Docking: Understand the details for ideal ship maintenance

The concept of maintenance is not limited to the idea of repairing or fixing something. It is also related to actions of preservation, conservation, and sustaining everything that is necessary to maintain its original characteristics. This includes equipment, machines, historical heritage, among others, with ship docking being one of them.

Therefore, the maintenance process concerns not only the correction of failures in a specific system but also the prevention of such failures. It can be applied to both simpler and more complex systems, consisting of various interconnected equipment and machines. In this sense, the failure of one component can result in harm to the entire system, as happens in the docking processes of vessels. To learn more about this topic, continue reading the post!

What is docking?

The docking procedure is nothing more than removing a vessel from circulation for maintenance. This is done by a specialized company, which can perform either dry or wet docking. When the vessel is taken to a dry area, comprehensive maintenance services are carried out, including painting, hull treatment, and other tasks that cannot be performed with the ship in the water.

Dry docking is, therefore, essential to extend the service life of ships and repair more serious defects. In other words, other types of failures that simple maintenance cannot fix — such as issues with the shafts, rudder, and propeller. Unlike these cases, repairs on the deck and holds can be performed in wet docking, which is quicker to start and finish.

Docking should preferably be done every two years to keep the vessel in good condition. It is a way to ensure the vessel is ready to operate and navigate with total safety and structural quality.

What services are involved? Let’s take a look!

What are the docking services?

Due to the existence of many different areas, each with distinct characteristics and needs, as well as various systems, docking is a complex procedure. Therefore, it is crucial to divide it into sections to facilitate the organization of maintenance and repairs.

This division is necessary because of the number of mechanical and structural problems, as well as potential electrical, hydraulic, pneumatic, and structural defects. Additionally, attention must be paid to the delivery of materials, document preparation, purchasing logistics, and the financial and accounting departments. All these actions are interrelated and depend on execution orders and deadlines. Thus, it is possible to divide the process into parts, as we will see below.

Replacement or inclusion of accessories

The hull of a ship has accessories that also need proper maintenance during docking. Some examples of items checked during this docking process include: sacrificial anodes, sea chests, and bottom valves, all of which are essential to ensure the vessel operates properly.

Therefore, inspection is responsible for a series of repairs, such as: cleaning, corrosion treatments, painting, restoration, and, when necessary, the replacement of certain accessories. This entire operation is vital for the vessel to be ready to operate with quality and safety.

Hull maintenance and repair

Ship docking is essential for the repair of vital components, such as the submerged hull, which supports the entire structure of the vessel. Therefore, it is necessary to keep it in good condition to ensure the integrity and safety of the entire ship.

Given its importance, during the docking procedure, various assessments are carried out on the hull. Visual inspections and tests are performed to check for potential issues in the steel, cracks, and other visible damage, including a thickness reading using ultrasound.

Ultrasound analysis is fundamental to identify the thickness of the steel plates and determine if replacement is necessary. This type of test is always important throughout the steel structure, especially for older vessels.

Another common procedure is hull cleaning to remove dense debris, such as crustaceans and other organisms attached to its surface. If these impurities are not removed, the vessel’s performance is compromised, causing slow speeds and reducing its useful life.

Hull painting and repainting

This service involves surface maintenance, preparing it to receive paint. This surface treatment includes: cleaning, removal of large debris and old paint layers. Additionally, desalting and corrosion protection are applied to preserve the ship’s metal structures and equipment in sectors like oil and gas, steel, and petrochemical industries. This ensures the surface is ready to be painted.

Subsequently, industrial painting is applied to the pipelines, hull, pressure vessels, tanks, accessories, and other metal structures and equipment. This treatment is crucial because, without it, paint will not properly adhere to the surface, harming the vessel.

Electrical installations maintenance

The electrical network consists of generators, panels, and electric motors, all of which require cleaning with specific chemicals during docking. However, not all repair and maintenance processes need to be done while the ship is docked. Depending on the section, the nature of the faults, and the complexity of what needs repair, some procedures can be done while the ship is operational.

Tank and hold cleaning and maintenance

Regarding the tanks, they are divided into ballast, freshwater, and fuel tanks, which are visually inspected to analyze their structural integrity.

Fuel and oil storage tanks must be inspected and cleaned with extreme care and safety. This is necessary to avoid contact with toxic substances and gases by cleaning personnel from offshore companies.

Freshwater tanks require highly meticulous cleaning to avoid water contamination since the water is used for human consumption.

As for the holds, these structures face impacts like deformations, wear, and chemical damage due to cargo movement and structural failures. Therefore, they undergo thickness measurements and structural evaluations. They also undergo treatment and painting processes.

Deck cleaning and maintenance

The deck houses the anchoring system, mooring system, cargo and unloading systems, as well as safety, fire-fighting, and rescue equipment. It contains holds, pipelines, cranes, and other components that require thickness measurements and painting services. Its cleaning and maintenance are vital for the vessel’s safety.

Superstructure repairs

The superstructure houses the crew, accommodations, navigation command system, and safety, communication, and firefighting equipment. Therefore, maintenance is required on the exhaust system, electrical network, and sewage and water systems.

When to dock a vessel?

There are several reasons for docking a vessel. They can be planned, such as mandatory inspections, routine checks, or in case of unforeseen events, such as accidents that cause damage.

Mandatory inspections

These are mandatory stops where the vessel must undergo inspection and adjustments, if necessary. This includes the renewal of statutory certificates from maritime authorities and class certificates.

Routine repairs

Even if no fault or damage is detected, this stop may be required for routine checks related to the vessel’s everyday operation. It is therefore advisable to synchronize routine stops with those scheduled for mandatory inspections.

Damages

These refer to damage, corrosion, or wear in the system or structure of the vessel. Moreover, just the suspicion of equipment failures is enough to resort to docking.

Conversions and modifications

These involve significant modifications to the ship, such as structural changes or modifications to its function, such as converting tankers into FPSOs.

Types of maintenance in ships

Some types of maintenance commonly used in other processes are also performed on ships during docking. Here are some of them!

Corrective maintenance

This repair is only performed after a failure is detected, meaning there is no prior planning before the machines stop functioning. Typically, this type of maintenance results in higher costs, so it is recommended only when failure cannot be prevented or when the costs for corrective maintenance are low.

Preventive maintenance

This type of maintenance is carried out periodically through systematic tasks at defined intervals. Here, the manager can maintain control over the equipment and proceed with repairs and part replacements before any failure occurs. While this type of maintenance generally costs more than corrective maintenance, the advantage is that it increases machine availability and reduces failures.

Predictive maintenance

This does not entirely replace preventive or corrective maintenance, but it can reduce their frequencies. Technology continuously monitors the electrical and mechanical conditions of equipment. The goal is to reduce losses due to breakdowns and failures by providing information exactly when equipment is due for maintenance.

Types of docking

There are essentially three types of docking commonly carried out, as follows.

Floating dock

In this case, the dock rises and sinks, eliminating the need to move the ship to a higher level and also removing the requirement for a gate. The downside of this method is its susceptibility to tidal changes.

Dry dock

A dry dock refers to a basin with three rectangular walls and a reinforced concrete floor that can withstand vessel loads, pressure, flotation force, and other conditions requiring resistance. On the fourth side of the rectangle is a special gate called a caisson, through which the vessel enters and exits the submerged dry dock basin. After the vessel enters, the dock is closed with the caisson, and the basin is emptied to keep the vessel in a dry area.

This system is used for both repairs and vessel construction.

Wilson Sons dry dock

The Wilson Sons dry dock is the largest at the Port of Santos. It ensures safety and agility with 80-ton cranes and a dock system designed to dock vessels up to 145 meters long and 25 meters wide. With a track record of over 200 dockings, the Wilson Sons shipyard is nationally recognized for its efficiency, quality, safety, and commitment to deadlines.

Syncrolift (vertical lift)

This mechanism consists of a platform that, when inclined into the water, lifts the vessel vertically from the sea to a dry area. It can be equipped with rails that move the vessel into the shipyard.

As we can see, ship docking is essential to keep all its systems functioning properly, thereby extending its useful life. It is also crucial to maintain the safety of everyone who works and travels on board. However, hiring qualified companies and professionals is equally important to ensure the work is completed in the best possible manner.