Tonnage What’s this?

[B BParticipant @bb42502]

where does it come from and what does it mean today?

[B BParticipant @bb42502]

I picked up book which was thrown out by a library from dump site. Actually there were more. Luckily they were not dirtied with muck yet. What a find! They are old books printed around 1949 which was agreat time for shipbuilding in general.

Ever wondered where the word ton comes from and how is was then altered to suit the ships of today?

Here goes: Often ships tonnage is expressed in either capacity of a ship or displacement of the vessel either loaded or unloaded. dead weight tonnage is the weightwhch brings a ship from light (empty) to the loaded draught of the ship. This includes all bunkers, fresh water, consumable stores and all cargo that is laoded into the ship.

 

 Yes Yes that is all fine but where does tonnage originat from?

 the term of capicity ton came into being in the early shipping days when the British shipping trade carried many cargos of wine from France. Thes wine casks were called TUNS and were pretty much all of the same size. Because ships differed in size a handy way of conveying the carrying capacity was to express the amount of space as so many Tuns of wine. This method became universal and even if it was not involved in carrying wine the space was still expressed as tuns. the word Tunnage was corrupted to Tonnage capcity and the ton is equal to 100cubic feet. Here we go again can’t we do it in Metric.

 

Gross tonnage of the vessel is calculated of the entire space inclusive of  all spaces in the superstructures. the only things excluded in this calculations are machinery spaces, crew spaces, wheelhouse galley/s ballast tanks. passanger accommodations gang ways and stair wells etc.

 

Well now there we have it!

 

 

[David WooleyParticipant @davidwooley82563]

Hi BB this is an interesting question. The origins of the word Tonnage evolve from the 14century in fact it was a tax levied by Edward 1st of England. This was followed by a further tax on imported wine to the value of 3shillings on each “Tun” of wine imposed by Edward 3rd in 1347. The rough tonnage for tax purposes was based on the simple calculation Vessels length in feet multiplied by her maximum beam in feet, multiplied by the depth of her hold below the main deck in feet divided by 100. This simple rule was amended in 1694 to  read divided by 94  and to  take into account  the vessel  when   fully laden, in ballast  and light     By 1773 a  more comprehensive and accurate set of calculations where introduced.

Dave Wooley

 

Edited By David Wooley on 16/09/2010 14:22:33

[B BParticipant @bb42502]

Yes that is correct about the taxes that were levied on the wine by Edward 1st of England. This is also mentioned in the book I found. Before this tax calculation came into being the only way to determine the carrying capacity was by the amount of wine tuns that could be loaded into a ship. As you stated the rough tonnage was calculated as you stated.

 It all becomes very interesting how this all evolved and how accurate it can be calculated with todays technology and formulas..

These old books I found, The book of the ship 1949, explains the whole process of what is all involved in the building of a ship and its working life with costsntil scrapping. We just can’t find books like that. The second book, Ship design,shipbuilding production 1952, is all about the disigning and the production of all the parts that go into a ship. the third book is, Bocks Weld schfahrt from 1890 to 1964. This is also very interesting as it progresses through all the different countries and the shipping lines vessels. It names the vessel, shows a black silhoette of the ship (all are to the same scale throughout the entire book. Where the ship was built and various other data. Very Very interesting.

Does anyone else have such old books lying around?

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