Page 352 - Ship Construction.DJ Eyres 6Ed

Ch30-H8070.fm Page 341 Wednesday, October 18, 2006 11:15 AM
Tonnage 341
dimensions are used. It is possible for the surveyor to compute tonnages
directly form the moulded lines of the ship or computer stored offsets. This
is in contrast to the previous regulations where the surveyor was required to
physically measure spaces to the inside of frames and linings.

PANAMA AND SUEZ CANAL TONNAGES Tolls for transiting the Suez
Canal are based on a net tonnage of the ship determined in accordance with
--- ใช้เพื่อการศึกษาเท่านั้น---
the regulations of the Suez Canal authority. Whilst IMO recommended
acceptance of the use of the Convention rule for the Suez and Panama
Canals in 1981 the Suez Canal Authority has maintained its own system.
งานห้องสมุด ศูนย์ฝกพาณิชย์นาวี
The Panama Canal Authority introduced a net tonnage measurement
system based on the 1969 Tonnage Convention in 1994. It has however sub-
sequently changed its charging regime from a flat rate for all ships to one
based on ship size and type and has separate locomotive usage rates. This being
considered a more equitable system, since charges are now applied according
to the transit needs of each ship. Further since 2005 a new measurement
and pricing system is being phased in for container ships and other vessels
with on-deck container carrying capacity. For container vessels the Authority
have adopted the TEU as the measurement unit. For other vessels with
on-deck container carrying capacity the Authority will continue to apply
ึ
the universal tonnage requirement to the underdeck spaces and will charge
a per TEU fee for the actual number of containers carried on deck.
Both the Suez and Panama Canal Authorities have recognised a number
of classification societies to undertake measurement and issue of tonnage
certificates on their behalf.

Compensated Gross Tonnage (CGT)

For many years the gross tonnage was used as a measure for comparing the
output of various shipbuilding countries. Gross tonnage was never intended
to be used for statistical purposes and, although it may have served this
purpose, it can give very misleading impressions. For example, the building
of a 65000 gross tonnage passenger liner may involve considerable more
man-hours and capital than the construction of a 150000 gross tonnage oil
tanker.
A system of compensated gross tonnage was introduced and adopted as a
means of overcoming this problem. Factors are given for each ship type and
the gross tonnage of the vessel may be multiplied by the appropriate factor
to give the compensated gross tonnage. Compensated gross tonnage factors
developed by the OECD in co-operation with the Association of West
European Shipbuilders and the Shipbuilders Association of Japan in 1968
are given in Table 30.1.