Hi

Fun question.I am no expert on these things but, for what it is worth - here are some thoughts. 

The classic answer,as you state, is the Liberty ships.

I sometimes work with offshore projects and in the latest round of offshore training, it was stated that vibration and corrosion currently are the two costliest items for offshore plant operation. So, I guess your question still is relevant. 

When training as motortechnician in the Swedish Navy in the mid 80s, I remember a lecture on the early diesel motors and how they quickly were scaled up from tiny to ship propulsion size - and, failed, due to fatigue as die casting at that time used sharp edges which initiate cracks.

I made a quick search and found these documents. Perhaps you can find something of interest in these?

 http://www.albadr.org/www/pdf/library/487.pdf

and

http://www.vaclavsmil.com/wp-content/uploads/docs/smil-article-20070000-jgh-2007.pdf

Ship engines (and reciprocating pumps) are hard to balance which make them exposed to significant dynamic loads as they land in the balance class g 2000-4000 (where a turbine rotor would be, say, g 2.5 with an unbalance force reduction proportional to the g class rating).

Also, multiplane balancing was rather difficult to make before the 1950's-1960's which well may have affected matters in VWI and VWII. 

I would not be surprised if vibration affected war ship targeting systems which is not fatigue as such but relate to vibration. 

Sincerely

Claes

Regarding Germany, real cases are unknown. But some examples could be hidden in:

Matthaes, K.: Untersuchung von Kurbelwellenbrüchen (Investigation of crankshaft fractures). Metallkunde 66 (1975) pp. 539-600.

For the time of the cold war I can contribute the following case:

Failure of the connecting rod of a ship's engine.

http://martin-moeser.de/Veroeffentlichungen/Bruch_Pleuel.pdf

Thank you for these kind replies.

Explicit references to warships are rare. One of these is:  

https://dome.mit.edu/handle/1721.3/48148.

which refers to axial vibrations in the propulsion machinery of WWII US battleships.

not sure whether this counts but what about the crippling of HMS Prince of Wales by the Japanese in 1941?  An aerial launched torpedo hit the A frame that supported the propeller shaft.  Although the torpedoes were too small to damage a battleship directly this caused the shaft to wobble which caused a mechanical failure flooding the engine room leaving the vessel vulnerable to the massed attack that sunk it.  If you want to explore mechanical failures in warships similar results seem to be quite common where  relatively minor battle damage triggered unforeseen mechanical failures.  Other possibilities include the failure of the engine on the scout seaplane of IJNS Tone at Midway, the delay in repairing this meant that Nagumo didn't learn the location of the American carriers until too late causing the Japanese defeat, also at Midway it has been alleged that the total loss of Yorktown and at least two of the Japanese carriers was due to the failure of pumps as much as the airstrikes that hit them.

Thank you for this information.

Another case was the propeller shaft failure of the german battlecruiser SMS Moltke in April 1918, which was one of the causes of the early withdrawal of the Hochseeflotte.

Would you characterise the failure of torpedoes due to unreliable detonators in the early phases of WWII as instances of mechanical failure affecting the outcome of an episode? I have just remembered possibly the most influential example of all.  In June 1943 Winston Churchill was due to fly back to the UK via Lisbon.  However, his plane was grounded due to a mechanical failure.  A civilian flight that took off BOAC 777 was shot down by the Luftwaffe.  Conspiracy theorists allege that Churchill's flight was grounded because it was known that the Germans were on standby to intercept it and mistook BOAC 777 for Churchill's plane.  If, however, it was a genuine case of mechanical failure then this undoubtedly counts. Of course the failure of detonators on Hitler's plane to explode and kill him may also count.  Neither are specific to military actions but the overall consequences of these examples of mechanical failure cannot be overestimated since they affect the overall course of the war rather than merely the loss of a single engagement.

Very interesting. 

Hi

Perhaps it is worth looking at the German Panther and Tiger tanks that were oversized with respect to suspension and drive train? 

https://www.quora.com/Why-were-German-WW2-tanks-mechanically-unreliable-despite-supposed-German-engineering-superiority

I looked around a little but did not find any specific mentioned wrt mechnical fatigue - just unreliable and overly complex. 

A reverse take on the matter might be the Pershing tank, where suspension actually was fatigue tested as part of the development, though it entered late in WW2. 

https://books.google.se/books?id=1QqFk2AR5moC&pg=PA64&lpg=PA64&dq=sherman+tanks+mechanical+fatigue&source=bl&ots=0iAsXvyBYO&sig=6URVZrk6g-kL92xeX5aTl6cSYWM&hl=sv&sa=X&ved=0ahUKEwjk5Myl6MnRAhXIliwKHRV9DIIQ6AEIIzAB#v=onepage&q=sherman%20tanks%20mechanical%20fatigue&f=false

Returning to motors. I remember from the Navy motor school an old Captain telling us that older motors had the Number-Of-Cylinders - 1 crankshaft bearings and that the crankshaft of such motors tended to fatigue and break. In the 60's design changed to the Number-of-Cylinders + 1 crankshaft bearings and crankshaft fatigue no longer was an issue. Perhaps you can find something in this vein, at least for road vehicles?

Last, a thought. When looking at offshore failure statistics, numbers are quite similar between the British and Norwegian sectors. There is one difference of 3% which in the Britsih sector is called vibration fatigue and in the Norwegian sector is referred to as material problem. I suspect the two to be the same. Perhaps a suitable search phrase is "material problem"?

/Claes

In "A Quarter Century of Propulsion Shafting Design Practice and Operating Experience in the U.S. Navy" (Jou Am. Naval Engrs, Feb 1959) the author writes that in the war years up to 1948 about 56% of the propeller shafts of US warships of all types showed fatigue-corrosion cracks, but he does not give more information, apart the case of a fatigue ruptured propeller shaft of the battleship USS Oklahoma, due to torsional vibration problems, short before her sinking at Pearl Harbour.

Regarding armored vehicles, perhaps something more can be found in books like "Repairing the Panzers: German Tank Maintenance in World War 2" by Friedli et al.

In war, obviously the technical main problem was that the shells bursted prematurely in the gun tube („in bore premature detonations“).

Samuels, L. E.; Lamborn, I. R.: Failure analysis of armament hardware. Metallography in failure analysis. Plenum Publishing: New York und London, 1978, pp. 167-190

http://link.springer.com/chapter/10.1007%2F978-1-4613-2856-8_7#page-1

Martin's answer is an interesting one in part because it reminds me of arguably the most famous example of this which I haven't previously mentioned due to it predating WWI, that is the testing of the Dahlgren guns prior to the ACW, the early test subjects were made with substandard metal and exploded during testing, the result was that when they were adopted into service the Federal Navy was afraid to use them to their full potential out of fear of the same thing happening in action, one spectacular example of the effects of this was the first ironclad clash at Hampton Roads, if used as designed the Monitor's gun was capable of penetrating the Virginia's armour plate, fear of catastrophic failure meant the crew did not exploit their vessel's full potential

Alex Henshaw was a test pilot during WW2 and had various engine failures while testing Spitfires (more ore less one each month, see: "Sigh for a Merlin [engine]").

Alec Harvey-Bailey in the book "The Merlin [engine] in Perspective - the combat years". wrote: 'The besetting problem was the bronze magneto skew gear which occasionally failed, losing the drive to both magnetos [ignition systems], when as one pilot drily observed, things went bloody quiet.'