A B G S h i p y a r d L t d

N e a r M a g d a l l a P o r t ,

D u m a s R o a d , S u r a t - 7

6 / 2 3 / 2 0 1 2

A G Nikhil

A report on activities carried out and knowledge

gained by Ambattuparambil Gopi Nikhil of IIT

Kharagpur at ABG Shipyard in his two months of

training (May & June)

REPORT – INDUSTRIAL TRAINING

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Contents

Topic Page No Certificate of Training 0 About ABG Shipyard 1 About Department of Ocean Engineering & Naval Architecture at IIT Kharagpur 2 Training Schedule 3 Safety Training 4 Design Office

Hull Design Outfit Design Machinery Design Electrical Design

5 5 8 13 16

Quality Assurance & Control 18 Production – HULL 25 Production – Piping 30 Conclusion & Acknowledgement 38

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Certificate

This is to certify that the Training Report submitted by Mr Ambattuparambil Gopi Nikhil,

student of Indian Institute of Technology Kharagpur, Department of Ocean

Engineering & Naval Architecture, on the training carried out by him during the period

from 2/05/2012 to 23/06/2012 was prepared under our supervision and guidance for

fulfilling the requirement of Industrial Training.

Submitted by:

A G Nikhil

Final Year Student

Department of Ocean Engineering & Naval Architecture

IIT Kharagpur

Date: 23/06/2012

Mr A Ramaprasad

Design Department

Mr S A Phadke

Quality Assurance & Control

Mr D Upendra

Hull Production

Mr Suraj Shetty

Piping Production

Training Guides

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About ABG Shipyard Ltd

ABG Shipyard Ltd., the flagship company of ABG group was incorporated in the year 1985 as

Magdalla Shipyard Pvt. Ltd. with the main objects of carrying Shipbuilding and Ship Repair

business. In a span of 20 years from the year 1991, the company has achieved the status of the

largest private sector shipbuilding yard in India with satisfied customer base all around the

world. The registered office and the yard are situated at Surat in the state of Gujarat and the

corporate office is in Mumbai.

The Shipyard has state of the art, manufacturing facilities including a “Ship-lift Facility” with a

lift capacity of 4500 tons, side transfer facilities, CNC plasma cutting machine, Bending rolls,

Hydraulic press, Cold shearing machine, Frame bending machine and steel processing

machinery. The Shipyard also has blasting shop and fabrication shop covered in 4 bays of 150 x

30 M each equipped with 20T EOT Cranes. The manufacturing process is in line with world-

class standards and the Yard is certified by DNV for ISO 9001:2008.

During past decade, the Shipyard has constructed and delivered One Hundred forty four(144)

Vessels including Specialized and Sophisticated vessels like Interceptor Boats, Self Loading and

Discharging Bulk Cement Carriers, Floating Cranes, Articouple Tugs and Flotilla, Split Barges,

Bulk Carriers, Newsprint Carriers, Offshore Supply Vessels, Dynamic Positioning Ships, Anchor

Handling Tug Supply Vessels, Multi-purpose Support Vessel, Diving Support Vessels, etc. for

leading companies in India and abroad.

The Yard has Multiple Building Berths, 2 Dry-docks, 125 m x 22.5 m x 5.6 m Fitted with

Computerized Synchronous Shiplift Platform, of 4500 Tonnes Lifting Capacity and 155 m X 30

m x 7.5 m, Graving Dry dock served by 80-T Goliath Crane span 50 m, height 35 m. and

substantial cranage like NCK Rapier 150T Capacity, Tata P & H Make, 60-T Capacity, HM

Make, 50-T Capacity, PPM 80T Capacity3 Tower Cranes, 11 Gantry Cranes of suitable

capacities. The “Ship lift Facility” enables the yard to simultaneously build and repair many

vessels and gives the yard a tremendous logistical advantage and flexibility.

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Department of OE&NA, IIT Kharagpur

The Department of Ocean Engineering and Naval Architecture was established in 1952 at Indian

Institute of Technology, Kharagpur. The department has always worked closely with all

shipyards, naval architecture consultancies, and naval science labs and research facilities. The

professors are up to date with recent technologies and developments and put forward their

knowledge in an innovative fashion. The professors are qualified in Marine Design, CAD-CAM,

Hydrostatics & Stability, Resistance & Propulsion, Hydrodynamics, Ship Strength, Marine

Construction and Welding, Ship Economics, Marine Production & Planning, Seakeeping &

Maneuvering, Vibration of Floating Structures, Offshore Technology, Computational Fluid

Dynamics, Oceanography.

The course of Bachelor of Technology in Ocean Engineering & Naval Architecture as well as the

Master of Technology in Ocean Engineering & Naval Architecture has been designed to conform

to the requirements of the present shipbuilding industry in India and the world. During the

nearly 60 years of its existence, the department has made significant contributions to the

development of shipbuilding and shipping industries in the country including the Indian Navy,

Indian Coastal Guard, DRDO and other allied organizations.

The department and its alumni have important and strategic links with universities round the

world and major shipyard and dock organizations in our country. The Naval Architects that

graduate from the department have been known to contribute greatly to the industry by opening

shipyards, joining classification societies, becoming senior Naval Architects in shipyards and

undergoing research and gaining professorship in institutions like IIT Kharagpur and Indian

Maritime University.

The facilities available in the department are known throughout the country and are used by the

industry and other educational institutions for a lot of purposes. Towing tank for resistance,

propulsion, seakeeping and maneuvering calculations, inclining experiment facilities, welding

equipment, circulation tank for turbulence modeling, CAD/CAM laboratories with softwares like

Maxsurf, NAPA and ANSYS, and Vibration analysis laboratories are available in the department.

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Training Schedule

Period Department Reporting to 02/05/2012 – 19/05/2012 DESIGN Mr. A Ramaprasad

21/05/2012 – 02/06/2012 QUALITY ASSURANCE &

CONTROL Mr. S A Phadke

04/06/2012 – 16/06/2012 HULL Mr. D Upendra 18/06/2012 – 23/06/2012 PIPING Mr. Suraj Shetty

DESIGN 1. Hull Design

2. Outfit Design

3. Machinery Design

4. Electrical Design

QUALITY ASSURANCE & CONTROL 1. Block Fabrication

2. Block Erection

3. Piping

HULL PRODUCTION 1. Y-353 Hull Erection & Dry Survey

2. Inclining Experiment at Y-240

3. Y-bracket alignment for Y-355

4. Major Structural Issues during Hull Fabrication & Erection

PIPING PRODUCTION 1. Piping System Components

2. Ensuring Piping Quality

3. Piping Systems in Diving Support Vessel (Y-382)

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Safety Training

Safety is a very important concern of any shipyard. ABG Shipyard has taken ample measures to

protect its employees from all types of dangers that may occur in a shipyard. All employees are

given safety training regarding the equipment they handle. Even we had to undergo training to

safely visit the shipyard.

The main areas of concern that were concentrated upon were the possibility of blasts that may

happen due to different sources of fire. The different types of sources were divided into different

classes according to the intensity of fire and the ease of dousing it. LPG, Wood, Paper, Oils,

Acetylene and other chemicals are the sources of fire in the yard. Welding tools that require

acetylene and oxygen to function are one of the main sources of negligence that may lead to a

fire especially in confined spaces like tanks. The increase of oxygen level in the tank can lead to

combustion of normally incombustible substances! It is considered to be more dangerous than

the leak of LPG due to the absence of smell.

Painting is also another source of fire. The gases that are released by the paint on drying are

highly combustible and can create a blast even by the spark inside a mobile phone. This is why

mobile phones are not permitted near newly painted surfaces.

Fuel oil tanks need to be checked for presence of flammable gases. This is because the area near

the tank can also catch fire if these gases are present during hot work. Fuel can vaporize and

create explosions when in contact with hot material.

Also, lot of emphasis was laid on the proper method of carrying out construction work especially

on carrying heavy material, transporting material from one place to another, and on electrical

wiring.

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Design Department

Hull Design Monitored and supervised by Mr. Sailesh Patel

During our time in Hull Design, we learnt to read drawings like “General Arrangement”, “Shell

Expansion”, “Profile and Deck”, “Typical Frame Sections”, “Midship Sections” and “W.T.

Bulkhead”, and utilize the drawings for various purposes. We studied these drawings for the

ship now under design stage (80 T BP AHTS). We got first-hand experience in

1. Checking the block drawing generated from these drawings for any discrepancies,

2. Calculating size and number of pillars required in the ship from drawings,

3. Nesting the plates required for a propeller nozzle construct from its section drawings,

4. Revising drawing as fitted in the yard.

Block 1702 of 80T BP AHTS The block analyzed was situated in between Frame numbers 78 and 89 and between 3900 ABL

(Tween Deck) and 6800 ABL (Main Deck). To check the generated block drawings, the following

drawings were referred:

Shell Expansion

Profile and Deck (FWD)

Typical Frame Sections of relevant sections (FR78 – FR89)

Two discrepancies were found:

At the hull, stiffeners used in the block drawing were found to be L125x75x10, although

the drawings referred sufficed the stiffener dimension to be of L125x75x8. However, this

was a purposeful change as this would make it a uniform stiffener size throughout the

ship’s hull.

A longitudinal girder at 3600 off CL was found to extend up to FR85 whereas the

“Typical Frame Section” drawing showed it to be up to FR82 only. This was found to be a

mistake in the frame section drawing as other drawings like the “Profile and Deck”

drawing showed it to be extended up to FR85.

Pillars’ count and dimensions “Typical Frame Section” drawings and “Profile and Deck” drawings of all sections were utilized

to count the number of pillars required throughout the ship and their sizes so as to give the

requirement to procurement section. A total of 35 pillars were found to be required in the entire

ship of which 22 pillars were found to be required under the Main Deck and were of uniform

size (200NB SCH 80 Pipe) while out of the rest 13 found to be between Forecastle Deck and

Upper Forecastle Deck, two were of 200NB size and 11 of 100NB SCH 80 Pipe size.

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The requirement list was submitted to Mr. Sailesh along with location of pillar and height.

Taking into consideration that pillars are available in standard sizes only and that a fraction of

error needs to be added to the final answer for errors while cutting, the requirement was

approximated to be about 100m for below Main Deck and 40m for above Main Deck.

Pillars below Main deck

Frame No No of pillars Position Height extent Dimension

14 1 CL TT – MD 2988

17 2 2400 off CL TT – MD 2988

21 1 CL TT – MD Approx[5300]

21 2 2400 off CL TT – MD Approx[5300]

29 2 2400 off CL TT – MD 5388

30 1 CL TT – MD 5388

34 1 CL TT – MD 5388

35 2 2400 off CL TT – MD 5388

48 2 1200 off CL TT – MD 5388

64 2 1200 off CL TT – MD 2584

64 2 1200 off CL TD – MD 2488

66 2 2400 off CL TT – MD 2584

66 2 2400 off CL TD – MD 2488 TT = Tank Top

TD = Tween Deck

MD = Main Deck

Dimension Requirement

5388 => 5400 11

2988 => 3000 3

2584 => 2600 4

2488 => 2500 4

Revision of Drawing “as-fitted” We were asked to revise two “Typical Frame Section” drawings as it was made in the yard.

Frames aft end ‘f’ to 10 as well as frames 18 to 29 were checked by visiting the yard and checking

dimensions of all the structural members in comparison with the drawings. The ship in

consideration was a Seismic vessel for “Scan Geophysical ASA” in Norway. This kind of ship is

being built in India for the first time by any shipyard.

Quite a few changes were found to be made in the yard and the additions were noted in the

drawings and changes made at the Design office using “Revision Cloud” tool of AutoCAD to

mark the changes that were found.

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Typical Frame Sections (f,e,d,c,b,a,0,1,2,3,4,5,6,7,8,9,10) Typical Frame Sections (18,19,20,21,22,23,24,25,26,27,28,29)

Kort Nozzle Plates’ Nesting A Kort Nozzle construct drawing was provided. We were asked to make a drawing of the plates

that would be required to construct the Nozzle (Nesting drawing). The existence of different

shapes and thicknesses of the plates required made the job challenging and interesting. A

screenshot of our work is shown below:

Previously unknown terms Skeg, stringer, swash plate, checkered plate, LAP, FB, FF, BP, TYP, Carling

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Outfit Design Monitored & supervised by Mr. J G Bhat

During our time with the Outfit Design team, Mr. J G Bhat was instrumental in instilling

practical knowledge about the different equipments and other outfit items used in a ship. The

ship discussed was again, the 80T BP AHTS (80 Tonne Bollard Pull Anchor Handling Tug &

Supply). There are various functions that the AHTS can handle. Those functions and their

equipments on the ship are given as follows as discussed with Mr. Bhat:

1. DNV 1A1 Tug Supply –

The owner requirement of the ship is 80T BP. Due to efficiency generated by the

alignment of skeg and propeller efficiency, the ship is able to generate 93T BP. It can

function as both pull and push.

For pulling, it has a “Stern Roller” at the aft area which is situated almost

completely below deck to prevent any damage on the deck. Pulling is

generally used when there is a minimum of 300m available space.

For pushing, “Fenders” are situated at the fore end of the ship. Pushing is

usually used for confined areas like harbors.

80T BP AHTS supplies cement, fuel oil and fresh water to offshore structures. It has

separate tanks for each of the supply items above. Since ships carrying fuel oil above

600m3 have requirement of double hull, the AHTS has a capacity of 590m3. Double

hull will reduce the capacity considerably making it infeasible economically to carry

fuel oil. It also has the provision of carrying containers on the deck. The containers

are loaded onto the deck using Tugger Winches.

2. FiFi-1

For fire-fighting, the minimum range of the projectile required is 125m and height of

75m. The pressure at the nozzle should be at least 12 bars. In this vessel, the FiFi

pump is directly connected to the shaft of the main engine. Having two main engines,

the minimum throughput was reduced to 1200m3/hr per pump. The engine used

allows the pump to have a throughput of 1800m3/hr.

3. DYNPOS – AUT

AHTS can also double up as a support vessel for dynamic positioning during offshore

structure installation and seismic vessel functioning. The two bow thrusters and the

one stern thruster help the ship to position any vessel.

4. OILREC

Oil Recovery is a new addition to the series of AHTS vessels that ABG has built.

Tanks that were used to carry cement and mud were converted to ORO Tanks to

store the oil recovered from oil spills. Provision for Oil Booms, Dispersant Booms,

Boiler Room and Oil Skimmer is available on the ship.

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5. TMON

TMON is an acronym for Tail-shaft MONitoring. It suggests the possibility of

changing the spring used to hold oil in the stern tube without spilling or loss of oil.

Accommodation

International Labour Organization (ILO) specifies minimum facilities that should be available in

a ship for the crew. The regulations specify requirements like minimum head area, minimum

room size, maximum number of crew in one bedroom, facilities for recreation, and availability of

laundry rooms. One important regulation is that all bunks should be arranged longitudinally

because of the higher pitch period over roll period.

Life Saving Equipment

SOLAS (Safety Of Life At Sea) requires the provision of life rafts and rescue boats on deck. This

provision is also met in the AHTS with a number of such boats of minimum 6 person capacity.

Windlass & Anchor

Anchor is an essential component among the outfitting equipments on board a ship. The mass

and hauling capacity is regulated by classification societies. Equipment Number is calculated to

find the requirement of number, mass and chain size of the anchors. Chain diameter can vary

according to the class of the material used to make the chain. During anchor hauling, a

minimum of 9m/s speed is required.

Capstan

Capstan is an outfit item used for mooring. A cable is thrown overboard to tie it on to the shore,

while being connected to the Capstan. It will slowly turn and reduce the distance between the

ship and the shore and thus help the ship to dock.

COLREG

The ship has facilities to satisfy Collision Regulation requirements. Mast lights, port & starboard

lights as well as Aft & Fore lights help the ship to operate safely without collision during night.

Engine

The engine room is located comparatively forward due to the unavailability of head room for the

engine in the aft area. Two main engines are connected to the twin CPP propeller system via

intermediate shafts, gear boxes and propeller shafts. The intermediate shaft diameter is less

than the propeller shaft diameter because of the higher stresses encountered at the propeller.

Roller bearings are used at the intermediate shafts while propeller shafts are simply supported

in the stern tube by two bush bearings.

The propeller revolves in a Kort nozzle that has been designed for optimal thrust. The nozzle is

fixed as the propeller is not SRP. The rudder is handled using steering gear located in the hull

above the rudder. There is also a provision for rudder pintle that supports the rudder at the

bottom.

Engine ventilation is provided at the top of the engine room using axial flow fans. Sea chest

provides sea water to exchange heat with the fresh water used in cooling the engine.

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AutoCAD work ABG had got an order for 2950T DWT Dumb Barge that they had earlier made in ’96-’97 from

Essar Steel. For re-approval by IRS, AutoCAD drawings had to be made from the hard copies

available from the time. We were asked to make 4 (out of the 16 required) such drawings: Tank

Testing Plan, Loadline Plan, Sounding & Air Pipes, and Details of Fenders. The experience made

us familiar with many commands in AutoCAD. We also got to learn a lot of commonly used

terms in drawings and the necessary rules to follow while making a drawing. We were privileged

to include our name in the ABG records.

We also understood that the following drawings need to be sent to IRS for re-approval:

1. General Arrangement Plan

2. Principal Structural Sections

3. Profile and Decks

4. F.W.D. W.T. Bhd & Frame Sections

5. Aft End Structure

6. Hawse Pipe, Anchor Pocket and Windlass Seating

7. Welding Schedule

8. Sounding & Air Pipes

9. Tug Barge Coupling Arrangement

10. Tank Testing Plan

11. Loadline Plan

12. Sea chest Detail

13. H/Cover Rigging Masts/Nav. Masts

14. Collapsible Mast

15. Bilge/Deck Wash Line Piping System

16. Detail of Fenders

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Previously unknown terms & information Stanchion – used for anchor handling and anchor chain storage

Scrambling Net – used for hauling men who may have fallen overboard

HIPAP – opening from main deck to bottom of ship for underwater surveying purpose

Oil Skin Locker Store – storage of oil soaked material to prevent fire

Service Trunk – used to transport provisions between decks

Boiler Room/Hot well – used to dilute HFO to MDO for easy combustion purpose

Bosun Store – Storage of working equipment like ropes, spanners, bearings, etc.

Dispersant Boom – used to control oil spillage that may occur from vessel by dispersing

AHU Room – air handling unit

F.O. Settling Tank – rule requirement for engine system along with daily service tank

Rig Chain Locker – used to store chain used for towing purpose

Rescue Zone – Only zone in ship used to haul man overboard with gates in place of bulwark and scrambling net

Flush Panel – provides direct access to engine for any repair or restructuring purpose

GMDSS Table – Global Maritime Distress Safety System

Up-Take/Engine Casing/Exhaust – Exhaust gas exit from engine room

C.L. – Chain Locker (fwd)

Davit – crane used to lower rescue boats and life rafts, or lift personnel overboard (rescue)

JASON’S CRADLE – light, rigid stretcher with flotation tubes in order to recover rescuer and casualty at same time

EPIRB

Oil Spill Equipment – Oil sorbents, oil spill kits, dispersants, etc are provided on board to deal with small oil spills

International Couplings/Shore connections – Standard sizes of fire-fighting equipments which are used to connect hoses and pipes on board to shore for fire-fighting; SOLAS regulates this.

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Piping Systems

Piping systems are one of the major equipments inside a ship. Piping ensures the working of all

other systems like a transport medium. Some of the major piping requirements include bilge

water suction, ballasting, fire-fighting, engine cooling, general service and fuel oil supply. Each

function has separate pumps, valves and pipes connecting them. One major feature of the ship

piping systems is that they are also inter-connected. This means that the pumps are able to

perform the functions of all the major systems. Fuel oil supply pipes are, however, one of the

exceptions as they carry fuel oil and thus shouldn’t carry water.

There is also a provision for an emergency fire piping system which is separate from the main

piping system kept as a standby in case of failure. The fire pumps are usually connected to the 2

sea chests at the bottom of the vessel. This highlights the importance of protecting the sea chest,

which in turn translates to more stringent rules and regulations governing sea chest

construction by classification societies. Any mishap in the sea chest can result in the flooding of

the entire ship.

Marine engines are water cooled because of the abundant presence of water as well as the high

specific heat of water. This is why fresh water is used for cooling of engines. Fresh water

circulates in a closed system in the ship near the engines. Sea water is used to cool the heated

fresh water with the help of long pipes that increase the contact surface area with the fresh

water.

Fuel oil tanks are usually separated from tanks containing water with the help of cofferdams as

any small leakage into the water tank can result in its contamination. A cofferdam is a void tank

with the presence of only an air pipe for air circulation and a manhole for checking. The

cofferdam is not sealed because of the possibility of explosion/tank rupture due to air

expansion.

Fuel supply to engines are regulated through Fuel Oil tank (where fuel oil is stored), Daily

Service tank (where fuel oil that is going to be used for the day is stored), and Fuel Oil Settling

tank (where fuel oil is sent to the purifier and further to engine).The transport of fuel oil in

between these tanks is through pipes. Pipes are also connected from the engine to the Daily

Service tank as 100% combustion never occurs. The extra fuel oil is pumped back to the tank for

re-use. The pumps used in this system are unique as they have to supply the engine which is at

approximately 4 bars. Gear pumps, piston pumps and positive displacement pumps are used

here.

Sounding pipes are used to check the level of liquid in a tank. This is a necessary requirement as

there is a possibility of presence of liquid in the tank while checking. All sounding pipes that

check double bottom tanks are of the “self-closing” types as this could also be a medium of

flooding of the ship in case of mishap in the tank.

Due to the major role that pipes, valves and pumps play in the functioning of a ship, there are

lots of rules and regulations that govern the piping system like the minimum thicknesses,

diameters, pressures and materials of the pipes and pumps. ABG has a piping section that

ensures that all these rules are followed and Life at Sea is safe.

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Machinery Design Machinery Design deals with the installation and order of main engine, diesel generators (DG)

sets, reduction gears and propellers, as well as the design of shafts and piping systems involved

in the functioning of the power generation & cooling systems. In order to familiarize ourselves

with the smaller equipments involved in the process, we were asked to go through the manual of

the equipment supplier, Sun Korea. We came across the drawings of many components and

parts of machineries that we had earlier only heard about. We also asked around for various

other terms that we did not understand in the drawings, some of which are:

Bottom Plug – located at bottom of tank to drain last few drops

Louver Ventilator – a type of ventilator with grill end

Chock – used to fix/flatten bottom of equipment with uneven bottom (like engine)

Hopper – funnel shaped tanks/collection points

Scupper

Suction Bell-mouth – reducer of pipe size in order to increase pressure and thus reduce

power intake of suction pumps

Hawse Pipe – pipe for anchor chain

Strainer - filter

Roller Fair Lead –guides for ropes/chains on rollers

Most medium size ships employ main engines which are connected to reduction gear by an

intermediate shaft which in turn is connected the propeller by a propeller shaft. Since there is a

limitation on the RPM of a propeller (higher RPM can lead to failure of blade of propeller), and

higher the RPM, higher the power in the case of main engine, there is a need of reduction gear to

reduce the RPM while still delivering the same power.

where L = length of cylinder, A = area of cross-section and N is RPM.

However, in the case of Diesel Generator, which is used for power generation, where constant

frequency is required, power generated is given by,

where p = no. of poles and f = frequency.

The main engine can be of broadly two types, viz. 2-stroke and 4-stroke. The 2-stroke engine is a

reversible engine, which means that to reverse the propeller (in order to reduce the speed of the

ship), the engine itself rotates in the opposite direction. This can result in the lack of need of the

reduction gear provided the engine RPM is adjusted by increasing length of cylinder and area of

cross-section.

The turbocharger increases the air-fuel ratio (from 1:12 to 1:17) increasing the efficiency of the

fuel by ensuring maximum combustion. Compressed air cylinders (at 30 bars) are provided to

be used in the starting pneumatic system, which starts the engine.

Fuel oil is fed into the engine using fuel oil feed pumps. These are regulated by governors which

monitor the load on the engine and accordingly allow a certain amount of fuel to pass through.

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Cooling in the engine is of majorly three types, viz. Lubricating Oil Cooling, Cylinder Jacket

Cooling and Exhaust Cooling for turbocharger.

Piping Systems in Engine Room

Starting Pneumatic

Starting pneumatic system is used to supply compressed air to the engine in order to “kick-start”

it. Compressed air need to be supplied continuously to the engine in order for the pistons to

move and generate power.

Fuel Oil

Fuel oil system is another essential part of the engine. The burning of fuel oil counteracts and

forms the opposing motion in the pistons of the engine. Fuel oil systems usually consist of a

storage tank, daily service tank and a settling tank.

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Lubricating Oil

Engines have a lot of moving parts and thus need lubricating oil to be continuously supplied to

it. The system also cools the lube oil as it gets heated up when in the engine.

Cooling Water

To cool the machine parts of the engine, cool fresh water is supplied to it. The hot fresh water is

cooled by cool sea water from the sea chest.

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Electrical Design Electrical Design involves the design of methods of distribution of power for other systems like

internal communication, navigation and dynamic positioning and their arrangement in the ship.

Power generated by the Diesel Generators (DGs) in the ship is transported to power utilizers in

the ship like accommodation areas and thrusters using cables.

Power Plan Scheme The first activity in electrical design is to make the power plan scheme in which all systems that

require electric power is connected to a DG set or more than one DG sets according to the power

requirement and power supply per DG set. This scheme is used to then finally decide on what

cable to go where and from where. For e.g., in the Y-240, there were 2 Shaft DG sets of 2000 kW

power each used to propel the thrusters and 2 DG sets of 500 kW power to run other equipment

on the ship like lights and alarms. Also, a provision for 1 Emergency Generator of 90 kW power

was given to run minimum requirements of the ship to stay afloat and in direction.

The generators mentioned above however provide AC current. Any requirement of DC current is

met through batteries. Also, there is a provision of using Shore supply. When using shore

supply, the generators are automatically shut down using an interlock. 4 busbars cater to the

needs of the ship. 2 busbars run the 2 bow thrusters and the stern thruster each requiring 900

kW.

The entire ship machinery can be controlled from the Engine Control Room near the Engine

room. All electrical switches are provided here.

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Cable Routing One of the major activities in electrical design is the routing of cables required for various

purposes across the ship from the power generators. Routing is done through perforated plates

which are installed wherever there is a requirement for a cable. The cable is then attached to the

perforated plate. According to the direction the cables have to go, these plates can be cable

hangars, ladders, T-bends or vertical bends.

Internal Communication All internal communication inside the ship like telephone, intercom and announcements comes

under the purview of the electrical design department. While telephone, intercom and

announcements require the presence of electric power, there is also a provision for manual

communication in which the power required for communication is provided manually by

rotating a lever. This is used especially in emergencies when power is not available.

Navigation Navigation requires a lot of calculations and speculation if done manually and without the help

of communication media like DGPS. Electronic & electrical systems required for the ease of

navigation is provided in the navigation bridge and is designed or contracted to third parties by

electrical design.

Dynamic Positioning Dynamic positioning is the process of adjusting the position of a ship according to its

requirements. At times, it is necessary for the ship to not move from its place. However, wave

forces and currents may force it to. Automatic systems are available that can position the ship

when the current is a maximum of 1.5km/hr, significant wave height is a maximum of 3m and

when the wind speeds are as high as 30km/hr.

Certain terms learnt Doppler log: Speed log of ship throughout voyage

DGPS: Dynamic Global Positioning System

EPIRB: “Black box” of a ship – records last few minutes of the ship before touching water,

gets released when in contact with water

SSAS: Alarm system for ship safety from pirates and other terrorism

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Quality Assurance & Control

Quality Assurance & Control department at ABG Shipyard Ltd is in-charge of internal inspection

of block fabrication & erection as well as piping systems installation inside the vessel. Internal

inspection involves checking quality of welds & adherence to drawings through “Dry-Survey”,

ensuring alignment of blocks during erection within permitted distortions, checking welds &

spools of the piping systems as well as adherence to quality requirements according to pressure

and nature of fluid flowing through the pipes.

Block Fabrication A ship to be built is divided into smaller units called blocks, for ease of production. A block

division plan is prepared taking into consideration the handling capacity available in the

workshop as well as the quality of the human resource available.

Block Fabrication is carried out in the following order:

1. Shot Blasting/Painting

2. Plate & Profile Storage

3. Welding Procedure Specification (WPS) Approval

4. Machine Shop (bending, rolling, lathe, CNC cutting of plates & profiles)

5. Material Issue to workshop

6. Study of Block Drawing & Loft Table

7. Weld Edge Preparation (WEP)/ Pre-fabrication

8. Skid level Check

9. Fit-up of components according to drawing (tack-welded)

10. Level Check (horizontality using water level & verticality using plumb piece)

11. Approval for welding from Production engineer

12. Quality welding according to WPS

13. Internal Inspection by QA/QC

Shot Blasting/Painting Plates & Profiles are ordered from a vendor according to the requirements of the block to be

produced. These are subjected to shot blasting to remove any impurities on the surface of the

plate or profile like corrosion. These plates & profiles are then immediately painted in order to

prevent any further corrosion, so as to store it till its requirement.

Plate & Profile Storage At ABG Unit-2, Shop No 2 is used for storage of plates & profiles till its requirement is

mentioned using Material Issue slip.

Welding Procedure Specification approval According to the type of plate/profile to be welded and position of the weld in the block/ship,

different types of welding are carried out. These procedures have to approved by classification

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societies by submitting a WPS document containing type of welding, electrode to be used,

shielding gas to be used, power source, DCEN/DCEP, voltage/current requirement, flow rate,

WEP, filler wire to be used, flux to be used, weld speed, polarity, wire angle, number of wires,

and stick out.

The quality of welders is regulated for different types of welding by means of a Welding Training

Centre, which trains & tests welders for a particular type of welding. Only welders certified by

class are allowed to carry out welding. This is regulated by QA/QC.

Types of welding used in ABG

SMAW (Submerged Metal Arc

Welding)/ MMAW (Manual Metal

Arc Welding)

SMAW is the most commonly used

type of welding in ABG. The lower

time requirement is the major

reason. However, quality of weld

using SMAW is low and has the least efficiency in heat input among all other types of

welding used in ABG.

In SMAW, the constant current is set according to heat input required. Voltage gets

automatically adjusted. There are two types of electrodes used in SMAW: E6013 and

E7018. E6013 is used for welding Carbon Steel and DCEP/DCEN is used. E7018 is used for

welding high tensile steel like mild steel. DCEP is used in this case. MMAW uses a

drooping power source which prevents freezing

FCAW (Flux Core Arc Welding)

The filler wire used in FCAW has a core filled with flux. If a solid filler wire is used, it is

coated with copper. The shield gas used is CO2. In this case, current & voltage, both, have

to be set and adjusted according to the required weld. The electrode used is E71T-10

GMAW (Gas Metal Arc Welding)

In GMAW, tungsten is used to provide the arc and

is non-consumable. Shield gas to be separately

provided. Argon gas is preferred due to its inert &

cheap nature. A small amount of CO2 or O2 is

added to it . Electrode used is SM-70 or AWSA5.18

A constant current power source is used in this

case, allowing the welder to control the arc length.

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SAW (Submerged Arc Welding)

SAW is a semi-automatic type of

welding that has high quality

finish. However, it is only used to

weld flat plates together. In SAW

the flux is provided separately.

Parameters such as Weld speed,

Polarity, Voltage, Type of flux

used, Size and shape of wire, Wire

angle, and Number of wires are

controlled to decide the quality of the weld.

Machine Shop The machine shop at ABG Unit-II consists of lathe, bending machine, rolling machine and CNC

cutting machine. These machines are used to bend/cut into shape steel plates and profiles

according to the requirement of the block under fabrication. The required shape is given to the

machine shop with the help of a wooden strip (rolling & bending) or a Nesting Plan (CNC

cutting).

Material Issue to Workshop The plates and profiles after being machined are sent to the assembly shops. The contractors at

the shops need to have a material issue slip signed by the preceding engineer. The engineer

regulates the material issue to maintain quality and over-load of activities in his shop. Also,

certain blocks may have priority and sometimes, material earmarked for a certain block is issued

to another one.

Assembly The different plates and profiles obtained for a block

are arranged according to the block drawing & loft

table available with the production engineer. They

are initially tack-welded and checked by the

engineer before approval. Also, the weld edge

preparation (WEP) is checked thoroughly.

Conformation to standard requirements according

to type of welding is ensured. Before welding, the

edges are cleaned and prepared. If enough angle is

not present on the plate edge, it is grinded and

prepared.

Another major concern is the horizontality and verticality of the plates that are fitted onto the

block. The horizontality is checked by checking the horizontality of the skid. A transparent

rubber tube filled with water is used to check the level. A level of 500mm above the lowest plate

on the block is marked at various points and the difference from the mark is measured.

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According to ABG standards, this difference shouldn’t be more than 10 mm. Some issues to

check before approval for welding are:

Adequate space (fit-up) between plates to be welded

No mismatch in the alignment of plates/profiles

Clean & evenness throughout the surfaces to be welded

Welding After approval from the production engineer, welding starts. In shipbuilding, there is no other

activity that comes close to the amount of welding that needs to be done. The different types of

administering the required weld are:

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Internal Inspection Internal Inspection is carried out before presenting the block for class approval in order to ease

the process of approval by finding defects in welding before the class could point it out.

Defective welds can, in future, be points of failure in case of extreme pressure and thus, should

be avoided at all costs. The common welding defects that are found during inspection are:

Cracks

Cracks are the most dangerous type of defect in welds. They are formed due to low ductility,

excessive dilution, hydrogen in weld atmosphere or highly rigid joints. To prevent cracks, pre-

heating of the base metal is employed while ensuring right welding current and travel speed.

Incomplete Penetration

Incomplete penetration of welds occur due to lack of sufficient root opening, insufficient heat

input or slag flooding ahead of welding arc. This can be prevented by ensuring proper geometry

of joint and by following proper weld procedure as outlined in WPS.

Inclusion

Inclusion is the entrapment of foreign material like slag in the weld when it doesn’t get the

chance to float during solidification of the weld. Inclusions lower the weld strength. They are

caused due to failure to clean surface before welding and usage of damaged electrode.

Porosity & Blow holes

Porosity or blow holes are small voids that are formed inside the weld after/during solidification

of the weld. They are usually entrapped gases. This can be avoided by using low hydrogen

welding, increasing shielding gases, using clean filler wires, and/or pre-heating.

Distortion

Distortion is the change in shape of the plates in the joint after welding. This is caused due to the

difference in temperature at the side of the plate where welding arc is being used (hotter) and

the side of the plate which is opposite to it (cooler). This sort of defect can be prevented by

placing weld near the neutral axis or by allowing the distortion in a desired direction.

Poor Fusion

Poor fusion is when the weld material doesn’t melt with the base metal and do not unite

properly. Usually incorrect heat input, weld position or type of electrode is the major reason for

this to occur. Unclean surface can also cause poor fusion.

Poor weld bead appearance

If the welding is not done by a professional/practised welder, the resultant weld will not be

uniform. It may have different widths at different places or the ripples may not be consistent.

This may also be because the job portion to be welded is not easily accessible.

Spatter

Spatter is small metal particles that are thrown out of the arc during welding. They get deposited

on the base metal. This may be caused due to excessive current, long arc or improper flux

ingredients in electrode.

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Undercut

Undercut is when a groove forms in the parent metal along the sides of the weld bead. This

reduces the thickness of the plate and thus makes the joint weak. Faster arcs and travel speeds

are the usual culprits.

Overlapping

Overlapping is the opposite of undercut. It occurs when the molten metal flows over to the

parent metal surface and stays there without getting fused properly. Slow travel speeds and

improper geometry can cause this.

Apart from welding defects, internal inspection also looks into conformation with drawings,

mismatch in alignment of plates as well as fairing of plates. If the plates are bent above the

allowable limit (3 mm), they are faired by pulling the plate to its required position and tack-

welding a profile on to it.

Block Erection After approval of the block fabricated at Unit-II by classification societies, the block is brought

to Unit-I and arrangements are made to erect the block on to the ship being built. Block Erection

in itself is an intensive process, perhaps more so than Block Fabrication.

A Gantry crane is used to lift the block to its position on the ship. While being erected, the edges,

in which connections with other blocks exist, are tack welded and supported using concrete

blocks at the keel. Care is taken to align it horizontally, vertically and such that its position from

the centreline is maintained. Verticality is checked with the help of a plumb piece and piano wire

while half breadth is checked by measuring distances from centreline of various components of

the block.

The erection engineer needs to ensure that fit up of joints is maintained with adequate weld

edge preparations and spacing between joints for welding. Another important check is the

alignment of girders and longitudinals that pass through both the blocks being welded together.

QA/QC also checks for welding defects (dry-survey) in components that are added during or

after erection.

Piping Piping inspection by Quality Assurance & Control starts with the verification of the grade of

pipes with the TC. The process is called Receipt Inspection (RI).

This is followed by Weld-Edge Preparation. The main two types of welds in piping are fillet

welds and butt welds. Fillet welds are used to attach flanges to pipes while two pipes are

attached using butt welds. A major factor that decides the quality of the welds is the throat & leg

length. It is ideal to have a 45o angle of weld.

Fit-up of sleeves and flanges on the pipes are checked before welding as well as fit-up of finished

items onto the ship.

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Common defects found are the lack of throat size, lack of penetration of weld in butt welds,

misalignment and poor quality of galvanizing. While piping arrangements are fitted, the

following considerations are taken:

Routing of pipes – Interference of pipes with other structural parts and systems

Pipes passing through tanks containing fluid of different specification/specific gravity

should comply with regulations – routed through sleeved pipe/higher grade of pipe etc.

Proper supports to be ensured – considering length of pipe and vibration in the vicinity

Ensure all open ends of pipes during fit up stages are blanked/closed

Pumps to be properly aligned with pipes – to prevent crack on flanges of pipes resulting

in leakage of pipe and failure of pump bearing

Introduce bellows at suction and discharge pipes connecting to pump

No penetration is allowed on seams or butts

Gauges are placed at easily accessible places

Stiffeners and carling are not cut to allow for passing of pipes

Colour coding of pipelines

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Production – HULL

Hull Production is a major activity in shipbuilding involving basically two steps: Block

Fabrication & Block Erection. Both these activities are carried out at ABG Shipyard Ltd with the

help of efficient machinery and manpower.

At the fabrication yard, plates & profiles are fitted together according to the block drawing

issued by Design Department by welders and cutters under the guidance of a Production

Engineer. Different shops are allocated to different production engineers who control all activity

at that shop. The shop consists of skids and cranes to assist in block fabrication. Welders &

cutters are trained nearby at the welding training centre and issued certificates by classification

societies according to their proficiency in the specific type of welding (1G, 2G, 3G, 4G). Only

certified welders are allowed to operate. Most fabrication happens at Unit No 2 of the ABG

Shipyard and the finished blocks are transported to the Erection yard at Unit No 1, as and when

required by Block Erection.

Different building berths are allocated to different ships being erected at ABG. In fact, at

present, only at Unit-1, there are 17 ships at different stages of construction being built in ABG’s

Surat yard. The ingenuity and efficiency with which the planning department facilitates such

construction is commendable. During erection, the following features are checked:

a. Water level (z-coordinate)

b. Verticality (x & y - coordinates)

c. Half Breadth (y-coordinate)

d. Fit-up (alignment with adjacent blocks, distance between plates, Weld Edge Preparation)

e. Welding & subsequent Dry Survey (check for weld defects & conformation to drawings)

f. Keel sighting

Y-353 – Ocean Research Vessel

(ORV) for National Institute of

Oceanography, Goa ORV is a unique type of research vessel to be used

for scientific experimentation and data collection

at sea. The vessel has facilities to accommodate

the scientists and conduct laboratory experiments.

The vessel is almost ready for launching. We

conducted dry surveys of the Bridge Deck with the

help of its block drawings (1501, 1502, 1601, 1602,

1701 & 1702) and approved structural drawings.

Dry survey of structures IWO A-frame & 2.5 T

crane aft of frame 1 (foundation details) was also

conducted.

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Mr Subrat Mohanty of the hull department was kind enough to give us details of hull erection &

subsequent tests carried out on the hull to check for weld defects. Other than the Non-

Destructive tests carried out by QA/QC, Dye Penetration, Hose, Air Pressure and Hydro tests are

done.

Dye Penetration test or Liquid Penetration test

Dye Penetration is carried out as follows:

Surface to be tested cleaned with cloth

Colourless dye applied

Left to dry for 2-3 minutes

Developer/penetrant (pink in colour) applied and left for 5-10 minutes

White dye applied revealing cracks on surface

Dye Penetration tests are usually carried out to reveal surface defects like cracks, porosity &

incomplete fusion. It is carried out before UT.

Hose test

During hose test, water at high pressure is ejected through a hose (12-inch nozzle) onto weld

joints while you check for water leakage on the other side. It reveals any hole that may have

formed during fabrication. Hose test is generally conducted in compartments attached to side

shell and below main deck at watertight bulkheads. Water at 2 bar pressure is used for the

purpose.

Air Pressure test

Air pressure test is carried out in tanks for checking for any leakage/holes. All weld joints are

covered with soap water in order to detect and soap bubbles that may form if there is a leakage.

This test ensures the water-tightness of the tanks. Air is maintained at 1.2 bar for the test.

Hydro test

The hydro test involves filling the tanks with water till 2.5m above the top end of the tank with

the help of a separate pipe fixed onto the sounding pipe. This helps in creating higher pressure

in the tank and thus in smoothening any structural deformity that may have crept in to the tank

structure during erection.

Inclining Experiment at Y-240 After major outfitting items are fitted on to the ship, inclining experiment is carried out to

determine the actual CG (centre of gravity) of the ship. The CG determined from drawings

theoretically is usually not same as the actual CG because of changes incorporated during

production constraints.

Procedure

Initially, it is ensured that the ship has zero heel by ballasting if necessary. Four blocks of

approximately 10 tonnes weight each were placed in the aft and forward parts of the ship. The

position of these blocks is decided such that we get maximum heeling moment from this

arrangement. One block was placed in the forward region and three blocks were placed in the aft

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region (as shown in diagram). The draft values at aft and forward were

checked from the draft markings at the aft and forward perpendicular with the

help of a boat. Generally, the trim has to be less than 0.1*LBP and the heel

should be less than 0.1 degrees. Ballast water is adjusted such that constraints

on trim and heel are satisfied. All excess items on the ship are removed or

aligned along centreline.

Generally, 2-3 pendulums (forward, amidship & aft) are used to measure heel

values. In this ship two pendulums were used one, amidship, and the other,

forward. The readings were taken on batons on which scales were placed. The

pendulums were immersed in oil so that small oscillations get dampened.

Blocks were moved according to a sequence from port to starboard and vice

versa:

Port Starboard Start Point A,B C,D Shift 1 B A,C,D Shift 2 - A,B,C,D Shift 3 B A,C,D Shift 4 A,B C,D Shift 5 A,B,C D Shift 6 A,B,C,D - Shift 7 A,B,C D Shift 8 A,B C,D

At each shift, the position of pendulum with respect to Start Point is marked on the baton. From

known values of length of pendulum and moment generated due to shift of blocks (from lever

and weight of block), the CG can be located.

Further calculations of what weights will come off the ship and which additional weights will go

on to the ship are assumed and the final CG is generated. The final lightship particulars for Y-

240 were found to be:

Weight: 1893.894 t

LCG: 29.495 m from aft

VCG: 5.624 m from BL

TCG: 0.068 m from CL (port)

Y-bracket alignment for Y-355 Y-bracket is used to support the propeller shaft outside the hull. It is shaped like a ‘V’ with both

open ends fixed to the hull. It helps in aligning the propeller, shaft and engine such that

maximum torque is transferred from the engine to the propeller. Any misalignment can cause

losses in the energy transfer. Hence, a high amount of accuracy is maintained in this case.

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The bracket was approximately 150mm thick and has a separate WPS compared to other welds

in the ship. Also, during welding with the bush, the bracket is locked (horizontally & vertically)

at 6-7 points to prevent any distortion due to heat.

Y-bracket is pre-heated to 150-300oC before welding starts. This is done because of the large

thickness of the plate which may result in formation of cracks if welding without pre-heating is

done. Without pre-heating, the other end of the plate during welding will remain cold. This

results in the weld being weak and prone to cracks.

Continuous welding is avoided as distortions are prone to occur otherwise. Every layer of weld is

allowed to cool before another layer is welded on.

A distance of 3-4mm is maintained between the bush and the bracket as WEP to ensure

maximum filler material. The Y-bracket is penetrated into the hull and supported with the help

of flanges and welded securely to the hull.

Major Structural Issues during Hull Fabrication & Erection Structural issues that creep in during the fabrication process may cause loss of strength in

members and may lead to further problems down the line. Some dos and don’ts that should be

followed are as follows:

1. Steel stacking during

storage using wooden

supports to prevent

undulations in plates

2. Skid level Check before

commencement of

fabrication and at random intervals during

fabrication

3. Cement blocks of appropriate weight applied on

plates before welding to avoid distortions or

buckling

4. Usage of electrode ovens to protect them from

moisture and contamination

5. If necessary, welding should be released and

refitted to solve buckling problems.

6. Horizontal supports to be provided while

fabricating bulkheads to prevent buckling.

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7. Finished blocks should always rest on flat surfaces.

Never store blocks on inclined supports

8. Ensure proper handling of blocks while shifting from

one unit to another. Incorrect handling might cause

bending of edges

9. Do not allow temporary scaffolding to be welded to

the hull. Use proper pipe scaffolding.

10. Ensure proper & safe housekeeping at berth and workshop.

11. Surveying & inspections (Dye penetration tests) to done on all back grinding joints to

detect major defects like cracks, porsosity etc. Also, Ultrasonic tests & Radiography tests

to be conducted on cross welds or as required by class.

12. Misalignments are not allowed for any structural

member such as stiffeners, decks, girders, floors and

brackets.

13. Do not allow welding without proper chamfering and

check angle of chamfer required with reference to

difference in thickness of plates.

14. Remove fairing defects immediately with

proper procedures like line heating. Provide

carling if necessary by taking approval from

class & owner.

15. Do not leave scallops without proper round-ups

16. Do not leave overhanging decks without proper

support after erection as they may lead to

deformation/sagging

17. Do not provide strong backs orthogonally for butt

joints. Keep them at an angle to allow for shrinkage

and only remove them by cutting (not hammering –

hammering may cause parent metal to be removed).

18. Always provide proper railing around manholes.

19. Proper supervision & signals needed to be used while erection. Guide ropes to be

provided at two opposite corners at least.

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Production – PIPING

Piping is a network of pipes, valves, strainers, pumps, etc. for transporting fluids from one point

to another for different operations of the ship. A ship has many piping systems. These systems

can be divided majorly into two different kinds:

1. Basic Ship Systems – They are common to all ships and are necessary for the safe movement

and survival of the ship & its crew. For example, air vents & sounding pipes, bilge system, ballast

system, fire system, fresh water system and fuel oil systems.

2. Specialised Ship Systems – They are specific to a ship type and caters to the functions that the

ship is designed for. They may not be necessary for the survival of the ship but they generate

revenue for the ship owner. For example, ORO system, External FiFi system, Oil Dispersant

system, Cargo systems, etc.

Piping System Components

Pipe A pipe is a fundamental unit of a piping system. It is manufactured by class-approved steel

plants. They are majorly manufactured in three different ways:

1. Seamless pipes – in which molten steel is allowed to pass through a hole generating die

2. ERW (Electrical Resistance Welding) – in which steel plates are made to bend into the shape of

a pipe and the joints are welded using ERW

3. SAW (Submerged Arc Welding) – in which steel plates are welded to make pipes using SAW.

These are used only when the thickness of pipes required are high.

Material

Materials used to make pipes vary according to the amount of pressure predicted to be exerted

on the pipe and the type of fluid to pass through them. The pipes used in ABG are usually of the

following material:

1. Carbon Steel (ANSI B31.6)

2. Stainless Steel

3. Precision Steel

4. Copper

5. Cu-Ni alloy

6. Al-Brass alloy

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Classification

According to the fluid pressure that is expected in the pipe, they are divided into 3 classes by

DNV (Det Norse Veritas):

Piping System For Class – I Class – II Class – III

P (Bar) t (oC) P (Bar) t (oC) P (Bar) t (oC) Steam & Thermal Oil >16 OR >300 ≤16 AND ≤ 300 ≤ 7 AND ≤ 170 Fuel Oil, Lubricating Oil, Flammable Hydraulic Oil

>16 OR >150 ≤16 AND ≤ 150 ≤ 7 AND ≤ 60

Other Media >40 OR >300 ≤40 AND ≤ 300 ≤ 16 AND ≤ 200 Class-I pipes have low carbon content giving them a high tensile strength able to withstand high

fluid pressures. Most common pipe class used is Class-II which can withstand most common

pressures. Class-III pipes are used for those pipes that do not have to withstand much pressure

like scuppers, drains, air vents and sounding pipes.

Finishings

Pipe finishings are divided into three grades according to their usage:

1. Grade ‘A’: Welded beads of inside pipes are finished with grinder and welding spatters and

slags removed as far as possible. This grade is applied to lube oil pipe, hydraulic oil pipe, fuel

oil burning pipe and fuel oil service pipe.

2. Grade ‘B’: Welding spatters and slags shall be removed and welded beads shall be cleaned

with wire brush or grinder as far as possible. This grade shall be applied to steam and

exhaust pipe, fuel oil transfer pipe, sea water cooling pipe, fresh water cooling pipe and

compressed air pipe except Class-I, fresh water pipe, hot water pipe, bilge and ballast pipe,

sanitary pipe, wash deck and fire fighting pipe, and tank heating steam and drain pipe.

3. Grade ‘C’: Welding spatters and slags of flange face shall be removed but welded beads

inside pipes shall not be finished. This grade shall be applied to all the pipes except those in

Grade ‘A’ and Grade ‘B’ such as scupper pipe, sounding pipe, air escape pipe, exhaust gas

pipe drain, overflows, steam escape & void tube, etc.

Different pipe sizes are used according to the pressure, temperature and flow requirements of

the system. These sizes are standardized using a scale as follows:

PN10 40NB SCH80

PN specifies the pressure rating, NB specifies the diameter of the pipe and SCH specifies the

thickness of the pipe.

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Flange Maximum pipe length fitted in a system is 3 m. This rule is

followed for ease of maintenance and construction. To join

two different pipes, flanges are fitted on both ends of the

pipes. Flanges make it possible to screw the pipes together.

They are welded on to the pipe with the help of fillet welds.

Sleeve Sleeves can be best described as small pieces of pipes that help another pipe of smaller diameter

to penetrate a bulkhead. Sleeves are welded to the pipes in question and the bulkhead.

Valves Valves are a major component of any piping system. They control the flow of fluids and ensure

human control of the flow.

Pumps Pumps generate the pressure required for flow of fluids in a piping system. They are responsible

for the movement. Different pumps are fitted according to the flow rate required.

Strainers Strainers are essentially a filter with wire mesh as filtering media. Some types of strainers are Y-

type, conical-type, basket-type and duplex.

Bellmouth Bellmouths are used to reduce the pressure in a pipe. They do this by increasing the cross

section of the pipe. An example of their use is at the end of filling pipes in tanks, where it is

preferred that the pressure with which the fluid is filled in the tank is small to prevent any

damage to the tank.

Reducer Reducers work opposite to bellmouths. They increase the pressure in a piping system.

T-joint T-joints consist of a pipe joining at a point in between another pipe at right angles to each other.

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Elbow Elbow is a 90o turn in a pipe.

Bellow Bellows are special equipments used to connect pipes to generators or pumps that may cause

high amplitude vibrations. This reduces any damage that may occur due those vibrations on the

pipe and system. It may be made of rubber or metal.

Ensuring Pipe quality

Flushing Flushing is the process of cleaning a piping system. The system is subjected to a certain medium

under designed pressure for a certain amount of time in order to cleanse the system of any

impurities that have remained after fabrication & fitting.

Acid Pickling After completion of NDT and Hydro tests, acid

pickling shall be carried out on following spools before

installation on board. For rust prevention after

pickling the inner surface of the pipes of item shall be

coated with suitable oil.

Lubricating oil pipes

Fuel oil service pipes for main engine (Diesel

generator and boiler burning line only)

Hydraulic oil pipes

Galvanization Galvanizing of pipes is to be carried out after fabrication

of pipes to prevent corrosion. The external damaged

parts are be touched up with zinc solution paint of high

purity and internal parts shall be touched up with same

purity as far as practicable. If welding has to be carried

out after galvanization, the zinc coat is removed by

grinding.

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Pressure Test Pressuring the spool with Water or Air up to the test pressure and checking for any leakage

ensure the soundness of a spool and it capacity to withstand pressure without any permanent

deformation. This test is known as Pressure Test. This procedure covers method of Inspection to

carrying out pressure test of pipe spool.

All classes I and II pipes and integral fittings and in all cases, all steam pipes, feed pipes,

compressed air pipes and fuel oil pipes having a design pressure greater than 3.5 bar and

relative integral fittings, after completion of manufacture, but before insulation and painting, if

any, shall be subject to a pressure test at the following pressure:

PH = 1.5 P (Only for Water media)

Where, PH = Test Pressure (bar)

P = System Working Pressure (bar)

Air Pressure Test is usually done for systems working under 6 bar pressure while Hydro

Pressure Test is used for systems having more than 6 bar pressure. Nitrogen is used instead of

Air in some cases like compressed air system eliminating possibility of moisture getting into the

engine during starting.

Piping Systems in Y-382

Air vents/Sounding/Filling/Discharge Air vents/pipes are used to maintain air pressure inside empty/half-filled tanks. It prevents air

from being trapped under pressure while the tank is being filled and vacuum from being created

when the tank is discharged.

Sounding pipes are used to measure the level of fluid present in the tank. A pipe extends from

the main deck to the top of the tank to be measured so that measuring equipments can be

lowered into it. There are different types of sounding pipes. One version extends the pipe to the

bottom of the tank and a floatable device measures the amount of fluid and reports it to the

main deck.

For filling & discharge of tanks, piping arrangements are provided. These are usually connected

to main deck, if the tanks cater to cargo.

Ballast Water ballast tanks are provided in a ship to prevent and/or adjust trim and heel conditions.

Ballast systems are provided on board a ship to pump or drain these tanks. The process of

pumping sea water from sea chest into ballast tanks is called ballasting. De-ballasting is the

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process of removal of ballast water from WB tanks. The water is ejected out of the ship through

drains available 700 mm above LWL.

Bilge Bilge system is used to remove water from spaces where accumulation of water is expected. This

water may cause water pollution if ejected from the vessel without treatment. The water

collected in bilge tank is thus, then subjected to oily water separator.

Fire/GS An internal fire fighting system is provided in all ships. This system may also be used for

General Service (GS) or for miscellaneous requirements of water like deck wash.

Cargo FW/FO Certain ships act as suppliers of Fresh Water or Fuel Oil and hence FW or FO is stored as cargo.

These require separate piping systems to cater to the cargo transport on/off the vessel.

OBD/Sea Chest For discharge of treated fluids, Off Board Discharge systems are provided on any ship. Sea Chest

allows storage of sea water collected from the sea during travel. This sea water is later used for

other purposes like cooling.

Cooling (SW/FW) Engine & Machinery cooling is carried out using fresh water. Hot fresh water is cooled using a

sea water cooling system that takes the sea water from sea chest.

Lubricating Oil Lubricating Oil is a major requirement of all machinery and shafts in a ship. According to the

type of LO, it may have to be circulated/replenished or cooled to prevent over-heating. Either

way, there is a requirement for a detailed LO piping system to cater to its needs.

Compressed Air Compressed air is used to start the main engine in most ships. This starting air/pneumatic

system requires high pressure pipes and specialised pumps & valves.

Accommodation HW/FW Accommodation areas need to be supplied with hot water and fresh water for various drinking

water & sanitary needs. Such piping systems require the usage of Cu-Ni or copper pipes as these

pipes do not rust.

Accommodation Black/Grey water Waste water generated by accommodation needs to transported from the accommodation areas

to the sewage storage tanks and to sewage treatment plants. Black water is transported using

vacuum piping while grey water uses gravity for its transport. The pipes used are also specialised

as they need to be highly resistant to corrosion.

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Hydraulic Hydraulic oils are used to cater to hydraulic lift systems like cranes. These oils need to be

replenished and circulated to make the systems ideal.

Oily water/Dirty oil Oily water collected from bilge systems and deck wash is collected in a dirty oil tank since it

cannot be thrown overboard according to MARPOL. Hence, piping systems are required to

transport them from oily water separators and oily water sources to those tanks.

Anti-heeling Anti-heeling system in Y-382 (Diving Support Vessel) provides an automatic system to control

the heel. This is preferred over manual control because during diving, the vessel should have

quick maneuvers to position itself in a particular position. An automatic system will not have

any time lag.

External Scupper The external scupper is used to drain water that may have been washed overboard.

External FiFi/Foam System An external Fire Fighting system is present in the Y-382 making it capable of dousing fires at sea

or near the shore.

Water Spray There is a water spray system that caters to the fire fighting needs of the accommodation area.

CO2 CO2 systems are used to douse fires that may occur in the engine room because water may not

work there. Also, water may damage the electrical connections. Piping arrangements transport

CO2 from the CO2 room to the engine room in the case of such an emergency.

Helideck Fire To cater to any emergency fire requirements on the helideck, there is a provision for fire safety.

Water is used to fight fire here.

Diving System The major function of the Y-382 is to provide support to divers. The diving support consists of

acclimatization measures using Diver Decompression Chambers (DDCs) and lowering of divers

into the sea using moon-pool. The vessel is capable of supporting depths of a maximum of

300m. To acclimatize the divers to the high pressures there, DDCs simulate that environment

(30 bars). A maximum of 6 men could be lowered into the sea at a time.

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Main DG Piping

Exhaust

All engine systems require an exhaust to release waste gases generated while burning of fuel.

Exhaust piping/vents ensure the transport of gases from the engines to treatment plants and

finally, into the atmosphere.

Starting Air

To start the engine, compressed air pipes are connected to the engine. The pneumatic system

that is formed “kick-starts” the engine.

FO

All engines require fuel oil (FO) to function. According to the type of engine, Heavy Fuel Oil

(HFO) or Medium Diesel Oil (MDO) is supplied to the engine. HFO requires a heating system

(steam) to be present in its storage tank as it needs to be maintained at a certain temperature.

FO systems usually consist of a storage tank, daily service tank and a settling tank (where it is

purified before daily use). Turbochargers recirculate unburnt gases back into the system

increasing the efficiency of the fuel.

LO

Lube oil is supplied continuously into the engine for the smooth movement of all machinery

parts.

Cooling

Engine cooling is carried out using pipes carrying fresh water. The fresh water thus, needs to be

supplied continuously. The hot fresh water that comes out of the engine is cooled using sea

water from the sea chest.

Emergency DG Piping An emergency Diesel Generator set is always present in any ship. This system consists of enough

power generating capacity to run the ship temporarily with least functional capabilities. It has its

own separate piping.

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Conclusion & Acknowledgements

Industrial Training at ABG Shipyard has been a great learning experience for me. The

theoretical knowledge I gained during my 3 years of study at IIT Kharagpur has been

complemented effectively due to the guidance and support provided by ABG employees. The

factors that need to be taken into consideration while designing a ship cannot be fully covered

theoretically. This practical knowledge can only be gained by handling those cases yourself or by

witnessing the process under guidance.

The shipbuilding process at ABG is a holistic one. ABG has been catering to Indian and

international clients with ease. The reason for the title of largest private shipbuilding company

in India was plainly visible. The minor hiccups that occur in the shipyard can improve with

emphasis on communication between departments.

I would like to acknowledge Mr. Panicker (HR) for allowing me to complete my training at ABG

under knowledgeable training guides who were happy to pass on their wisdom gained over

experience. Also, I’d like to acknowledge my guides for allowing me to experience work hands-

on towards the end of training in their respective departments. The process of teaching and

giving practical experience soon after, was an effective one.

I would also like to my college and department for making such training compulsory for

students and for providing me an opportunity to visit ABG Shipyard.

In conclusion, the training at ABG Shipyard has helped me gain practical skills like reading &

interpreting production drawings, ability to solve practical everyday problems that may occur

during construction and self-dependence. It has taught me how to interact professionally with

my peers. I’m highly indebted to ABG and hope for an opportunity to serve it better in future.

Ambattuparambil Gopi Nikhil