:max_bytes(150000):strip_icc():format(webp)/directly-above-view-of-cargo-ship-on-sea-594481899-5a0374849e9427003c7480a5.jpg)
..........................................................................................................................
Deadweight Tonnage
The Meaning of Deadweight Tonnage of a Ship
by Paul Bruno
Deadweight tonnage (DWT)
refers to the carrying capacity of a vessel.
Deadweight tonnage can be
figured by taking the weight of a vessel which is not loaded with cargo and
subtracting that figure from the weight of the vessel loaded to point where it
is immersed to the maximum safe depth.
This depth is noted with a
marking on the ship's hull, the Plimsoll line.
The safe depth varies by the
time of year and water density and, in the case of DWT, the summer freeboard
line is the measurement used.
The displacement of water due
to the load is measured in metric tons (tonnes or 1,000 kilograms).
The deadweight tonnage
includes not only cargo, but also the weight of fuel, ballast,
passengers and crew, and all of the provisions. It only excludes the weight of
the ship itself.
Example
A vessel that weighs 2000 tons
unloaded carries 500 tons crew and supplies. It can take on 500 tons of cargo
in port, at which time it floats at the summer line of its Plimsoll line. The
deadweight of this vessel would, therefore, be 1000 tons.
Deadweight Tonnage vs. Displacement Tonnage
Deadweight tonnage is distinct
from displacement tonnage, which includes the weight
of the ship as well as its carrying capacity.
Lightweight tonnage is the
weight of the ship itself, including the hull, decking, and machinery, but not
including ballast or any supplies that could be consumed, such as fuel and
water (except for the liquids in the engine room systems).
Deadweight tonnage is the displacement
tonnage minus the lightweight tonnage.
Paul
Bruno
United
States Coast Guard licensed Ship Master with Passenger Certification.
A
marine contractor familiar with all ship systems who has worked in the industry
for more than 20 years.
Has
a USCG Master's License and a degree in Creative Nonfiction and
Technical Writing, from the University of Wisconsin.
Experience
Paul
Bruno is a former writer for ThoughtCo who contributed work for over five years
on the maritime industry. He has worked with a variety of vessels throughout
his maritime career, including various commercial ships as well as the Great
Lakes schooner reproduction "Dennis Sullivan." As a marine
contractor, Paul is familiar with all ship systems, and his lifelong passion
for electronics has led to a focus on marine hardware and software development.
When he is not working, Paul's favorite hobby is knot work, keeping busy with
the nearly 4,000 documented knots, splices, and eyes.
Education
USCG
Master's License, 1993
Creative
Nonfiction and Technical Writing, University of Wisconsin, Milwaukee and
University of Waikato, Hamilton NZ
Paul
Bruno
ThoughtCo
and Dotdash
ThoughtCo is a premier
reference site focusing on expert-created education content. We are one of the
top-10 information sites in the world as rated by comScore, a leading Internet
measurement company. Every month, more than 13 million readers seek answers to
their questions on ThoughtCo.
For
more than 20 years, Dotdash brands have been helping people find answers,
solve problems, and get inspired. We are one of the top-20 largest content
publishers on the Internet according to comScore, and reach more than 30% of
the U.S. population monthly. Our brands collectively have won more than 20
industry awards in the last year alone, and recently Dotdash was named
Publisher of the Year by Digiday, a leading industry publication.
No comments:
Post a Comment