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
Types A and B Type C z1 z2
150 220 230 71.5 81.5 200 100 16 10 16 8 5
200 288 300 93.5 102.5 20 12 20 10 6
250 357 370 113.5 119.5 22 12.5 22 11
300 417 430 128.5 130.5 225 125 24 13 24 12 6.5
350 472 490 145.5 152.5 26 17 26 15 8.5
400 540 560 154.5 164.5 250 150 28 18 28 17 9
450 600 620 167.5 179.5 30 20 30 20 10
500 655 680 178.5 195.5 32 22 34 23 11
Nominal size Dn SWLc Calculated weight (for reference only)d
kg
θb = 90° θ = 0°
kN t kN t H = 500 H = 1000 H = 1500
150 265 27 186 19 55 115 198
200 441 45 314 32 86 169 278
250 579 59 412 42 113 210 335
300 726 74 510 52 145 256 395
350 1040 106 736 75 201 358 552
400 1246 127 883 90 255 436 657
450 1599 163 1128 115 314 530 791
500 1942 198 1373 140 383 636 938
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
