The problem was that the Allied did not follow it up, Speer wrote that while the Allied destroyed the dam they didn’t do much while the German was repairing it, which was a difficult work and could be easily disrupted by even low yield bombing.

And there’s a good reason why they had to resort to it,

Torpedoes don’t work, because the German was not stupid enough and deployed multiple layer of anti torpedo nets to protect the damn.

Bombing the damn from above with direct impact bombs is ineffective as well because the damage is limited if you just bomb it from above owing to dam structure shape and also because of the difficulty of getting a direct hit.

They didn’t develop the method and technique for the heck of it,
They did so because there were NO OTHER effective method to do so at the time

The box at the rear is the standard stowage box fitted to the rear of the turrets.

There was a loading tray that could be used which meant no part of the loader had to be exposed – this was awkward to use so mostly they were loaded by hand, the loader only having to expose his hands and for a short time.

Lots of myths still circulate with much getting into books about how it was loaded – mostly believing a crew member had to exit the tank to load.

Ignoring the obsene material requirements, another significant issue was building the dammed thing – the only place it could feasibly be built was Canada. There you are limited to doing most building work during the summer months, however the sheer size of the final design was estimated to have taken the best part of 3 years; and that was with a sufficient level of manpower to do the building, which there probably wasn’t.

I have a replay here somewhere of a 580-someodd meter “snipe” on Sand River that takes several seconds to reach a stationary sniping T-28, its unfortunate victim.

Them derp guns, sure are inaccurate ey wot.