Now we have drifted off again into imaginary Bismarck firing regimes.
will not change what crude figures (not a biased mathematical distortion,
What is actually lacking is enough data to provide any worthwhile analysis
. It is not the figures that are crude, since they don't exist in sufficient numbers, but merely the analysis.
I hope readers will indulge a longer post. These are engineering matters which can be discussed and comprehended, and are surely less wearing than lengthy theoretical extrapolations of what such and such shell might do against a particular armour at such and such range when combat shows it was largely unpredictable.
Barben's explanation requires that despite the shell ring being full (16 shells) and there being no need for the vertically-sliding flash protection doors between shell room and shell ring to be open, they are open, allowing yet another shell to slide uncontrollably forward into the boundary between the fixed structure and the rotating ring because of operator failure. The doors close off four circular ports through which the shells pass from shell room to shell ring. In the shell room four fixed waiting troughs/trays take the shells as they are deposited by overhead grab. Power rammers are required to push the shells forwards into the shell ring. The "hinged or bridging trays" according to Peter Hodges diagram, are on the periphery of the shell ring, ie inboard of the flash protection doors. Presumably they are hinged so they move to an upright position once the shell has moved across it onto the ring proper, like a wagon entering a castle over a medieval drawbridge. Once the shell has entered the ring, the hinge trays come up, protected presumably by anti-surge stops that prevent the shell sliding either forwards or backwards. When the ring has rotated and positioned the loaded tray correctly, rammers push the shell forward into the cages to be lifted to the gun house.
To me in is unimaginable that the forward surging stops in the waiting tray are not interlocked to the flash door opening and the power rammer. There would no point in enabling a crew member to release the stops before the door is clear and for flash protection (remembering Jutland), the door must be shut as soon as a shell is loaded. The anti-surge stops are supposed to be designed precisely to stop a shell moving uncontrollably in a seaway, and therefore whatever Leach does with the helm this accident is not his fault.
On the other hand Godding's explanation makes far more sense, with an equipment failure, ie inadequately-strong and therefore sheared shell rear anti-surge stops allowing the shell to slide back, pushing the hinged trays down and impacting parts of the fixed structure. The only query is why this would cause "mayhem" in the shell handling rooms, the hinged trays are on the far side of the flash doors. The reason for not moving the shell ring is presumably that brave men must climb into this space to clear the damaged hinged trays and further movement might cause further damage.
Whichever explanation is nearer to the truth, the witholding of that part of Barben's material not supplied to Dunmunro and might hold clues is indefensible. If the failure actually happened at salvo 20 and there were 3 accessible quadrants of the shell ring loaded with 12 shells, why didn't Alywin, who is theorised to be making excellent LC shooting, according to A & A 's photo anaylsis, just keep going until the Cease Fire order?
Maybe the problems described happened earlier, and manifested themselves at salvo 20.
Having seen Mr Jurens expounding on shell handling aboard USS Texas in a recent documentary (I got my hat there too) maybe he can provide some further insight.
All the best