Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Don.
I am reverting to page 84 in your Skizzenbuch and my photo of a T tool from an early VIIC and three of the crew is seen in the engineroom hatch opening. One of my red arrows is pointing at an assumed "T tool". Having looked at several old U boat photos I discovered some uboats have next to the entrance hatches a T support used as a supporthandle for getting in and out of the hatch. This handle was obviously made of steeltubes having a larger diameter than the "T" tools, but looks very much the same and can easily be taken for a "T" tool. I cannot remember we had this support on our VII Cs. Below is an image showing a genuine "T" tool in the engineroom and some T supports on some late and early Uboats, some of them not VII Cs. On one image you see a crew member obviously operating a T tool, however this is an IXA boat. I discussed the T tool elongation earlier on this thread with Simon and he made a sketch showing the engineroom arrangement a small part of it is shown on my image.
Tore 

[tore]

Don.
Two small details in you skizzenbuch. Page 69 photo of the main engine the description says fuellines goes to the front of the engine where the manual starting and throttle control levers are located-  As you know there are no throttles (gasoline system) on a diesel engine (diesel, direct injection) thus the lever is the fuelrack control lever.
On page 142 you have an interesting photo of the pressurehull and saddletanks with a slightly confusing text as it looks like the stb ventvalve and ducts for the saddletanks  two and four are not yet fitted. It seems to me that you see the connectionflanges for same and the stb duct for MBT 3.
Tore

[Don Prince]

Hello Mr. Tore,


I corrected the item on page 69 and removed throttle to "manual starting and fuel rack control levers"...


Thank you for finding my screw-up of just pasting in old photos and info...  It sure was WRONG!!!  I have redone that entry and let me know if you think it is acceptable..


Kind regards,
Don_.

[tore]

Don.
I guess you are right in your assumption, it could be a photo of the U 995 Restoration. However I believe the stb. MBT 3 vent duct is still visible, not missing. As a curiosity I can mention this particular area just in front of the conningtower stb side was completely smashed and the whole casing was gone during a heavy NorthSea gale  November 1953. We were able to repair it temporally in UK. When returning to our base in Trondheim, Norway the damage was evaluated and the KNM Kaura ex U-995 was on the point of being scrapped.
The rest of your corrections are OK.
Tore

[Don Prince]

Hello Mr. Tore,


I made the correction to page 142...  In addition, I added your comments about your November 1953 North Sea experiences.  That is what makes Skizzenbuch so unique; your first hand knowledge!  I hope you don't mind me doing so, and I really appreciate your help.


FYI -  According to the web site where I merge the 3 word documents to create the Skizzenbuch.pdf file this is my 85th version...


Kind Regards,
Don_

[tore]

Don.
Correction OK, feel free to use the November incident. A small comment on your enginetelegraph description, page 190. You are correctly explaining the order respond from the engineroom, however on the photo you are referring to, the port engine telegraph of the museum U 995, somebody has nicked the responding handle on this telegraph which might be confusing, stb engine telegraph is OK. see my image below.
Tore

[Don Prince]

Hello Mr. Tore,


I used your photo and uploaded Skizzenbuch version 86 to dropbox...


Regards,
Don_

[tore]

Don.
Page 86 checked OK.
 A remark on your description of the cooling water system. May be you should deal with the cooling system continuous as you now have pages 120, 126 132 photos of pressurehull interfering with the cooling water system sketches.
As to the cooling water system you have a general central main cooling water pipe going from main coolingwater distribution chest up front in the engineroom all the way to the aft torpedoroom able to serve all coolinginstallations from all the pumps connected to the mainpipe thus it creates a very flexible system.
 The compressors are in general selfsupported by a centrifugal pump for the E compressor and a rotary vane pump for the Junker compressor. Alternative supplies are from the central main pipe and whatever pump may be connected to same. In addition to the cooling components mentioned by you it is a branch off to the cooling of the sternshaft packing boxes and to the aft torpedo compensating system.
On the sketch below I have tried to put up the aft coolingwater system, blue is the suction line, red is the outlet- and green is the supply line and Junker cooling line overboard.
Tore

[Don Prince]

Hello Mr. Tore,


About pages 120, 126, and 132...  These photos and many others were inserted into Skizzenbuch in order to get the Plate diagrams on an odd numbered page.  That way when the book is opened to read, the plate text or a photo is to the left and the plate diagram is almost always on the right side (odd numbered page).


I will look into updating and adding your comments in about the water cooling system...


Thanks again.


Regards,
Don_

[Don Prince]

Hello Mr. Tore,


I placed your info on the Water Cooling System on page 112 and 113, re-indexed and uploaded the latest version of Skizzenbuch (88) to dropbox...


Regards,
Don_

[tore]

Don.
Showing the British plate 13 of the cooling watersystem, may be you should mention the red arrow points to the mistake (no connection) in the sketch. There is no connection to the common discharge pipe from the thrust bearing coolingdischarge.
Tore

[Don Prince]

Hello Mr. Tore,


Dose the GREEN supply line cooling water that goes to the Junkers muffler exit to the sea?  It looks so, but I just want to be sure...


Regards,
Don_

[tore]

Don.
If you remember a few weeks back we discussed the Junker exhaust outlet in connection with the aft buoyancy tank ventvalve,  I guess there has apparently been some alteration in the system due to flooding trouble, however I believe the exhaust hullvalve has a watercooled housing where the coolingwater is discharged  in a simpler manor as the main engine system. This means that the Junker overboard coolingwater discharge is via the exhaust coolingwater jacket as indicated by the green lines. See my assumption sketch on page 155.
Tore

[Don Prince]

Hello Mr. Tore,


I updated page 113 and uploaded the latest version of Skizzenbuch to dropbox...


Regards,
Don_

[tore]

Don.
A remark to you last update. I am not sure about the final arrangement on the Junker exhaust cooling watersystem. As mentioned it is obviously redesigned after the system shown on plate 13. As the germans experienced waterintrusion in the exhaustsystem I believe they introduced a second shutoff exhaustvalve almost like the mufflervalves for the main engines.
On the sketch below I have shown this valve in the systemsketch. We have discussed this second valve before, including the grinding , waterblowing system and interlock to the aft buoyancy tank venting. I have to emphasize though: this arrangement is an assumption from my side as I can not remember the details and have not seen any sketches or other documentation on the subject.
Tore