This is the
Ardeer Aggie, a proposed replacement for the Churchill AVRE during the Second World War. Only a single prototype was made which currently still exists and is located somewhere in Britain. What differs this vehicle from the regularly run of the mill
Churchill AVRE is what you may have noticed from the images, the gun. It uses a 300mm L/10 gun with a 3 metre long gun barrel which fires 20kg (44lb) HE-filled projectile at an effective range of 410m. (450 yards) This differs to the
Churchill AVRE observed in World War II as the
Churchill AVRE uses a 290mm Petard Mortar firing a 18kg (40lb) HE-filled projectile nicknamed the “Flying dustbin” due to it’s poor flight characteristics at an effective range of approximately ~140m (~150 yards). As you can see the
Ardeer Aggie has quite a heavy improvement, not only does it have a much heavier payload and can also be loaded inside the vehicle while the
Churchill AVRE requires to be loaded from the front, but the range also is now much further. The vehicle uses a unique method to achieve the recoilless effect, they put a form of counterweight behind the charge in which when the gun recoils (which could have injured or killed anyone around or behind it) which According to
World of Tanks - For the Record,
to improve the gun recoilless effect, they did put a sort of “counterweight” behind the charge itself (a package of sand allegedly). When the gun shot, this charge was propelled violently to the back (away from the turret), compensating for the majority of recoil
due to the fact that the gun demanded far larger quantity of gunpowder then normally necessary. This however proved to be cumbersome, as not only would the shell need to be loaded but also the charge and then the counterweight each time the gun would be fired and with each time the gun fired the recoil would be heavy enough to injure the crew capable of concussions and broken bones if they had contact with the gun or surrounding mechanisms or turret which jerked violently. After firing, the gun itself would also reach high temperatures further increasing the crew's health and safety risks. However it was also unsafe to operate around the vehicle itself when firing the bag of sand and the following gun blast which could injure or kill any infantry taking cover behind the vehicle. There were attempts to mount a form of blast collector behind the turret however it was not effective. The project was cancelled as the increased range was not deemed necessary in exchange for the safety of the crew and other friendlies in or around the vehicle.