Entanglement Removal

Removal of foreign bodies such as mooring ropes, fishing nets or lines are usually entangled in the propeller (tail-end-shaft) or the bow thruster which are removed by cutting. The entanglement of ropes in the tail-end-shaft is a common problem in the cases during ship-to-ship operations in bad weather condition. This problem, if not treated quickly may be fatal to the tail-end-shaft as the ropes can melt and go inside it.

A propeller is a rotating fan-shaped structure that is used to propel the ship. Depending on the speed and manoeuvring requirements of the vessel, a ship may have one, two, or even three propellers. However, many times, a fishing net or rope gets wrapped around the propeller. Significant damage can happen to the shaft if the net or rope is left too long. In fact, foreign bodies tangled on it will block the axis and blades, causing serious problems to the engine as well as put the safety of the ship and crew at risk. 

If the engine speed has decreased or feel some abnormal vibrations, there might be a possibility that the rope could have become entangled to the propeller. The ship will slow down and the engine will shut down by itself in a few moments. It is therefore important to hire commercial divers for Rope Removal from Propeller. 

Objectively, the signs of entanglement of rope/ fishing net are

• If the craft is powered by a motor, there is a rapid loss of power
• The engine stalls and cannot be started
• The vessel may stop and does not move forward.

Cutting the rope from the propeller

Preferably, removal of the rope/ fishing net entanglement in a propeller should be done during daylight. The rope cutters/ knives used for this operation should be in a such a way that it can be used with the limited access in the rope-guard or entanglement area. First, the diving personnel will assess the entanglement, the thickness and type of entangled material. Then the required number of divers will be deployed to carry out the operation. The divers will pull out the entanglement as much as possible from the accessible area of operation and will use knives or rope cutters as and when required. 

What to check after removing the rope

• If there is a propeller with a valve, it’s all ok
• If there is a sail drive propeller, there is an oil seal behind it
• Check the condition of the oil as it looks, if the oil is white as milk, it is an emulsion, there is water in the gearbox, the bearings on the gears are endangered

How to avoid network entanglement

• Use cutting blades that can be attached to the propeller
• The cutter can cut the ends of the rope and the wire of 5mm steel
• Cutters cannot cut ropes and metal cables thicker than 5 mm

The following may be noticed after a successful entanglement removal operation:

Increases Speed:

Unmaintained propellers can reduce the power and speed of your vessel by a significant percent. However, with a clean and smooth propeller, the ship can glide effortlessly at maximum speed and power. In addition, a smooth surface will not allow marine organisms to attach. 

Minimizes Fuel Consumption:

Unmaintained or rough propeller can significantly affect the vessel’s fuel consumption. Removing rope from the propeller can ensure peak performance and minimize fuel consumption. Thus, regular propeller cleaning and polishing should be a part of your business fuel efficiency program. 

Increases Lifespan:

Regular maintenance can help prevent the formation of calcium deposits and cavitation. Cleaning and polishing by a professional will ensure that the propeller always remains in best condition. All this will thereby extend the lifespan of the propeller. 

 Thus, if the propeller is not regularly maintained, it may result in lost thrust, shaft damage, and fuel inefficiency. All this can increase fuel costs and affect profits and competitiveness of your business. This is why regular cleaning is important for unwanted bio-fouling and Rope Removal from Propeller. However, ensure to choose qualified professionals that use expert techniques to reduce the surface roughness of the propellers.