18.05.2020
TANKER CHARTERING

This is one of the most useful publications on tanker chartering of those available today. The volume was developed and released by one of the most recognized organization of today’s maritime world. The readers will start with some brief information about the historical background and development of the tanker shipping; here, the structure and arrangements on the tankers will also be addressed.

After that, the chapter devoted to the tanker chartering geography will go, followed by the one dealing with the structure of the market from new construction of the tankers and up to their scraping. The voyage estimating has been covered in the next chapter with the attention paid to the route, bunkers, port time, expenses and other aspects. The remaining chapters of this publication are dealing with the chartering market practice, lay time and time-charters, financial elements and charter parties, etc.

The closing part of the book provides information about the major organizations in the industry, such as the AAA, BIMCO, ACOPS, FONASBA, ICS, ECASBA, ICS, ITF, INTERTANKO, OSRL and many others. Several appendices provide supplementary information such as the firm offer form, voyage tanker checklist, examples of bill of lading, letters of indemnity etc.

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18.05.2020
ROUTE PLANNING WITH ECDIS

This training file is in fact not the actual video but rather a sort of presentation providing necessary information about planning the ship’s route using the ECDIS. It will be very good both for people wanting to get the general idea of what the electronic navigation means is, and also practicing navigators who need some more info on the practical use of the system.

They will get to the better understanding of the ways to comply with the relevant rules and regulations, and know how to use all the functions and features of the electronic navigation charts. The main emphasis has been made on the voyage planning. The main objective of it is to ensure that the vessel can be safely navigated from one port to another. For this, the most safe and favorable route shall be established for the vessel and, of course, the safety aspects shall be taken into account at the first place.

The navigators shall consider so many factors when developing the voyage plan – among those factors are the type of the cargo being carried on board, marine environment, reliability of the navigation charts available for the proposed plan, routing constraints, weather conditions, availability of the navigation aids and so many others.

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17.05.2020
Vibrational Habitability

On board ships equipped with machinery developing power for propulsion and auxiliary purposes, personnel are subjected to vibration. The vibration may cause annoyance, physiological damage to body organs, psychological disturbance of the crew or damage to shipboard equipment.

The effect of vibration upon equipment installed aboard ship has been one of the major factors resulting in premature failures of equipment which has previously proved satisfactory in land-based installations. The equipment supplier must consider the vibration aspect of the shipboard environment in the design and construction of marine hardware.

A magnitude of vibration which can do no harm to equipment or structure can, however, be a great nuisance to the crew. The degree of human perception to vibration in the frequency range of 30 to 4800 cycles per minute is a function of the amplitude of the vibration. Frequencies below 0.5 Hz may cause motion sickness.

While it is difficult to define precisely acceptable limits of intensities of vibration, two figures in this article identify vibration zones which may be used as a guide in determining general acceptability. Zone A defines that area within which a high probability of vibration difficulties exist; Zone С defines that area within which no vibration difficulties are anticipated; Zone В defines that area within which the subjective nature of vibration does not permit a reasonable assurance of acceptability.

 

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17.05.2020
Acoustical Habitability

The human ear has certain interesting characteristics. The normal hearing range for a young person extends from about 20 to 15,000 Hertz (Hz) (cycles per second), with the greatest sensitivity around 1,000 Hz. Aside from the noise attributes of loudness and annoyance, there is the factor of physical tolerance to noise, that is, the noise sound-pressure levels which the ear can stand without discomfort or damage.

The effect of noise on the human being with regard to hearing loss and communication has been studied and design criteria established through extensive habitability research in naval ship design. The effect of noise annoyance is, however, not as well defined. The wide range of noise levels' which various persons find disturbing makes this aspect of noise control more subjective and difficult to define. Factors which influence a person's reaction to noise include interest of the listener in the sound, whether the noise is unnecessary and could be avoided, the degree to which the listener can disregard the noise, the activity with which the noise interferes, the character of the listener.

For the more noisy spaces aboard ship, it has been determined that people can readily adjust to various Acoustical Habitability - 2environments and actually consider them normal, once they are conditioned to accepting them, provided the environment includes no hostile sounds. How well the naval architect can handle the problem of acoustical habitability depends largely upon how well he can control the magnitude of sound levels and how much he can shape the noise spectrum in any of the various ship's spaces.

The reduction of noise within certain spaces may produce counter-productive results. For example, staterooms normally receive a high degree of isolation from passageway noise, however, the resultant number and location of general alarm bells must be carefully reviewed to assure audibility within all staterooms. Also, the enclosing of machinery control stations has prompted some reaction from operating personnel that not hearing the machinery has degraded their effectiveness.

The major sources of noise generation aboard ship may be categorized into flow generated noise and mechanically generated noise. Each of these general categories contains several elements each of which must be considered by the designer to preclude objectionable noise conditions aboard an operational ship. Flow generated noise is produced by a fluid in motion. The fluid may be either a liquid or gas and may be either within the ship envelope or external to it.

Noise Generated by Ship Mooing Through the Water

Flow of water around the hull of a ship is almost completely turbulent, particularly in the bow and stern areas. The Acoustical Habitability - 3turbulent water flow path produces pressure fluctuations which tend to drive the hull plating into vibration. The resultant noise may be transmitted within the hull either as airborne noise or as structureborne noise. Discontinuities of the hull such as sonar domes, sea chests, and shaft struts function to increase the turbulence within the boundary layer thereby tending to be sources of external flow noise.

Propeller Generated Noise

Several different types of noise may be generated by the ship's propeller. The two types of propeller noise associated with fluid flow include cavitation and vortex shedding. When a ship's propeller is rotated at high speed cavities can form and collapse radiating a loud and continuous noise. Also vortices are shed from the trailing edges of the propeller blades. If the frequency of this shedding corresponds with a resonant frequency of the propeller blade the blade vibration will radiate a loud ringing noise.

Fluid Flow Noise

The noise sources within piping and duct systems are similar to those produced by the ship moving through the water and the propeller. The flow of fluid through a piping system may produce noise due to turbulence, cavitation and vortex shedding. In piping systems the noise may be intensified by the organ pipe effect of the pipe or duct. Restrictions or obstructions in the fluid flow path which increase the velocity are prime sources of cavitation and turbulence generated noise. Dampers and splitters within ventilation ducts may also produce noise due to vortex shedding.

Mechanically generated noise usually originates in rotating and reciprocating machinery. The sources of such noise may be the result of improper balancing, excessive tolerance between mating parts such as gears or the result of loose or worn parts. The characteristics of the machine and the noise produced may provide an indication of the problem area.

Design Implications

The acoustical aspects of controlling the ship's interior environment must be included at the beginning of the design process. In many cases, it is extremely difficult and expensive to correct a noise problem whereas the impact of Acoustical Habitability - 4precluding the problem at the early design stage would be minimal.

When addressing the acoustic or noise considerations both the noise source and the transmission path must be reviewed. Control of noise at the source may be accomplished by improved dynamic balance of rotating machinery, limiting velocity within fluid systems, avoiding turbulence within fluid systems, improved tolerance between mating parts, and application of suppression material to the noise source. In addition, the noise level within spaces such as staterooms may be controlled by locating them as remote as practical from spaces having a higher noise level. For example, it would not be prudent to locate a stateroom adjacent to a fan room.

Noise may be transmitted from the source to other areas via the structure as vibration, as airborne noise or as fluid-borne noise. Structureborne noise usually originates at machinery or equipment foundations. Transmission of noise from a machine to the supporting structure may be reduced by mounting the unit on resilient mounts or distributed isolation material.

Where such type mountings are used, isolation of the connecting piping or ductwork must also be accomplished. When resilient mounts are employed, care must be taken to assure the natural frequency of the mount does not coincide with the exciting frequency of the vibration source.

Acoustical Habitability - 5Airborne noise may be reduced by locating the offending unit within a space lined with sound absorbent material or, as in the case within the engine room, as remote as practical from the operating station.

Fluidborne noise may best be controlled by eliminating the source where practical. If a large pressure drop is induced by a single orifice in a piping system, consideration should be given to a multiple-step orifice thereby reducing the velocity through each step. If the source of the noise may not be eliminated as in the case of ventilation fans, absorbent material may be installed in the ductwork or, in some cases, the ductwork must be increased in mass to reduce the amplitude of response of the ductwork to the vibratory excitation.

With respect to naval vessels, acoustical considerations may extend well beyond the element of habitability due to the nature of the ship's function. The methods employed aboard submarines, for example, for controlling noise are several orders of magnitude more extensive than those normally encountered in merchant ship practice.

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17.05.2020
MEDICAL FIRST AID — MODEL COURSE 1.14

The present IMO Model Course has been developed for the candidates who will be providing medical first aid on board vessels and shall get prior training as per the relevant provisions of the STCW Code. The syllabus of the training course is covering all applicable requirements of the convention. The people who min the minimum competency standards will be considered competent and will be authorized to provide medical first aid should any illness or accidents take place on board.

The trainees taking subject course are expected to complete the Model Course 1.13 – Elementary First Aid which would provide the necessary essentials. The trainees will start with the information on the immediate action and the first-aid kits kept on board ships. After that the content of the course covers the structure and function of the human body, and various toxicological hazards commonly existing on board vessels. The examination of the patients has been addressed within a separate chapter.

Then, the different problems have been covered including but not limited to the spinal injuries, muscular injuries, heat and cold effects, scalds, burns, fractures and many others. Also, useful information on the pharmacology and sterilization has been included. Note that the volume also covers the cardiac, psychiatric and psychological issues.

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17.05.2020
PORT STATE CONTROL — TIGHTENING THE NET

Shipping is vital to the world economy, but it must be of a good standard and properly operated, so it is not to danger the crew, risk the cargo and damage the environment. Towards the end of the last century, a series of shipping incidents led to suspicions in Europe that poorly operated ships were escaping the net of the established regulatory bodies. Discussion began on inspecting ships in port under the SOLAS Convention.

It was clear that, to be effective, countries had to act together. So, in 1982 in Paris fourteen European countries signed the Memorandum of Understanding, an MOU on Port State Control. The Paris MOU currently includes twenty-seven countries. Other MOUs were established in the Asia-Pacific region, South America, the Caribbean, the Mediterranean, the Indian Ocean, West Africa, the Black Sea and the Arabian Gulf.

Now, there are nine MOUs incorporating nearly 140 countries. The USCG also inspects ships under port state regulations. The objective of all these countries is to ensure that the ships entering their waters are properly maintained and properly run. Although port state control is intended to benefit the port states, it is benefit to both ships’ crews and ship operators. As soon as the ship is scheduled to arrive, the port state authority examines its records and recent MOU inspection history.

If the ship has had problems in the past or has not been inspected recently, it will go into selection list for inspection. Each MOU has its own method for selecting ships. Many look at the ship’s history and also its type. If it is of the type and age considered high risk, it will go on the selection list. If it is Flag State or Recognized Organization that has a poor record of detentions, the ship will go on the list.

If a complaint has been received, either from a previous port, a crew member or a pilot, that will also put the ship on the list. Once the ships have been selected, the port state control officers are assigned. The ship is not informed – they always arrive without warning. The objective of port state control is to ensure that all the ships passing through the port state waters, are operated according to international standards.

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16.05.2020
THE SAILING YACHT

This famous book will provide readers with the truly remarkable collection of useful information about sailing yachts. It is one of the most comprehensive and professional studies conducted on the subject, covering virtually all important areas. The text part of the volume is supplemented with the perfectly detailed and colorful illustration making the understanding much easier.

All technical information is presented in a very simple and clear way, so the book will be useful even for the newcomers to the world of yachting. Among the topics covered by the authors there are classes of the sailing yachts, history of yachting, navigation aspects, sails, theory of aerodynamics and so many others. The development of the modern sailing yacht and rig has been addressed separately. Particular attention has been paid to the yacht stability being one of the critical factors affecting safety of navigation.

The types of the yachts covered in the pages of this volume include cruisers and larger yachts, dinghies and the ocean going yachts of relatively smaller sizes. The content of the book is not limited to the sails and the author has also addressed the engines installed on board yachts, and included all necessary information about the yacht propellers.

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16.05.2020
SHIP TO SHIP TRANSFERS — CONSIDERATIONS APPLICABLE TO REVERSE LIGHTERING OPERATIONS

The present publication developed and officially reversed by one of the most respected entities in the modern international maritime shipping industry, will provide all necessary instructions for the ship-to-ship, or STS, operations including valuable guidelines related to the reverse lightering, or topping-off. This is the operation where a laden ship, which would usually be an Aframax or Suezmax tanker, is being brought close to the partially laden vessel, normally ULCC or VLCC to transfer the cargo from smaller vessel to a larger one.

This is what differs the reverse lightering from the other ship to ship transfer operation where the maneuvering ship is ballasted. It is very important to pay all due attention to the fender selection as it becomes critical for the provision of the safety of STS operations. In addition to that, all aspects shall be thoroughly considered including, but not limited to the stand-off distances and energy absorption.

The publication is quite compact but it contains all necessary information. First two sections are covering the procedures to be followed when selecting the fender, and characteristics of the energy absorption by the fender. Three other sections are dealing with the approach velocities, availability of the equipment used in the course of the operations, and stand-off distances mentioned above.

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