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[raflaunches]

Hi everyone


A bit of help required- does anyone know what the three letter acronym B.V.P. stands for? It’s something to do with weapon lifts on aircraft carriers on the drawings I have seen. Not sure if they are vents. The drawing is of a 1960s Royal Navy aircraft carrier. Cheers.

[Capt Podge]

Ballistics ventilation platform? - just a wild guess though.


... or Ballistics ventilated platform.


Ray.

[raflaunches]

Hi Ray


Many thanks for the suggestions- I’ve also been told it could possibly be Blast Vent Projection which with your suggestion would possibly suggest it’s a door or hatch for blast release from any inadvertent explosion.
It’s all very interesting and I wondered how they would look on a model- probably a pair of hinged doors to allow any blast to escape overboard.

[Netleyned]

Blowout Vent Panel.
Ned

[Geoff]

I think Ned has it right! Hopefully you won't need working ones in your model!!


Cheers


Geoff

[Netleyned]

Might need them if using cheapo chinese esc's😁
Ned

[Akira]

RN battleships used them regularly. Look at the Nelsons and the KGV's. mostly in the area of side protection to vent torpedo hits.

[mudway]

Aren't these them on Diamond?

[Akira]

I am not sure what those are on Diamond, but on your BB's they were built into the bulkheads and decks of the torpedo protection and thus weren't really visible. Also, they were bolted on plated designed to fail at specific pressures. I'll scan some images, after my morning coffee kicks in.

[Colin Bishop]

Those plates on Diamond are crew escape hatches. During WW2 sailors were trapped below in sinking ships because the standard scuttle was too small to admit a human body. The hatches were provided to allow emergency evauation of compartments if the normal means of escape were inaccessible.

Blast blowout plates can often be seen on the top of battleship anti torpedo bulges to defelect the effect of explosions. There is also a photo I have seen of the Nelson class with lots of these plates around the waterline although I think they may subsequently have been sealed up.

Colin

[Geoff]

If I recall correctly the Nelson class were designed to treaty limits and had for the time a very advanced ant-torpedo protection system. The fundamental theory at the time was as the explosive gasses expand and enter the ship if there are blow off plates the internal pressure would be significantly reduced and the actual damage much less. It is these plates which show on Nelson and Rodney along the waterline.


Nelson/Rodney also had internal sea water flooding spaces which formed part of the protection system - water compartments slow down fragments and the weight of the sea water whilst contributing significantly to their protection did not count towards the treaty tonnage limit so there was a double advantage.


I also believe that later experiments showed he value of the blow off plates were much less than anticipated and hey may have been welded closed. Hence the next generation KGV dis not have this feature.


Typical anti-torpedo systems are like a vertical sandwich of air, fuel, air and a flexible internal bulkhead up to two inches thick but obviously this can only be applied in large ships.



Its a very complex area of design and an exception being the Pugilese system in Italian battleships - basically a round cylinder filled with air surrounded by water so when the torpedo hit the explosive energy was used to crush the cylinder thus dissipating he force and minimizing internal damage!


Cheers


Geoff

[Colin Bishop]

Hood and some other RN ships of the time had sealed 'crushing tubes' in their anti torpedo bulges. These were from 6 t0 9 inch diameter apparently but were not carried in water filled compartments. There are reports that some of these tubes were seen floating on the surface fter Hood sank.

Colin

[Geoff]

Yes, you are quite right - I'd forgotten those - they came from late WW1 designs. The tubes were steel but with the ends plugged with wooden plugs. They were designed to absorb the explosive force and "crush" and also to slow sown outer skin splinters. I believe they were quite effective but weighed quite a lot!


Cheers


Geoff