What have you learned about WW2 recently?

Discussion in 'General' started by dbf, Oct 22, 2010.

  1. Owen

    Owen -- --- -.. MOD

    Maybe because to us Brits "Provo" means the IRA.
    Not in a WW2 context of course.
     
  2. Chris C

    Chris C Canadian

    Ahhh.

    The ship was apparently named after a town in Utah.
     
  3. Dave55

    Dave55 Atlanta, USA

  4. Sheldrake

    Sheldrake All over the place.... Patron

    He also claimed that his doctor prescribed whisky for his injuries - enabling him to breach prohibition laws.
     
    JimHerriot likes this.
  5. TTH

    TTH Senior Member

    That was a very common dodge in the US at that time. Many American doctors willingly wrote such bogus scripts for a consideration.
     
    JimHerriot likes this.
  6. Dave55

    Dave55 Atlanta, USA

    One area where the Americans contributed to the greatness of the Merlin was the crankshaft bearings. US aircraft engine manufacturers had determined that a silver-lead alloy with indium plating provided long wear and exceptional corrosion resistance. Thankfully, German engineers who evaluated captured American engines falsely deduced that the indium was merely an impurity. Packard shared the secret bearing formula with Rolls-Royce who incorporated it into the Merlin.

    https://jrcengineering.com/wp-content/uploads/2020/10/Packard-Merlin.pdf
     
    Chris C and JimHerriot like this.
  7. I'm not completely convinced by that article, it has at least one apocryphal statement in it.
    What is certain is that post-war US Merlin engined racing aircraft often have V-1710 con rods installed.
     
  8. Dave55

    Dave55 Atlanta, USA

    I'm not doubting it but I'm not knowledgeable enough to spot any glaring mistakes. What was it?
     
  9. The tale about the Rolls-Royce warranty, I heard the same story 30 years ago except it was a car in Australia.
    Also incorrectly naming British Imperial units and US customary units (although I accept this may be common in US jounalism). I'm off to the pub now but tomorrow I will delve into my bible on this matter and look at detail into the engineering claims.
     
    Dave55 likes this.
  10. Dave55

    Dave55 Atlanta, USA

    I missed that one but I agree. Maybe my brain has started filtering silly stuff like that.
     
  11. So it turns out that Rolls-Royce used lead-bronze with a lead-indium flash whereas Allison used siver with a lead-indium flash on crankshaft bearings.
    The real improvement was in the finishing of the crankshaft itself. Rolls-Royce machined the surface to a high finish, turning a 500 lb forging into a 120 lb finished crankshaft which was time consuming and expensive. Allison achieved the same fatigue resistance by forging the crankshaft to the correct size and shot-blasting it, which seriously improved production times.
    The whole story of US built Merlins is a great example of technology sharing between Rolls-Royce and Allison/Packard.
     
  12. ltdan

    ltdan Nietenzähler

    Same for the 40-mm Bofors, by the way: If I remember correctly, one of the people responsible for production said that the original building plans were apparently conceived to get all the unemployed of the Great Depression off the streets.
     
  13. But not true for the saga of US built Hispano cannon.
     
  14. A-58

    A-58 Not so senior Member Patron

    upload_2021-9-13_22-5-14.png
     
    CL1, dbf, TTH and 7 others like this.
  15. Dave55

    Dave55 Atlanta, USA

    Chris C and CL1 like this.
  16. TTH

    TTH Senior Member

    Exactly. Get hit in the engines or the cockpit and you're not coming home.
     
    A-58, Chris C and CL1 like this.
  17. A-58

    A-58 Not so senior Member Patron

    The "survivorship bias" theory is difficult to accept at first reading, but it does make sense if you really let go of the idea that the military planners had in reinforcing the areas not hit. Fascinating concept actually. I like fascinating concepts.
     
    TTH and CL1 like this.
  18. CL1

    CL1 116th LAA and 92nd (Loyals) LAA,Royal Artillery

    Makes total sense and very interesting
     
    A-58 likes this.
  19. A-58

    A-58 Not so senior Member Patron

    Si Kaddour Benghabrit, the rector of the Grand Mosque of Paris, helped Jews survive during the Nazi occupation of Paris. The mosque would give Jews certificates of Muslim identity and offered refuge.
     
    TTH, 4jonboy and dbf like this.
  20. A-58

    A-58 Not so senior Member Patron

    More on the fascinating concept of survivorship bias.

    Abraham Wald's contributions in WW2 is considered seminal in the then-nascent discipline of operational research. During the war, Wald was a member of the Statistical Research Group (SRG) at Columbia University, where he applied his statistical skills to various wartime problems. These included methods of sequential analysis and sampling inspection. An example of this work is mentioned in my earlier post w/diagram.

    Another example of survivorship bias is when the Brodie helmet was introduced during WWI, there was a dramatic rise in field hospital admissions of severe head injury victims. This led army command to consider redrawing the design, until a statistician remarked that soldiers who might previously have been killed by certain shrapnel hits to the head (and therefore never showed up in a field hospital), were now surviving the same hits, and thus made it to a field hospital.

    I always liked the Brodie helmet. It was cool looking.
     

Share This Page