Tores mailbox VIIC and VIIC/41 operation and technical details

[NZSnowman]

Hi Don & Maciek

I am trying to model the top of the CT, do you guys have any good photo's?


This images has been resized. Click to view original image.


This images has been resized. Click to view original image.


This images has been resized. Click to view original image.

[Don Prince]

Hello Mr. Tore and Maciek,


Wow! I had it completely wrong in Skizzenbuch about the design of the drive shaft mechanism for FBT 2 and FBT 4.  I just ran into this misunderstanding on my part yesterday when discussing the sunken U-Boat with Maciek.  That 2nd screw jack mechanism led me to believe that Q Tank was blown apart. I didn't know that there was two (2) screw jack mechanisms in each saddle tank blister (FBT 2 and FBT 4, Port and Starboard).  I sure hope I don't have anymore of these lightning strikes...


Simon,


I have photos in books showing the tower in detail at the factory when being built.  After I get Skizzenbuck straightened out, I will copy the photos and email them to you...


Regards,
Don_

[Don Prince]

Hello Mr. Tore and Maciek,


I have corrected Skizzenbuch to reflect the correct information about the number of drive mechanisms for FBT 2 and FBT 4.  Would you all please review pages 334 and 335 and let me know if anything needs corrected or changed in any way?


The new file Skizzenbuch 11 x 17 - M + Index.pdf in in my dropbox folder...


Regards,
Don_

[SnakeDoc]

Hi Don,

I have corrected Skizzenbuch to reflect the correct information about the number of drive mechanisms for FBT 2 and FBT 4.  Would you all please review pages 334 and 335 and let me know if anything needs corrected or changed in any way?

I would change the sentence in bold.

The Type VII C U-Boat schematic below has the port Kingston Flap valves highlighted to show their location within the lower section of the saddle tanks for FBT 2 and FBT 4. Of course, there will be similar Kingston flap valves on the starboard saddle tanks. The four (4) individual Kingston flap valves are controlled (open or shut) by two (2) removable hand crank that attach to the drive shaft which passes through the pressure hull and engages the screw jack mechanism for each of the four (4) tank (FBT 2 and FBT 4, port and starboard). The locations of the drive shafts are designated by numbers 1 through 8 in the schematic. The mechanical diagram to the left shows the hand crank attached to the Kingston drive shaft which turns the screw jack external to the pressure hull, but within the saddle tank structure. The saddle tank Kingston flap valves open inward and swing from the bottom of the flap. The image of U-995 shows two (2) of the Kingston flap valves highlighted in YELLOW, and the protective grill for the Q Tank mushroom valve to the right. It may be difficult to read the numbers, but the saddle tanks have two different metal cover plating thicknesses; FBT 2 and FBT 4 have 6 mm thick outer plating, while R1, R2, and Q Tank have 11.5 mm thick plating because they are pressurized.

Maybe something like this:

The four (4) individual Kingston flap valves are controlled (open or shut) by two (2) removable hand crank that are attached to two (2) drive shafts which passes through the pressure hull and engage two (2) screw jack mechanisms (one for mechanism for two (2) flaps, two mechanisms for four (4) flaps).


The label at the bottom of the drawing:

Drive Shafts for the Kingston Flood Valves (2 per shaft)

Drive Shafts for the Kingston Flood Valves (2 flood valves per shaft)

--
Regards
Maciek

[Don Prince]

Hi Maciek,


I will make the changes as suggested...


U-352 Q Tank grill is correct; only half was blown away...


Regards,
Don_

[Don Prince]

Hello Mr. Tore, Maciek and All,


I updated the the image of the saddle tank/expansion tank on page 83 after viewing the photos that Simon posted.  I believe the current version better reflects the actual design (drawing attached).


Thank you Simon...


Maciek, I made the text changes to page 334 and the image change.  I did a little re-wording and made the long sentence into two shorter ones and eliminated all the brackets.


Let me know if it's OK...

[SnakeDoc]

Hi Don,


now it looks good to me.


--
Regards
Maciek

[NZSnowman]

Simon,


I have photos in books showing the tower in detail at the factory when being built.  After I get Skizzenbuck straightened out, I will copy the photos and email them to you...


Regards,
Don_

Don, here the update top of the CT.

[NZSnowman]

Port Side Main Exhaust Valve

For the last several weeks I’ve been working on the exhaust valve, and for the first time I feel like I’ve made some significant improvements on the section of the U-boat. The drawings below are based on U-352 and are as accurate as I can make them base on the imaging of this boat. There are still details that are missing that I will have to guess.

I have also modelled all the internal structure, or was much as I can

Detail that I’m missing or cannot find are:

• The inbound cooling water flange (I believe it must be near the top of the main valve).
• The pressure release valve.
• How the box (which houses gearing that opening and closing of the valve inside) is attached to the side of the main exhaust valve.
• How the grinding teeth seats when the main exhaust valve is closed (I imagine there must be a small internal flange?).
• The hinge mechanism for them main exhaust valve.

Fig. 1. Looking Inboard, to the stern.


Fig. 2. Looking Inboard, to the bow.


Fig. 3. Looking outboard, to the stern.


Fig. 4. Top.


Fig. 5. Looking to the stern.


Fig. 6. Looking outborad.


Fig. 7. Looking inborad.

[NZSnowman]

Cross-section Views







As always all can be resized, by clicking on the original image.

[NZSnowman]

Don, Tore & Maciek.

• Any idea how the grinding teeth are seated when the main exhaust valve is closed?
• Are there any example of this type grinding hinge mechanism? I search the internet but can't found anything

[Don Prince]

Hi Simon,


This is what I have in Skizzenbuch from Mr. Tore...


Regards,
Don_

[maillemaker]

Hi Tores,

Do you have any knowledge about how to obtain/compute firing solution information?  I am trying to use the RAOBF (range and angle on bow finder) and other tools playing the Silent Hunter 5 simulator on 100% realism.  I'm am finding the finding of target speed, range, and AoB tricky.

Generally I opt for 90-degree approaches so that range is irrelevant.  I use a "fixed wire" method to compute speed by adjusting my heading to match target bearing (0 degree bearing) and then use the stopwatch to measure how long it takes the target to traverse the vertical reticle in seconds.  If I know the ship length from the recognition manual I can then calculate target speed.

How did you guys come up with the target information?

Steve

[SnakeDoc]

Hi Steve,


for historical methods of determining target data check this site:
http://tvre.org/en/acquiring-torpedo-firing-data


--
Regards
Maciek

[Don Prince]

Hello Mr. Tore and All,


Tuesday morning my Post Leather Bound First issue of Skizzenbuch was delivered to my doorstep via UPS. There was a litter inside the box taped to the binder stating that Schiffer Publishing LLC has decided not to publish the book. After a year and a half, now 2 months before the release date they canceled the book! They say the niche market is too small at this time.


To say the least; I'm a little %$*&T#, and I'll have to think about the situation...


Don_