Foreword At its forty-eighth session (June 1983), the Maritime Safety Committee (MSC) of the lnternational Maritime Organization (IMO) adopted far-reaching amendments to the lnternational Convention for the Safety of Life at Sea (SOLAS), 1974, by resolution MSC.6(48). The amendments consisted of complete replacement texts of chapters Ill and VII and changes in chapters 11-1, 11-2 and IV. The new chapter VII made the provisions of the lnternational Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code), which had been adopted by resolution MSC.5(48), mandatory under the 1974 SOLAS Convention. The new 1993 edition of the IGC Code incorporates amendments adopted by the MSC at its sixty-first session (December 1992) by resolution MSC.30(61). These amendments will enter into force on 1 July 1994 once the procedures for acceptance have been fulfilled. Contents Page Preamble ................................................... 1 Chapter 1 . General 1.1 Application ............................................. 3 1.2 Hazards ................................................ 4 1.3 Definitions ............................................. 4 1.4 Equivalents ............................................. 9 1.5 Surveys and certification ................................ 10 Chapter 2 . Ship survival capability and location of cargo tanks 2.1 General ............................................... 14 2.2 Freeboard and intact stability ............................ 15 2.3 Shipside discharges below the freeboard deck ............ 16 2.4 Conditions of loading ................................... 16 2.5 Damage assumptions ................................... 16 2.6 Location of cargo tanks ................................. 17 2.7 Flooding assumptions ................................... 19 2.8 Standard of damage .................................... 20 2.9 Survival requirements ................................... 21 Chapter 3 . Ship arrangements 3.1 Segregation of the cargo area ............................ 23 3.2 Accommodation, service and machinery spaces and control stations ..................................... 24 3.3 Cargo pump-rooms and cargo compressor rooms ......... 25 3.4 Cargo control rooms .................................... 26 3.5 Access to spaces in the cargo area ....................... 26 3.6 Airlocks ................................................ 27 3.7 Bilge, ballast and fuel oil arrangements ................... 28 3.8 Bow or stern loading and unloading arrangements ........ 29 Page Chapter 4 . Cargo containment 4.1 General ............................................... 4.2 Definitions ............................................ .......................................... 4.3 Design loads ..................................... 4.4 Structural analyses ............. 4.5 Allowable stresses and corrosion allowances 4.6 Supports .............................................. ...................................... 4.7 Secondary barrier ............................................. 4.8 Insulation 4.9 Materials .............................................. ............................... 4.10 Construction and testing ............ 4.11 Stress relieving for type C independent tanks 4.12 Guidance formulae for acceleration components ......... ....................................... 4.13 Stress categories Chapter 5 . Process pressure vessels and liquid. vapour and pressure piping systems ............................................... 5.1 General .............................. 5.2 Cargo and process piping ....................... 5.3 Type tests on piping components .................... 5.4 Piping fabrication and joining details ...................................... 5.5 Testing of piping ..................... 5.6 Cargo system valving requirements ..................................... 5.7 Ship's cargo hoses ................................ 5.8 Cargo transfer methods ............................. 5.9 Vapour return connections Chapter 6 . Materials of construction ............................................... 6.1 General .................................. 6.2 Material requirements .................... 6.3 Welding and non-destructive testing Page Chapter 7 . Cargo pressurelTemperature control 7.1 General ............................................... 91 7.2 Refrigeration systems .................................. 92 Chapter 8 . Cargo tank vent systems 8.1 General ............................................... 94 8.2 Pressure relief systems ................................. 94 8.3 Additional pressure relieving system for liquid level control ........................................... 96 8.4 Vacuum protection systems ............................ 98 8.5 Size of valves .......................................... 99 Chapter 9 . Environmental control 9.1 Environmental control within cargo tanks .............................. and cargo piping systems 102 9.2 Environmental control within the hold spaces (cargo containment systems other than type C .................................... independent tanks) 102 9.3 Environmental control of spaces surrounding .............................. type C independent tanks 103 ............................................... 9.4 lnerting 103 .......................... 9.5 Inert gas production on board 104 Chapter 10 . Electrical installations ............................................... 10.1 General 105 ................................... 10.2 Types of equipment 105 Chapter 11 . Fire protection and fire extinction ................................ 11.1 Fire safety requirements 108 ............................. 11.2 Fire water main equipment 108 .................................... 11.3 Water-spray system 109 ......... 11.4 Dry chemical powder fire-extinguishing systems 110 .................... 11.5 Cargo compressor and pump-rooms 112 ....................................... 11.6 Firemen's outfits 112 vii Page Chapter 12 . Mechanical ventilation in the cargo area 12.1 Spaces required to be entered during ...................... normal cargo handling operations 114 ........................... 12.2 Spaces not normally entered 115 Chapter 13 . Instrumentation (gauging. gas detection) ............................................... 13.1 General 116 ......................... 13.2 Level indicators for cargo tanks 116 ...................................... 13.3 Overflow control 117 13.4 Pressure gauges ....................................... 118 13.5 Temperatureindicatingdevices ......................... 118 ............................ 13.6 Gas detection requirements 119 Chapter 14 . Personnel protection .................................. 14.1 Protective equipment 122 ...................................... 14.2 Safety equipment 122 .................................... 14.3 First-aid equipment 123 14.4 Personnel protection requirements ................................. for individual products 123 Chapter 15 . Filling limits for cargo tanks ............................................... 15.1 General 125 ............... 15.2 Information to be provided to the master 126 Chapter 16 . Use of cargo as fuel 16.1 General ............................................... 127 ......... 16.2 Arrangement of machinery spaces of category A 127 ........................................ 16.3 Gas fuel supply 127 ............ 16.4 Gas make-up plant and related storage tanks 129 ................... 16.5 Special requirements for main boilers 130 16.6 Special requirements for gas-fired internal .............. combustion engines and gas-fired turbines 131 viii Page Chapter 17 . Special requirements 17.1 General .............................................. 132 .............................. 17.2 Materials of construction 132 .................................... 17.3 Independent tanks 132 ................................. 17.4 Refrigeration systems 132 .................................... 17.5 Deck cargo piping 133 .................... 17.6 Exclusion of air from vapour spaces 133 ...................................... 17.7 Moisture control 133 17.8 Inhibition ............................................ 134 ............... 17.9 Permanently installed toxic gas detectors 134 ......................... 17.10 Flame screens on vent outlets 134 17.11 Maximum allowable quantity of cargo per tank ......... 134 ...................... 17.12 Submerged electric cargo pumps 134 ............................................ 17.13 Ammonia 135 ............................................. 17.14 Chlorine 136 ..................... 17.15 Diethyl ether and vinyl ethyl ether 138 ........................................ 17.16 Ethylene oxide 139 .................. 17.17 lsopropylamine and monoethylamine 140 17.18 Methyl acetylene-propadiene mixtures ................. 140 17.19 Nitrogen ............................................. 141 17.20 Propylene oxide and mixtures of ethylene oxide- propylene oxide with ethylene oxide content of ......................... not more than 30% by weight 141 ........................................ 17.21 Vinyl chloride 145 Chapter 18 . Operating requirements .................................... 18.1 Cargo information 146 18.2 Compatibility ......................................... 146 .................................... 18.3 Personnel training 147 ..................................... 18.4 Entry into spaces 147 .................. 18.5 Carriage of cargo at low temperature 148