Real german subs and diesel engine damaged?

[Schunken]

Hi captains...

I make my way 1/3 to the first Book "The Hunters" of Clay Blair and...

...beside of the giant torpedo problem I noticed another big problems of the Kriegsmarine:

I read more than 30 times that german submarines must cancel the patrol because dame to the diesel engines.

Was the diesel engines at this times so unreliable? I mean they did not make high rpm and have a own engineer who nurse them all the time....

Anybody know what the problem was? Valves, Pistons or overheating???

Todays 6-cylinder Diesel engines in a bick truck make often more than 500.000 miles....


Enlight me, gentleman ;)


Andreas

[Weather-guesser]

I read more than 30 times that german submarines must cancel the patrol because dame to the diesel engines.



Those "dames" on boats will get you every time! ;)

[Sailor Steve]

Don't know the answer to that one. Doesn't he say?

[Webster]

i would think the biggest issue was spare parts, space is so limited on a sub what parts do you have room for?

i think a few basic tools and some seals, bearings, and gaskets would be about all they had room to carry and anything that got bent broken or seezed needed a replacement part or machining.

[AVGWarhawk]

Good right up on diesels:

http://www.maritime.org/fleetsub/diesel/chap1.htm

Early diesel were unreliable. The HOR in particular. I was pronounced 'whore' as the HOR was that bad. Not to sure about the German diesel. It was an intricate machine. More so than I would say Fairbanks Morse used in the US submarines.

[AVGWarhawk]

i would think the biggest issue was spare parts, space is so limited on a sub what parts do you have room for?

i think a few basic tools and some seals, bearings, and gaskets would be about all they had room to carry and anything that got bent broken or seezed needed a replacement part or machining.

You made the parts Webster. At least the US boats had work tables, vise and tools to weld, create new parts while at sea. Known gasket that cause trouble had spares put aboard. US boats anyway. In particular were radar shaft bearings and seal issues. Sea water, bearings and electronics were never best friends. Also, if sea water entered the fuel oil or engine combustion chambers....forget it. The US boats had the capability to lift off cylinder heads to make repairs. I believe the Germans had similar.

[Nisgeis]

US Boats had a lathe on board - did the German boats have similar?

[AVGWarhawk]

You are correct Nisgeis. The lathe is located in maneuvering against the bulkhead between maneuvering and the aft torpedo room. all tools to make parts at sea!

[gandalf71]

Moin

putting into consideration that there were more than 700 Type VII boats built and how many patrols they fulfilled during the war, 30 aborted missions due to engine failures doesn´t sound like a major issue to me.

On the other hand missing spare parts and tools were certainly an issue during a patrol and if one diesel was out of action the risc of continuing a patrol with only one engine working was not acceptable.

Another issue I can imagine was that the decreasing quality of boats might have been an issue during the war. Caused by shortages in certain raw material and increased production numbers with less qualified workers.

Cheers,
Michael

[flag4]

i have read that as the war progressed sometimes sabotague was a problem, plus, metal ore to make the parts got harder to get. inferior parts often ment breakdowns.

[Sailor Steve]

You are correct Nisgeis. The lathe is located in maneuvering against the bulkhead between maneuvering and the aft torpedo room. all tools to make parts at sea!
Now that would be a cool thing to see - engines being repaired and parts made when needed...:sunny:

[urfisch]

i have read that as the war progressed sometimes sabotague was a problem, plus, metal ore to make the parts got harder to get. inferior parts often ment breakdowns.

thought the same. normally the diesels where very reliable...but as to the limited space inside the sub a greater repairs where not possible and the boat had to return in such a case.

mostly dc´s had their effect on the diesels...often the hard hits and the shaking lead to damages of the diesel sockets. and due to the vibrations of running diesels this lead to damages inside the diesels.

:know:

[flag4]

To AVGWarhawk...

i love the squirrel. he is drinking a special beer...it never runs out..:har:

[Nisgeis]

You are correct Nisgeis. The lathe is located in maneuvering against the bulkhead between maneuvering and the aft torpedo room. all tools to make parts at sea!

In a German sub? They don't look big enough. Got any pics?

[Heretic]

To AVGWarhawk...

i love the squirrel. he is drinking a special beer...it never runs out..:har:

It's a new product made by the same company that makes ammunition magazines for hollywood movies. It's still in the animal testing phase so not available to the general public. Breweries, of course, are trying to block it's release.

[AVGWarhawk]

It's a new product made by the same company that makes ammunition magazines for hollywood movies. It's still in the animal testing phase so not available to the general public. Breweries, of course, are trying to block it's release.


Yeah, Rambo has these magically refilling clips for his .50!

[Jimbuna]

Yeah, Rambo has these magically refilling clips for his .50!


LOL :DL

[PhantomLord]

In a German sub? They don't look big enough. Got any pics?

Definitely no lathe in german boats. Space was limited and filled with food, spare parts, ammo, crew and their bunks. I often wonder where they stored the timber (to reinforce the bulkhead in case of heavy damage).
Fighting strenght was the first and only priority. No "comfort" like in the US-subs.


Agree with Gandalf71 and urfisch about the diesel reliability. 30 out of 700 under sometimes extreme stress for the engines is good rate.
Not comparable with modern truck diesels. They have regular routine maintenance (oil change, filter service etc. etc.) and no DC'ing all the time :D

[Schunken]

ahm...wait a minute.... I count 30 times a diesel failed and just read the book to early 1940. And at this time there maybe only 50-80 Subs was on regular patrols....

Anyway surely all combustion engines improoves alot until today and a compare with a modern truck engine is unfair...

I only think a diesel with low rpm and a good hp/volume ratio normaly should last longer...

Some of you remember the (europe) Ford RS turbo? 1.6 litres engine and sqeeze out over 170hp....This baby blows up all the time... I got 2 new engines in first year and after warranty I quick sell it...:o

Andreas

[PhantomLord]

But remember.. the invention of the diesel engine was 1892...
- First installment on a ship (river boat) was 1903
- 1910 - first ocean going ships with diesel - expedition ship "Fram" and freighter "Selandia"

Research and developement was interrupted by WW I, the Weimar Republic (which was turbulent time with political downtim and almost no economical and scientifical advance), and last but not least the versaille treaty which was a big brake shoe for nearly every military R&D in germany.

[Frederf]

You know, until now I never figured out why "sabotage" was a problem on submarines. I mean it's just the hand-picked crew who should be loyal! Are French resistance swimming up and sneaking in at night? Then it occurred to me, the sabotage happens when the parts are manufactured... I'm such a dummy! :har:

[Bilge_Rat]

Or when repairs or overhaul were carried out in french shipyards by french workers. Substandard pipes, joints or welds may not be apparent to the naked eye, but can be deadly 150 meters below the surface. No one knows how many of the U-Boats which disappeared without a trace were lost for that reason.

[Jimbuna]

You know, until now I never figured out why "sabotage" was a problem on submarines. I mean it's just the hand-picked crew who should be loyal! Are French resistance swimming up and sneaking in at night? Then it occurred to me, the sabotage happens when the parts are manufactured... I'm such a dummy! :har:

I once read an article where a 2 foot welded seam on the pressure hull was little more than a piece of rope dipped in oil to resemble the weld to the casual glance.

Another article told of dead rats being found in the bottom of fresh water drinking containers.

[JScones]

Re sabotage, read Steel Boat, Iron Hearts by Hans Goebeler (with a grain of salt though). The author devoted a whole chapter to sabotage.

Here's what sabotage allegedly occurred on U-505 during just ONE patrol:
-leaky starboard propeller shaft caused by faulty shaft seal (reduced max depth to 40m)
-FuMB Metox electrical short circuit
-GHG underwater listening device out of action
-radio direction finder antenna could not be deployed
-relief valve seals faulty
-emergency valve seals faulty
-diving tank seals faulty
-battery cell seals faulty
-fuel bunker seals faulty causing oil slick which had pinpointed their position from when they left port to when they returned.

The faulty seals were caused by someone pouring battery acid on them.

This patrol was by no means an exceptional example either, I might add.

Other examples of sabotage (some effected on U-505 over the next three patrols and others experienced by other boats):
-sugar in the lube oils
-dead dog in the water tank
-botulism
-drilled pencil hole in fuel bunkers (this little hole plus some other sabotage caused U-505 to return to port at least 4 patrols in a row as it wasn't picked up by the workers)
-poor welding causing stress cracks
etc etc

[java`s revenge]

Forgive me if i write something wrong.

In the movie Schindler`s list you could see that the "prisoners" made
shells which had their malfunctions.

[java`s revenge]

But how were the uboat in WWI? These had also diesel engines...:hmmm:

[THE_MASK]

I read somewhere that while on the surface in the med in a uboat a plane suddenly appeared . They never heard the plane because of the noisy diesel engines of the u boat .

[java`s revenge]

Wow, that would be a great detail in the game. Very realistic.

[msxyz]

Starting from type VIIB forced induction was added to increase power output of the diesel engines. Initially only superchargers (compressors moved by the motor shaft) were used. Quite a few units from VIIC onwards were equipped with turbochargers in an attemp to increase fuel economy. The turbine however proved to be troublesome and prone to failures.

Despite superior engineering, the Germans always faced shortages of the raw materials needed to develop hi streght alloys for engines or other critical components (ie bearings)

The situation in the aviation industry was particular severe; many german aircraft engines started malfunctioning after only a few hours of operation, much to the discomfort of pilots and officers. It didn't help that germans had to push the envelope in engine design as only low octane gasoline was available to them.

Back to sub and diesles... with sabotages, this problem was quite severe when production started to be decentralized to factories in occupied countries.

[Seafireliv]

That squirrel seriously makes me want to go and drink a pint of guinness.

[Bilge_Rat]

Blair, vol.1, p. 423 has a short paragraph on this.

As I understand it, the problem was not the design of the diesel engines, but the way the type VII was used. It was designed for short patrols around the british Isles, but quickly was forced to carry out longer patrols in the middle/western Atlantic and engage in lengthy convoy chases. The Type VIIs only had two (2) diesel engines and they wore them out by pushing them to the limit.

By contrast, the U.S. Fleet Boats which were designed for long range patrols had four (4) diesel engines.

[msxyz]

Even large, ocean going type IXs had only two diesel engines, albeit much larger. The sole exception was type IXD2 which had an additional pair of engines (500hp each) paired to electric generators.

Type VIIs had engines made both by MAN and GW. During the early stages of the conflict MAN engines mounted on type VIIA caused some troubles but this was resolved later and both engine manufacturers continued to produce diesel engines for this submarine family. The only other recorded source of trouble was, as I said in my other post, the turbocharger.

[Nisgeis]

I once read an article where a 2 foot welded seam on the pressure hull was little more than a piece of rope dipped in oil to resemble the weld to the casual glance.

That's amazing. In all the accounts of US Fleet Boat repairs, the crew were usually insistent that the repairs to critical areas were only ever carried out or supervised by someone who was going on patrol with them.