Show In Shipping How Much Is a Ton Even Experts Trip Trying To Explain Puzzle Can Mean Several Things WASHINGTON How How How much is a aton aton aton ton of ship Even the experts stumble on the answer to that one as demonstrated recently in a dispute between the Truman committee and Secretary Knox over the tonnage of Allied ship ship- shipping shipping shipping ping lost and built last year I A pertinent point it develops is the formula used in determining the various tonnage figures involved And I that congressional experts said makes a lot of difference To To begin with a ton of warship l and a ton n l of mt m merchant ch t either er cargo or passenger are entirely dif dif- different different different ferent things Warships are measured in displacement dis displacement displacement placement tons which means the actual weight of the vessel 1 i t I I ing lag hull and machinery arms ar- ar armor I arI armor I I mor and ammunition with ships ship's stores and personnel aboard and i ready to go to sea except for water I I in the boilers and nd fuel oil I J I I Displacement Is Basis Vessels thus hus equipped are weight t-I t I I by the volume of water dis als- displaced placed under the principle discovered discovered discovered ered 2500 years ago by the Greek scientist Archimedes that a floating body displaces a volume of water equal to its own weight On the other hand a liton of merchant ship is a unit of measure measure- measurement measurement measurement ment of the vessels vessel's carrying capac capac- capacity capacity capacity ity arrived at by several different methods of computation and except when expressly referring to dis dis- displacement displacement displacement placement has no connection with the weight of the ship itself The most frequently used tonnage figures for merchant vessels are gross deadweight and registered or ornet ornet ornet net Gross tonnage is the figure usually employed and it is this type of ton ton- tonnage tonnage tonnage nage generally referred to in fig fig- figures figures figures ures on Gross tonnage is the capacity or volume of the enclosed area of a ship expressed in terms of one ton for every cubic feet of space a standard adopted by both the United States and British navigation laws The ton per formula is applied regardless of the type of cargo actually carried I Deadweight Measure Deadweight tonnage on the other hand is the weight in tons of a ships ship's cargo passengers crew fuel and stores which can be carried I when fully loaded and is measured by the difference in displacement of the vessel when light and when load load- loaded ed Deadweight tonnage is the fig fig- figure figure figure ure usually employed in construction I statistics The loading limit of a merchant ship is marked by the load line or II mark painted on the hull The other common formula for I measuring tonnage registered or ornet ornet ornet net represents the gross tonnage less the space taken up by propel propel- propelling propelling ling machinery crews crew's quarters and other necessary purposes which represent no earning power It is this figure which is used for regis regis- registration registration tr tion or documentation under the navigation laws Thus the wide variations in the different tonnages of a particular ship may be easily understood A cargo ship with a nominal dead dead- deadweight deadweight deadweight weight tonnage of about tons might have a displacement of per per- perhaps perhaps haps tons a gross tonnage of and a registered tonnage of |