In the works IV

Sometimes our design cycle just works and a model is ready to go right away. One example is our model of the Swedish Ikv 91. A follow on the Ikv 72 series, the 91 was a purpose built infantry assault gun with a low velocity 90mm gun in a turret mount firing HEAT and HE, excellent mobility and operational range and full amphibious capability. Production began in 1975 with upgrades featuring laser rangefinding, an improved ballistic computer and hunter killer capability. By the 80s it was clear that 90mm HEAT was not going to cut it and a number of upgrades were considered. The end of the Cold War put an end to the Ikv 91’s service as well as attempts to market an improved version internationally.

Ikv 91

Sometimes our design process needs several iterations before it works out. That was the case with our model of the British Conqueror heavy tank, much like the tank itself. The Brits had been working on a follow on to the Churchill infantry tank, designated A45, but post war plans changed all that. The FV200 series planned to use variations on one hull for everything, with Centurion handling most duties with an improved 17lbr and the redesignated FV201 picking up a 20lbr along with the heavy tank role.

The first of the post war tank panics changed plans again. After getting a good look at the IS-3, Centurion switched to the 20lbr and the newly re-renamed Caernavon took Centurion turrets in 17lbr and then 20lbr varieties while work began on a 120mm rifle. This wound up being the L1 120mm rifle, taken from the US M103 heavy tank, and the first Conquerors entered service in 1955. The commander’s cupola incorporated a unique fire control system: it was capable of 360 degree traverse and had a coincidence rangefinder forming the basis of an early hunter-killer system. The commander would find and range a target, the gunner could then traverse to a mechanically indicated cue. Once on target, the commander could move on to the next target while the gunner engaged.

Ultimately Conqueror, much like the M103, resembled the King Tiger in some unfortunate ways. Armed with a massive, long range gun, a huge turret with 7 inches of steel armor (10 on line of sight), good terrain handling characteristics, a worryingly short operational range of only about 100 miles, a painfully low top speed of only 22 mph and high cost resulting in low numbers, Conqueror might have suffered the same fate: deadly at the tactical level, hopeless at the strategic and operational levels of war. It was withdrawn from service in 1966. The armor was insufficient to handle ATGMs and with NATO going to the L7 105mm rifle on faster, cheaper tanks Conqueror was a tank without a mission.

Turning Conqueror into a printable model was also a challenge. Our first attempt was true scale, with all the bits reproduced at 1/100 scale.

Looks good, right?

Maybe not.

Unfortunately, true scale has problems. The Browning machine gun up top is going to break off in a stiff breeze, the bustle rack fell apart on the way off the printer, and those little handles on the skirts and turret broke when I handled the tank to clean it up. Another problem is that CAD doesn’t really draw curves, it creates a series of points connected by straight lines that create planes. More points and lines can create the illusion of a curved surface at the cost of complexity. Unfortunately the turret was a little too simple, which caused those facets.

Win some, lose some

Our next try fixed the bustle rack and handles, improved the commander’s Browning, got a much smoother curve on the turret and corrected the look of the skirts… right up until they fell off. And the cupola needed a fair bit of filing before it fit, which no one wants to mess around with.

Just about got it

Another pass largely fixed it. The Browning is now strong enough, the skirts look right and, crucially, are not falling off, both the turret and cupola fit and traverse nicely. Just about ready to put up for sale.

Now that this model’s problems have been conquered, back to the land of beer and schnitzel.

The new German military had a whole series of problems. Nobody trusted it, all it’s senior officers and NCOs and also all the weapons designers might be arrested for war crimes at any moment, the industrial base had been bombed flat and what hadn’t been destroyed had been looted taken as reparations, half the surviving politicians had switched from National Socialism to International Socialism, and International Socialism was right across the inter German border with a very large army that seemed ready to make Socialism a little more International whether West Germany wanted it or not. Once the new Bundeswehr had been set up with American equipment, work started on kit that was a little more to German tastes.

One of the first projects was an early infantry fighting vehicle. Halftrack mounted panzergrenadiers had worked out well in the war, but halftracks had turned out to be a dead end with all the disadvantages of both wheels and tracks while the advantages never quite made up for the problems. A fully tracked vehicle was called for, and Hispano Suiza of Switzerland had one. The HS30, also called the Schützenpanzer 12-3 lang was intended to be the basis for a range of vehicles, from a 20mm cannon armed IFV with an eight man squad to mortar carriers, anti-tank vehicles, scouts and more with a planned fleet of more than 10,000 vehicles intended to enter service in 1958. Unfortunately, HS 30 could be summed up with the phrase “and then it got worse“. It was plagued with reliability problems and difficult maintenance that stemmed from design flaws that featured the worst tendencies of both Swiss and German engineers. Not only did it cost too much, production problems (West German industry wasn’t interested in building something it was illegal for them to export) meant that the initial production had to be imported, with more than 1000 vehicles built in the UK by workers who might not have been all that keen on giving the Huns new panzers. A series of procurement scandals discredited Hispano Suiza, the former Wehrmacht officers who lobbied for them, the former Wehrmacht officers in the Bundeswehr and Ministry of Defense they were lobbying and the politicians. To make matters even worse, the rear door was blocked by engine components, so the infantry could only mount or dismount via the top hatches which were 6 feet above the ground. And then it got worse again. The engine was underpowered, so on paper the HS30 had trouble keeping up with M47s and had no hope of keeping up with Leopards. Except that in the field, the front suspension was much too weak, so drivers couldn’t exceed about 12 mph cross country lest they break it. But then it got worse again: to get full access to the engine, maintainers had to remove both tracks and the whole back end of the vehicle.

It was with considerable relief that the Bundeswehr got rid of the last HS30 with the switch to Marder.

Looks pretty neat, unless you have to use it

With a breech loading 81mm mortar

Adding a 106mm recoilless rifle for even more dakka!

We’re also going to offer 120mm mortar, SS-11 ATGM and artillery observer variants as part of our Bundeswehr release starting next month.