Naval Architecture I (NAI) - CM - I

• Ship Construction I

• Control Trim, Stability and Stress - Ship Construction

• Welding

• Gas or Oxy fuel welding

• Manual Electric arc welding

• Automatic welding process

• Electro -Slag

• Electro-Gas

• TIG

• MIG

• SAW

• Resistance Welding

• Butte Lap and Fillet Welds

• Preparation of plate edge for welding

• Use of tack welding

• Weld faults - lack of fusion, penetration, reinforcement, root penetration, slag incursion, porosity, overlap, undercut

• Various Test for welds

• Purpose of flux

• Single pass, multi pass and Back run

• Full penetration fillet weld

• Distortion due to welding and measures to minimise them

• Classification societies requires tests on weld materials and electrodes before approval

• Framing system

• Transverse framing system

• Longitudinal framing system

• Bulkheads

• Regulations of Classification Societies regarding Bulkheads

• Regulations of SOLAS Convention, 2020 regarding Bulkhead

• Watertight Bulkhead

• Watertight Bulkheads

• Weather tight bulkheads

• Oil tight Bulkhead

• Corrugated Bulkhead

• Openings in watertight Bulkheads

• Purpose of wash bulkheads

• Use of cross ties in tankers

• Procedure for testing of bulkheads

• Cofferdam

• Racking stresses and transverse bulkheads

• Watertight and weather-tight doors

• Watertight Doors

• Watertight door

• WT doors, mechanisms, indicators and all associated valves must be inspected once in a week

• All WT doors in main transverse bulkhead must be operated daily

• Drills for operating WT doors, side scuttles, valves and closing mechanism must be held weekly

• Records of drills and inspections to be entered in log book with regard to defects

• Categories of Watertight Doors

• Rules regarding the number of openings on passenger ships and watertight doors

• Difference between water tight and weather tight doors

• Arrangement of Power operated sliding WT door

• Hinged WT door and means of securing

• Ramp door of Ro-Ro ships

• Ship side doors

• Corrosion and Its Prevention

• Corrosion, Erosion and the Corrosion Triangle

• Formation of corrosion cell

• Galvanic series of metals

• Stress concentrations leading to corrosion cell formation

• Difference in surface conditions leading to formation of corrosion cells

• Cathodic protection using sacrificial anodes

• Impressed current system

• Measures to minimise corrosion

• Treatment of steel in shipyard

• Structure of paint and purpose of each constituent

• Purpose of Material Safety Data Sheet (MSDS)

• Common paint vehicles - Drying oils, oleo resins, alkyd resins, polymerizing chemicals, Bitumen and suitability of each for various applications.

• Paint schemes for Underwater areas, boot topping, top sides, weather decks, super structures and tank interiors

• Surface preparation for painting

• Safety Precautions when Using Paints

• How Anti-fouling paint acts

• AFS Convention

• How Anti-corrosive paint acts

• Wetted surface area text S = 2.58 times sqrt{triangle times text{length of ships}}

• Surveys, Certification and Dry Docking

• Statutory and Mandatory Surveys and Certificates

• Initial, Intermediate, Annual and Renewal Survey

• Periodic Survey

• Harmonised System of ship survey

• Enhanced Survey

• Conditions Assessment Scheme (CAS)

• Conditions Assessment Programme (CAP)

• Ship Stability - I

• Control trim, stability and stress - Ship Stability

• Approximate calculations of Area and volume

• Simpson Rules 1,2 and 3

• Calculation of area and volume using Simpson's rule

• Calculation of Geometric centres of area and volume

• Calculation of TPC, FWA using Simpson rules

• Effect of density TPC, FWA DWA calculations

• Effect of change of density of water on TPC

• Calculation of draft of vessel fore and aft due to change in density

• Calculation of Free surface effect

• I=LB³/12 for Rectangular Areas

• FSC = I x RD of liquid in the tankW

• FSC = Free Surface Moment in tonnes meters Displacement in tonnes (FSML)

• Moment of Inertia of tank using Simpson's rule

• Simplified stability data

• Maximum Dead Weight moment

• Minimum Permissible GM

• Maximum Permissible KG

• Use of diagrams of Dead Weight moment

• Trim and List

• Trim

• LCG, LCB

• Effect of LoadingDischarging and shift of weight on LCG

• Effect of change in underwater volume on LCB

• Trimming Moment

• Moments required to change trim by 1 cm (MCTC)

• MCTC=(∆×text{GM}_L100×LBP)

• Why BM_L is used instead of GM_L for MCTC

• Effect of change in density on MCTC

• Trim: Trimming momentMCTC

• Change in trim = Change in draft forward + Change in draft aft

• Use of trim table

• Centre of Floatation is centroid of water plane area

• LCF is the tipping centre or the pivoting point about which the vessels change her trim

• Change in draft aft Ta = (Tc * LCF)/LBP

• Change in Draft = [Tc

• Calculation of quantity of cargo to be loadeddischargedshifted to produce a requried trim

• Calculation of Final FWDAFT Drafts

• Calculation of quantity of cargo to be loadeddischarged to keep forwardaft draught constant

• Calculation of quantity of cargo to be loadeddischarged to reach desired forwardaft draft

• List

• Cross curves of stability and KN curves

• How to determine GZfrom crossKN curves

• Effect on GZ values due to shift of weights

• Pure loss of stability

• Effect of increased lengthbreatht freeboard on the curve of stability curves

• Calculation of Angle of list resulting from transverse and vertical movement of weight using GZ curves

• Calculation of Area under GZ curve using Simpson's rule

• Dynamical Stability

• Statical stability requirments as per SOLAS

• Dynamical Stability at stated angle of heel represents potential energy of the ship

• Potential energy is used in overcoming resistance to rolling and in producing rotational energy

• Dynamical stability = W x Area under GZ Curve

• Intact stability requirements for carriage of grain

• Intact stability requirements for the carrige of grains

• Volumetric heeling moments (VHM) caused due to shift of grain in partially filledfull compartments

• Use of Maximum permissible VHM curves

• Calculation of Heeling arm ) and = 0.8 xint_O

• Drawing - Heeling arm curve on Righting arm curve for given ship's condition and determining angle of heel

• Comparison of the results with criteria set in Reg 4 of Grain Code

• Dry-docking and Grounding

• Dry docking of a vessel

• Declivity of docks

• Part of the weight is taken by blocks as soon as the ship touches the blocks and reduces buoyancy force by same amount

• Critical period

• Critical instant and and Why GM must remain positive until the critical instant

• Up thrust P: (MCTC x T_c)Distance from the Center of Flotation and Resultant virtual loss of GM

• Vessel taking the blocks first at any point on the ships length

• Floating Dry Dock

• Minimum ships GM to ensure stability until the ship sits on the blocks overall

• Maximum trim to ensure ship remains stable at the point of ship taking the blocks overall

• Virtual loss of GM and Drafts after water level has dropped by a stated amount

• Draft on Taking the Blocks overall

• Loss in GM for fall in water level after taking the blocks overall

• How the stability of a ship that has grounded at one point on the centerline is reduced the same way as in dry dock

• How up thrust increase with fall in tide, increases the heeling moment and reduces the stability

• Virtual loss in GM and drafts of a ship after tide has fallen by a stated amount

• Point of grounding given initial drafts and drafts after grounding