An eductor is a simple version of a pump used to move a liquid form of a fluid out of a certain place. However, unlike more complex versions of pumps, they do not have any mechanised components or moving parts that create an external force to transport a certain quantity of water. Instead, they rely on the simple theory of Bernoulli’s principle and a specific case of this, the Venturi effect. What is Bernoulli’s principle? As we know from the classical theory of fluid mechanics, Bernoulli’s principle states that a change in fluid velocity is marked within any system due to the pressure diffe ..read more

The available sea depth, the distance from the mean water level to the seafloor, is often an essential parameter for consideration. For navigation of vessels (refer to the article on underwater keel clearance), fishing, oil explorations, rigging, research, and various purposes, estimating the depth of the ocean bottom is indispensable. An echo sounder is a system that helps understand what is underneath and has been used by most seagoing ships for a long time. This system, which is one of the simplest applications of the Sonar (sound navigation and ranging) technique, uses the fundamental pri ..read more

While most of the time, gigantic ships take our breath away with their sheer size, it is the engineering marvel behind them that makes them truly remarkable. Propellers that move ships forth are of a size to bear the weight of such a huge ship. Hence, it’s only fair some credit be given to them and their size. Here is a list of the biggest ship propellers the marine world has seen. 1.  Emma Maersk The marine propeller made by German company Mecklenburger Metallguss GmbH can easily be called the biggest marine propeller with its 131 tons weight. Emma Maersk itself is the largest containe ..read more

Cruise ships house thousands of passengers and crew, which leads to enormous wastewater generation of up to 1000 cubic metres per day. Hence, Wastewater management has become a critical aspect of everyday operations.  A cruise ship needs to be self-reliant in this aspect, as it stays away from land for a considerable period of time.  Wastewater onboard cruise ships are categorised into two types, namely, greywater & blackwater. Greywater comes from bathrooms, showers and washbasins. The water from galleys, meat rooms, fish rooms and laundries is also greywater. However, such wat ..read more

A remotely operated underwater vehicle also called an ROV, is unmanned and usually tethered to the operator. It is an underwater robot that collects data about the underwater world about subsea structures or geological formations like hydrothermal vents. It uses a Remote pilot and automated control technology, making it safe and convenient to operate. Observation-class ROVs are used for ocean exploration and provide hd images and high-definition video for research and study purposes. The uncrewed vehicle is fitted with additional equipment like water samplers, manipulator arms, etc. Modern RO ..read more

I still remember the day when I joined my maiden vessel more than a decade ago. A Supramax bulk carrier with the least automation and the most troubles. I was welcomed by a lot of judgemental yet uncaring eyes. A new Cadet is on board! To add some spice to it, he’s a first-timer and presumably stupid; An old and tough Soviet Chief Officer who’s pissed because he couldn’t sign off in the last port. Rain poured down the sky, and the day couldn’t get gloomier beyond imagination. I was shown my cabin and asked to change and to report immediately to the Training officer, who didn’t give a damn abo ..read more

Every seafarer is familiar with the term bunkering and has either participated in or at least seen the operation of bunkering whilst he or she is on board. They may have also seen samples collected from the bunker manifold through drip sampling. Taking four samples is the norm, 1 for the supplier, 1 for MARPOL, 1 for the ship and 1 for lab analysis. Shipping companies have a tie-up with bunker sample analysing labs, and the labs provide ships with a sampling kit. Using the kit, samples are collected and sent to the laboratory for testing. Most of the time, only heavy fuel oil samples are sent ..read more

The role of fire-fighting systems on ships cannot be more emphasized. Time and again, deadly fires have ravaged merchant ships at sea, away from the land without any hope of shore-based assistance and have caused large-scale destruction to the ship, cargo and, even worse, resulted in the loss of human lives. Now imagine such a scenario on a passenger ship with thousands of lives on board; the mere thought is terrifying as the loss of lives could be potentially much more. For this reason, it is critical for the cruise ships to be fitted with means of fighting fires, both in the passenger areas ..read more

As anyone working in the shipping industry will attest to, bunker (or fuel) is one of the biggest expense items for any container shipping company. According to most estimates, bunker costs comprise circa 50% to 60% of a carrier’s total operating expense, thus making it by far the largest component of the carrier’s variable cost base. Bunker prices consequently exert an inordinately higher influence on any shipping company’s cash flows and have the potential to make or mar its fortunes. Matters are aggravated by the inherent volatility in bunker prices, which show violent fluctuations consequ ..read more

The generator onboard, being the powerhouse of the ship, requires regular maintenance and overhauling to ensure efficient and safe operations. A responsible marine engineer will never wait to carry out maintenance procedures until its machinery is on the edge of a breakdown. Instead, he/she will take all necessary precautions to prevent his ship from any impending troubles, which can take place because of engine room machinery failure or breakdown. There is a thin line between the starting of a problem and the problem taking the shape of a major issue.  It is only a s ..read more