Boat Repair

    Every machine needs repairing, maintenance and constant upkeep for smooth functioning. Dry Docking is the process followed for the periodic repair and maintenance of ships, boats and watercrafts.

Dry Docking is a method of ship repair being practiced for decades. It is a process of manufacturing, repair and maintenance of ships in an area known as the ‘lock’. In simple words, a lock is like a ‘garage’ for repairing ships. The only difference being, a lock is constructed aligning the shore for easy manoeuvre of the ship and sea water drainage.

The main purpose of a Dry Dock is to expose the underwater parts for inspection, repair and maintenance. The ship to be repaired is hence manoeuvred into the lock and the gates are sealed post which all the sea water accumulated in the vessel is drained for better inspection and repairs.

According to SOLAS, active ships that fall under the 100A5 category have to be subjected to a bottom survey twice every 5 years. Also, a Merchant Vessel which is older than 15 years needs to be checked for breaches or any defaults twice in every five years. In case of Passenger Ships, the repair period is every two years.

Dry Docking Boats and Watercrafts

Aside from saving the boat hull and drives, proper dry-docking also greatly enhances access to the watercraft for boarding, fueling and maintenance. Plus a dry-docked boat needs no lines or bumpers and avoids scrapes and bruises from bouncing around in a tied-off wet slip mooring.

Preparations and Parameters before Dry Dock

There are various detailed steps to be followed before Dry Dock, as given in sector-specific manuals and literature. But, for our better understanding, here are the three most important aspects to be followed.

1. Balanced G.M component: While the ship is brought to the dock, the centre of gravity (G) increases as a result of the ‘contact’ with the docking surface. This, subsequently changes the metacentric height (M). For a smooth docking process the values of G and M need to compensate each other or in, simple words – balance out.

2. Position of the Vessel: During the Docking process, the vessel is supposed to be in an upright position. Care should be taken to ensure that there is no port or starboard list while the ship docks.

3. Small or Moderate Trim Aft: The slight trim allows the accenting of stern and bow in tandem rather than simultaneously as it will reduce the load and pressure on hull and the keel of vessel.

Safety measures to be followed

   Dry Docking is a massive and risky activity. Getting the ships onto the dock, repairing them and then putting them back involves high risk to the life of the workers and to the equipments being used on the dock. Before starting the dock process, Dry Docks need to follow a set of safety rules :

  1. Escape route. Two fixed gangways, independent of each other.
  2. Safety plan of the vessel available at gangways.
  3. Suitable communication system and routine for alarm in emergency situations
  4. Ship watch round regularly
  5. Contact with fire-brigade ashore
  6. Water under pressure to the vessel’s fire-hose and sprinkler system.
  7. Hot work permit
  8. Fire watch at least during hot work plus two hours
  9. Portable extinguishers and a connected fire-hose where hot work is performed.
  10. Secondary fire alarm system where necessary
  11. Debris contributing to fire load sent ashore
  12. Fire-doors or WT-doors fully operational at all time
  13. Gas free certificate

Choosing a shipyard for repairing your vessel

   While all the above-mentioned information will help you understand what Dry Dock is all about, choosing a shipyard that best suits your requirements is a decision that requires evaluation of multiple parameters.

  • Trading area
  • Cost
  • Time
  • Safety record
  • Technical ability
  • Local infrastructure
  • Financial situation
  • Weather/season in the area
  • Operational restriction – tides