Underwater Propeller Cleaning Kamsar
The propeller turns the ship's engine power into thrust, and its blades work best when they are smooth. Fouling on the blades disturbs the flow of water, reduces thrust and raises fuel consumption. In the warm water of Kamsar, a propeller can be heavily fouled in a few weeks. Underwater propeller cleaning in Kamsar removes this growth while the ship is afloat and often takes only a few hours.
Why Propellers Foul So Quickly
Propellers are usually made of nickel-aluminium bronze, which does not carry antifouling paint. Once the ship stops, growth settles on the blades easily, and a bulk carrier waiting at the anchorage area may sit still for days. Slime comes first, then weed and barnacles, which attach firmly to the blade surface. The longer the delay, the harder the growth is to remove, so early cleaning is cheaper and gives a better result.
The Effect on Performance
A blade covered with slime or barnacles loses efficiency, because water no longer flows smoothly over it. Industry estimates suggest that a heavily fouled propeller can reduce propulsive efficiency by several per cent, and in severe cases more. The engine must then burn extra fuel to keep the same speed, and the ship may also suffer vibration or noise caused by uneven fouling on the blades.
Our Cleaning Process
- The master and chief engineer lock the shaft and isolate the main engine before the Diver enters the water.
- A CCTV inspection records the condition of each blade before cleaning.
- The Diver cleans both faces of every blade, plus the hub and cone, using rotary brushes and hand tools suited to the growth.
- Hard growth is removed carefully so that the bronze surface is not scored.
- A second CCTV inspection and photographs record the result.
Cleaning Compared With Polishing
Cleaning removes growth, while polishing smooths the metal surface itself. Many owners combine the two: first clean, then polish if the blade surface is rough. If the blades are only lightly fouled, cleaning alone gives a good improvement. If the surface is pitted, eroded or has hard residues, polishing gives a further gain. We advise on the best option after seeing the blades.
Checks During Cleaning
While the Diver is at the propeller, we check for nicks, bends, cracks, rope or net wound on the shaft and loose cone fasteners. These checks cost nothing extra and often find problems early. Any damage is photographed and reported to the chief engineer so that the ship can plan the next step.
Frequency and Planning
Many owners clean propellers every 3 to 6 months, and more often when ships sit idle in warm water. Cleaning at Kamsar before the ship sails for the discharge port gives the best effect on the loaded passage. We plan the job around slack water and the ship's schedule, and a typical single propeller takes about 2 to 4 hours.
Book Propeller Cleaning
Send us the ship's details and last cleaning date, and we will confirm time, boat and quotation.
Combining Propeller Cleaning With a Hull Check
While the Diver is at the propeller, a quick look at the rudder, the aft end of the hull and the shaft seal area adds little time and can reveal early problems. We normally include a short CCTV pass of the stern area with every propeller cleaning, at no extra charge in the standard scope. The result is a cleaner propeller and a quick health check of the stern gear.
Frequently Asked Questions (FAQ)
Q1. How long does it take to clean a propeller underwater?
About 2 to 4 hours for a single propeller of a bulk carrier, including inspection and photographs.
Q2. How often should a propeller be cleaned?
Commonly every 3 to 6 months, and sooner after long idle periods in warm water.
Q3. How much efficiency can a fouled propeller lose?
Several per cent in moderate cases, and more in severe fouling, according to industry estimates.
Q4. Does a propeller carry antifouling paint?
Normally no. Most propellers are bare bronze, so growth must be removed by cleaning and polishing.
Q5. Is it safe to clean a propeller at anchor?
Yes, if the shaft is locked and the engine isolated before the Diver approaches, and if the dive is planned for slack water.