Bofors Strv-103 (S-Tank)

Notes: In the mid -1950’s, the Swedish Army was looking for a tank that combined several of the new features that had been developed for tanks, including a low profile, an autoloader, a high-caliber (for the time) main gun, and excellent speed. They were also looking for a replacement for the Swedish version of the Centurion, which was only marginally more effective than the T-55, and was rather large, mechanically unreliable, and fuel-hungry. They studied several countries’ tank designs, especially several French proposals, and even flirted with contacting the Warsaw Pact. In the end, they went with an…interesting new design built by Bofors. The Strv-103, commonly called the S-Tank, was a radical departure from normal tank design, with no turret and a hull-mounted gun, hearkening back to some of the tank destroyer designs. Though in other armies it would be considered a tank destroyer, the Swedes consider it a main battle tank. Though the design brings a number of benefits, such as a very low profile of only 2.14 meters and light weight, it also presents a number of deficits, as will be described below. The S-Tank is primarily a defensive weapon, suited to the unique requirements of the Swedish Army of the time. First deliveries began in 1967.

The S-Tank was revolutionary in many ways; if it had a turret, it might have had export sales (some countries were actually interested in the S-Tank, but the lack of a turret was usually the sticking point; another problem, though more easily fixed, was the S-Tank’s lack of power.

The S-103A

The S-Tank’s turretless design makes for a low profile; it was also felt that, because the S-Tank had almost no profile when fighting from a hull-down position, the S-Tank could get away with less armor than most contemporary designs.

The autoloading main gun allows the crew to be reduced to three, but the layout is not what you might think. The driver doubles as the gunner (he is not expected to be driving and gunning at the same time), and he can also fire the sponson machineguns. Behind him is a radio operator; he can thus operate several radios at once, and the S-Tank can function as a command tank. The driver’s hatch is on the left glacis, with the radio operator using the driver’s hatch. The commander has a cupola on the right side of the main gun; the cupola has a traverse of 208 degrees and the commander has auxiliary controls for the main gun, and can also double as the gunner; he also has a set of driving controls and can double as the driver.

The S-Tank’s 105mm main gun, though based partially on the British L-7A2, has some unique design elements, especially in the breech area, since it is fed by an autoloader. This gun also utilizes a very long 62-caliber barrel, possible since a large portion of the length is supported directly by the hull. This gives the main gun exceptional range, and it uses NATO-standard 105mm gun ammunition. However, the design of the S-Tank means that the main gun has no traverse and no elevation. Elevation is accomplished by rocking the tank on its suspension; the S-Tank can almost run its gun barrel into the ground, or raise it as high as 30 degrees. Traverse is done by pivot steering the S-Tank, and it can turn through 360 degrees almost fast enough to get the crew sick. This method of traverse and elevation has a major drawback, however – the S-Tank, since it uses the suspension to aim the main gun, cannot fire on the move, unless the crew hopes to get a lucky hit. (In game terms, firing on the move is done with no gun stabilization and done with a -4 deficit which is not mitigated by the S-Tank’s normal bonuses as well as being one level harder.) The commander has a machinegun mounted on a special antiaircraft mount; two more bow-mounted machineguns with limited traverse and elevation of their own are found on sponsons on the fenders, and these can also be fired by the commander. The M-2HB is found on the right sponson and the Ksp-39 on the left sponson.

The S-Tank’s engine arrangement is also unusual. The primary engine is a multifuel 240-horsepower engine. However, the S-Tank also uses a supplemental gas turbine engine, developing 300 horsepower. The engines are both connected to the drive train, and all the driver must do is flip a switch to turn on or off the gas turbine engine. The S-Tank is meant to cruse and travel on just the primary engine; the supplemental is designed to give the S-Tank a boost in power in combat. (They can’t run both at the same time unless the S-Tank is stationary; this allows the gas turbine to help start the primary engine in cold weather.) Though this sounds complicated, the switch in engines is smooth, maintenance is not unduly arduous, and the system is very reliable. The S-Tank was the first production combat vehicle to use a gas turbine. The stats below include two travel and combat movement figures and two fuel consumption figures; the first is for the primary engine, the second for the gas turbine secondary. (The increase in fuel use when using the gas turbine in combat is negligible for game purposes; if you want to be picky, the gas turbine engine uses about 0.006 extra liters per minute of combat).

The suspension of the S-Tank is designed for rough terrain. In addition to being used for elevation and depression of the main gun and hull machineguns, the S-Tank can raise and lower its profile by up to 13 centimeters using the suspension. The suspension is hydropneumatic and very responsive, as well as being reliable. The S-Tank is also amphibious with preparation; a fording screen must be erected around the hull, which takes 15-20 minutes.

Armor is essentially steel plate, again relying on the low profile and speed for survival. At the front of one tank per platoon is a dozer blade, which can clear obstacles or brace the S-Tank when firing its main gun; it can also help protect the vehicle. If the S-Tank is hit by the front, it is 50% likely to hit the dozer blade, which adds 10 points of armor to that hit and acts as spaced armor. At the rear is an unditching beam; above that are armored boxes for the crew’s gear and equipment.

It should be noted that only 80 S-103As were produced in one production batch, and virtually all of them were quickly thereafter upgraded to the then-new S-103B standard.

The S-103B

The S-103B is for the most part like the S-103A, though the armor is thickened, especially on the glacis. The S-103B introduced the bar/slat frontal armor to help pre-detonate HEAT rounds; this is treated like spaced armor, but 50% of the time it stops 2d6 of damage, and the other 50% of the time, 4d6 damage. At the time of the S-103B;’s deployment, this bar/slat armor was considered secret and was to be mounted only in wartime. The side skirts also received an update in protective value. The S-103B’s primary engine remained the same, but the supplemental gas turbine was replaced by one developing 490 horsepower. The engine change was done to help rectify the lack of oomph in the S-103A’s power, and to help with the heavier weight of the S-103B. (Nonetheless, the S-103B is sloooow.) The S-103B added a laser rangefinder to the fire control suite (this is useless, of course, if the S-103B attempts to fire on the move). The right-side M-2HB sponson-mounted machinegun was replaced with a Ksp-39.

An interesting development for the S-103B took place at Ft. Knox in the US in 1975. The US Army was toying with the idea of procuring a lightweight tank destroyer, and leased two S-103Bs for this purpose (including two Swedish crews, who were reportedly paid US TDY money in addition to their normal pay). The results indicated that the S-103B was more accurate than the M-60A1E3 (the latest version of the M-60 at the time), particularly at long ranges; however, target acquisition took 0.5 seconds longer, though actual firing was 1.5 times faster. Similar tests were conducted by the Norwegians (in 1967 with S-103As) and the British in 1968 (with S-103Bs), with similar results. In all three cases, the testing officers could not identify any significant tactical disadvantage of the turretless design, except for the slightly slower target acquisition.

The S-103C

In 1986, an upgrade program began to update the S-103B as much as possible. Armor efficacy was further improved (just a bit), and the dozer blade became standard on all S-103Cs, instead of having one dozer-equipped S-103 per platoon. The primary engine was replaced with a US-designed 290-horsepower diesel engine (the previous engines were British-designed), though the gas turbine secondary remained the same. The new diesel engine was smaller, allowing for the installation of larger fuel tanks. The laser rangefinder was replaced with an improved model, and a ballistic computer was added. The autoloader was redesigned, as was ammo storage, to allow for the storage of more modern ammunition. The crew compartment was given full NBC overpressure with a collective NBC backup, as well as radiation shielding. Unfortunately, this redesign as well as an increase in armor made the S-103C a bit heavier; it is also some 20cm wider. On the sides of the tank, a pair of 6-barreled Lyran smoke grenade launchers were added. The S-103 was first issued in 1988, but it was the last hurrah for the S-Tank – by the mid-1995s, the S-103C was relegated to a driver training role, and they were finally phased out in 1997, being replaced by the Leopard 2.

The S-103D: The S-Tank That Almost Was

In the mid-1990s, Bofors made a last attempt to keep the S-103 in service, resulting in one S-103D prototype that was heavily upgraded from an existing S-103C. Virtually every aspect of the S-103C was upgraded. The S-103D had the latest in fire control equipment, including an up-to-date ballistic computer that responded within milliseconds to the suspension changes and slewing necessary to aim the main gun, as well as having some control over the movements of the suspension itself to assist the gunner (whether the gunning was being done by the driver or commander). The driver and commander also had updated laser rangefinders as well as thermal imagers; the driver also had a short-range passive IR viewer added to his vision suite as well as to the backup camera. The suspension was modified to allow faster movement and better off-road performance, and the engines were replaced with more powerful versions of the S-103C’s engines. Applique armor was added to the sides and rear of the S-103D, and composite armor was even seriously considered for the glacis (though never actually installed). Floor armor was slightly thickened as an anti-mine measure.

In the end, however, the S-103D idea was rejected, as the Swedes were receiving better versions of the Leopard 2; they were also improving the Leopard 2s they received, and even better ones were to be acquired in the future. Only one S-103D prototype was actually built, and this one now resides at the Avall Armor Museum. It should be noted that this S-103D prototype is being kept in perfect working order, along with most of the museums assets; this would be a good hook for a Twilight 2000 game.

Vehicle

Price

Fuel Type

Load

Veh Wt

Crew

Mnt

Night Vision

Radiological

S-103A

$323,085

D, G, AvG, A

600 kg

37 tons

3

11

Image Intensification (D, C)

Enclosed

S-103B

$418,782

D, G, AvG, A

600 kg

39.7 tons

3

12

Image Intensification (D, C)

Enclosed

S-103C

$379,387

D, A

600 kg

41.2 tons

3

14

Image Intensification (D, C)

Shielded

S-103D

$553,754

D, A

600 kg

40.2 tons

3

18

Thermal Imaging (D, C), Image Intensification (D, C), Passive IR (D)

Shielded

Vehicle

Tr Mov

Com Mov

Fuel Cap

Fuel Cons

Config

Susp

Armor

S-103A

61/43; 70/49

14/9/2; 16/10/2

850

113; 147

Stnd

T4

HF48 HS12 HR8

S-103B

47/50; 92/65

11/7/1; 21/13/3

850

121; 245

Stnd

T5

HF52 HS13Sp HR9

S-103C

65/46; 89/63

15/10/2; 20/13/3

960

139; 255

Stnd

T5

HF54 HS14Sp HR9

S-103D

80/57; 110/78

19/13/3; 25/16/4

960

171; 314

Stnd

T5

HF60Cp HS16Sp HR10**

Vehicle

Fire Control*

Stabilization*

Armament

Ammunition

S-103A

+1

Fair

105mm L-74 gun, Ksp-39 (Bow), M-2HB (Bow), Ksp-39 (C)

50x105mm, 1375x7.62mm, 825x.50

S-103B

+2

Fair

105mm L-74 gun, 2xKsp-39 (Bow), Ksp-39 (C)

50x105mm, 2750x7.62mm

S-103C

+3

Fair

105mm L-74 gun, 2xKsp-39 (Bow), Ksp-39 (C)

50x105mm, 2750x7.62mm

S-103D

+4

Fair

105mm L-74 gun, 2xKsp-39 (Bow), Ksp-39 (C)

50x105mm, 3500x7.62mm

*These modifiers do apply if the crazy S-103 is crew is trying to fire on the move; see above.

**Floor armor for the S-103D is 7.

Swedish Centurions

Notes: After World War 2, the Swedes began looking for a new main battle tank; though Sweden did not directly participate in World War 2, they were able to get a good look at modern armored warfare and realized that their tank force was obsolete. The Swedes decided that the tank that best suited their needs was the British Centurion tank. Unfortunately, Sweden had to wait a while before Britain could spare any Centurions to sell them – British production facilities for tanks had to be rebuilt, and then the Korean War intervened. Deliveries of Sweden’s first Centurions therefore did not begin until May of 1953. The version first bought by Sweden was the Centurion Mk 3, which the Swedish Army designated the Strv 81. Many Swedish Centurions served so long that some fathers and sons were crews of the Centurion, and in one documented case, a father and (many years later) a son were crewmembers of the same Centurion.

The Strv 81

For the most part, the Strv 81 is identical to the Centurion Mk 3. Therefore, some information will be repeated here from the Centurion entry in British Tanks for convenience. A trivia note: the designation "Strv 81" comes from the fact that the Strv 81 is the first tank in Swedish service with a main gun in the 8cm (80mm) range.

The Strv 81 (originally called the Strv C III – the name stuck for several years after the designation was changed) was armed with an 84mm main gun (20-pounder gun in British terms of the time). However, the twin Besa coaxial machineguns were replaced with twin Ksp m/39 machineguns; these are variants of the Browning M-1919A4. The Strv 81 used a Meteor Mk 4B gasoline engine developing 650 horsepower; this resulted in a very fuel-hungry tank. The Strv 81 could carry the Centurion Mk 3’s auxiliary fuel tanks on the rear deck (holding a total of 273 liters of extra fuel), however; this pair of tanks could be triggered to drop off by the commander inside the turret. As they were not armored, they were not meant for use in combat; they were to be used only to increase the Strv 81’s range before entering combat. The Strv 81 had an 11.5-horsepower Morris APU to further reduce fuel consumption during halts and silent watches. (British Centurion Mk 3s also had a Morris APU, but theirs was an 8-horsepower model.) The Strv 81 had the Centurion Mk 3s adaptations for better performance in cold weather and arctic environments, but Swedish engineers further increased the effectiveness of these improvements. Like the Centurion Mk 3, the Strv 81 was a handful to drive due to a balky transmission and problematic brakes. The Strv 81 used different tracks than the British Centurion Mk 3; these tracks were wider and designed for better traction in the Swedish winters.

Due to high fuel consumption and the use of gasoline as fuel, the Strv 81 could also tow fuel trailers carrying 909 liters that were modified to feed fuel directly into the Centurion’s engine. These were armored to a point, but crews still regarded them as a pain in the butt. These fuel trailers entered service in 1953; in Twilight 2000 v2.2 terms, they have an AV of 4 for their bodies, a suspension of W(2), and a cost of $3000. (Interestingly, the fuel trailer proved to be an asset in one particular situation – updated Strv 81s, called Strv 102s, were rear heavy, and they could back into prepared positions and then end up stuck, front end up. The trailer prevented this.)

Layout was identical to the Centurion Mk 3, essentially conventional and similar to modern tanks. The commander’s hatch was on the left turret deck, the loader’s hatch on the right turret deck, and the driver’s hatch on the left hull front. The commander had all-around vision blocks, along with a periscope at the front with magnification. The driver had two wide vision blocks in front of his position, and the gunner and loader both had a periscope to see outside of the turret. Unusually for a tank of its time, the Centurion had no radio operator/hull machinegunner; there simply wasn’t room in the front hull, and the loader became a loader/radio operator. Instead of a turret bustle rack, the sides of the turret had large stowage boxes. In an interesting touch, a small water heater that could boil water or heat rations was found inside of the turret.

The Strv 81 also had some of the Centurion Mk 5’s improvements. The radios were a bit more up-to-date, reducing the workload on the loader. The commander had auxiliary controls for the main gun at his station, including his own rangefinder. However, the commander had only manual controls for the main gun, and did not have access to the powered controls of the gunner. Moreover, he had no way to rotate the turret. The Strv 81 also had a number of small but important improvements to the electrical system and some of the mechanical systems.

The Swedish Army had a bit of difficulty with the Strv 81 in the tool department. The Swedish used the metric system, but the British at the time were still using English measurements. This tended to confuse the Swedish crews and mechanics at first, and also meant that a special set of tools was required to work on the Strv 81. Likewise, even common spare parts like nuts, screws, bolts, and suchlike had to be made to English measurements instead of the metric system.

An interesting variant of the Strv 81 was tested, but not put into production. This version had three launchers for SS-11 ATGMs (Swedish designation is Rb 52) mounted on the turret. One launcher is at the right rear of the turret, one is on the right side of the turret, and one is to the right side of and above the main gun. No ATGM reloads were to be carried. Special sights and controls were added for the SS-11s, which were to be fired and guided by the commander from inside the cupola; however, the SS-11s would basically be day weapons, as the Strv 81 had no night vision equipment. The idea was to give the Strv 81 additional antitank range; in the end, this variant was deemed unnecessary, however, as more up-to-date Centurions were soon to arrive. I have called this the Strv 81/SS-11 below, though I have been unable to find any official designation.

The Strv 102

I’ll grant you that this part of the entry is out of sequence, but this is because the Strv 102 is a modification of the Strv 81.

In 1964, the Swedes decided to purchase the Centurion Mk 10 with its then-new 105mm L-7 main gun. As the Swedes also had on hand a bunch of relatively-new (at the time) Strv 81s, the Swedish Army decided to re-arm 240 Strv 81s with the L-7 gun. This work was accomplished between 1964 and 1966, and the resulting vehicles designated the Strv 102 (second tank armed with a 10cm-class main gun). The installation of the 105mm main gun was not the only improvement the Swedish Army made to the Strv 81; the Swedish had to make other modifications to accommodate the 105mm gun, and opted to apply others.

The entire main gun was replaced, as were the turret mounts, gun mantlet, and sights. The turret had enough room to accommodate the L-7, so the turret design itself needed no modification. However, to the tank mechanics, an even more important modification was made – the English-measurement parts (and as a result, the tool kit) were modified to use the metric system; this modification actually took the longest of the upgrades. Another upgrade was to incorporate larger 960-liter internal fuel tanks; the Strv 102 also retained the ability to mount external fuel tanks and tow the external fuel trailer. Armor was also improved on the glacis and the gun mantlet. Another upgrade was the addition of a commander’s machinegun. Some tweaks were made to the machinegun ammunition storage, and the Strv 102 carries more machinegun ammunition than the Strv 81.

Originally, the Swedish Army planned to retire the Strv 102 (and Strv 101) was to begin phasing out in the early 1970s, to be replaced by more up-to-date versions of the Centurion and possibly some even newer tanks. (The Swedish Army planned to scrap the hulls and mount the turrets in static positions at airfields to use in a defensive role.) Instead, budgetary problems intervened, and the Swedish Army wasn’t able to get everything they wanted. The Swedish Army had to do some budgetary triage, and replacing the Strv 102 and 101 came behind upgrading the APC and light armored vehicle fleet, acquiring new trucks, and buying more ATGMs. This meant that the Strv 102 and Strv 101 would have to soldier on into the early 1990s.

This led to progressive upgrades of the Strv 102 under the REMO program (which started in 1973), in an (most thought over-optimistic) attempt to keep the Strv 102 viable for the time deemed necessary. The Swedish simply succeeded in making an obsolete tank less obsolete. The Strv 102 did soldier on, but the general mechanical condition of the Strv 102s still deteriorated; by 1985, the Strv 102s were deadlined (mechanically unusable until repairs could be made) 40% of the time on the average.

Strv 102 upgrades for the first decade of the REMO program were largely to keep the Strv 102 mechanically operational. In 1983, the Strv 102 was given a major upgrade to the fire control system; the sighting system was completely replaced with a new system that included a laser rangefinder, a ballistic rangefinder, and new day telescopic sights. Though short-range night vision equipment was installed for the gunner, the Swedish Army decided to forgo better night vision equipment or to equip the commander and driver with night vision equipment. Instead, the smoke grenade mortar was replaced with a pair of Lyran illumination mortars externally at the rear of the turret, reachable by the commander and loader. In addition, despite clamoring by the crews, the Meteor gasoline engine was not replaced with a diesel engine as the Swedish Army originally intended to do as part of the REMO program. Radios were also replaced with modern ones. Lugs for ERA were added to the glacis and turret front. The modified tanks were designated Strv 102R.

The Strv 101

About the same time that the Strv 81 was being upgraded to the Strv 102 configuration. The Swedish acquired the Centurion Mk 10 from the British. When the Swedish delegation went to Britain to inquire about purchasing the Mk 10, it came as a surprise to the British – the Mk 10 upgrade to the Centurion was still considered a secret, and the British were surprised that Sweden knew about it, as was the 105mm L-7 gun. After secret negotiations, the Swedish were able to purchase the Mk 10, on the condition that they pretended that it was a Mk 5 upgrade that they had undertaken with British help. (Of course, the secret of the Mk 10’s existence soon came out, and the Swedish didn’t have to pretend anymore.) The Swedish took delivery of 110 Mk 10s in 1966, and quickly made improvements and adjustments for their own needs.

Many of these adjustments and improvements mirrored those of the Strv 102. For one, the Strv 101 used metric-measurement parts and tools as much as possible. The Strv 101 also had the same larger fuel tanks as the Strv 102, while still being able to mount external fuel tanks and tow the special fuel trailer. Unfortunately, this was necessary because the Strv 101 still had the same gasoline engine as previous members of the series and Centurions of the time. The Strv 101 was already equipped with rudimentary short-range night vision for the gunner; a white light/IR searchlight was optional. Like the Strv 102, armor was increased on the glacis and gun mantlet, and also increased across the entire turret front. This is in addition of the already improved armor of the Centurion Mk 10. The ammunition storage for the main gun rounds was rearranged to accommodate a few more rounds, and machinegun ammunition storage was also increased. A commander’s machinegun was mounted. Gun stabilization was improved with the Centurion Mk 10, and the smoke grenade mortar was also deleted on that type; these changes carried over to the Strv 101.

The Strv 101 was also modified under the REMO program. Unfortunately, like the Strv 102, the Strv 101 was forced to keep going much longer than it should have, and suffered from the same maintenance and downtime problems. For the most part, the REMO upgrades were essentially the same as those of the Strv 102 – fire control, night vision, illumination mortar, radios, and ERA lugs; the technical details were somewhat different, as the Strv 102 and 101 were slightly different. The resulting vehicles were designated the Strv 101R.

The Strv 104

Though some Strv 101Rs and 102Rs continued to soldier on until as late as 2000 (mostly as training vehicles), most were stripped of usable parts and then scrapped or used as targets on gunnery ranges. However, 84 Strv 102Rs got a new lease on life, being further updated into the Strv 104. These upgrades were done from 1992 to 1993, a bit later, some 180 more such modifications were done.

One of the upgrades that made the Centurion crews happiest was the replacement of the Comet engine and transmission with a complete, integrated powerpack based on a diesel engine and automatic transmission. This modification was borrowed from the Israelis, who had performed the same modifications on some of their Centurions to produce the Sho’t. The engine used was the US-designed AVDS-1790-2DC, a modified version of that used on the M-60A1 tank; it was a supercharged diesel engine with far less fuel consumption than the Comet engine, but with more power at 750 horsepower. It was coupled to an automatic transmission that made the Centurion far easier to drive. The fuel savings were deemed to be enough that the APU could be deleted; this, coupled with the smaller engine and transmission, meant that the size of the fuel tanks could be dramatically increased. The suspension was also improved to match the extra power of the engine and efficiency of the transmission. The new powerpack and suspension was also much less maintenance-intensive.

Fire control was also improved, primarily by the addition of a better laser rangefinder and a more advanced, more compact ballistic computer with better software. Gun stabilization was also improved, but not enough to take into account by Twilight 2000 v2.2 rules. A small amount of appliqué armor was added to all faces except the rear hull, hull deck, and turret deck, as well as lugs for ERA on the glacis, turret front, and turret sides. (The ERA is of Swedish design and looks very much like thick appliqué rather than ERA; rumors state that this ERA is in fact similar in design to Israeli ERA, but covered by thin layers of aluminum so that it looks like a few large pieces of appliqué rather than small blocks of ERA.) The floor armor was also thickened just a bit. The main gun was fitted with a thermal sleeve to fight barrel droop, but new sensors also helped compensate for any barrel droop when firing, as well as wind conditions. A smaller modification was the replacement with the retention straps for the M-45 submachinegun with ones that will fit the AK-5, and boxes that can hold AK-5 magazines and 5.56mm NATO ammunition.

The commander received a new cupola; again, this was Israeli-inspired, and similar to the Urdan cupola in the hatch design. The commander could lock the hatch completely open or halfway open; in addition, the hatch could be raised straight up a bit and locked in place, so that the commander can see all the way around him without the restriction of the vision blocks, yet have overhead cover from the hatch and not have to raise himself up completely in the hatchway. Essentially, the hatch becomes an armored roof, with the hatch about 300mm above the cupola, enough for the commander to peek out. The commander must still fully open the hatch to operate his machinegun or the Lyran illumination mortars, and the loader has no such fancy hatch. Main gun ammunition storage was again rearranged; less ammunition is carried, but almost all of it is kept in the bottom of the hull and turret basket in armored bins that have an explosion suppression and automatic fire extinguishing system of their own. The interior of the tank itself also has such protection, as does the engine compartment (including the fuel tanks).

The Strv 105

The Strv 105, also called the "Super Centurion," was supposed to be the next upgrade for the Centurion, and would have been done in the mid-to-late 1990s. A few working prototypes were in fact built; plans called for 180 Strv 104s to be upgraded to the Strv 105 standard.

However, the Swedish military’s budget and political events intervened. The Germans were looking to sell most of their Leopard 1s in the late 1980s and early 1990s in order to field as many of the then-new Leopard 2s as possible. They also developed excess Leopard 2 production capability in order to fill export orders. By the time Sweden was to begin the Strv 105 upgrades, the Swedish Army realized that they could do the Strv 105 upgrades, of buy the superior Leopard 2A4 at half the (real-world) cost. That decision was a no-brainer; the Swedish Army bought some 160 Leopard 2A4s with some modifications they requested. Other than the prototypes, no Strv 105s were therefore built. One was retained as a museum piece. This decision also meant that the Strv 104 would have to soldier on a bit longer – they weren’t retired until 2000.

The Strv 105, compared to the Strv 104, did not have as comprehensive an upgrade package, but it would have been an expensive upgrade (real world cost). The biggest modification was to the fire control and gun stabilization; it fully modernized the fire control system, with rock-steady stabilization, a new ballistic computer with up-to-date software and a more compact design, a second ballistic computer for the commander along with access to the gunner’s sights for the commander; night vision for the commander and driver; and a French-designed thermal imager for the gunner. The little-used searchlight was deleted. The commander and gunner had flat-panel displays for gunnery and vehicle state information; the commander also had a new version of the Strv 104’s cupola that could rotate independently of the turret. The commander also had his own laser rangefinder, along with equipment to help him accurately call for fire support from artillery and mortars. Ammunition storage was rearranged, and a large increase in main gun ammunition was possible due to an upgraded electrical and electronics system that took much less room than that of earlier Swedish Centurions. The new ammunition storage layout also allowed the carriage of the new long-rod penetrators (including newer APFSDSDU and APFSDS-T rounds). A slight increase in machinegun ammunition carried was also accomplished. On the turret sides ahead of the stowage boxes, the Strv 105 had four smoke grenade launchers, for a total of eight. A slight increase in base armor protection was also done, and the suspension was redesigned to allow better off-road performance as well as a smoother ride. As with the Strv 104, lugs for ERA were put on the glacis, turret front, and turret sides. In addition, the Strv 105 had armored side skirts. Despite all these improvements, the Strv 105 weighed little more than the Strv 104, due to new technology.

Vehicle

Price

Fuel Type

Load

Veh Wt

Crew

Mnt

Night Vision

Radiological

Strv 81

$298,896

G, A

450 kg

50 tons

4

19

Headlights

Enclosed

Strv 81/SS-11

$376,396

G, A

450 kg

50.2 tons

4

21

Headlights

Enclosed

Strv 102

$353,423

G, A

450 kg

50 tons

4

19

Headlights

Enclosed

Strv 102R

$488,597

G, A

450 kg

50 tons

4

20

Passive IR (G)

Enclosed

Strv 101

$552,489

G, A

450 kg

52 tons

4

20

Active IR (G), WL/IR Searchlight

Enclosed

Strv 101R

$673,783

G, A

450 kg

52 tons

4

20

Passive IR (G), WL/IR Searchlight

Enclosed

Strv 104

$449,230

D, A

450 kg

54 tons

4

18

Passive IR (G), WL/IR Searchlight

Enclosed

Strv 105

$589,202

D, A

450 kg

55 tons

4

22

Thermal Imaging (G), Image Intensification (G, C), Passive IR (D)

Enclosed

Vehicle

Tr Mov

Com Mov

Fuel Cap

Fuel Cons

Config

Susp

Armor

Strv 81 (Both)

102/71

23/15

790

601

Trtd

T6

TF42 TS12 TR6 HF53 HS10 HR6

Strv 102/102R

102/71

23/15

960

601

Trtd

T6

TF45 TS12 TR6 HF58 HS10 HR6

Strv 101/101R

98/68

22/14

960

613

Trtd

T6

TF45 TS17 TR11 HF68 HS13 HR8

Strv 104

107/73

24/15

1200

407

Trtd

T6

TF47 TS18 TR12 HF70 HS14 HR8**

Strv 105

105/72

24/15

1200

415

Trtd

T6

TF48 TS18 TR12 HF72 HS16Sp HR8**

Vehicle

Fire Control

Stabilization

Armament

Ammunition

Strv 81

+1

Basic

84mm (20-pdr) Mk 1A gun, 2x7.62mm Ksp m/39, 51mm Smoke Mortar

65x84mm, 3500x7.62mm, 30x51mm Mortar

Strv 81/SS-11

+1*

Basic*

84mm (20-pdr) Mk 1A gun, 2x7.62mm Ksp m/39, 3xSS-11 ATGM launchers, 51mm Smoke Mortar

65x84mm, 3500x7.62mm, 3xSS-11 ATGM, 30x51mm Mortar

Strv 102

+1

Basic

105mm L-7A2 Gun, Ksp m/39, Ksp m/39(C), 51mm Smoke Mortar

64x105mm, 4250x7.62mm, 30x51mm Mortar

Strv 102R

+2

Basic

105mm L-7A2 Gun, Ksp m/39, Ksp m/39(C), Lyran 71mm Illumination Mortar

64x105mm, 4250x7.62mm, 20x71mm Mortar

Strv 101

+1

Fair

105mm L-7A2 Gun, Ksp m/39, Ksp m/39(C)

68x105mm, 4250x7.62mm

Strv 101R

+2

Fair

105mm L-7A2 Gun, Ksp m/39, Ksp m/39(C), Lyran 71mm Illumination Mortar

68x105mm, 4250x7.62mm, 20x71mm Mortar

Strv 104

+3

Fair

105mm L-7A2 Gun, Ksp m/39, Ksp m/39(C), Lyran 71mm Illumination Mortar

65x105mm, 4250x7.62mm, 20x71mm Mortar

Strv 105

+4

Good

105mm L-7A2 Gun, Ksp m/39, Ksp m/39(C), Lyran 71mm Illumination Mortar

72x105mm, 5000x7.62mm. 20x71mm Mortar

*These modifiers do not apply to the SS-11 ATGM sights, and the SS-11 does not benefit from even the basic stabilization of the main gun.

**Floor armor for the Strv 104 and Strv 105 is 5.

Swedish Leopard 2s

Notes: Sweden got their first batch of Leopard 2A4s in 1994. Before this, they had been testing several other tanks to find a replacement for the Strv 81 series, including the M-1A1 Abrams, Challenger 1 and 2, the French Leclerc, and even Polish versions of the T-80U. But in 1993, the Germans needed to get rid of a bunch of older tanks, including Leopard 1s and Leopard 2 models up to the Leopard 2A4 version, and they needed to do it quickly. They shed these tanks to a number of countries at cut-rate prices; they had stalled for too long on complying with a new Arms Reduction Treaty in Europe that included large cuts in German armor forces, and now they had to go, quickly. The Swedish Army was therefore able to obtain a cut-rate, 15-year lease on 160 Leopard 2A4s (though the Germans will almost certainly not ask for them back at the end of the lease or charge the Swedish any additional money once the lease is up).

The Strv 121

The Leopard 2A4s received in 1994 were almost totally stock Leopard 2A4s, and very few changes were made to them. Virtually all of those initial changes were minor ones to facilitate interoperability with other Swedish Army assets, and Krauss-Maffei, Scania, and Hagglunds teamed up to make those changes. Some changes were made to the electrical system; smoke grenade launchers with more barrels (a total of 16, eight on either side of the turret) replaced the original smoke grenade launchers, the radios were replaced with Swedish radios, and plastic "steps" were added to the side skirts to help the crew to climb up on tank more easily.

A more substantive change was the tie-down points to fit the Barracuda Signature Reduction system to the Strv 121. The Barracuda System is basically a set of form-fitting camouflage nets that have some radar-scattering ability and also greatly dampen the Strv 121’s IR signature. (The Strv 121 is also lighter than the Leopard 2A4; I have not been able to discover why, and it may be simply a differences in sources. Nonetheless, I have used the weight listed in several Swedish sources. These sources also list dimensional differences.)

However, for the most part, the Strv 121s received from the Germans are Leopard 2A4s. Therefore, I will repeat some of the information about the Leopard 2A4 here for convenience. The Leopard 2A4 is the culmination of a set of incremental changes that started in the early 1980s and continued to the late 1980s. The Strv 121 has an advanced thermal imager for the gunner, image intensifiers for the gunner and commander, and passive IR for the driver. The commander can also access the gunner’s thermal imager and gunsights, and has auxiliary controls for the main gun and coaxial machinegun. The main gun is the NATO-standard 120mm Rheinmetall gun; the Swedish Army also opted to retain the Leopard 2A4s MG-3 machineguns, designating them the Ksp m/94. The commander and gunners sights have deflectors to keep flying dirt off of them, and are mounted in the front of the turret. The NBC system, an overpressure system with collective NBC backup, also has such a deflector to prevent clogging. The Strv 121 has an automatic fire detection and suppression system. The gunner’s equipment includes an advanced ballistic computer (with software in Swedish), full stabilization, an up-to-date laser rangefinder, and ammunition racks that are identical to those of the M-1A1 Abrams (they are behind blast doors, and have blow-off panels for the ammunition in the turret). This allows the Strv 121 to carry virtually any type of 120mm ammunition. Armor is a combination of the German version of Chobham, titanium/tungsten/steel sandwich armor, and RHA armor plate.

The Strv 121 has an integrated power pack using an MTU MB-873 turbocharged diesel engine developing 1500 horsepower. This is coupled to a fully automatic Renk HSWL-354 transmission, with the driver having a control yoke and conventional gas and brake pedals. The suspension uses seven steel rubber-tired roadwheels on either side, with the torsion bar system designed for difficult terrain. The Strv 121 also has a 5kW APU, designed for a decreased IR signature and easy access for maintenance.

By 2006, the Strv 121 fleet had all been mothballed in favor of the Strv 122. They are for the most part maintained in working condition, though some are part of museum exhibits or are on static display. If necessary, they could be put back into action quickly, but currently, budget difficulties have prevented the Swedish Army from actually using them. Some of the Strv 121s have been picked over for spare parts that are common to the Strv 121 and 122.

The Strv 121 Upgrades that Never Happened

Before the budget-based decision to mothball the Strv 121 fleet in favor of the Strv 122, the Swedish Army operated both versions of the Leopard 2. They also planned to keep most of the Strv 121s in service, and give them a major upgrade and refit to allow then to inter-operate better with the Strv 122. Other than a few prototypes, however, this refit never happened. The proposed upgrades revolved primarily around fire control, night vision, and armor protection. The upgrades would bring the Strv 121 almost up to the Strv 122 standard (at the time), merely lacking in some armor protection, some details of the suspension, and parts of the electrical system. I have called a Strv 121 with these upgrades the Strv 123 below, though this is by no means an official designation.

The fire control system was to be upgraded mostly by installing improved sights and an improved ballistic computer. The gunner and driver would also have LCD screens to allow them to monitor the Strv 123’s targeting status, position, ammunition available, and the mechanical status of the tank. The night vision/day vision suite would be integrated and brought up to the standard of the Leopard 2A5, though using Swedish components. The commander would have an independent sight head that would give the Strv 123 a true hunter/killer capability, as well as his own laser rangefinder; the commander could also receive input from the ballistic computer without interfering with the gunner’s work. The new sights would require that they be moved to the turret roof and placed in armored heads. The rear camera for the driver would have a wider angle of view and night vision capability. The Strv 123 would be equipped with a GPS positioning system.

Armor improvements would be made partially by a complete replacement of some faces of the armor (primarily the frontal armor), and adding appliqué armor to others. Most of this additional armor would consist of an added layer of a sandwich of steel, ceramic, tungsten, and titanium. The armor of the turret front and glacis would be replaced with more advanced composite armor. Lugs for ERA would be added to the turret front, turret sides, hull front, and (possibly) the hull sides. An improved anti-spalling liner would be added to the interior of the crew compartment and the turret bustle. The side skirts would be replaced with ones that are stronger, yet lighter. Hydraulically-assisted hatches for the crew members would be added, as the hatches themselves were to be much heavier and better protected. Other hydraulic or partially hydraulic controls like the turret rotation and gun elevation would be made all-electric, making them more reliable and saving some weight.

That would have been the first set of upgrades. Later, plans would have called for the addition of the TCCS, which is a digital command and communication system similar to those being used by several other countries, and already used on the Strv 122. I have chosen to call this variant the Strv 124, though again this is not an official designation. The TCCS would involve the installation of a new communications system including a new radio set that can transmit both voice and digital data, encrypted and at high speed. A new computer with a lot of storage space and computing power would also be installed, along with another LCD for commander that displays the positions of friendly and enemy units, and allows updated information to be displayed as it arrives. The driver would also have an LCD, allowing the commander to give him the exact course and destination he wants the driver to follow. The driver would also have access to known information about terrain and other hazards. The computer would have a mapping system based on GPS and software maps that would be accessible to both the commander and driver. The driver would also have access to the tank’s fuel state and mechanical condition. The TCCS would also assist the commander to a large degree in calling for supporting fires and directing air strikes.

The Strv 122

The Swedish Army took its first deliveries of the Leopard 2A5 in 1997. They bought these the "normal" way – i.e, they weren’t tanks that the Germans had to get rid of quickly to comply with treaties, but instead the Germans were offering the Leopard 2A5 for sale on the international market. (Reputedly, the Swedish nonetheless got a very good deal on their Leopard 2A5s, due to good relations between the Swedish and Germans and the high rate of production of the Leopard 2A5 in order to satisfy the many export orders they were receiving.) The Swedish Army designated their Leopard 2A5s the Strv 122 – but again, their Leopard 2A5s were modified versions, and are referred to by Krauss-Maffei/Wegmann as the Leopard 2A5S (or simply Leopard 2S).

The Strv 122 has essentially the same armament, stabilization, and fire control as the Leopard 2A5 (though details vary in the fire control system). Most other details of the Strv 122 are also the similar or the same as the standard Leopard 2A5, so again I will repeat some of these from the German Tanks page here for convenience.

The armor suite of the Strv 122 is basically the same as the Leopard 2A5, including improved armor over the Strv 121, and the characteristic wedge-shaped turret front that results from the greatly-increased protection. This wedge shape also helps deflect shots, and has a side effect of slightly reducing the radar signature of the Strv 122 when viewed from the front. The new armor package consists of updated Chobham-type armor, along with an extra layer of a sandwich of steel, ceramic, tungsten, and titanium. The gun mantlet is also modified in shape to match the frontal armor shape and composition. The side skirts were replaced with ones that are stronger, yet lighter; though details are classified, though it is probably composed of the same sort of armor sandwich as the appliqué mentioned above. An improved anti-spalling liner was added to the interior of the crew compartment and the turret bustle. The new armor is also modular, allowing for quick armor repairs in the field or improvements to the armor suite in the future. In addition, the Swedish used a slightly different armor sandwich for the appliqué armor on most of the faces, giving the Strv 122 slightly better protection than the Leopard 2A5. Lugs for ERA can be found on the glacis, hull sides, turret sides, and turret front.

The gunner’s sight was moved to the roof to avoid having to make large modifications to the new armor of the turret front and having to put a large extension on the sight equipment (which would have compromised accuracy). The commander also received his own sight system, including his own laser rangefinder, in the form of a CITS. Hydraulically-assisted hatches for the crew members were added, as the hatches themselves were made much heavier and better protected. Other hydraulic or partially hydraulic controls like the turret rotation and gun elevation were made all-electric, making them more reliable and saving some weight. The rear camera for the driver has a wider angle of view and night vision capability.

Perhaps the largest upgrade the Swedish Army applied to the Strv 122 was the addition of the TCCS (Tank Command and Control System). This is described above in the part of this entry listing one of the proposed upgrades to the Strv 121 (the version I have referred to as the Strv 124). In addition, virtually all of the proposed upgrades for the Strv 121 are already present on the Strv 122. Like the Strv 121, the Strv 122 can be equipped with the Barracuda Signature Reduction System, though the version for the Strv 122 is of a different shape than that of the Strv 121 (especially in the area of the much-larger turret).

Another major upgrade is the replacement of standard German smoke grenade launchers with the Gallix System. The Gallix System is essentially a soft-kill active defense system with a few extra wrinkles. The system uses nine grenade launcher tubes on either side of the turret, both of which can be rotated from +45 degrees to -5 degrees, independently of each other. (Standard elevation is 30 degrees, if none other is selected.) The Gallix System also includes sensors atop the turret to detect and warn of incoming targeting lasers and active IR targeting systems. The system can be set to launch one or more smoke grenades (either standard smoke or IR-obscuring smoke) automatically if lasers or IR targeting is detected, or the commander can choose to launch them at his command. Any of the grenade tubes can also be loaded with antipersonnel close-defense grenades (similar to the tactical buckshot or flechette rounds of grenade launchers); these must be fired by the commander (there is no provision for automatic firing of these grenades). Other types of grenades that can be used in the Gallix System include HE-Blast grenades and fragmentation grenades; again, these must be fired deliberately by the commander.

Recently, the Swedish Army has introduced the Strv 122M variant (also called the Strv 122B). Ten such modifications have been carried out as of the time I write this (early October 2009). The Strv 122M modifications focus on mine protection, and include appliqué armor for the floor and front lower hull, better protection for the vision heads, vision blocks, rear camera, and the laser designator apertures. A special anti-spall liner is also added to the tank’s floor, and stronger tracks and roadwheels are mounted. The final drives are also better protected, and the ammunition that is not in the turret bustle is restowed and provided with extra protection. The crew seats (especially the driver’s seat, which has almost no contact with the floor of the tank and is basically a suspended web) are essentially suspended to help absorb concussion forces, and some areas of the interior of the Strv 122M are padded (again, especially in the driver’s compartment). While total protection against mines is impossible, the crew is much more likely to survive a mine detonation even if the Strv 122M is immobilized.

Twilight 2000 Notes: Most of the Swedish Leopard fleet consists of Strv 121s without any of the upgrades mentioned. However, some 10% of these tanks have been upgraded to the Strv 123 standard. The Swedish Army has no other versions of the Leopard 2 in service in the Twilight 2000 timeline.

Vehicle

Price

Fuel Type

Load

Veh Wt

Crew

Mnt

Night Vision

Radiological

Strv 121

$552,145

D, G, A

700 kg

55.15 tons

4

28

Passive IR (D), 2nd Gen Thermal Imaging (G), Image Intensification (G, C)

Shielded

Strv 123

$650,591

D, G, A

700 kg

60.4 tons

4

30

Passive IR (D), 2nd Gen Thermal Imaging (G), Thermal Imaging (C), Image Intensification (G, C)

Shielded

Strv 124

$953,591

D, G, A

700 kg

60.7 tons

4

31

Passive IR (D), 2nd Gen Thermal Imaging (G), Thermal Imaging (C), Image Intensification (G, C)

Shielded

Strv 122

$995,122

D, G, A

700 kg

62.5 tons

4

30

Passive IR (D), 2nd Gen Thermal Imaging (G), Thermal Imaging (C), Image Intensification (G, C)

Shielded

Strv 122M

$1,009,799

D, G, A

700 kg

63.2 tons

4

30

Passive IR (D), 2nd Gen Thermal Imaging (G), Thermal Imaging (C), Image Intensification (G, C)

Shielded

Vehicle

Tr Mov

Com Mov

Fuel Cap

Fuel Cons

Config

Susp

Armor

Strv 121

180/126

40/24

1200

827

Trtd

T6

TF152Cp TS39Sp TR24 HF160Cp HS25Sp HR15

Strv 123/124

164/115

36/22

1200

869

Trtd

T6

TF160Cp TS41Sp TR26 HF200Cp HS28Sp HR16

Strv 122

159/112

35/21

1200

803

Trtd

T6

TF162Cp TS42Cp TS28 HF203Cp HS30Sp HR16

Strv 122M

157/111

35/21

1200

807

Trtd

T6

TF162Cp TS42Cp TS28 HF203Cp HS30Sp HR16*

Vehicle

Fire Control

Stabilization

Armament

Ammunition

Strv 121

+4

Good

120mm Gun, Ksp m/94, Ksp m/94 (C)

42x120mm, 4750x7.62mm

Strv 122/122M/123/124

+5

Good

120mm Gun, Ksp m/94, Ksp m/94 (C)

42x120mm, 4750x7.62mm

*Floor armor for the Strv 122M is 12Sp.