As a general conclusion, it can be said that CLT propellers may provide
important FO savings at constant ship's speed and noticeable gains in speed at constant
ship's propulsion power or FO consumption. Percentages of such savings or gains may of
course vary with the type, the speed and the size of the ships concerned, but for ships
like the small bulk carriers considered in this paper, it can be established that FO
consumption are reduced by at least 14%, or speeds increased by at least 5%.
Significant part of modern marine engineer training should be given to
ecological impacts of shipping and international conventions on prevention of oil
pollution and other relevant documents. The current estimate is that 2.5 million tonnes of
oil per year enter the marine environment from all sources and this estimate is highly
influenced by number and size of shipping spills each year. At least 15% comes from
natural oil seeps. Anthropogenic sources include chronic discharges from storage
facilities and refineries, discharges from tankers and other shipping along major routs,
and accidental events such as oil spills and ruptures of pipelines.
Due to measures required by international conventions on prevention of
oil pollution, the input of oil into the marine environment from maritime operations has
decreased during the past three decades (from 1,5 million in 1981 to 0,5 million in 1989,
by estimate IMO, 1990).
Crankcase oils are an important source of polycyclic aromatic
hydrocarbons (PAH) and lead, as well as other contaminants in the marine environment.
Sediments contaminated with high levels of crankcase oils, having PAH concentrations in
the range 3...5 mkg/g, are expected to be toxic.
Wide information of this kind as well as the information about other
pollution of marine and air environment from ships and their engines (for example, of Nox
from diesel-engines), regulations for the control of discharges of wastes from ships and
offshore platforms have to be established on the national, regional and global level. And
apparently at the first turn it is the goal of training in different marine colleges and
their curriculum of MET(E).
In particular the corresponding part of MET(E) curriculum accepted by
Maritime Academies of Russia has these subjects as well as subjects with characteristics
of modern board devices intended to meet the requirements of international conventions.
As concern cutting of ship crew it seems that the old idea is tightly
connected with new ship board technology. But some works of Japanese Maritime Research
Institute have shown low effect of cutting down of manning for long oceanic lines of
highly-automatized ships (Fig.4). And the problem itself is not elementary. Considering
the ship maintenance
