[LMB] OT: Romans

Howard Brazee howard at brazee.net
Sun Aug 25 22:02:05 BST 2019



> On Aug 25, 2019, at 2:10 PM, markus baur <baur at chello.at> wrote:
> 
>> Overshot waterwheel, which was much more efficient than undershot
> 
> yes, no, sort off
> 
> the romans did know and use the overshot waterwheel .. look at the roman "mill factory" of Barbegal
> 
> which type of wheel is more efficient is a question of available amount of water and drop head .. undershot does better with large amounts of water and very little drop head, overshot does better with little water and large drop head
> 
> (its similar to the question if a Pelton wheel is more efficient than a Kaplan turbine - and a Francis fits right into the middle between thgese two .. plus a number of alternative designs)

Agreed.    But *sometimes* overshot waterwheels are much more efficient.  Knowing how to make both and selecting the best option is useful.


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