From S-Tank to ikv 88 Fire-Support Vehicle
Rather than simply retire the strv 103 fleet it was decided to turn these tanks into infanterikanonvagn or infantry gun carriers. In effect, these turreted ikv 88s would perform the fire-support role of an IFV (albeit, without the infantry dismounts). The 10,5 cm kan strv 103 was removed [1] and the rear compartment revised for the installation of a 2-man turret. Initially, that turret was to be an advanced version of the turret being designed for the future srtf 90 - a genuine Infantry Fighting Vehicle. However, plans shifted.
Considerable debate occurred over the main armament needed for this form of Ikv. The ideal piece was seen to be variant of Bofors' 5,7 cm anti-aircraft gun - however, that gun would require an entirely new turret design. One alternative considered was a 'ground' derivative of another AA gun - the Bofors 4 cm L/70. But that would mean no ammunition commonality with the pending strf 90 IFVs. [2] So, a compromise was arrived at. A hybrid variant would be developed by Bofors - essentially the strf 90's 4 cm akan m/70 breech and recoil mechanism mated to the longer L/70 barrel. The resulting autocannon was designated 4 cm akan m/87.
As built, the base turret was heavily clad in kompositpansar panels and the gun-mount strengthened for the new, long-barreled Bofors 4 cm akan m/85. The commander's cupola anticipated that of the strf 90 which its intermediate 'umbrella' positioning. Other than in changes to accommodate the new turret ring, the former strv 103 hull remained largely intact. However, like the new turret, the hull was also clad in kompositpansar panels for added protection. These panels were less thick than those of the one-off strv 103D but were uninterreupted on the long and now-gunless upper glacis plate. 'Diesel-pansar' jerry cans held over from the strv 103 helped protect the lower hull sides.
The ikv 88 was considered successful as a fire-support vehicle but had a comparatively short life-span within the mekaniserade brigader. Shortly after service introduction, the planned AT4 recoilless gun became available. Four were mounted on adjustable rear turret swivels. In 1997, less than a decade after service introduction, the Ikv 88s were stood down in Sweden's regular force Thereafter, the infanteriregementen received fire-support from strf 90s. The Ikv 88s were then passed on to the Hemvärnet (Home Guard) - making up the Hv's first use of heavier armour. New Hv-MekB units were formed on a mix of pbv 301s and ikv 88s. The Hv infanterikanonvagnikv went through their own rebuild programme in early 2000. The planned ikv 88A engine updates were passed over to an ikv 88B programme where the Hv vehicles also received standard 'short-barreled' 4 cm akan m/70 guns from strf 90s. [3]
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[1] These Bofors L74M L/62 gun would be transferred to the Stridsvagn 1988 programme to create the strv 108D upgrade variant. The strv 108Ds would also receive strv 103C commander's cupola (now surplus to the Ikv 88 rebuilds).
[2] The 4 cm akan m/70 - a derivative of the Bofors 40mm L/60 - fires 40×311mmR rounds. The more powerful L/70 AA gun fires longer 40×365mmR cartridges.
[3] The long-barreled Bofors 4 cm akan m/85 guns were used to re-arm strf 9040Cs (which then became strf 9040Gs). The ikv 88 turrets - modified strf 9040A types - were showing the strain of their more powerful guns. It was felt that the base strf 9040C turrets of the strf 9040G could better-handle firing loads. It was also believed that regular armén strf 9040Gs would make better tactical use of the increased firepower.