Evening star. [volume] (Washington, D.C.) 1854-1972, 1907-11-01
A SHIPS TONNAGE.
What It Means and the Method of
It's Determination.

rom the BOSTON Transcript.
On shore everybody knows that ton
is 1000 pounds. if a short ton. or e,240 a
long ton. Therefore. il seems TO the land
lubber that one-thousand ship ought
to be. if it is not a ship which can
carry a thousand tons weight Of cargo
AS a matter OF fact. d thousand-ton ship
can probably convey about thirteen or
fourteen hundred tons Of coal or heavy
merchandise.
Yet the, tonnage Of shipping is not SO
arbitrary as II seems. :. follows a fixed
standard established by national law
There are two kinds of tonnage reCos-
7izod by our government authorities
gross tonnage ana net tonnage. The gross
tonnage OF vessel is its entire internal
capacity measured in tons of zoe cubic
feet-and the naysa ton laws of the
United States prescribe in careful detail!
how this measurement for tonnage shall
be ascertained. Net tonnage Is measured
by subtracting frons the gross tonnage OF
vessel all space used for the accoihiho-
dation Of officers and crew. Tor certain
gear for the working of the ship. ana II
a steam vessel for her prnpelllng power
machinery including boilers and en-
gines. In other words, the net tonnage OF
a snip Is virtually the space, expressed in
tons of 100 cubic feet. available for the
carrying Of passengers or cargo IN the
case of sail vessels, from which no ma
gross tonnage and net tonnage OF a yes
sci are very nearly the same But IN
steamers the two measurements are vide
~ different.
In all. or nearly all. of the ports of the
world, ship taxes. or dues. are based upon
tonnage--in the United States upon net
tonnage. This is also the standard or
tolls for the Suez canal. AS result, the
effort 0f naval architects and Shipbuilders
and ship owners generally is to keep
the net tonnage Of a ship small as pos
s!be. and many ingenious devices for
cheating measurement have been adopt.
ed--1esigners of merchant vessels being
adept in this art as designers of racing
yachts But the navigation laws Of the
United States are exceedingly Vlglant
on this poin+ and re regarded as fair
and reasonable In their requirements, so
that this evil OF fraudulent tonnage is be
licved 10 he less serious under the faS
Of the United States than the merchant
navies of some other countries.
I.andsmen may well be pardoned Tor
their perplexity that tonnage. in the YER
nacu!ar Of the sea. should mean some
times one thing and some INES another
The Navy department adds to the m
evitable confusion by describing our SHIPS
of war in terms. not of gross register or
net register but of displacement. lhus
the Massachusetts is spoken Of officially
as a battleship Of 10000 tons and the
Vermont which has Just sailed from boS-
ton on her first cruise. as battlesilp OF
IS 900 tons This means, in each cast"
that the ship displaces 50 many tons OF
water But the Massachusetts,, It meas
ured as merchant vessels are Heasnleu
would have a net tonnage Of only ), 2o4
and would have to pay dues on that only,
If passing through the SueZ canal rms
practice Of the Navy Department OF using
displa CO ment tonnage instead OF net ION
mage gives the public an exaggerated idea
of the actual size of ships of war
These national measurements OF snip
ping though apparently arbitrary. are m
C!ispensable; for ships cannot be cIaSSiIeQ
18th any exactness on the basis of the
tons ms Of cargo they viii actually carry. \
ship which could receive. I'D transpoir5
safely 5000 tons weight Of pig iron WouLd
Therefore. the governments of the word
have had to prescribe measurement STAND.
ards Of their own. in which the srtat
ma ~iue insurance companies nave h"u
+,o,,arf,l hand And the tendency IS 70
BRING these standards into more and more
complete Conformity.