Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: tons in records : are they metric ?

  1. #1
    Join Date
    Nov 2007
    Location
    Aubers, France
    Posts
    2,385
    Thanks
    0
    Thanked 3 Times in 3 Posts

    Default tons in records : are they metric ?

    hello to all,

    I'm researching archives for a friend, related to "Crossbow". I provided him lots of documents from TNA, but he asks me a question, about the tonnage of bombs dropped : They are given in 'tons' in these documents which were produced mostly in 1944.
    Are these 'metric', as we have in France (I doubt it) ?
    Or are they equals to 20 cwt, hence making 1017 kg (in metric system) ?
    Would short tons (US), 907 kg, be used in these documents (they also contain figures from U.S. bombing missions, and copies were forwarded to US Intelligence as well).

    Thanks in advance

    Joss

  2. #2
    Join Date
    Nov 2007
    Location
    Lancashire
    Posts
    528
    Thanks
    0
    Thanked 3 Times in 3 Posts

    Default

    RAF missions will have been quoted in Imperial tons. I have no idea what a US "short ton" is, the term is new to me. In the UK, if we wanted to deal in metric units (post 1970, or thereabouts) then we used the term "tonnes" to distinguish between the two.

  3. #3
    Join Date
    Nov 2007
    Posts
    200
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Hi Joss,
    I would expect that they are all quoted using imperial measurement. One ton is 1000lbs. The USA would also use this system.
    Regards,
    RobJ

  4. #4
    Join Date
    Nov 2007
    Location
    Aubers, France
    Posts
    2,385
    Thanks
    0
    Thanked 3 Times in 3 Posts

    Default

    hello,

    So if I understand you both, these tons are 907 kg.

    Graham, the US 'short ton' comes from my old anglo-french dictionnary.

    Thanks for your help.

    Joss

  5. #5
    Join Date
    Nov 2007
    Location
    Berkshire
    Posts
    2,210
    Thanks
    1
    Thanked 0 Times in 0 Posts

    Default

    Hi Joss
    Be careful, the US Ton is 2000 Lbs as opposed to the Imperial 2240lbs and hence it is referred to as "short" in many contexts, it has wider use than the USA and it may simply have been adopted by the USA . The US gallon was also a smaller quantity than it's Imperial equivalent.I would expect that wartime UK Docs would ,as Rob suggested ,use Imperial measures, but I don't know the history of US measurements well enough to comment on what they would have used.
    I'm sorry Rob but 1 Ton was never 1000Lbs.
    Regards
    Dick
    Last edited by Dick; 16th November 2008 at 10:09.

  6. #6
    Join Date
    Nov 2007
    Location
    Canada, eh
    Posts
    1,217
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Being stuck between the US and the UK, as it were, we Canadians are forced to be fluent in both country's languages. I can confirm that the US term "short ton" refers to 2,000 pounds, while Imperial tons are 2,204 pounds. In canada, "tons" has sometimes meant Imperial ton (most likely prior to about 1930), short ton (anybody born between 1930 and about 1970) and metric tonnes (anybody born after about 1970). It makes things very interesting.

    Another note: engineers usually "round things off" to a shorter term (because we are naturally lazy), so references to a "one ton bomb" can mean just about anything from around 1800 to 2400 pounds. Some records will record bomb loads by adding up the number of rounded off ton devices dropped. The end result is that these reports should be considered as + or - 20 %.

  7. #7
    Join Date
    Nov 2007
    Location
    Aubers, France
    Posts
    2,385
    Thanks
    0
    Thanked 3 Times in 3 Posts

    Default

    hello,

    I knew I was right to ask this question. The answer is not so simple, as anticipated.

    As for the Crossbow documents I'm studying, the tonnage of bombs dropped seems to be the sum of the bombers bomb load, for example 16 x 500 lb bombs, x numbers of attacking bombers, etc... informations from the Squadron, through the Groups, to HQ Bomber Command.

    Joss

  8. #8
    Join Date
    Nov 2007
    Location
    Peterborough UK
    Posts
    381
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Joss,
    It would depend on who originated the report. If it came from the RAF, then the tonnage would have been in Imperial measure ie. 2240lbs. If from the USAAF, then the American "short ton" would apply (2000lbs). British and American forces never seemed able to adopt a common usage for anything! Even their phonetic alphabets were different until quite late on in the war.
    Cheers,
    Bill.

  9. #9
    Join Date
    Nov 2007
    Location
    Aubers, France
    Posts
    2,385
    Thanks
    0
    Thanked 3 Times in 3 Posts

    Default

    hello Bill

    These reports in the AIR 14 section in Kew are definitively RAF, so I'll go on with imperial tons, = 2240 lbs.

    Cheers

    Joss

  10. #10
    Join Date
    Dec 2007
    Posts
    1,011
    Thanks
    1
    Thanked 5 Times in 5 Posts

    Default what about a mixed mission?

    Hello all,
    In the early days of the 8th AF, they ‘borrowed’ DB7 a/c. Did they ‘borrow’ the bombs? I know nothing about whether the US and British bombs/bomb racks were interchangeable, but now that the subject is open, it could be an interesting detail for the research I am doing which includes 8th AF Mission 13, a mixed bag of B-17s and borrowed DB-7s. My main source is an RAF document describing a US mission consisting of US B-17s and borrowed RAF DB-7 a/c, and I now see that it potentially mixes the two units of measure.

    (Well done, Joss. Very good question)

    Bruce

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •