Feature Articles

Article by Phil Duffy MIIMS
Principal Surveyor at Interface Marine Yacht and Boat Surveyors France

The focus of this article is on the process and the logistics involved in surveying large crewed yachts, rather than on the practicalities of the survey. The areas of inspection are basically the same as on any pre purchase survey, albeit larger and with regard to machinery systems can be more technically involved, the time frame of course is much longer.

One question I often get asked is how to get the business, or how to make the jump from surveying small pleasure craft to larger vessels…. As always, the client will need to trust your ability to carry out the job, and for that you will need to prove your track record with references etc. It can be a chicken and egg situation, unless you have worked for one of the larger surveying companies or are able to assist on some large yacht surveys and gain an insight that way. In my case it was quite an easy transition, as during my career at sea I have held both Engineer and Captain Positions of large yachts.

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The Report Magazine went to interview Ian Millen, COO of Dryad Maritime, a specialist company providing a range of maritime security products and services that are essential in times of heightened security risks to keep seafarers safe. Dryad Maritime says it is a maritime operations company with a high grade intelligence capability. But what does this actually mean? Mike Schwarz went in search of some answers.

Q. Your company slogan interests me: ‘Dryad Maritime is a maritime operations company with a high grade intelligence capability’. What are the core services that you provide? I understand it is more comprehensive than just giving details of the threat of worldwide piracy attacks?

Continue reading “The Ian Millen Interview: Maritime surveillance and security”

By Patrizia Heidegger, Executive Director of NGO Shipbreaking Platform

More than 70 percent of the world’s obsolete tonnage ends up polluting the Indian sub-continent and putting workers’ lives at risk. The Report Magazine invited Patrizia Heidegger, Executive Director, NGO Shipbreaking Platform to give an overview of their work. In this thought provoking article, she explains the issues and problems caused by some of the unsafe methods and procedures utilised to break end-of-life ships on tidal beaches.

Every year, more than 1,000 obsolete cargo and container ships, oil and gas tankers, passenger and ro-ro vessels have to be dismantled as they are not economically viable anymore for their owners. The NGO Shipbreaking Platform keeps track of these global shipbreaking trends: in 2014, out of a total of 1026 ships dismantled globally, 641 – representing 74% of the total gross tonnage (GT) scrapped – were sold to substandard shipbreaking facilities in India, Pakistan and Continue reading “Dangerous and Dirty Ship Demolition and Shipbreaking”

Feature article written by Eur. Ing. Jeffrey Casciani-Wood HonFIIMS

As the propeller turns it absorbs the torque developed by the engine at given revolutions i.e., the delivered horsepower – and converts that to the thrust which, in turn, pushes the vessel through the water. According to Bernoulli’s law the passage of a hydrofoil (propeller blade section) through the water causes a positive pressure on the face of the blade and a negative pressure on its back. It is the resolution of the pressures that results in the torque requirement and the thrust development of the propeller. The negative pressure causes any gas in solution in the water to evolve into bubbles similar to those found when opening a bottle of lemonade or champagne. These bubbles collapse and can cause hammer like impact loads on the blades often in excess of 7 kg/cm2. It is the collapse of these bubbles that results in the observed damage to the propeller blade surfaces.

The ratio of the absorbed power or the delivered thrust to the total blade area of the propeller is called, respectively, the power and the thrust loading. If either of these exceeds a certain value which depends upon a complex relationship between the propeller type, the flow in which it works and its mean depth below the water relative to its diameter then the flow pattern of the water over the propeller blades breaks down causing a severe loss of thrust and, eventually, physical damage to the surface of the propeller blades and, also, the rudder and local steelwork of the vessel’s hull. That flow breakdown is called cavitation and is strictly analogous to the water hammer often heard in old plumbing systems. Cavitation is a highly complex phenomenon and the pitting damage it causes usually – but not necessarily – appears on the back of the blade following a clear radial pattern. It can also appear as similar damage on the driving face of the propeller in which case, almost certainly, a further factor has entered the problem in the form of an incorrect pitch distribution along the length of the blade. Most small craft propellers are usually of constant pitch over the blade length and that regime is accurate enough for 99% of boats but on high speed boats with large propeller loading factors the pitch should vary over the length of the blade i.e., the boat should be fitted with a varying pitch propeller. The effects of cavitation including loss of speed and damage to the propeller blades can be minimised by ensuring that the propeller has sufficient blade area relative to the area of the circle described by the propeller blade tips.

Continue reading “An introduction to propeller cavitation”

Article written by Luc Verley MIIMS

The Kra-Canal project, sometimes also called the Thai-Canal, is an ambitious plan that would create a connection between the South Chinese Sea on the East in the Gulf of Thailand with the Andaman Sea in the West by passing through Southern Thailand.

This would shorten shipping distances by 1,200 Nautical miles around peninsular Malaysia and Singapore. Ships would avoid passing through the piracy risky area in the Strait of Malacca. The Strait of Malacca is one of the busiest shipping lanes in the world, with 60,000 passages annually.

At the narrowest part of peninsular Thailand, in Kra Isthmus the width is only 44 kilometres, the challenge however is a mountain stretch which reaches 75 metres above sea-level. Therefore, most proposals for the Kra-Canal vary with lengths between 50 to 100 kilometres in order to minimise the excavation.

Continue reading “The Kra-Canal Project”