Ships and Marine Technology — Ship's Mooring and Towing Fittings — Pedestal Fairleads
1 Scope
This standard specifies the design, size and technical requirements for pedestal fairleads.
This standard is applicable to the design, manufacture and acceptance of pedestal fairleads.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 13755 Ships and Marine Technology — Ship's Mooring and Towing Fittings — Steel Rollers
IMO Circular MSC/
Circ.1175 Guidance on Shipboard Towing and Mooring Equipment
3 Terms and Definitions
For the purposes of this document, the following terms and definitions apply.
3.1
safe working load (SWL)
maximum load, in kN, on the rope that should normally be applied in service conditions
4 Nominal Sizes
The nominal sizes, Dn, of pedestal fairleads are denoted by reference to the outside diameter of the roller in millimeters from a basic series of preferred numbers. The nominal sizes are: 150, 200, 250, 300, 350, 400, 450 and 500.
5 Dimensions
Pedestal fairleads have dimensions and particulars in accordance with Table 1, and Figures 1 and 2.
Dimensions in millimeters
Key:
1 — top plate;
2 — body;
3 — reinforcement;
4 — rope guide;
5 — steel roller, see ISO 13755.
a Height is to be determined in accordance with actual mooring rope height through the pedestal fairlead.
b Diameter D3 is to be calculated depending on the height of the pedestal , H [D3 = D2 + 2×(H - t1) × tan10°].
c SWL marking.
d Seam.
Figure 1 Assembly of pedestal fairleads
Dimensions in millimeters
Key:
1 — top plate;
2 — body
3 — reinforcement;
4 — rope guide.
a SWL marking.
Figure 2 Detail of pedestal fairleads
Table 1 Dimensions and SWL of pedestal fairleads
Dimensions in millimeters
Nominal size Dn D1 D2 de h h1 t1 t2 t3 Welding leg lengtha
a When welding with various groove types, it is not necessary to follow the welding leg height in the table, but welding with chamfering is available based on the same welding volume/strength.
b θ is the relative angle of ropes on the pedestal fairlead (refer to Annex A).
c The SWL is the maximum applicable rope tension based 90° ( θ = 90°) and 180° ( θ = 0°) defection of rope direction by the pedestal fairlead. The SWLs shown in this table are for reference only. These are based on the loadings as mentioned in Annex A.
The “SWL” may be adjusted depending on the actual loading conditions, and the actual marking shall be agreed between the user and the manufacturer.
d The calculated weight is for reference excluding the steel roller on the pedestal fairlead.
e d shall be decided depending on the type of steel roller (Type A and B or Type C), as specified in ISO 13755.
6 Materials
The material used for manufacturing the pedestal fairlead shall be weldable steel plates having a yield point of not less than 235 N/mm2
Foreword II 1 Scope 2 Normative References 3 Terms and Definitions 4 Nominal Sizes 5 Dimensions 6 Materials 7 Manufacturing and Inspection 8 Marking Annex A (Informative) Basis for Strength Assessment of Pedestal Fairleads Annex NA (Informative) Marking Bibliography
说明： 1——顶板； 2——本体； 3——加强板； 4——挡缆板； 5——导缆滚轮，见ISO 13755。 a H值由使用者选定，实际情况应参考甲板的坡度。 b 直径D3是根据立式滚轮导缆器的高度H计算得出，[D3＝D2＋2×(H－t1)×tan10°]。 c SWL标志。 d 焊缝。 图1 立式滚轮导缆器 单位为毫米
公称尺寸Dn的数值 NA.2 标记示例 公称尺寸为300的立式导缆滚轮器标记如下： 立式导缆滚轮器 GB/T 37453—2019 300 参考文献 [1] ISO 2408 Steel wire ropes for general purposes—Minimum requirements [2] IACS UR A2，Shipboard fittings and supporting hull structures associated with towing and mooring on conventional vessels [3] OCIMF，Mooring Equipment Guidelines(MEG3)
