ISO 5778 pdf download.Ships and marine technology — Small weathertight steel hatches
1 Scope
This International Standard specifies the main dimensions, location and number of fittings, materials and quality of manufacture for small weathertight steel hatches for application on board ships in order to ensure interchangeability of the hatches. The remaining dimensions are left to the manufacturer. The hatches are suitable for loading operations and for giving access to storage compartments and dry cargo holds. The hatches are not suitable as an access to any kind of tanks and shall not be used as escape hatches. These hatches generally conform to the requirements of the International Convention on Load Lines 1966 (LLC66). The possibility for application in position 1 and position 2 has to be considered for each situation and, where necessary, the hatch covers shall be provided with additional stiffening. NOTE — Users of this International Standard should note that while observing the requirements of this standard, they should, at the same time, ensure compliance with such statutory requirements, rules and regulations as may be applicable to the individual ship concerned.
2 Normative reference
The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 262:— 1) , ISO general-purpose metric screw threads – Selected sizes for screws, bolts and nuts.
3.2 Upper part of coaming The upper part of the coaming shall conform to the details of figure 2 and table 2. The coaming may have square or rounded corners as shown in figure 2. In order to prevent damage of the hatch seal, the edges of the upper part of the coaming should be rounded or chamfered.
4 Materials
The coamings and covers shall be manufactured from weldable steel of 340 N/mm² minimum tensile strength or equivalent shipbuilding-quality steel. The hatch-seal retaining bars, wing nuts, hinges, lugs and ancillary fittings shall be manufactured from weldable mild steel of 340 N/mm² minimum tensile strength. The toggle bolts and their pins shall be manufactured from corrosion-resistant materials of 350 N/mm² minimum tensile strength. The quality of the resilient seal material forming the hatch seal shall be satisfactory for service under marine conditions and shall provide effective and lasting sealing and resealing properties when the hatch is tightened under normal conditions.
5 Quality of manufacture
Coamings and covers shall be free from distortion. Coamings, covers and fittings shall be free from any exposed rough edges likely to cause injury to persons. For coamings see also 3.2. The coamings and covers shall be suitably treated by blast cleaning or another process to remove scale and surface deposits and shall be given a priming coat of paint to inhibit subsequent corrosion. Upon assembly of the completed coaming and cover, the manufacturer shall ensure that there is correct registry of the edge of the coaming with the hatch seal material and continuous contact between the two components when the hatch is closed.
6 Testing of weathertightness
The completed hatch, when installed on board ship, shall be closed and secured in a normal manner, and then subjected to a test (hose test or equivalent test) carried out to the satisfaction of the representative of the regulatory body concerned.