special air - cushion carts to feed cartridges onto a loading table . From the loading table the cartridge is fed through a hoist system and loaded into the gun using a pendulum loader . Spent cartridges are passed down a chute into a space at the bottom of the gun well , which is over deep on tapj 9101 and a few meters less on tapj 9102 . The turret is manned by 3 men ( gun commander , traverse operator and elevation operator ) with the rest of the gun crew working in the magazine or the installation below . < br > To protect the gun system from ground shockwaves and overpressure in case of a nuclear detonation , the barrel is lowered into its storage position in a special " ground attachment fork " and the turret is hydraulically lowered and anchored to its foundation . The muzzle is automatically sealed when the barrel is lowered into storage position . During a nuclear attack , the turret crew may not stay in the turret because of the initial radiation , but they may reoccupy it and be ready to fight immediately after the attack thanks to a special liner which reduces induced radiation to such a point that it is safe to immediately reoccupy the turret . Supporting installation . Each gun emplacement is supported by an installation which contains power supply , accommodation and a galley . This enables at least 60 days endurance when cut off from the outside world . It consists of a steel - framed structure placed on rubber cushions for protection from ground shockwaves . On a type 9101 emplacement , this installation is a 3 story structure placed below the magazine . < br > The command and control center is a larger installation consisting of a 5 story building of a similar design which also has a more capable kitchen and a sickbay with surgery capability . In addition to cables and ordinary radio masts , the 12 / 70 command features reserve masts which are normally stored in silos below ground and may be raised as needed . Fire control . The 12 / 70 system marked the first use of the ArtE 724 digital fire control system . This may be fed information from several type of ranging stations , chiefly a radar system called HSRR which consists of a radar antenna normally stored below ground under an armored hatch . At least 2 surveillance radars are attached to the battery , and when a target is detected the HSRR may be raised and used for ranging reducing the time it is exposed above ground . < br > The other main ranging instrument is a laser rangefinder called AML 702 installed along with a low - light TV camera in an armored turret called the " laser eye " . This can be remote controlled from the ranging station or command center and takes the place of the periscopes used in older installations . Second series . A second series of 4 ERSTA batteries was planned but never realized as political priorities changed in the late 1970s , downplaying the threat of a nuclear attack . The fire control and radar systems meant for series # 2 were redirected to a few older installations that were modernized in the mid - 1980s as a very cheap and effective way to improve performance . Modifications and final disposal . The Swedish 12 / 70 system was slated for modernization in the early 2000s but with the 1999 decision to abandon all invasion defense it was selected for scrapping instead . One gun emplacement , gun # 3 at Landsort , has been declared a State Construction Memorial and will be preserved , although it is presently unclear if it can be shown to the public other than on special occasions due to its remote location , modern accessibility requirements etc . Norwegian export . In the late 1980s 8 guns were exported to Norway , where they were installed in two 3 - gun batteries and one 2 - gun battery between 1989 and 1994 . Unlike the Swedish installations the Norwegians decided to implement EMP protection and enlarge the supporting installations in order to improve crew comfort . The Norwegian installations , being about 10 years newer , also feature a more modern fire control and communications system . Gun number 1 at Meløyvær will be kept as a museum , the remaining 7 guns will be dismantled .