Piaggio P.108B, command cupola for Breda Z2 turret

[AlexM]

Hello there. I’m trying to make a 3d-model of the Piaggio P.108B for 3d-printing. I have the very nice Ali d’Italia book, as well as digital scans of a part catalogue “Piaggio P108B 1a Serie 1941 Bozze (CA462) CN” (unfortunately no pictures, only text), and the manual Piaggio P108B 2a Serie MM24315-24326 1942 MI. For the Bread Z2 turrets, which were mounted at the outboard engine nacelles, and the corresponding command cupolas on the upper fuselage, I have the part catalogue Torretta Breda Z2 1940 CN, which contains text and pictures of the individual parts.
Talking about the Z2 turret, maybe I could get some more information how they were mounted and operated. The geometrical shape is no solid of revolution, with one side of the cupola ending in a straight line at the bottom. Here are some pictures of the cupola from the sources mentioned above:



Am I right to assume that the upper part of the cupola could be rotated 360°, with the sight facing at the somehow flattened side of the cupola to aim at targets?
There is a “tube” coming out of the upper center of the cupola. I assume this tube doesn’t rotate with the rest of the cupola, with the other end of the tube being connected at a certain position to the fuselage. Is there a picture showing where exactly the tube is connected with the fuselage? As far as I see it on side-views of the aircraft, it seems to be forward of the cupola, maybe somewhat to the left (10-11 o’clock position when viewed from above on the cupola?).

The 3d-model in the game War Thunder shows the tube rather at the 8 o’clock position. Additionally, there is some kind of bent metal bar at 10 o’clock position, which isn’t there on the pictures of the cupola posted above, so I wonder how the designers of the game came up with this interpretation.


The full 3d-model from the War Thunder game can be seen here:
https://gamemodels3d.com/games/warthund ... 08b-serie1

But then, there is a picture of the crashed aircraft with US-markings, where there seem to be two tubes/bars per cupola, somewhat similar to the War thunder 3d-model (hard to tell due to the resolution):
https://i.pinimg.com/originals/e7/0d/7a ... ec934a.jpg



I also wonder how the cupolas were manned. If I correctly measured the plan from the manuel, the distance from the fuselage floor to the upper fuselage openings already is about 207 cm at the position of the forward cupola, and about 197 cm at the position of the rear cupola. From the interior pictures in the manual and the Ali d’Italia book, I can’t see anything for the men to sit or stand on, so that their heads would be high enough so see out of the fuselage

I have more questions about the P.108, but that's it for now.

Cheers
Alex

[RetiredInKalifornia]

Piaggio P.108 wing gun turrets & sighting systems long have garnered my interest, had the Ali d’Italia book also, couldn't find anything more about them on Internet. My Special Hobby P.108A & B model build photos up on STORMO Gallery show turrets & sighting stations being repositionable, had to guess how turrrets & sighting stations turned relative to each other assuming guns swept 180 degrees hemispherically lateral to fuselage.

Obviously the guns couldn't be lowered flush to forward wings because of propellers, fixed gun training guides on turret mounts countoured fields of fire whilst rotating most likely with mechanical feedback to gunners manipulating turret control sticks whenever traving though protected areas such as propeller arcs they - the guides - if there as I'd described defining their fields of fire. Far as I know no other operational WWII airplane had remotely operated & sighted wing mounted gun turrets, those on some Messerschmitt 323 top wings me thinks were manned, horrible it was knowing their gunners stood near zero chance surviving when shot down!

[AlexM]

Thanks for your input. Do you have an idea how the cupolas were manned (regarding the height of about 2 meters between fuselage floor and ceiling)? I couldn't find anything in the photos and drawings that the men could have been standing on.

This picute is from the manual, showing the tubes (?) facing forward to the cupolas:


I also have a digital copy of a document about the P.108 from CMPR - Club Modellismo Plastico Ravenna, which contains some photos I couldn't find anywhere else. I'm not sure if I can post photos from this cocument here without breaking copyright. On one pictue, the tubes (?) are also facing forward to the cupolas, but they appear larger than on the photo above, more resembling curved metal bars than tubes.
On another photo from this document, one can see those parts as thin like on the photo above, looking indeed like tubes, but in this case, they are facing backwarts from the cupolas. So, apparently there were variations.

[RetiredInKalifornia]

Thanks for your input. Do you have an idea how the cupolas were manned (regarding the height of about 2 meters between fuselage floor and ceiling)? I couldn't find anything in the photos and drawings that the men could have been standing on.

This picute [not shown] is from the manual, showing the tubes (?) facing forward to the cupolas...

I also have a digital copy of a document about the P.108 from CMPR - Club Modellismo Plastico Ravenna, which contains some photos I couldn't find anywhere else. I'm not sure if I can post photos from this cocument here without breaking copyright. On one pictue, the tubes (?) are also facing forward to the cupolas, but they appear larger than on the photo above, more resembling curved metal bars than tubes.

On another photo from this document, one can see those parts as thin like on the photo above, looking indeed like tubes, but in this case, they are facing backwarts from the cupolas. So, apparently there were variations.

The domes might had been motorized for turning them & the gun turrets, arm strength alone me thinks couldn't had be enough to turn both via cabling! Am guessing gunners stood on portable adjustable platforms set for their heights, question I've got is whether they had to foot-shuffle on the platform as the domes turned. Powered turrets on Allied bombers turned really fast, gunners literally part of the them, gunners for P.108s sighting domes might had servo power linkage to rotating platforms they were standing on they having to be time-synced with the domes. I'm betting gunners foot-shuffled with the domes, question is to what & how they'd be tethered to whilst standing in combat & moving around sometimes erratically, not at all good keeping in plane with target sighting recticles that's for sure!

[AlexM]

Talking about the speed, I found the following information in the P.108B manual:

Tempo per manovra a terra della torrettea Z2: rotazione in 8''

So, if 8'' means 8 seconds, than it seems pretty fast. For comparison, according to a document about the Martin 250 CE turret (like it was used on the B-26 Marauder), it made a rotaion in 18 seconds in "normal speed" and in 8 seconds in "high speed".

[RetiredInKalifornia]

Talking about the speed, I found the following information in the P.108B manual:

Tempo per manovra a terra della torrettea Z2: rotazione in 8''

So, if 8'' means 8 seconds, than it seems pretty fast. For comparison, according to a document about the Martin 250 CE turret (like it was used on the B-26 Marauder), it made a rotaion in 18 seconds in "normal speed" and in 8 seconds in "high speed".

...turrets themselves am assumming rotated at that speed though appear to be cable-pulled from gunner cupolas they - the cupolas - most likely were motorized for rotation.

Question for me is why Giovanni Casiraghi who'd designed the P.108 & worked in USA 1927-36 knowing of advancements in powered gun turrets didn't go for dorsal fuselage ones. Two would had given near full topside hemispherical gun coverage with added benefit of both gunners concentrating gun fire on attacking individual aircraft within the coverage area and not only that, recharging & unjamming them whilst in flight. Casiraghi me thinks might had gone for clean as possible fuselage aerodymamics over potentially better defensive gun coverage with draggy manned turrets. It also could be argued two remotely operated dorsal fuselage gun turrets could had been operated by a single gunner even with powered cable controls he theoritically being able to independently operate well as coordinate them to lay fire on single attacking aircraft.

A dual fuselage turret "What-If" Special Hobby P.108A "model-mod" would had been a terrific build for the Beyond The Sprues website folks given they'd loved my four 12.7 Breda SAFAT Macchi C.202 "What If" FROG & AIRLINES builds, haven't posted them here on STORMO knowing its devoted to serious Italian aviation history.

[AlexM]

I just stumbled across the drawing in the Ali d'Italia book on page 54, upper left corner, showing some kind of - I don't know -baskets hanging under the cupolas. It seems like the gunners could stand in those "baskets" and so could look out of the copulas to operate the guns.
Strangely enough, those "baskets" are not visible on all the photos of the real interior fuselage showing the underside of the cupolas

Maybe this drawing is from a parts catalog. As I stated in my first post, I have a digial copy of a parts catalog (catalogu nomenclatore), which unfortunately only contains text but no pictures. I wonder if there is an illustrated parts catalog somewhere. That would be a great resource for modelling this interesting aircraft.

[Bruno P]

Hi you all!
Breda Z2 fuselage station were fixed and not rotating. The support beam (not a "tube") insn't clear in which position was fixed: on my model I've positioned it on 12 just for logical assumption.
Gunners, which controlled electrically wing turrets, is not clear how do they could stand safely during combat: this was a huge doubt when I've realized my model. In a picture of "Manuale Istruzioni Piaggio P.108B 2a serie" you can see some kind of bin that I couldn't explain its function. I think there were a couple for this use. But this is just my assumption.
Bye

Bruno

[Editor]

Welcome to Stormo and thank you for your post. Outstanding job on the interior in such a small scale. Please post more of your work. Thanks again.

[Bruno P]

Hi Editor!
Thanks for your kind words!!!
I don't wanna clog this site with too many pictures of my model.
I post just a few. Who is interested can see whole report on my site at http://brunoperfetto.weebly.com
An article is also been published on Sky Model n. 126.
Thanks for watchin'!!!!

Bruno

[davenport49]

Wow! Amazing!

[Bruno P]

Thanks so much!

[RetiredInKalifornia]

Indeed most civilized especially on these limited-production bombers! Short Sunderland flying boats had proper porcelain flushing toilets, other RAF & USAAF metal chemicals, highly unpopular so I've read, not read up yet whether Soviet or Japanese aircraft also had toilets, will do so later. I'll never fly again in a commercial airliner as detest the TSA, don't miss the toilets, do wonder whether the best First Class airlines have real toilets, checking on that later also.

[Bruno P]

The P.108 design solutions were avant-garde and significantly surpassed those of direct Allied competitors such as the B-24 Liberator or the B-17 Flying Fortress. But the step from the design phase to the construction phase was too long for the Italian industry of the time. The big Achilles' heel lay in the engine plant, which included 4 Piaggio P.XII RC35s at full capacity, which limited its performance.
Theoretically it could fly with just two engines but it became famous for engine failures that were never resolved. Bruno Mussolini died due to an engine failure.

Bye

[Editor]

Very nice work, send in a short article for the Gallery. thank you for sharing your work.