Page 26 - Introduction to Naval Architecture

14 DEFINITION AND REGULATION

Volumes of appendages are included but spaces open to the
sea are excluded.
(5) GT and NT are stated as dimensionless numbers. The word ton
is no longer used.

Other tonnages
Special tonnages are calculated for ships operating through the Suez
and Panama Canals. They are shown on separate certificates and
charges for the use of the canals are based on them.

REGULATION

There is a lot of legislation concerning ships, much of it concerned
with safety matters and the subject of international agreements. For a
given ship the application of this legislation is the responsibility of the
government of the country in which the ship is registered. In the
United Kingdom it is the concern of the Department of Transport and
its executive agency, the Marine Safety Agency (MSA). Authority comes
from the Merchant Shipping Acts. The MSA was formerly the Surveyor
General's Organisation. It is responsible for the implementation of the
UK Government's strategy for marine safety and prevention of
pollution from ships. Its four primary activities are related to marine
standards, surveys and certification, inspection and enforcement and
keeping a register of shipping and seamen. Some of the survey and
certification work has been delegated to classification societies and
other recognized bodies.
Some of the matters that are regulated in this way are touched upon
in other chapters, including subdivision of ships, carriage of grain and
dangerous cargoes. Tonnage measurement has been discussed above.
The other major area of regulation is the freeboard demanded and this
is covered by the Load Line Regulations.

Load lines

An important insurance against damage in a merchant ship is the
allocation of a statutory freeboard. The rules governing this are somewhat
complex but the intention is to provide a simple visual check that a
laden ship has sufficient reserve of buoyancy for its intended service.
The load line is popularly associated with the name of Samuel
Plimsoll who introduced a bill to Parliament to limit the draught to
which a ship could be loaded. This reflects the need for some minimum