LIVE GRAVING DRY DOCK

PROJECT PRESENTATION TEAM 2

DRY DOCKDry docking is a process, which consists of a set of

coordinated and controlled activities with start and finish dates, undertaken to achieve an objective to specific requirements (IMO, SOLAS, Flag State or PSC’s requirements), including the constraints of time, cost and resources

A Dry dock is a narrow basin or vessel that can be flooded to allow a load to be floated in then drained to allow that load to come to rest on a dry platform

Construction, maintenance, and repair of ships

Maintenance of under water parts such as hull, propeller, rudder etc.

As per SOLAS requirement all merchant vessels require a complete inspection of hull in a dry dock twice within 5 year period and the intermediate survey must not be more than 36 months

TYPES OF DRY DOCK

• GRAVING DRY DOCK

• FLOATING DRY DOCK

GRAVING DRY DOCK

This type is normally constructed on a land near the coastal water with a rectangular solid concrete construction with blocks, walls and gates.

Vessel is shifted inside the dock and rested in the blocks. After the ship is in required position, gate is closed and water is removed.

FLOATING DOCK

• Floating dry docks are structures with sufficient dimensions, strength, displacement and stability to lift a vessel from the water using buoyancy

• Vessels can be transferred to and from shore relatively easily

• The dock can be moved away from land to deeper water for docking and undocking operations. This can reduce or eliminate dredging and bulk-heading requirements

LIVE GRAVING DRY DOCK MODEL

LIVE GRAVING DRY DOCK MODEL

• The model illustrate the working of Cochin Shipyard dry dock

• It consists of a land part with the dock in it and the water part

• The dock part is separately made from metal and is joined with a tank which depicts the water part

• A tank made of fibre glass forms the water part and is supported on the table

• Full operations of the dry dock is controlled from a control panel using micro controller

METHODOLOGY

• PLANNING AND DESIGNING

• FABRICATION

• TEST AND TRIAL

PLANNING

• Team visited the graving dry dock of Cochin ship yard and all the information about the construction and working of the dock was collected

• Cochin Shipyard dry dock has the capacity to accommodate a maximum of 125000dwt ship

• dock has a length of 270m, breadth 45m and height 9m

• In the shipyard dry dock, they use 3 electrical motors, two for the opening and closing of gate

• motors have a power of 18kw, and both take a load of 25 tons

• Cochin ship yard dry dock is a rigid structure made of concrete blocks

• Three pumps are used for pumping out water from the dock after closing the gate

• The pump rating is 3.3 Kv 650kW. Three pumps pump out 4220 litres of water per second. Pumping out will take 4 hours

• Flooding is controlled by a 2.2m diameter butter fly valve and it takes one hour for flooding the dock

• Cochin Shipyard dry dock has a flap type gate which is opened and closed by two motors each of 25 tonnes capacity

DESIGN

Wooden Table

• Table dimensions: 200×65×80 cm• The wooden table supports the full project• The dimensions were made considering the

dimensions of both dock part and the tank

DRY DOCK

• depth of the dock had to be changed for the visualisation of working,

• Mild steel is used for construction of the dry dock body

• The keel blocks are designed on the dock according to the docking plan of the ship

GATE DESIGN

• The gate used in the model is a flap type gate, hinged at the bottom

• mild steel is used for the construction of the gate

• Mild steel of 3.5mm thickness is hence used for withstanding high pressures

SHIP MODEL

• for the construction, the dimensions of “Dimitris Manios”, a 37.664 D.W.T. bulk / lumber carrier were considered

• The ship is only a model to show the working of dry dock. So it is built with basic dimensions only. Importance is not given for the design aspects of the ship model.

• The materials used for making ship are Fibre, resin, Plaster of Paris, Plywood and Paint

• LOA- 50 cm• LBP- 46 cm• BREADTH- 15 cm• DEPTH- 15 cm• DRAFT - 9 cm

Tank

• The tank is made of fibre glass• It has 110 cm length, 65 cm width and 30 cm

depth

MECHANICAL AND ELECTRICAL COMPONENTS• dc motors – 4. Two 12v, 10 rpm dc gear

motors are used for the opening and closing of the gates. The other two 12v dc motors are used for the towing purpose of the ship

• A micro controller is programmed to control the dry dock operations from a control panel

• The pump used is a centrifugal type mounted on a 12v dc motor

• Pipes and Pipe fittings

CONSTRUCTION

• The dock part is fabricated from MS sheets of 3.5mm thickness

• The gate is fabricated separately and fitted on to the dock with hinges

• Dock has two tanks that act as wells in an original dock

• Two 12v dc motors are used for towing the ship and other two 12v dc motors are used for the opening of the gates

• A centrifugal pump driven by a 12v dc motor is used for pumping out water from the dock

• Mechanical valve is used in place of a butterfly valve which serves the function of flooding the dock

MODEL OF SHIP

• The model has 50 cm length over all, 9cm height.• A mould for the model ship as per dimensions is

made using plasterofparis• Mould is coated with fibre and resin .And again

is coated with plasterofparis• Plaster of paris mould is removed and the hull

form is taken out. Checked for leakage and leak was filled.

• Deck is constructed using plywood and plastic

MECHANICAL AND ELECTRICAL INSTALLATION

• The model uses four motors, a pump and a mechanical valve for the dry docking operations

• two 12v 10 rpm dc gear motors used for the opening and closing of the dock gate

• A nylon rope is used for holding the gate and also is tied to the motor for the operation

• two other motors, 12v dc motors, are fixed for towing of the ship

• The pump used is a centrifugal type mounted on a 12v dc motor and pump takes suction from the tank provided for the purpose

• The valve is a ball type valve which is hand operated

MODEL OPERATION• The dry dock which is opened in position is ready to admit the

ship inside it. A ship comes in for repairs is shown virtually by the fabricated model. In practical aspect patient ship is tied with a rope which have to be connected to the tug boats. But due to our limitations the team will move the ship manually by tying rope and move it near to the dry dock .After that the team will connect the other end of the rope to the winches which is connected to a motor. A centreline marked rope is tied normal to the dry dock which helps in placing the ship in the keel block during pumping out. When the winches started working the ship will slowly enter the dry dock. When the bow of the hits the centreline marked rope the team will switch off the working winches

• Now the ship is in correct position. Now the team can do the pumping out action. The centrifugal pump will be switched on and the pumping will takes place. After sometime the whole water inside the dock is pumped out. Now the team can do the maintenance and other works. The team have valves for flooding. After the maintenance the team will open the flooding valves .The flow will be in controlled manner. After reaching a certain level the team will open the valve fully .Next step is opening of the gate. Before opening the gate the team must check the level of water in dock and back water. Otherwise the back pressure from the back water opposes the opening of gates. After checking all things the team will open the gates. Now the ship can take out. Remove all the ropes and tugs can take the ships to sea.

FINAL MODEL

CONCLUSION

• All operations carried out successfully