Name (required):

  Expression ^{(Optional mood/title along with your name) Examples: (happy, sad, The Joyful, etc.) help)}

  E-mail address (optional):

* Type your message here:
>>I am trying to get a clearer understanding of the >>effect of coppering a warship had in terms of the >>weight added by the process and the expense involved. >>Specifically, how expensive a process was coppering, >>what were the dimensions and thicknesses of the >>individual plates, how much did the plates weigh? I >>would also be interested in determining when coppering >>was introduced in different navies. >> >>Thanks, John Tredrea > >Here is something I sent to John last night in the >middle of an e-mail discussion of this topic, for the >information of other readers and updated in light of >some additional information here. > > Lavery, <i>The Ship of the Line,</i> vol. II, says >that "thick plates, 32 ounces per square foot, were >used on the parts [of the hull] most vulnerable to >wear . . . thinner plates of 28 ounces per square foot >were used on the rest of the hull." Boudriot, ><i>74-Gun Ship</i>, III, 242 says that the French used >sheets 5 feet/1.63m (5'4.2") × 18 in./49cm (19.3") and >1/3 of a "line" or 0.75mm thick. That's 0.030 inches. > These sheets weighed 6.85kg or 15.1 lbs. The "thick" >British copper sheets weighed 2 lbs/ft². The French >gauge of 15.1 lbs/8.59 ft² = 1.76 lbs/ft², or just >about exactly the "thin" British gauge of 28 oz/ft². >We can thus estimate that the thicker British sheets >were 0.3*(32/28) = .034 in. thick. The 22-pound gauge >would be about 0.3*(22/28) = .024 in. thick. So the >three British thicknesses would be: >32-ounce (per square foot): 0.034 inches or 0.86mm >28-ounce (per square foot): 0.030 inches or 0.75mm >22-ounce (per square foot): 0.024 inches or 0.60mm

Notice: Copies of your message may remain on this and other systems on internet. Please be respectful.