Biologists Conclude that Fish feel Pain

It is a long held traditional belief that fish do not feel pain the way that humans do, largely due to the fact that they have unsophisticated nervous systems, and lack brains complex enough to generate a conscious awareness of pain. However, after extensive research, fish biologists around the world have put together considerable evidence to indicate that fish do, in fact, feel pain.
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What you need to Know about Dripless Shaft Seals

There are several types of seals, which are divided into two key groups – face seals and lip seals.
Both use an articulated rubber sleeve to keep the water out, and are similar in appearance, but lip seals seal via a lip, or sometimes two, whereas a face seal uses a collar that attaches to a surface on the end of the articulated hose.
FACE SEALS

Considered the most efficient way to seal a shaft, the PSS (Packless Sealing System) shaft seal is a mechanical face seal, which uses the seal created between the flat surfaces of the rotating stainless steel rotor and the stationary carbon flange. The carbon flange is attached to the stern tube via an articulated rubber bellows. The carbon flange contacts a stainless steel rotor that fits securely around the shaft, and is fastened on with grub screws and seals via two O-rings sunken into its bore. The bellows is installed on the stern tube and is then compressed a set distance by the stainless collar, creating a solid and even seal between the carbon flange and the stainless rotor.

LIP SEALS

Volvo Rubber Stuffing Box

Volvo Penta’s solution is commonly called a ‘rubber stuffing box’, and is quick and easy to install, and takes up minimal space, as it combines the rubber hose with a lip seal in one assembly, with no moving parts. It has an internal, water-lubricated bearing and lip seals which must be greased annually. It comes with a single, wide hose clip, secured with machine screws, to clamp on to the stern tube. As it does not have a pressurised water feed, after launch, it must be ‘burped’ to remove air.

Tides marine Sure Seal and seriesOne

This is a propeller shaft sealing, which is suitable for a wide range of shaft speeds and ambient operating temperatures, and commonly fitted to power boats, yachts and commercial crafts. Created from fiber-reinforced composite material that is non-corrosive, it is strong, durable and practical, as there are no moving parts. A pressurised cooling water supply is required to lubricate the lip seal and alignment bearing in the seal head. The seriesOne model is produced in the same way as the Sure Seal, yet is designed for smaller, single-engine vessels with stainless steel propeller shafts.

Robot Speedboats Help Improve Safety and Efficiency in Tian’e Lake in China

Robotic speedboats could soon replace human lifeguards in ensuring the safety of thousands of people during busy periods in Tian’e Lake in Hefei, China.

Designed to detect moving targets, the automatic boats are equipped with a GPS, cameras, and acoustic and infrared sensors, with the ability to alert swimmers to move into safer parts of the water, when hitting danger zones. Those struggling and in danger in the water can also grab onto the boat and be brought back to shore, as the patrol boat uses sonar and other underwater detectors to track the location of the swimmer and alert assistance.

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Understanding Your Compass

A compass is a device that indicates direction. It is one of the most important instruments for navigation. Magnetic compasses are the most well-known type of compass. They have become so popular that the term “compass” almost always refers a magnetic compass. While the design and construction of this type of compass have changed significantly over the centuries, the concept of how it works has remained the same.

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Diesel Electric Propulsion: Is This A Safer, More Efficient Solution For Your Vessel?

Although the idea of powering your vessel with the indirect, two-step diesel electric energy transfer system may appear to be unnecessarily complex, its many advantages can make it a compellingly attractive alternative to a conventional direct mechanical prop-shaft drive. When under way all of the electrical power required by the vessel can be supplied from the diesel electric propulsion system, eliminating the need to run a genset.

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Controllable Pitch Propeller

Two types of propellers are commonly found in merchant vessels: Fixed Pitch Propeller (FPP) and Controllable Pitch Propeller (CPP). The mechanism of fixed pitch propeller is self-explanatory by its name; the blades in such propeller are joined with the propeller boss hence its pitch remains unchanged. On the other side, in controllable or variable pitch propeller, the propeller blades are affixed to the boss while allowing the pitch to modify through hydraulic system.

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Rogue Waves And Their Effects

To understand the effects of rogue or freak waves on ships at sea, it is vital to first develop an understanding of rogue waves in itself, the occurrence of such a phenomenon and the reason behind such an occurrence. The occurrence of sea waves is an uncertain phenomenon. That is, if you consider a certain area of the sea surface, the waves passing through that area would definitely be periodic in nature, but the parameter of each wave (amplitude, time period, frequency, wave height and wavelength) will vary at a rate that cannot be determined to any exact measure.

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