Common Structural Rules - Common Structural Rules for Bulk Carriers and Oil Tankers, January 2019 - Part 1 General Hull Requirements - Chapter 1 Rule General Principles - Section 4 Symbols and Definitions - 2 Symbols
2 Symbols
2.1 Ship’s main data
2.1.1 Unless otherwise specified, symbols regarding ship’s main data and their units used in these Rules are those defined in Table 2.
Table 2 : Ship’s main data
| Symbol | Meaning | Units |
| L | Rule length | m |
| LLL | Freeboard length | m |
| LPP | Length between perpendiculars | m |
| L0 | Rule length, L, but not to be taken less than 110 m | m |
| L1 | Rule length, L, but need not be taken greater than 250 m | m |
| L2 | Rule length, L, but need not be taken greater than 300 m | m |
| B | Moulded breadth of ship | m |
| D | Moulded depth of ship | m |
| T | Moulded draught | m |
| TSC | Scantling draught | m |
| TBAL | Ballast draught (minimum midship) | m |
| TBAL-H | Heavy ballast draught | m |
| TBAL-E | Emergency ballast draught or gale ballast draught | m |
| TLC | Midship draught at considered loading condition | m |
| TF-f, TF-e | Minimum draught at forward perpendicular for bottom slamming, with respectively all ballast tanks full or with any tank empty in bottom slamming area | m |
| Δ | Moulded displacement at draught TSC | t |
| CB | Block coefficient at draught TSC | - |
| V | Maximum service speed | knot |
| x, y, z | X,Y, Z coordinates of the calculation point with respect to the reference coordinate system | m |
2.2 Materials
2.2.1 Unless otherwise specified, symbols regarding materials and their units used in these Rules are those defined in Table 3.
Table 3 : Materials
| Symbol | Meaning | Units |
| E | Young’s modulus, see Ch 3, Sec 1, [2] | N/mm2 |
| G |
Shear modulus,
|
N/mm2 |
| ReH | Specified minimum yield stress, see Ch 3, Sec 1, [2] | N/mm2 |
| τeH |
Specified shear yield stress,
|
N/mm2 |
| ν | Poisson’s ratio, see Ch 3, Sec 1, [2] | - |
| k | Material factor, see Ch 3, Sec 1, [2] | - |
| Rm | Specified minimum tensile strength, see Ch 3, Sec 1, [2] | N/mm2 |
| RY | Nominal yield stress, taken equal to 235/k | N/mm2 |
2.3 Loads
2.3.1 Unless otherwise specified, symbols regarding loads and their units used in these Rules are those defined in Table 4.
Table 4 : Loads
| Symbol | Meaning | Units |
| Cw | Wave coefficient | - |
| Tθ | Roll period | s |
| θ | Roll angle | deg |
| Tϕ | Pitch period | s |
| ϕ | Pitch angle | deg |
| ao | Common acceleration parameter | - |
| az | Vertical acceleration | m/s2 |
| ay | Transverse acceleration | m/s2 |
| ax | Longitudinal acceleration | m/s2 |
| fp | Probability factor | - |
| kr | Roll amplitude of gyration | m |
| GM | Metacentric height | m |
| λ | Wave length | m |
| S | Static load case | - |
| S+D | Dynamic load case | - |
| Pex | Total sea pressure, see Ch 4, Sec 5, [1.1] | kN/m2 |
| Pin | Total internal pressure due to liquid, see Ch 4, Sec 6, [1], or due to dry bulk cargo, see Ch 4, Sec 6, [2.4.1] | kN/m2 |
| Ps | Static sea pressure | kN/m2 |
| Pls | Static tank pressure | kN/m2 |
| Pw | Dynamic wave pressure | kN/m2 |
| Pld | Dynamic tank pressure | kN/m2 |
| PD | Green sea deck pressure | kN/m2 |
| Pslh-j | Sloshing pressure, j=direction | kN/m2 |
| Pdl | Total pressure due to distributed load on deck or platform, see Ch 4, Sec 5, [2.3] or Ch 4, Sec 6, [5.2] | kN/m2 |
| PSL | Bottom slamming pressure | kN/m2 |
| PFB | Bow impact pressure | kN/m2 |
| Pfs | Static pressure in flooded conditions | kN/m2 |
| Pfd | Dynamic pressure in flooded conditions | kN/m2 |
| PST | Tank testing pressure (static) | kN/m2 |
| FU | Total force due to concentrated load on deck or platform, see Ch 4, Sec 5, [2.3] or Ch 4, Sec 6, [5.3] | kN |
| Msw-j | Vertical still water bending moment, j = h, s, p (hog, sag, harbour) | kNm |
| Qsw | Vertical still water shear force | kN |
| Mwv-j | Vertical wave bending moment, j = h, s (hog, sag) | kNm |
| Qwv | Vertical wave shear force | kN |
| Mwt | Torsional wave moment | kNm |
| Mwh | Horizontal wave bending moment | kNm |
2.4 Scantlings
2.4.1 Unless otherwise specified, symbols regarding scantlings and their units used in these Rules are those defined in Table 5.
Table 5 : Scantlings
| Symbol | Meaning | Units |
| Iy-n50 | Net vertical moment of inertia of hull girder | m4 |
| Iz-n50 | Net horizontal moment of inertia of hull girder | m4 |
| ZD-n50, ZB-n50 | Net vertical hull girder section moduli, at deck and bottom respectively | m3 |
| zn | Vertical distance from BL to horizontal neutral axis | m |
| a | Length of EPP, as defined in Ch 3, Sec 7, [2.1.1] | mm |
| b | Breadth of EPP, as defined in Ch 3, Sec 7, [2.1.1] | mm |
| s | Stiffener spacing (see Ch 3, Sec 7, [1.2.1]) | mm |
| S | Primary supporting member spacing (see Ch 3, Sec 7, [1.2.2]) | m |
|
|
Span of stiffeners or primary supporting member (see Ch 3, Sec 7, [1]) | m |
|
|
Bracket arm length | m |
| t | Net thickness with full corrosion reduction | mm |
| tn50 | Net thickness with half corrosion reduction | mm |
| tc | Corrosion addition | mm |
| tgr | Gross thickness | mm |
| tas_built | As built thickness | mm |
| tgr_off | Gross thickness offered | mm |
| tgr_req | Gross thickness required | mm |
| toff | Net thickness offered | mm |
| treq | Net thickness required | mm |
| tvol_add | Thickness for voluntary addition | mm |
| tres | Reserve thickness | mm |
| tc1, tc2 | Corrosion addition on each side of structural member | mm |
| hw | Web height of stiffener or primary supporting member | mm |
| tw | Web thickness of stiffener or primary supporting member | mm |
| bf | Face plate width stiffener or primary supporting member | mm |
| hstf | Height of stiffener | mm |
| tf | Face plate/flange thickness of stiffener or primary supporting member | mm |
| tp | Thickness of the plating attached to a stiffener or a primary supporting member | mm |
| de | Distance from the upper edge of the web to the top of the flange for L3 profiles | mm |
| beff | Effective breadth of attached plating, in bending, for yield and fatigue | mm |
| Aeff or Aeff-n50 | Net sectional area of stiffeners or primary supporting members, with attached plating (of width s) | cm2 |
| Ashr or Ashr-n50 | Net shear sectional area of stiffeners or primary supporting members | cm2 |
| Ip | Net polar moment of inertia of stiffener about its connection to plating | cm4 |
| I | Net moment of inertia of the stiffener, with attached shell plating, about its neutral axis parallel to the plating | cm4 |
| Z or Zn50 | Net section modulus of a stiffener or primary supporting member with attached plating (of breadth beff) | cm3 |
| Copyright 2020 Clasification Society, International Maritime Organization, International Labour Organization or Maritime and Coastguard Agency. All rights reserved. Clasification Society, its affiliates and subsidiaries and their respective officers, employees or agents are, individually and collectively, referred to in this clause as 'Clasification Society'. Clasification Society Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Clasification Society entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract. |  |