Section 6 Magazine design and construction requirements

6.1.1 The design, construction and maintenance of magazines are to be in accordance with the specified magazine safety standard, see Vol 1, Pt 1, Ch 2, 1.1 Framework of Classification 1.1.15. All Regulations, recommendations and requirements are to be confirmed to have been applied.

6.1.2 Where standards have not been specified the following requirements apply. A Risk Assessment, in accordance with Vol 2, Pt 1, Ch 3, 18 Risk Assessment (RA), may be used to justify alternative arrangements. This is to be approved by the Owner and Naval Administration. All recommendations and requirements are to be demonstrated to have been applied.

6.1.3 A statement of magazine requirements is to be defined and is to include:

1. Armaments requirement; listing the expected munitions and materiel to be carried in magazines. Identifying the items which can or are to be co-located and those which must be stored separately or separated. Any special requirements for the storage of particular items are also to be listed including:

   1. environmental conditions; and

   2. conductive deck coating requirements.

2. Construction materials requirement; describing the permissible materials or required alternatives for magazine structures and munition stowages.

3. Magazine Labelling requirement; describing the required labels and their locations.

4. Fluid Systems requirement; describing the operating fluids and operating pressures of all fluid systems within the magazine boundaries.

5. Munition handling requirement; describing the equipment and space requirements to enable the munitions to be safely handled, maintained and stowed.

6.1.4 Munition securing and handling equipment is to be in accordance with requirements of the Armaments Requirement or, with special consideration, LR's LAME Code. Explosive stores are to be classified and stowed in accordance with the armament requirement, see Vol 1, Pt 4, Ch 1, 6.1 General 6.1.3.

6.1.5 Ready use magazines are not to be used for the permanent stowage of munitions. They are to comply with the requirements of this Section for the appropriate magazine type.

6.2.1 Munitions are a complete device (e.g. missile, shell, mine, demolitions store, etc. charged with explosives, propellant, pyrotechnics, or initiating composition), for use in conjunction with offensive, defensive, training, or non-operational purposes, including those parts of the weapon systems containing explosives.

6.2.2 Explosives are all weapons, missiles or stores containing substances especially designed to produce an explosive, propulsive, incendiary or pyrotechnic effect for use in conjunction with offensive, defensive, training, or non-operational purposes.

6.2.3 Integral magazines are those which are bounded by the elements of the main hull structure. They are specifically designed and constructed for the safe permanent stowage of the main outfit of designated munitions defined in the armaments requirement, see Vol 1, Pt 4, Ch 1, 6.1 General 6.1.3.

6.2.4 Independent magazines are those that are non integral, portable magazines greater than 3 m³ and the requirements for integral magazines are to be applied where applicable.

6.2.5 Small magazines are compartments opening off the upper deck which are of shape and size which does not permit walk-in and where the contents are handled from outside. Small magazines are to be specifically designed and constructed for the safe permanent or ready use stowage of munitions defined in the armaments requirement, see Vol 1, Pt 4, Ch 1, 6.1 General 6.1.3.

6.2.6 Magazine lockers are magazines less than or equal to 3 m³, designed and constructed for the safe stowage of explosive stores for which in built magazine facilities have not been provided. They are to be free standing and surrounded by an air gap such that they do not have an adjacent compartment.

6.2.7 Magazine boxes are non-integral, portable magazines with a capacity less than or equal to 3 m³ and capable of being jettisoned overboard.

6.2.8 Pyrotechnics lockers are to comply with the requirements for small magazines, magazine lockers or boxes as appropriate.

6.2.9 Class A fire divisions are those divisions formed by bulkheads and decks which comply with the requirements of IMO resolution MSC 61 (67) Fire test procedures code, Annex 1,Part 3 - Test for “A”, “B” and “F” Class Divisions.

6.3.1 Integral magazines and small magazines containing munitions or propellant are not to be sited adjacent to high fire risk and other compartments of high fire risk listed below:

1. Machinery spaces of category A.

2. Galleys.

3. Switch boards or electrical control rooms.

4. Tanks containing liquids with a flashpoint lower than 60^oC or with a temperature above 32^oC.

5. Compartments containing liquid oxygen.

6. Fuel, petrol, oil or lubricant pump spaces.

7. Accommodation spaces.

8. Control Spaces.

6.3.2 Access is not permitted from any of the spaces defined in Vol 1, Pt 4, Ch 1, 6.3 Arrangement of magazines 6.3.1, to the magazine.

6.3.3 For ships where the above arrangement is completely impracticable the magazine is to be separated from the high risk space by a minimum 600 mm wide cofferdam and constructed of steel or an A-30 fire division. Cofferdams are to comply with the requirements of Vol 1, Pt 3, Ch 2, 4.9 Separation and protection of tanks, are to be ventilated and are not to be designed or used for stowage purposes.

6.3.4 No gasoline or pressurised bottle stowage is to be within a 6 m radius of any magazine or locker.

6.3.5 Integral magazines and small magazines containing munitions may be sited adjacent to the following compartments of moderate fire risk provided that they are separated by an A-30 fire division:

1. Auxiliary machinery spaces including pump rooms air condition plant spaces, refrigeration compartment spaces and hydraulic compartments not containing flammable hydraulic fluids.

2. Service spaces, including laundries and workshops.

3. Uptakes and downtakes.

4. Hangars, docks and vehicle decks.

5. Paint, flammable, battery and acid stores.

6. Tanks or compartments containing independent tanks, of liquids other than sea or fresh water.

6.3.6 Magazine lockers are to be sited in a safe location on a weather deck, surrounded by an air gap of at least 300 mm on all sides and where applicable protected from direct sunlight by fitting solar cladding over top and sides with an air gap of at least 25 mm.

6.3.7 Within magazines arrangements are to be such to ensure that all munitions, including those in transit packaging, are safely stowed and suitably restrained in their stowage for predicted motions and environmental conditions as identified in the armaments requirement. Separate stowage is to be provided for each type of explosive except where specified by the armaments requirement, see Vol 1, Pt 4, Ch 1, 6.1 General 6.1.3.

6.3.8 Magazines are to provide suitable electromagnetic screening and earthing arrangements for munitions as identified in the armaments requirement, see Vol 1, Pt 4, Ch 1, 6.1 General 6.1.3.

6.3.9 Magazine boxes are to be sited on a weather deck with an air gap of at least 300 mm between the box and the deck or surrounding deck houses. They are to be located in a position suitable for jettisoning of the contents and capable of remote release.

6.3.10 Detonators are to be stowed separately from other explosives in dedicated lockers or storerooms; such spaces are to be treated as designated danger areas. Co-location may be allowed as identified in the armaments requirement, see Vol 1, Pt 4, Ch 1, 6.1 General 6.1.3.

6.4.1 Integral magazines are to be of permanent watertight or gastight construction (see Vol 1, Pt 3, Ch 2, 1.3 Watertight and weathertight integrity and Vol 1, Pt 3, Ch 2, 7.7 Unusual designs) and formed by permanent A-15 class divisions. A-0 class divisions may be allowed if spaces adjacent to the magazine do not contain flammable products.

6.4.2 Independent magazines are to be of weathertight metal construction, see Vol 1, Pt 3, Ch 2, 1.3 Watertight and weathertight integrity. The interior is to be insulated with a non-combustible insulation providing an A-15 standard.

6.4.3 Magazine lockers and magazine boxes are to be constructed of steel. Other material may be accepted as identified in the construction materials requirement, see Vol 1, Pt 4, Ch 1, 6.1 General 6.1.3.

6.4.4 The scantlings of integral magazine boundaries are to be determined from Table 3.3.15 Magazine bulkhead and deck scantlings in Pt 6, Ch 3 for NS1 ships and the general plating and stiffening equations in Vol 1, Pt 5, Ch 3, 5.8 Design pressures for watertight and deep tank bulkheads and boundaries for other ships. The design pressure, P _mag, is to be derived as shown in Vol 1, Pt 5, Ch 3, 5.11 Design pressure for magazine decks and bulkheads.

6.4.5 If venting from the magazine space is via a vent trunk, the required scantlings for the vent trunk structure are to be calculated as for magazine boundary requirements.

6.4.6 Vent plate structure and fittings are to be designed to meet the appropriate deck or bulkhead pressure requirements according to location.

6.5.1 The temperature of the magazine is to be maintained at the environmental conditions required by the armaments requirement, see Vol 1, Pt 4, Ch 1, 6.1 General 6.1.3. Generally munitions are to be stored at temperatures greater than 7^oC and less than 35^oC with a relative humidity between 30 and 70 per cent. Munitions with propellant are to be maintained below 32^oC.

6.5.2 The air conditioning may be recirculatory if confined to the ventilation of magazines only. If the magazine is to be ventilated with other compartments then the magazine is to vent to atmosphere. High fire risk and high value compartments should not share ventilation with magazines.

6.5.3 Where a magazine or magazine complex may require to be manned, fresh air make up, via the Air Filtration Unit is to be provided.

6.5.4 Emergency life support apparatus is to be sited in magazines where personnel are required to be permanently working.

6.5.5 Ventilation trunking is to be of an equivalent fire integrity standard as the magazine.

6.5.6 Air conditioning and ventilation systems are to be designed to maintain watertight integrity and flash.

6.6.1 Clear labelling of all magazine openings and equipment is to be maintained in accordance with the magazine labelling requirement, see Vol 1, Pt 4, Ch 1, 6.1 General 6.1.3 The following requirements are to be applied as a minimum:

1. Integral, small and independent magazines:

   1. the space is a magazine.

   2. open lights and flame are to be kept away.

   3. the magazine door is to be kept shut.

   4. sources of ignition such as matches,lighters and pocket torches are to be removed prior to entry.

   5. not to lift with contents (in the case of independent magazines).

   6. magazine otherside markings in adjacent compartments.

2. Magazine lockers and boxes:

   1. the container is a magazine locker or box.

   2. open lights and flame are to be kept away.

   3. the box is to be kept shut.

   4. not to lift with contents.

6.6.2 Magazines are to be insulated with non-combustible material as necessary to prevent the condensation of moisture.

6.7.1 Openings in the magazine and lockers such as doors, hatches and escape scuttles are to be of equivalent strength and fire integrity as the surrounding structure.

6.7.2 Accesses to magazines are to be fitted with suitable security arrangements to prevent unauthorised access. Openings are to be capable of being secured from the inside and fitted with external locks. Emergency escapes are to be opened from the inside only.

6.7.3 Locking arrangements on all magazines and lockers are to be designed to prevent the possibility of entry by removing the hinge pins.

6.8.1 In order to eliminate potential sources of ignition in a magazine in which flammable mixtures are liable to collect, hazardous areas for magazines are to be identified and electrical equipment within the magazine is to be selected and installed in accordance with the requirements of Vol 2, Pt 9, Ch 5, 4 Electrical equipment for use in explosive gas atmospheres or in the presence of combustible dusts.

6.8.2 Lighting is to be operated from outside the space. Indication is to be provided at the switch location when circuits are energised.

6.8.3 All apparatus fitted in magazines is to be capable of being isolated on all poles from any source of electrical energy. The preferred method of isolation is by means of a multipole switch. Services that operate on low power at low voltage and are required to operate continuously do not require local isolation. Fire and flood detection and internal communications systems are included amongst such services.

6.8.4 Only services which are required for equipment in the magazine are to penetrate boundaries of the magazine.

6.8.5 Air and hydraulic systems used within magazines are to be low pressure systems only. Non-flammable hydraulic fluid is to be used.

6.8.6 Electrically controlled handling machinery may be fitted in magazines provided that continuous earth monitoring is provided in the control circuits of the machinery.

6.8.7 Equipment and light fixtures installed in magazines which may be subjected to mechanical damage are to be equipped with suitable protection against such damage. All protective metal guards for apparatus and cabling as well as the apparatus itself must be effectively earthed. Where required, conduit is to be electrically continuous and bonded to earth to form an effective shield.

6.9.1 Integral and small magazines are to be fitted with a spray system capable of rapid reaction, with manual activation and a suitable permanent drainage system.

6.9.2 The spray system is to be capable of delivering 30 litres/m²/min. Large compartments may be fitted with independent spray systems covering separate areas.

6.9.3 Spray heads are to be arranged within magazines so that all stowages and boundaries are covered when sprayed.

6.9.4 Spray systems for integral magazines are to be fed from two separate sections of the ship's water supply.

6.9.5 Magazine lockers and boxes are to be fitted with flood and drainage systems. The flood system is to be operated by a manual control adjacent to the locker but at least 5 m away or 3 m if suitably screened and fed from a pressurised water supply.

6.9.6 Compartments other than tanks or void spaces adjacent to magazines are to be fitted with smoke or fire detectors.

6.9.7 Locking arrangements are to be fitted to all spray, flooding, drain valves and cocks with the exception of spray control valves when housed in a lockable cabinet.

6.9.8 Magazines are to be provided with fire extinguishers commensurate with risk classification, size and type of vessel. Generally one extinguisher should be fitted on the inside and one on the out side of the magazine.

6.9.9 Designated danger areas (DDA) where munitions are handled such as weapon lifts, transfer passages, weapon preparation areas, hangars, flight decks, docks and RAS points are to be fitted with similar fire protection systems to the magazine, commensurate with the risk classification and type of vessel. LR may allow system requirements to be reduced to the provision of sufficient hose points based on the risk classification.

6.9.10 Magazines are to be coated with fire resistant paint and the deck covering is to be non spark and non slip. Any requirements for a conductive deck area and personnel will be identified in the armaments requirement, see Vol 1, Pt 4, Ch 1, 6.1 General 6.1.3. Where there is a conducting deck requirement an anti static precaution notice is to be displayed.

6.10.1 Magazines are to be tested in accordance with the gas tight requirements of Vol 1, Pt 6, Ch 6, 7.6 Gastight testing.