Everyoneisawarethat regulaor prpeller polishing is beneficial for ships as it allowsbetterfuelefficiency and ensures a standard maintenance programme to most ofthevessels
typically for six to twelve months. There are numerous factors likemarinepollution,the material of the propeller, deposition of calciumcarbonate,corrosionof the metal,hydrodynamic cavitation and mechanicaldamagethatresults in the roughness of thepropeller.
The ship requires frequent polishing of the propeller because the rough propellerincreasestheconsumption of fuel in high proportion. As proved, a propellerwithasmaller surface result in loss of energy gain, half of which theship’shullcreates. The repairing cost of the propeller is relatively muchsmaller than the repairing cost of the hull. Therefore, propeller maintenanceisaquick and simple process with a high return investment.
Polishingofthe propeller can be done underwater or over the dry dock. It is essentialforthe
shipowner to know when is the best time to polish their propeller. Forabetter
result of polishing, it is necessary to know which option is better -underwaterpolishing
propeller or polishing propeller over the dry dock.Although,the decision is often made topolish the propeller when the vessel isindrydock. Let’s study what is the difference?
Under-waterpolishing
Underwaterpropellerpolishing promises some notable advantages such as enhancing the
vessel’sperformance, decreasing the consumption of fuel, lessening the emissionofgases in the marine environment, rising the vessel’s speed, reducing theannoyingvibrations,increasing its reliability and expanding the vessel’smaintenancecycles.Anaverage surface finish of 1 micron or better (Rupert Grade A) is delivered whenapropeller ismaintained and polished underwater. Due to the rotation of thepolishingpad, it creates a centrifugal suction of up to 120 kg/cm2, that holdsthepolishing pad 100 per cent flush to the propeller bladesurface a very finefinishis possible. Due to the presence of water, the necessary cooling of thesurfacethe finish is achieved which results in a much finer finish than that canbeachieved in a dry environment. Therefore, underwater polishing ensures finerfinishing.
It makes the process easier by providing the necessary cooling forbetterfinishing.
Drydock polishing
Whena standard polishing in a dry dock is done, the best result is a surface finishof three to four microns (Rupert Grade B). A dry dock polish is expensive.Getting access to the propeller is the first thing. It requires scaffoldingsince the technician needs to reach the entire propeller. Comparatively, drydock polishing on average costs 50 per cent more thanunderwater polishing.Since the technician requires centrifugal suction, the final quality ofdrydock polishing wholly depends upon the skill set of the technician executingthe work.Dry dock polishing leaves “banana-shaped” marks on the blade surfaceafter polishing as the polishing tool is pushed to the blade surface at anangle.
In-wateror Dry dock?
In-waterpolishing not only offers finer surfaces and lower costs, but also ensures
additional benefits if planned smartly. Underwater polishing permits the vessel
owner to monitor faults while their vessel is still in service. Report on
condition of paint, anodes, rope guard and the rubber can be made by divers
while the ship is still in service since it will preventfuture expenses.
Early intervention allows savings. Underwater propeller polishing presents
extra benefits comparing to dry dock polishing. In-water polishing saves both
cost and docking time as it require 1-2 working hours, while the ship is
at the berth. Underwater polishing is a faster process that makes a lasting and
better result due to the presence of natural lubrication of the liquid element.
It is obvious the often the ship’s is cleaned and polished, the more money is
saved due to the reduction of the consumption of fuel. Therefore, the
underwater polishing cost gets outweighed and brings profit and even greater
economic benefits.
Conclusion
Thearticles discuss underwater propeller polishing and dry-dock propellerpolishing. It also mentions the difference between them and highlights which process is a better option.
15 Best Things to Do in Andaman and Nicobar
4.Bumper Ride
The Banana Ride is a fun and exciting activity for both children and the parents. The minimum age of rider is 10 years above.The Banana Boat Ride in Andaman is accommodate around 5-6 people. In this there provide the life jackets to every one for there safety.Now what are you waiting for just pack your bags and visit in Andaman with your family or friends.
6.Speed Boat Ride
Speed Boat Ride is a fastest water adventure as compare to the other water adventure.In this adventure , you see the fresh blue water or waves and fresh cool air which make you fresh.Now what are you waiting for just pack your bags and visit to Andaman and Nicobar with your family or friends
7. Havelock island
8.Elephant Beach
If you have visited to the Havelock island and not to the Elephant Beach, you missed a something very good. In Elephant Beach there is a white sand beach and there is a blue green water. The boat ride to the Elephant beach passed through the lighthouse and this are the reasons to visits to the Elephant Beach.
9.Parasailing
One of the most awaited activity in the Andaman Islands has started very recently in the Andaman Islands. Travelers can now experience Parasailing at, Port Blair etc.The perfect combination of the air and the water in the Parasailing. In this water adventure you feel like a birds who is fly in the sky. In Parasailing,one end of rope is tied with the boat and second rope is tired with the parasailor and harnessed with a parachute fly in the sky
10.Undersea walking
In the Andaman and Nicobar Islands, undersea walk or helmet diving it means helmet walking is conducted at North Bay Beach near Port Blair and at Elephant Beach in Havelock Island. It means you will provide the helmet and the oxygen pipe which you can breath in under the sea water and enjoy the under sea walking.
11. Snorkeling
Snorkelling is a process of swimming through a entire body in water outfitted with a designed tube is known as snorkel
Snorkel is also used by scuba driver when there surface area of the water. A snorkel is a tube around 30cm long and the inside diameter of between 1.5 and 2.5 . In this ride you will swimming with fishes or you can touch the fish. In the sea there is colourful fishes in the surface area.
12.Dolphin Watching
Who does not loves dolphin? Dolphin watching is also favorite activity in Andaman which attract the people. If you not visit there then you have missed something very good view in Andaman. You should visit the Lalaji Bay Beach on Long Island, located in the National Park, Havelock Island. You should Watch the Dolphin swimming in water with your friend or your family.
13.Surfing
There are lot of beaches which are the best for surfing in Andaman and Nicobar. Surfing is a difficult sea water sport in Andaman and Nicobar. Surfing the surfers use a 2-4 m long surfing board which depends on the wind which will help him to surf in the waters. This is the one way to overcome your fears while you surf. This sea water sport is difficult but full of fun and enjoy.
14.Sport Fishing and Angling
On other sea water sport like surfing, scuba diving and other are full of fun and exiting adventures. In sport fishing is you doing fishing in the sea or you catch any fishes you can eats that fish .This sea water sport adventure is very popular in the Andaman and Nicobar.
15.Glass Bottom Boating
Image Credit
Glass bottom Boating is the boat with glass bottom where you can see the inside water life from the outside.You should take the Glass Bottom Boating in the Andaman and Nicobar. It is definitely an amazing experience. So that you cannot forget the Glass Bottom Boating in Andaman. This is most wonderful boating to see the colorful fishes from outside the water
It is advisable to maintain the roughness of propeller surface roughness at or near-equal to Rubert scale A. comparatively, the propeller has a small surface area than the hull, but rough and unmaintained propeller results in increasing the vessel’s fuel consumption.
The spinning of the propeller produces thrust that allows the ship to move forward.
Some of the common attacks that increase propeller’s roughness are –BiofoulingElectrolytic actionCavitation erosion The help of a small rotating disk that easily conforms to the complex shapes of the blades without gouging helps in regular underwater cleaning and reconditioning of the surface of a propeller.
Such tools allow to remove all fouling and generate a very fine surface scratch pattern in the range of 1 to 2 um.
The globally recognised standard for propeller blade roughness is the Rubert scale.
Boosts business profits – the cost of fuel speaks volumes in regards to profit and unmaintained vessels affect the annual profit since the consumption of fuel is increased.Removes unwanted biofouling – Due to the accumulation of biofouling, the ship uses about 40% more fuel therefore, it is better to conduct propeller polishing regularly to save money.Increases lifespan – when propeller polishing is practised regularly, it prevents the formation of calcium deposits and cavitation that ultimately, extends the lifespan of the propeller.Minimizes fuel consumption – when underwater propeller polishing is conducted every three to six months, it helps in minimising the fuel consumption and ensures peak performance.Balances surface texture – polishing service helps balance the surface texture in terms of roughness.Increase speed – unmaintained propeller results in reducing the speed of the vessel by up to 5%.
Marine GPS systems have come a long way since their introduction to the market, and you don’t have to be an expert of the sea to use one effectively.
Before you buy marine GPS navigation online, let’s talk about what are they, what they do and why you might need one.What are GPS marine navigation systems?Marine GPS systems are designed especially for the marine setting.
These gadgets are strongly recommended because of the increased safety they offer to the navigators in the open water.
In fact, sailing courses these days widely use GPS systems within their training programs.Different types of GPS marine navigation systems available:Handheld:Though these are the cheapest of devices they’re generally just as accurate.
Handheld devices can also be used in other situations like hiking or in the car.
Chartplotters: Compared to the handheld GPS marine navigation systems the chartplotters are a significant improvement.
