1、 Guide for Enhanced Shaft Alignment GUIDE FOR ENHANCED SHAFT ALIGNMENT NOVEMBER 2016 American Bureau of Shipping Incorporated by Act of Legislature of the State of New York 1862 2016 American Bureau of Shipping. All rights reserved. ABS Plaza 16855 Northchase Drive Houston, TX 77060 USA Foreword For
2、eword The ABS Guide for Enhanced Shaft Alignment has been developed to address requests from owners and operators who wish to perform a more detailed shaft alignment analysis and installation assessment. Vessels designed, constructed and operated in compliance with the requirements of this Guide may
3、 be assigned the Class Notation ESA. Assignment of the ESA Notation requires the review of plans and calculations by an ABS Engineering Office and the attendance of an ABS Surveyor during additional shafting alignment efforts. The intention of the Guide is to address shafting arrangements that may b
4、enefit from a more detailed analysis and a more accurate and structured procedure so as to optimize the shaft alignment and improve the service life of the vessels powertrain. This Guide is intended to apply mainly to shaft alignment-sensitive vessels, as defined in this Guide, although it could app
5、ly to a wider range of powertrains including geared installations. The main aspects that distinguish compliance with this Notation from the standard Rule application are: A final Shaft Alignment sighting is to be conducted after the engine or gearbox and other heavy machinery are installed on board
6、and all major steel works are completed at the aft part of the vessel. Shaft alignment optimization calculations are required. Compulsory inclusion of hull deflections to be taken into account in the analysis. Requirement for Lateral Vibration (Whirling) analysis of the powertrain shafting system. S
7、haft alignment verification at more than one service condition. The vessel must be assigned the Tailshaft Condition MonitoringTCM Notation. The ABS Guide for Enhanced Shaft Alignment is to be used in conjunction with all other applicable Rules, Guides and Guidelines published by ABS. This Guide beco
8、mes effective on the first day of the month of publication. Users are advised to check periodically on the ABS website www.eagle.org to verify that this version of this Guide is the most current. We welcome your feedback. Comments or suggestions can be sent electronically by email to rsdeagle.org. i
9、i ABSGUIDE FOR ENHANCED SHAFT ALIGNMENT .2016 Table of Contents GUIDE FOR ENHANCED SHAFT ALIGNMENT CONTENTS SECTION 1 General 1 1 Introduction . 1 1.1 ESA Notation . 1 1.3 Definitions 2 3 Application 3 3.1 General 3 5 Documentation 4 5.1 Documentation to be Submitted 4 TABLE 1 Propulsion Types and S
10、haft Alignment Systems that can be Covered by the ESA Notation . 4 FIGURE 1 Selected Differences between ESA Notation Requirements and ABS Rules 1 SECTION 2 Calculation Requirements for the ESA Notation . 6 1 Calculations 6 1.1 General 6 1.3 Additional Specialized Calculations . 6 3 Hull Girder Defl
11、ections 10 3.1 General 10 FIGURE 1 Schematic Showing the Requirement of the Gearbox Forces Calculation in the Shaft Alignment Analysis Report 7 FIGURE 2 Stern Tube Bearing Contact Analysis Screenshot from the ABS Shaft Alignment Software . 8 FIGURE 3 Representation of Critical Speeds for a Whirling
12、Calculation using a Campbell Diagram 9 FIGURE 4 Screenshot from the ABS Shaft Alignment Software Showing Typical Data Required for Fast Determination of Hull Deflection for Shaft Alignment Optimization Analysis . 10 FIGURE 5 Typical Finite Element Model for the Purposes of Hull Deflection Calculatio
13、ns . 11 ABSGUIDE FOR ENHANCED SHAFT ALIGNMENT .2016 iii SECTION 3 Alignment Procedure . 12 1 General Requirements 12 1.1 Major Stages . 12 3 Shaft Alignment Installation Procedure . 12 3.1 Conditions 12 3.3 Means of Bearing Reaction Measurement and Verification . 12 3.5 Recordings 14 TABLE 1 Perform
14、ance Characteristics of Typical Measurement Techniques 13 FIGURE 1 Bearing Reaction Values During Sea Trials for Different Vessel Conditions for the Forward Sterntube Bearing (FWD), the Intermediate Bearing (IB) and the Aftmost Main Engine Bearing (ME) 14 FIGURE 2 Correlation between Measured and Ca
15、lculated Bearing Reaction Values for a Specific Vessel Condition 15 SECTION 4 Sea Trials 16 1 General Requirements 16 1.1. Test Procedure 16 1.3 Running-in Procedure 17 FIGURE 1 Bearing Temperatures Monitored during Acceptance Sea Trials . 16 SECTION 5 Maintenance of ESA Notation . 18 1 Maintenance
16、of ESA Notation . 18 SECTION 6 Surveys . 19 1 Initial Survey 19 3 Surveys after Construction 19 APPENDIX 1 Definitions of Shaft Alignment Optimization . 20 1 Shaft Alignment Optimization Alternative Definitions . 20 FIGURE 1 2D Design Optimization Mathematical Concept . 20 FIGURE 2 3D and higher Des
17、ign Optimization Mathematical Concept . 21 APPENDIX 2 References 22 iv ABSGUIDE FOR ENHANCED SHAFT ALIGNMENT .2016 ABSGUIDE FOR ENHANCED SHAFT ALIGNMENT .2016 1 Section 1: General SECTION 1 General 1 Introduction 1.1 ESA Notation Requirements of this Guide are optional for classification purposes. H
18、owever, where assignment of the optional notation ESA Enhanced Shaft Alignment is being requested, provisions of this Guide are compulsory. This Guide provides criteria for additional calculation requirements, such as design optimization, as well as more detailed requirements regarding the shaft ali
19、gnment procedures in support of the optional notation ESA - Enhanced Shaft Alignment. Typical differences can be explained through the flowchart examples of Section 1, Figure 1. FIGURE 1 Selected Differences between ESA Notation Requirements and ABS Rules (1 November 2016) ABS Steel Vessel Rules4-3-
20、2/11.1.2(e)Shaft Alignment CalculationsHull Deflections Available: Bearing Reaction verification measurements taken in one condition (such as Dry Dock or Very Light Ballast condition).Hull Deflections Not Available: Bearing Reaction verification measurements taken in multiple loading conditions, as
21、agreed.Whirling Calculations Requirements No forward ST bearing Bearing Span 450d Supports outside of hull Cardan shafts incorporated Calculated with all bearings loadedTCM Notation OptionalESA NotationShaft Alignment CalculationsHull Deflections Compulsory Load measurements taken under ballast and
22、fully laden conditions, as per 2/1.1.1(a) and 2/1.1.1(b) of the ESA Guide.Whirling Calculations Requirements Unanimously (i.e., all cases under ESA Notation) Calculated with all bearings loaded Calculated with fore ST bearing unloadedTCM Notation CompulsoryFinal sighting to be conducted after engine
23、 or gearbox or other heavy machinery are installed onboard and all major steel works are completed OptionalFinal sighting to be conducted after engine or gearbox or other heavy machinery are installed onboard and all major steel works are completed CompulsorySection 1 General 1.1.1 Objective The obj
24、ective of this Guide is to identify additional requirements and procedures beyond the minimum requirements currently specified in the ABS Rules for Building and Classing Steel Vessels so as to further enhance the shaft alignment. Vessels designed, constructed and operated in compliance with the requ
25、irements of this Guide may be assigned the Class Notation ESA. 1.1.2 General Requirements (1 November 2016) The shaft alignment procedure for vessels with the ESA Notation requires that the final shaft alignment sighting is to be carried out after the vessel stern blocks are fully welded and all of
26、the heavy stern structure is in place, such as any stern accommodation block, including the main engine and/or gearbox. This is to be verified by the attending Surveyor. 1.3 Definitions 1.3.1 ABS Rules The ABS Rules for Building and Classing Steel Vessels is hereafter referred to as “Steel Vessel Ru
27、les”. 1.3.2 ESA Notation The notation granted based upon compliance with the requirements described in this Guide. 1.3.3 FEA Finite Element Analysis. 1.3.4 MCR Maximum Continuous Rating. 1.3.5 Very Light Ballast Condition The condition in which the vessel is either in dry-dock or afloat at a quay wi
28、th minimum ballast nearing a “lightship” condition. This condition is expected to have the least influence in the calculations with hull deflections that would affect the shaft alignment and therefore, it is considered as a condition without hull deflections. 1.3.6 Global Reference Line In the shaft
29、 alignment sighting, the global reference line is the 0 (zero) datum used as the reference for all bearing offsets. All bearing offsets values are recorded based on this datum. 1.3.7 Shaft Alignment The configuration of the shafts and bearings relative to the centerlines of the bearings from the the
30、oretical straight line condition, so as to achieve an acceptable bearing load distribution. 1.3.8 Alignment Optimization Alignment optimization is a condition where a mathematically predicted set of bearing offsets produces a satisfactory bearing load distribution for more than one alignment conditi
31、on. The shaft alignment optimization estimates the most possible uniform bearing load distribution for any given vessel loading case., It will produce an optimum set of bearing offsets, which will satisfy the vessel loading conditions from very light ballast to the fully-laden condition. Knowing the
32、 hull deflections envelope together with the required operating conditions (e.g. fully loaded, hot dynamic), a bearing offsets range can be defined within which acceptable bearing load distribution. Performing a reverse engineering calculation with the desired bearing load distribution as input and
33、the bearing offsets range also as input, a specific set of bearing offsets can be calculated (usually more than one) as output, which is to be acceptable under all loading conditions. This set of bearing offsets is said to be optimal and the shaftline is said to be optimum for alignment purposes, in
34、 accordance to the definition given to the alignment optimization. 2 ABSGUIDE FOR ENHANCED SHAFT ALIGNMENT .2016 Section 1 General 1.3.9 M/E Main Engine. 1.3.10 TCM ABS Tailshaft Condition Monitoring Notation. 1.3.11 Shaft Alignment Sensitive Vessels Large tank vessels such as Suezmax, VLCC, ULCC, L
35、NGC, large bulk carriers, such as Capesize and VLOC, and large container vessels, i.e. above 9000 TEU are considered to be shaft alignment sensitive vessels. In addition, the following propulsion systems are considered to be potentially shaft alignment-sensitive installations: Directly driven propel
36、ler installations Low speed diesel installations Systems with relatively short and rigid shafting Vessels with a relatively flexible hull structure Vessels with twin screw installations 3 Application 3.1 General (1 November 2016) 3.1.1 Notation Assignment Vessels designed and constructed in complian
37、ce with the optional requirements of this Guide may be assigned the Class Notation ESA. While the notation has been developed primarily for shaft alignment sensitive vessels and propulsion systems, other types of vessels and other types of powertrains may be granted the ESA Notation. 3.1.2 Survey Th
38、e Surveyor is to attend all stages of alignment as described herein. The shipyard is to produce a log with the recordings of all the shaft alignment installation steps, including the sighting data recorded along with the manufacturers acceptance criteria. The same is to be submitted to the ABS Engin
39、eering Office for review and for future reference. 3.1.3 Correlation with Calculations The onboard shaft alignment is to be consistent with the system description and input parameters as listed in the approved calculations. Correlation between measurements and calculations for various shaft alignmen
40、t conditions is to be verified at all times and stages of the process. The correlations criteria between calculations and measurements are defined in 3/3.5xxiv). 3.1.4 Other Powertrains The Class Notation ESA is not applicable to ships designed with azimuthal thrusters or nonconventional shaft lines
41、 intended for main propulsion, or as otherwise deemed inappropriate by ABS. 3.1.5 Applicability Requirements Class Notation ESA may be assigned to ships designed with one or more propulsion shaft lines that comply with the following: i) Propulsion types of direct drives and geared drive installation
42、s, as shown in Section 1, Table 1 ABSGUIDE FOR ENHANCED SHAFT ALIGNMENT .2016 3 Section 1 General ii) The additional calculation requirements of Subsection 2/1 including hull deflections and shaft alignment optimization iii) The shaft alignment processes described in Section 3 of this Guide. iv) Pos
43、sess the TCM Notation as per 4-3-2/13 of the Steel Vessel Rules 3.1.6 Geared Installations For geared installations, as the low speed shaft will be stiffer than the high speed shaft, only the propeller to gearbox shaft alignment is required to be submitted to ABS for approval. 3.1.7 Alternative Shaf
44、ting Arrangements Shafting arrangements applicable for the ESA Notation are shown in Section 1, Table 1 below. In cases of specific shafting arrangements not covered by this Guide, ABS may require additional calculations to verify compliance with the ESA Notation requirements. TABLE 1 Propulsion Typ
45、es and Shaft Alignment Systems that can be Covered by the ESA Notation Propulsion Type Prime Mover Alignment System Direct drive installation Low-speed diesel/gas engine from propeller to crankshaft Electric motor from propeller to rotor shaft Geared drive installation Medium-speed diesel/gas engine
46、 from propeller to main gearbox output shaft Steam/gas turbine Electric motor 5 Documentation 5.1 Documentation to be Submitted 5.1.1 Drawings i) Shafting arrangement ii) Intermediate shaft, propeller shaft drawings iii) Couplings integral, demountable, keyed, or shrink-fit, coupling bolts and keys
47、drawings iv) Shaft bearing drawings v) Shaft seals drawings vi) Propeller drawings vii) Gearbox drawings, as applicable, as necessary viii) Stern tube bearing and intermediate bearing drawings 5.1.2 Data (1 November 2016) i) Rated power of main engine and shaft rpm ii) Allowable bearing loads iii) A
48、ctual Propeller mass and inertia iv) Hull deflections data for light ballast, ballast and fully laden condition. Hull deflections data for light ballast, ballast and fully laden condition. In the ballast condition hull deflections are to be analyzed with the aft peak tanks full. 4 ABSGUIDE FOR ENHAN
49、CED SHAFT ALIGNMENT .2016 Section 1 General v) Crankshaft Deflection allowable limits vi) All Bearing Stiffness values and information vii) Propeller forces and moments for the following conditions: a) Straight course, at full speed, in a fully laden condition b) Straight course, at full speed, in the ballast condition c) Full rudder starboard and port turns, at full speed, in a fully laden condition d) Full rudder starboard and port turns, at full speed, in the ballast condition 5.1.3 Calculations (1 November 2016) i) Details of
