In general, during the Second World War, the Soviet army was armed with a lot of rockets. The most famous of them - M-13, they were installed on the first "Katyusha". We will not list all of them, but will focus on the M-20 and M-30, for it is these rockets that are considered the beginning of heavy rocket artillery.
M-13, of course, were good for their time! Unexpected and massive shelling caused a terrible srach in the German ranks and so on, but, for full-fledged offensive actions, the M-13 were not suitable due to low damage. It was necessary to destroy both heavy equipment and enemy fortifications. Around the middle of 1942, the M-20 entered service with the Soviet army, the warhead of which was three and a half times more powerful than that of the M-13. Very soon, the M-30 was also put into service - six times more powerful than the M-13.
The M-20 was easily bolted to the Katyusha, but due to its slightly larger size, these rockets had to be fired in one row, and not in two, like the M-13. But under the M-30, the guides could not be altered in any way (it is worth noting that they were nevertheless attached to Katyusha, but only in the 44th year). Therefore, to launch the M-30, we installed launchers with a simple tilt angle adjustment system ...
On such a machine, right in the factory packaging, first four, and then eight M-30s were laid. The volley was fired using a conventional electric sapper machine, and, as a rule, several machines were included in the chain. The simultaneous start-up ensured the addition of shock pulses, which greatly increased the effect compared to individual launches.
And so, due to the usual and quite understandable reluctance of end users to read the documentation (more precisely, the manuals simply went to hand-rolls), the following often happened on the battlefields. During preparation for launch, they often forgot to remove the spacers that held the projectile in a wooden box (original packaging) during transportation. If the spacers were not removed, then this whole xy # t @ started together with the box, and there were times that together with the machine!
This design had dimensions of about 1.5 by 2 meters, which led to conversations in the ranks of the Germans that the Russians really @ x ... ate and shoot at them in sheds!