Hull roughness has an astonishing effect on efficiency. Research had shown that there is a direct relation between the overall roughness of a hull and the amount of energy required to propel it through water at a given speed. The rule-of-thumb in this regard is that for every 10 microns of increased roughness, there is a 1% increase on fuel requirement in the range of 0-250 microns. Beyond 250 microns, the increased is .5% for every 10 microns. There are many factors affecting hull roughness and commonly it is the mechanical condition of the actual structure. Protruding weld seams or attachments will also take their toll. Mechanical damage also contributes to the mechanical roughness of the vessel. Dry spray, sagging, runs, blisters, peeling, paint overlap areas of damage, grit inclusions and other indictors of poor workmanship all contribute massively to the over smoothness. Most importantly, the forming of marine growth drastically reduces the vessel's efficiency and increases the consumption of fuel during voyages and increasing the amount of time needed for travel between ports.

Underwater Submerged Hull Cleaning

Dive-Marine Services Pte Ltd have two different underwater cleaning machines namely The Typhoon MC311 and The Brush Kart to cater to different underwater hull cleaning situation.

Typhoon MC311  

The MC 311 hull cleaner consists of a lightweight, welded aluminum frame, within which all components are mounted. This component consists of three rotary brushes, two rear wheels and a double front wheel, all driven by hydraulic motors. The motors are mounted on swivels and inside universal joints to allow linear motion in one plane and rotation around two axes. With this unique arrangement, the brushes can adjust themselves freely to any contour of the surface. The downward pressure of the brushes can be adjusted effortlessly whenever required during the operation, thus the cleaning power is a major technical breakthrough in underwater cleaning technology. Different types of fouling and underlying paint or coatings can be treated with the appropriate pressure and tools.

Brush Kart  

The Brush Kart is a sophisticated piece of marine equipment and similar to the Typhoon MC311, they are hydraulically operated. The powerful brushing action of this machine allows the independent forward propulsion of the unit underwater. The machine can remove almost all kinds of marine growth including barnacles, serpulid worms, etc without the removal of the external paint coatings. There are two rear wheels and a double front wheel, by which only the front wheels are driven by hydraulic motor. The speed of the machine can be adjusted during the operation to accommodate the tidal currents and the diver operating the machine. Different types of fouling and underlying paint or coatings can be treated with the appropriate brushes.