According to different classification societies, ships are required to dry dock twice every five years. The cost of having a ship in the dry dock can be astronomical, which is why ship owners cautiously manage their dry docking programme, take their time deciding when to go to dry dock and also carefully select the location where they will dock their vessel(s).
Ship owners have always been looking at ways in which they can reduce the time their vessels spend in the dockyards. The longer the vessels are docked, the more money it costs ship owners, not only in increased docking fees, but also a reduction in income as the vessels are not working.
If shipyards make money from ships being docked in their yards, then why would they want these ships to be there for a shorter period of time?
In an ideal world, shipyards would like vessels to be docked in their yard for the longest time period possible as this will bring them more revenue. However, many factors are now becoming apparent which raises the question as to what benefits shipyards can achieve by reducing the docking period for ship owners.
Quite simply, the quicker they can return the vessels to charter, the more vessels they can dock. If they can reduce a vessel's time spent in the dry dock, the more likely these vessels are to return to this shipyard in the future. It is therefore beneficial for shipyards to return vessels to charter in the quickest time they can.
So how can ships reduce their dry docking periods?
The surface preparation methods used and choice of coating systems selected play a major role in the overall dry docking period.
Abrasive blasting will always offer the best surface preparation. This is the method traditionally utilised for all conventional paints. Unfortunately, abrasive blasting encompasses a lengthy setup, large labour squads and extensive equipment requirements. Abrasive blasting also involves many time consuming operations; containment, collection, removal and disposal of the abrasive. All these factors result in more time and cost being spent in the shipyard.
Conventional paint systems are also solvent-based. Solvent-based paints themselves have their own problems. They are hazardous which means that all other work within the vicinity must be stopped; resulting in lengthy, unneeded and undesired project delays. Solvent-based paints also have humidity and dew point restrictions which means that additional equipment requirements have to be used to control the environment during their application.
However, by electing to use alternative surface preparation methods, such as water jetting and mechanical preparation, and solvent-free coatings the time and cost spent in the shipyard can be significantly reduced.
So what the answer?
Chemco International have developed a range of solvent-free, wet & rust tolerant coating systems which can be used for almost all areas of the ship including almost all tank internals, decks, superstructures, pipework, engine rooms, plus many more areas.
Any surface preparation method can be utilised when applying these coatings, with surface standards as low as WJ-3/4 or St 2 acceptable. This means that for many applications the expensive and time consuming use of abrasive blasting is not essential.
Chemco's IMO approved coating systems offer long-term maintenance-free protection, even when applied to rusty or poorly prepared and wet surfaces, where the coatings exhibit outstanding adhesion.
There are no humidity or dew point restrictions with these coatings, therefore there are no extensive and expensive dehumidification or ventilation equipment requirements.
The environmentally friendly nature of this process (no grit blasting and solvent-free coatings) also allows other refurbishment work within the vicinity, including hot work, to continue without disruption.
Chemco's solvent-free, wet & rust tolerant coating system can also 'continue to cure' underwater. This means that if the ballast tanks are the last or only areas to be coated during the docking period, that the vessels can be put back into service much quicker than using conventional paint systems.
Vessels can begin to ballast again within 4-8 hours as opposed to conventional paints which could be anywhere from a few days to two weeks.
All of these factors mentioned above will result in not only an environmentally friendly application, but will also significantly reduce the dry docking period for all vessels. By saving the ship owners time and cost by reducing their docking period, these ship owners are likely to use their shipyard again. It also gives the shipyard the opportunity to dock more vessels. As previously mentioned, it is therefore beneficial for shipyard to return vessels to charter in the quickest time they can.
Source: Chemco (by Ian Gold)
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