Evening star. [volume] (Washington, D.C.) 1854-1972, 1918-09-15
EXPLAINS TONNAGE
FOR LAND[UbBERS
Seafaring Terms Which Puz-
zIe in Frequent Use
Nowadays.
MEASURING OF VESSELS
BY HARRY n. ROEsER,
Private, U. 8. Engineers.

The enormous Increase in the ship
ping industry and newspaper accounts
Of the enemy's submarine activities
have brought our landlubber popuia-
ton into intimate contact with tho
seafaring terms ton" and tonnage.
Both Of these fundamental terms dit-
fer in many respects from their COM
mercial usages inland, and as result
their application is perhaps more
generally misunderstood than any
other terms introduced into the cur
Besides the universally recognized
use of the word ton" as a unit of
weight. shippers generally use 1t also
as a unit Of capacity, or volume. ana
in this respect there are two main APP
plications; namely, the register ton
and the measurement, or cargo. ton or
forty cubic feet. There are many
others such as the timber ton OF for
ty feet, the flour ton OF ten par
rels, the wheat ton of twenty bushels.
the lime ton of forty bushels. but
their use is local and the meanings
are not consistent from place to place.
What TONNAGE Means.
The word tonnage" is generally used
in respect to the capacity and dimen-
sions of ships and to the amount OF
cargo. Accordingly, there are two dis
| tinct kinds of tonnage. namely, vessel
tonnage and cargo tonnage, and each OF
| these is used in various meanings
The several kinds Of vessel tonnage
are rs follows:
Gross tonnage is the total cubical
capacity Of a ship expressed in register
tons Of 100 cubic feet, or zoo cubic
e.1r1o hQtChWaYS.
| bakeries, ETC., as are exempted from
measurement by different governments.
Official merchant marine statistics of
| most countries are published in terms
Of the gross register tonnage. Press
references to ship tonnage are usually
/ to the gross tonnage. For instance.
| when the vitriolic Won Tirpitz an
nounced his program Of sinking l,oOo.-
900 tons of allied shipping a month ne
meant 100. 10000 cubic feet Of ships and
| not 1000, OOO, 900 pounds of avoirdupois
Of ships, as those uinitiated persons
might infer who understand ton TO Do
1000 pounds.
| The methods and mathematical for
mulas by which leading maritime ma
lions have agreed to compute gross ton
mage were devised by George MORRISON
of England in 1852. at which time the
English government revised its method
of measuring and registering vesseis.
These rules were incorporated in the
| Engi1Sn shipping laws ia loo1' oaio 49,
subsequently adopted by other nations.
The net tonnage, or register ton
mage, is the gross tonnage less the
different spaces specified by maritime
nations in their measurement ruies
and laws. The spaces that are dc
Quoted are those totally unavailable
! for carrying cargo, such as the engine
room, coal bunkers. crews quarters
chart and instrument rooms, etc. inc
net tonnage is the basis Tor tonnage
dues. wharf and other commercial
charges. Statistics Of entrances and
| clearances to ports are in terms OF the
| net tonnage.
| The under deck tonnage Is the ca
nacity of a shin below her tonnage
deck expressed in register tons. The
tonnage deck is the upper deck IN all
ships that have less than three decks.
and the second deck from below In all