Shipyard Visit

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INDUSTRIAL VISIT REPORT TEBMA SHIPYARDS LTD PLATE STORAGE STEEL GRADE: Each steel grade has a number of explicit attributes associated with the particular standard that it complies with, whereas a general term can cover more than one grade or standard. When steel is purchased to meet a particular standard, the purchaser is assured that it will meet certain chemistry and/or mechanical property requirements. HEAT NUMBER : An example of a heat number on a plate. A heat number is an identification number that is stamped on a material plate after it is removed from the ladle and rolled at steel mill. Industry quality standards require materials to be tested at the manufacturer and the results of these tests be submitted through a report, also called a Mill Sheet or Mill Certificate. The only way to trace a steel plate back to its Mill Sheet is the Heat Number. A heat number is similar to a lot number , which is

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Transcript of Shipyard Visit

INDUSTRIAL VISIT REPORT

TEBMA SHIPYARDS LTD

PLATE STORAGE STEEL GRADE: Each steel grade has a number of explicit attributes associated with the particular standard that it complies with, whereas a general term can cover more than one grade or standard. When steel is purchased to meet a particular standard, the purchaser is assured that it will meet certain chemistry and/or mechanical property requirements. HEAT NUMBER:

An example of a heat number on a plate.

A heat number is an identification number that is stamped on a material plate after it is removed from the ladle and rolled at steel mill. Industry quality standards require materials to be tested at the manufacturer and the results of these tests be submitted through a report, also called a Mill Sheet or Mill Certificate. The only way to trace a steel plate back to its Mill Sheet is the Heat Number. A heat number is similar to a lot number , which is used to identify production runs of any other product for quality control purposes.NESTING PLAN: an optimized steel plate cutting plan saves shipyard cost on raw

material. An optimized steel plate cutting plan helps shipyard both time and material savings, increase production efficiency, in return enhance the companys competition capability. HIGH TENSILE STEEL

INDUSTRIAL VISIT REPORT

High tensile steel may have ten times the tensile strength of wood, and more than twice that of mild steel, but it would be a mistake to overestimate the importance of this single quantity, as Fuller seems to do The toughness of metals is generally reduced by the process of increasing their tensile strengths, but the failure of a structure may be due largely to the stiffness, rather than the strength of the materials used. The larger the structure of buildings and ships, and so on, the lower the acceptable stress, for safety reasons. It follows that high strength metals are more safely used in small structures. This should perhaps be borne in mind when contemplating mega structures. FABRICATION: CONVEYER: A conveyor belt (or belt conveyor) consists of two or more pulleys, with a continuous loop of material - the conveyor belt - that rotates about them. One or both of the pulleys are powered, moving the belt and the material on the belt forward. The powered pulley is called the drive pulley while the unpowered pulley is called the idler CNC CUTTING: The CNC Plasma Profile/Plate Cutting will complement the Ship-Block construction line of activity as a process of backward-integration and as a diversified business. Plasma works by sending a pressurized gas, such as nitrogen, argon, or oxygen, through a small channel. In the center of this channel, you'll find a negatively charged electrode. When you apply power to the negative electrode, and you touch the tip of the nozzle to the metal, the connection creates a circuit. A powerful spark is generated between the electrode and the metal. As the inert gas passes through the channel, the spark heats the gas until it reaches the fourth state of matter - plasma. This reaction creates a stream of directed plasma, approximately 30,000O F (16,649 C) and moving at 20,000 feet per second (6,096 m/sec) that reduces metal to molten slag. Plasma cutting is not as accurate as laser cutting but the advantage of the plasma cutting process is much faster cutting rates.

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GAS BANK: Gas bank supplies the fuel and inert gasses to the cnc cutting machine. Through pipe lines . which is operated by means of control panel DEBONING AREA The cut plates are moved to the deboning area for stacking by means of magnetic lift cranes SHIP BUILDING PRESS A 375 tones ship building press is used for bending operations. Since rolling machines are not available in this yard , rolling activities are also done in this press LINES HEATING: The forming process consists of heating at a (steel) plate in a predetermined pattern of lines by means of a gas torch so that the plate assumes a Certain, curved shape. Thus, the method is an alternative or supplement to other forming methods such as pressing and rolling. Today, few skilful shipwrights are capable of performing the art of line heating, as the amount of heating and the position of the lines are entirely based on experience

TEBMA (Erection yard)SPACE UTILISATION The most important aspect in shipyard management is space management. In the available space we need to find the maximum available utilization. The concept of block erection must be fully utilized for this purpose. As the blocks are manufactured in another area the space on the yard is actually only utilized to erect the ships.

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ERECTION JOINT The erection joint is the most important of all joints in a ship. As soon as the blocks are in place a piece of metal similar to a cover plate is affixed onto the two blocks to hold them in place. Then the blocks are welded together, usually in one stretch. Ceramic strips may be used to cover one side of the weld. The welding is done on the interior of the hull. DOCK BLOCK WEDGE The dock block wedge is the special wedge that forms the extreme end of the dock block. These are usually of timber. These are wedge shaped so that they can easily be knocked off and removed. Another point to be noted is the difference between sand and pebble in the load carrying capacity. Sand transfers the load transversely and pebbles shift the load longitudinally. As a result pebbles provide good support but hard launching and sand vice versa. GRID BLASTING This involves using a blast of fine particles at high pressure which in turn removes the rust and finishes off the surface. Steel grids are used to blast. The air is sucked in filtered and compressed. This compressed air is used to blast the surface. After blasting the debris are collected to reuse. Here S70 and S30 size grains are used to blast the surface at 10bar pressure. The surface preparation requirement isSA2.5 TRANSPORTER A schewerle SPMT( self propelled modular transporter ) is used to carry blocks and equipments to the erection yard , which is carried from manufacturing yard by means of a barge. A Power Pack Unit (PPU) supplies the hydrostatically driven SPMT with pressure oil for the drive, steering and lift operations. The electronic steering system is controlled by means of an on-board computer that can be configured to control an individual vehicle or groups of coupled units. A 6 axle transporter is used for the ease of flexibility

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Bharathi shipyardMangalore yard is one of the green field projects of Bharati Shipyard. It has already started its operations to a build shipyard in Thannerbavi village, close to the New Mangalore Port Trust (NMPT) on the banks of Gurupura river. This would be the first shipyard in Dakshina Kannada of Karnataka state to start building ships. The yard is located at Kudroli West, about 7.5 kilometers south of New Mangalore Port. The onshore shipyard facilities will be developed in an existing 28.3 acres of land belonging to the Mangalore Port in CRZ area wherein the most modern infrastructural facilities for ship building are being created. The layout has been effectively designed by Korean Experts & the yard has commenced production with a Platform Supply vessel of 2900 DWT for MAN Ferrostal AG Germany & in future it has been aimed at building of vessels up to 1,00,000 DWT within a span of 10 years.

FABRICATION: fabrication of blocks of maximum 10m length are made above skids. Skids are metal frame systems, acts as a platform for construction of blocks

ErectionShip hull blocks brought in the dry dock for the erection are a kind of completed structures, most of outfits, paintings and accuracy controls been progressed. But, in the dry dock, welding and other mechanical loads for the erection itself causes additional excessive deformations at each plate panels, which needs a lot of time and costs to correct them. Also it can make the ship owners discontented with the quality of entire ship. This is a primary factor to lower the productivity of dry dock and quality of ship hull blocks. So erection is to be given utmost care. In this

shipyard the erection process was upside down to facilitate easy joining and to reduce the loads during erection

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CNC CUTTER: Plasma cutting is a process that is used to cut steel and other metals ofdifferent thicknesses (or sometimes other materials) using a plasma torch. In this process, an inert gas (in some units, compressed air) is blown at high speed out of a nozzle; at the same time an electrical arc is formed through that gas from the nozzle to the surface being cut, turning some of that gas to plasma. The plasma is sufficiently hot to melt the metal being cut and moves sufficiently fast to blow molten metal away from the cut. Some plasma cutter manufacturers build CNC cutting tables, and some have the cutter built in to the table. CNC tables allow a computer to control the torch head producing clean sharp cuts. Modern CNC plasma equipment is capable of multiaxis cutting of thick material, allowing opportunities for complex welding seams that are not possible otherwise

PIPING SECTION The flange to flange distance of a piping system are called spool . the pipes are manufactured with reference to the spool drawing. The material selection is depending on the service class. After the manufacturing the pipes are pickled .

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PICKLING: Many hot working processes and other processes that occur at high temperatures leave a discoloring oxide layer or scale on the surface. In order to remove the scale the pipe is dipped into a vat of pickle liquor. Pickling process time in various chemicals is Alkaline-1 min Water 10 min Acid-1 min Water(ph is maintained