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organisms as well. The content of nutrients, salinity,
oxygenation level and the degree of pollution of the
aquatic environment are of key importance. Algae, like
many species of marine organisms, develop best in
warm waters with high salinity, which makes vessels
operating in such regions particularly vulnerable to
intensive fouling.
Furthermore, the rate of biofouling settlement and
growth is influenced by technical factors, which may
vary depending on the specifics of a given vessel. The
speed of the vessel plays a key role – slower vessels are
more susceptible to the attachment and accumulation
of organisms on the surface of the hull plating. The
location of the port, the length of stay, the frequency of
inspections and cleaning of the hull and the use of
modern anti-fouling agents are also important. Proper
maintenance and protection of surfaces reduce the
negative effects of fouling, which can lead to increased
hydrodynamic resistance and increased fuel
consumption.
Hull damage or fouling can not only affect the
vessel’s speed and fuel efficiency but can also be
hazardous to cargo and have a negative impact on the
marine environment. It is estimated that a
contaminated hull can increase fuel consumption by as
much as 6% to 14% [6, 10]. Although necessary, hull
inspections can be an extremely difficult task, but they
play an important role in maintaining the operational
efficiency of vessels. Traditional methods of cleaning a
ship's hull can use chemicals that can be harmful to the
marine environment. The rapid development of
robotics and advanced sensor systems is opening new
possibilities for automating this process.
This review article presents the application of
solutions using Remotely Operated Vehicles (ROVs),
as a safe, fast and efficient way to conduct hull
inspections. Furthermore, the study discusses
advanced technologies employed for hull surface
cleaning, which contribute to reduced downtime,
lower maintenance costs, and minimized
environmental impact on the marine ecosystem. The
use of remotely operated vehicles is an innovative
approach that not only improves cleaning processes
but also increases the safety of operations and
contributes to sustainable fleet management. This
publication is organized as follows. Section 2 entitled
"Materials and Methods" presents traditional ship hull
cleaning techniques, which are then contrasted with
modern methods using ROV units, describing the
cleaning process and the tools used. Section 3 entitled
"Discussion" considers the modern cleaning techniques
presented in the article as an alternative to the
traditional stay of the ship in the shipyard dock. The
article ends with general conclusions on the use of ROV
units during underwater hull inspections.
2 MATERIALS AND METHODS
2.1 Traditional cleaning techniques
Conventional hull cleaning is carried out at the
shipyard, where it is necessary to place the ship in a
dry dock. The duration of this period is determined by
the degree of hull fouling, as well as its technical
condition and the scope of shipyard work. On average,
it is from 7 to 10 days. However, such a stay requires
temporary suspension of operations. The main
cleaning technique involves the use of a high-pressure
jet operating at 350 bar. In connection with the above,
together with the removed organisms, loose fragments
of antifouling paint and rust are torn off from the shell.
Certain parts of the hull such as screws, rudder blades,
thruster grids, due to their design, often require
manual cleaning with the use of tools such as scrapers
and brushes. If high-pressure water alone is
insufficient for complete cleaning, sandblasting of the
steel hull surface is performed. This involves spraying
quartz sand at high pressure to effectively remove
deposits from the plating. Use of above-mentioned
technique significantly increases the downtime of the
ship and causes significant pollution of the working
environment. The limitations of traditional hull
cleaning techniques are shown in Figure 1.
Figure 1. Traditional hull cleaning methods – challenges and
limitations [own study].
2.2 Underwater cleaning techniques
The development of technology, robotics and
automation causes traditional methods of cleaning
ship hulls to become less effective and more expensive.
From this perspective, underwater cleaning using ROV
technology has become beneficial compared to the
manual cleaning performed on the shipyard dock [7,
10]. The impact and cost savings results from many
factors, which are presented in the following Figure 2
[3,12].
Figure 2. Advantages of hull cleaning with ROV [own study].
Cleaning the submerged part of the hull using ROV
is based on the use of electromagnets, which ensure
stable adhesion to the steel surface of the ship's plating.
That allows effective cleaning regardless of the
environmental conditions. The system ensures
effective operation even in ports, where the presence of
strong currents, waves and winds could hinder the
operation [1,4,11].