Barrels

[Maury S]

[Roger Pellett]

Maury,

 

Thanks for posting this.  The Naval architecture concept of tonnage developed from the large barrel that you show called a Tun.  In the 1500’s wine was a major commodity imported by England and the king, either Henry VII or VIII, needed a way to levy taxes associated with shipping.  The easiest method was to rate a ship by the number of Tuns that she could stow.  This morphed into a system where Tunnage could be predicted by multiplying length x width x depth under the main deck  and dividing the result by  100.  This concept still survives to this day but the calculations are more complex.

 

Tonnage is therefore a measure of volume, not weight.

 

The weight measurement Ton also derives from the carriage of wine as a Tun of wine weighed 2240 lbs, one “long ton.”

 

Roger