Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Don.
Orders, particulary on a submarine have to be clear and not to be misunderstood, the various navies have a standard vocabulary  to be used in their own language in order to prevent misunderstandings. It is a challenge to translate a submarine manual into a correct naval wording, as you got to have substantial naval submarine experience in both relevant navies to use the right wordings. In our navy we experienced this difficulty during WW2. Before the war our submarines were designed based on German technology and a substantial part of our submarine wordings derive from the german language. During the German occupation of our country, the Norwegian navy continued to fight the war out from UK, eventually getting British submarines and training. Our submarine language was thus very much "anglofied" and adapted to the Roayl Navys (RN) technology. After 5 years of exile our navy returned to Norway and eventually took over some VIICs, again the manuals were translated based on German naval language into Norwegian UK navy language.  A typical difficult translation is the order for the use of "Untertriebzelle" which is a bit different from the UK submarines "Q" ( quick diving tank).  A german submarine, operating in hostile waters very often have the "Untertriebzelle" filled and used  to overcome the "surface resistance" during a quick diving.
The "Untertriebzelle" was blown at some 10-14 meters to save air. At that depth the order "Aussgleichen" was given and the "Untertriebzelle"s kingston was shut and an inboard venting relieved the pressure in the "Untertriebzelle".  Such procedure was not used in the RN and thus no relevant RN english word exist for the "ausgleichen",  some English translator have made a word for "ausgleichen" calling the order "Express" which for me is a strange word for the procedure. We used " vent Q", meaning shutting the Kingston and open the vent, relieving the air through the silencer into the control room. Sorry for the long story, hopefully it might describe the problem of finding adequate naval words for translating. I guess the similar problems exist between the US and RN english, the worst would be to mix the two languages, to my opinion any manual or technical book on submarines should mention which naval language is used.
In a RN submarine training course it is emphasised, no use of the word close, only shut is to be used.
Tore

[NZSnowman]

Has anyone see a photo(s), or know the pipe diameter of the Exhaust Gas Blowing Manifold? http://www.uboatarchive.net/U-570/U-570Plate16.htm
 
It was tight the first time I added the Manifold, but now after adding the Vent valve for MB & RFO 4 Tank (Stb), I would not say not tight no more, I almost look imposable

[NZSnowman]

Tore, I imagine the drain valves for the piping of the MB & RFO tanks 2 and 4 will be at the lowest point? http://www.uboatarchive.net/U-570/U-570Plate16.htm (valve 'm')

Plus, any idea that it may look like?

[tore]

Simon.
I guess placing the ventduct draining valves close to the gatevalves would be OK. I don`t have any images of same but I think the look would be pretty much like the drainvalves on the outboard exhaust cooling system (silencer) which I presume you have drawn previously.

Tore

[Don Prince]

Hello Mr. Tore,


Are the dual fuel oil filters mounted on the maneuvering panel on the GW Diesel engine the last filters before the fuel oil injection pumps.  I would think so, but I guess I need to consult the expert...


Regards,
Don_

[tore]

Don.
I am afraid not, after the dual fuelfilters you have a knifefilter placed between cyl 1 and 2  just behind the HP fuelpumps. From this filter you have a drain to the dirty fueloil container placed next to the crankcase cover 1. See image below.
Tore

[Don Prince]

Hello Mr. Tore,


Do you know how often the duel fuel oil filters were replaced?  They seem to be a pre-filter for the knife canister fuel filter which can drain its contaminant...


The fuel oil cleaning stages are as follows:


1. the gravity tank (contaminant separation and drainage)
2. the dual filters (replaceable cartridges)
3. the knife canister filter (contaminant drainage)


and finally to the 6 fuel oil injection pumps.


Regards,
Don_

[tore]

Don.
I don`t think the fuelfilters were replaced like disposable paper inserts, only cleaned. The double filter allowed one filter to be in operation while the other filter was cleaned. I cannot remember the exact frequency of cleaning.
Tore   

[tore]

Don.
May be more complete fuelcleaning stages would be as indicated on plate 9 where the filters in the supply lines to fuel bunkertank and the day- (setling)tanks are indicated.
The system plan 9 might be a bit confusing as they have not used a GW arrangement but the fuelpipe arrangement of a MAN engine having the engineattached fuel supplypump and filters placed aft. The final knifefilter in the supply pipe to the HP fuelpumps is not shown.
Tore

[tore]

Fuel filters.
In order not to create confusion it might be good to mention that the first filters in the fuelling pipe were not really filters but mainly strainers having a coarse mesh basket. We used to call it the nuts and bolts filter. Sometimes you could really be astonished as to what some fuelling stations could "supply" and the nuts and bolts filter really caught nuts and bolts.
Tore

[Don Prince]

Hello Mr. Tore,


I believe the diesel engineer is facing the maneuvering panel and the stern of the U-Boat with either diesel engine; GW or MAN.



The last drawing has me slightly confused...  Plan 9 shows the cap and the fuel oil loading connection which is on the port side of the U-Boat.  Your Plan 9 photo inserts seem to indicate the loading strainer/filter is located on the forward starboard side of U-995 against the bulkhead, although close to the diesel engine room walk-way???


Regards,
Don_ 

[tore]

Don.
I agree with you it seems confusing, as you have two fillingpipes on each side of the engineroom door. May be we should not focus on the placing of the pipe on pipescheme. Below I have tried to indicate the system. The port hullvalve and strainer is for luboil bunkering. High up on the port side of the engineroom door you may see the plate on the strainercasing (difficult to read)  but seems to be mot. oelfilter (motoroelfilter) English "motoroilfilter". If the filter was a fuel filter the sign would read Trieboel, german for fueloil. Allthough the sign is doubtful I cannot make the nameplate read Trieboel. As the spare electric driven luboilpump can be used as a fueltransferpump, the fuel pipescheme shows a connection to the luboilsystem, however when fuelling, the shore fueldelivery usually had sufficent pressure to force out the compensatingwater and this pump was normally seldom used as fuel transfer pump when fuelling. I guess the fuel intake and strainer is on the starboard side having a short crossoverpipe from the strainer under the floorplating, going under the engineroom doorstep to the fuledistribution chest under the writing desk on port side.
I have tried to put up the idea on the sketch below.
Tore

[Don Prince]

Hello Mr. Tore,


If water got into the lube oil system/collection tank 1 or 2 through the piston rings...  Was there a drain cock that would allow you to drain the contaminating water from those tanks?

on second thought, after looking at Simon's drawing of those tanks, I don't believe there are any drain cocks for those 2 tanks...  if water got into one of those tanks, then how did you get the water out???


Possibly a access cap at the top to get access to the tank contents, and then use a hand pump with a flexible hose to evacuate the water???

Regards,
Don_

[tore]

Don.
When the Germans removed the luboil sentrifuges of the VIICs they installed under the floorplating large filters with water drain , I guess something like my image below. In addition they kept the handpump system shown on my 2. image below. As you can see when the lubeoil settled in the system tanks, water would be collected in the bottom of the tanks and could be pumped out by the handpump on the aft port engineroom bulkhead and discharged either to the dirty oiltank or overboard. The main problem was that in some rare cases the lubeoil emulsified and the water integrated in the oil, making a homogenius mixture with the oil and impossible to separate. In such cases you had to change the oil completely. It happened to me once.
Tore

[Don Prince]

Hello Mr. Tore,


Do you have this image without markings?  Also, I believe valve "C" is in the shadows below.  Do you have a photo without the dark shadow? Was the lube oil hand pump on the aft Stb side?


Question - When you had the lube oil to emulsify; did you have to shutdown the diesel engine on that side? Was the results damage to the bearing journals, and most other moving parts? Or was you able to dump the emulsified LO and pump uncontaminated LO in to recover the engine?


Regards,
Don_