1、ABSGUIDE FOR BUILDING AND CLASSING ITB COMBINATIONS INTENDED TO OPERATE ON THE GREAT LAKES .2002 1GUIDE FOR BUILDING AND CLASSINGINTEGRATED TUG-BARGE (ITB) COMBINATIONSINTENDED TO OPERATE ON THE GREAT LAKESNOVEMBER 2002IntroductionThis Guide is prepared for the building and classing of Integrated Tu
2、g-Barge Combinations Intendedto Operate on the Great Lakes. In addition to the class notation as specified in Section 1 of this Guide,the following special comment, as applicable, will also be published in column 5 of the Record forboth the tug and barges in compliance with the Guide:Special Comment
3、 24: This vessel is fitted with special arrangements to be part of an integratedtug/barge combination.(The vessel indicated in parenthesis forms the other part of the integratedtug/barge.)Special Comment 25: Classed to operate as an integrated tug/barge combination.(The vessel indicated in parenthes
4、is forms the other part of the integratedtug/barge.)Special Comment 27: This vessel is part of an integrated tug/barge unit but is not limited to onetug/barge combination.In view of the nature of the intended operations within the recognized boundaries of the Great LakesSystem, all statutory require
5、ments as required by the Flag Administration are to be complied with(e.g. the Code of Federal Regulations 46 and NVIC 2-81, “Coast Guard Inspection GuidanceRegarding Integrated Tug Barge Combinations” for US-flag vessels). Under the Title 46 CFR, all tugsintended to operate on the Great Lakes are ca
6、tegorized as “uninspected vessels”. The Coast Guardmaintains an “Uninspected Towing Vessel Exam Checklist” on their web site, which lists specificrequirements as required by the CFR, Titles 46 and 33.)The requirements in this Guide are primarily applicable for new construction and become effectiveup
7、on publication.2 ABSGUIDE FOR BUILDING AND CLASSING ITB COMBINATIONS INTENDED TO OPERATE ON THE GREAT LAKES .20021 General1.1 ClassificationAn Integrated Tug-Barge (ITB) is a tug-barge combination wherein a tug is mated to a barge with aspecially designed connection system such that the tug is secur
8、ed in the barge notch or on fenders bymechanical means of any type whatsoever other than just wire ropes, chains, lines or other tackles.The tug and the barge are to be classed as two separate vessels but will be cross-referenced in column5 of the Record.1.1.1 Towing Vessel Dual Mode (Articulated Co
9、nnection)The tug will be classed and distinguished in the Record by the notation A1 TowingVessel Great Lakes Service, DM, which is in full compliance with the requirements ofthe Part 5, Chapter 8 of the Rules for Building and Classing Steel Vessels Under 90 Meters(295 feet) in Length, and signifies
10、that the vessel has the dual mode (DM) capabilities,pushing the barge in ITB mode and towing the barge by hawser in a separate mode.1.1.2 Integrated Towing Vessel Pushing Mode (Rigid Connection)The tug will be classed and distinguished in the Record by the notation A1 TowingVessel Great Lakes Servic
11、e, PM. This class notation will be assigned to a tug whichdoes not meet the requirements for intact stability during tow as specified in the Part 5,Chapter 8, Section 2 of the Rules for Building and Classing Steel Vessels Under 90 Meters(295 feet) in Length, but does meet the requirements of the res
12、t of the above Rules, and isintended to operate in a pushing mode (PM) only and remain fixed to the barge throughoutthe voyage under all weather conditions.1.1.3 Barge ClassThe barge will be classed and distinguished in the Record by the symbols and designations inaccordance with paragraph 1.11.2 of
13、 the Rules for Building and Classing Steel Bargesfollowed by the geographical/operational limitation, Great Lakes Service, DM or GreatLakes Service, PM, whichever is applicable.1.3 ApplicationThe requirements of this Guide are applicable to integrated tug-barge combinations intended tooperate on the
14、 Great Lakes in addition to the relevant requirements for hull structure, equipment, andvessel systems in Part 5, Chapter 8 of the Rules for Building and Classing Steel Vessels Under 90Meters (295 feet) in Length, the Rules for Building and Classing Steel Barges or the Rules forBuilding and Classing
15、 Bulk Carriers for Service on the Great Lakes, as appropriate. For the samedesign, for any aspect of the hull structural design that is covered by more than one of these Rules, itis not valid to switch between criteria in these Rules.1.5 Definitions1.5.1 Rigid Connection SystemA rigidly connected in
16、tegrated tug-barge combination designed for pushing mode only is onein which the tug is connected to the stern of the barge in such a manner that there is norelative motion between the tug and barge, resulting in the two vessels acting as a single unitin a seaway.ABSGUIDE FOR BUILDING AND CLASSING I
17、TB COMBINATIONS INTENDED TO OPERATE ON THE GREAT LAKES .2002 31.5.2 Articulated Connection SystemAn integrated tug-barge connected by a system for dual mode operations that allows relativemotion between the tug and the barge in one or more degrees of freedom is deemed to have anarticulated connectio
18、n system.1.5.3 Length of Combination (Lc)The combined length Lc, is to be measured with the tug and barge connected in their pushingmode. The combined length Lcis to be taken as the distance, in m (ft), measured on awaterline at 85% of the least molded depth of the barge, from the fore side of the s
19、tem of thebarge to the after side of the rudder post or stern post of the tug. Where there is no rudderpost or stern post, Lcis to be measured to the centerline of the rudder stock of the tug. Lc,however, is not to be taken less than 96% and need not be taken greater than 97% of the totalwaterline l
20、ength of the combination measured at 85% of the least molded depth of the barge.3 PlansIn addition to the plans required to be submitted by 5-8-1/7 of the Rules for Building and ClassingSteel Vessels Under 90 Meters (295 feet) in Length and 1.13 of the Rules for Building and ClassingSteel Barges, th
21、e following plans are to be submitted in the same manner.General Arrangements of Combined UnitLoading ManualHull structural details in way of the connection of tug and barge for each vesselStructural analysis of the connection5 Longitudinal Strength5.1 Integrated Tug-Barge (ITB) with Rigid Connectio
22、nWhere Lcof a rigidly connected Integrated Tug and a ship-shaped Barge (ITB) exceeds 122 meters(400 ft), the ITB is to have longitudinal strength in accordance with the requirements of Section 2 ofthe Rules for Building and Classing Bulk Carriers for service on the Great Lakes. Where the Lcof arigid
23、ly connected ITB is less than 122 meters (400 ft.), the ITB is to have longitudinal strength inaccordance with the following requirements:SM = c1c2Bd cm2-m (in2-ft)wherec1= 1.15c2= 3618)31(5.1018)31(4.62+ + ccLLLc 67 m= 82.6 + 2.08(Lc 67) 67 m Lc 90 m (295 ft)ii) Section 3-2-9 of the Rules for Build
24、ing and Classing Steel Vessels under 90 Meters (295 feet)in Length where, Lc 90 m (295 ft)A tug forming part of a rigidly connected ITB and which is intended to remain fixed to the bargethroughout the voyage under all weather conditions must nevertheless have the strength, stability,characteristics
25、and sea-keeping capabilities to operate on its own in open waters in order that themaster may have the option of separating from the barge in extreme situations.7.3 Barge Hull StructureFor ship-shaped and proportioned barges, material grade and location requirements and scantlingrequirements in gene
26、ral are to be in accordance with the applicable sections of the Rules for Buildingand Classing Bulk Carriers for Service on the Great Lakes. For rectangular non-ship shaped barges,these are to be in accordance with the applicable requirements of the Rules for Building and ClassingSteel Barges. In th
27、e case of a rigidly connected ITB, the combined length Lcis to be used as the lengthparameter in the various structural requirement equations whereas the barge length L, as defined in 2.1of the Rules for Building and Classing Steel Barges may be used in the case of an ITB with anarticulated connecti
28、on.ABSGUIDE FOR BUILDING AND CLASSING ITB COMBINATIONS INTENDED TO OPERATE ON THE GREAT LAKES .2002 57.5 Collision Bulkhead LocationThe barge is to have a collision bulkhead located in accordance with Section 6.2.1 of the Rules forBuilding and Classing Bulk Carriers for Service on the Great Lakes us
29、ing the combined length, Lc, todetermine the appropriate location.7.7 EquipmentA tug intended to operate in dual mode (DM) is to have anchoring equipment in accordance with3-5-1/3.5 of the Rules for Building and Classing Steel Vessels Under 90 Meters (295 feet) in Length.The barge is to be provided
30、with equipment of anchors and cables in accordance with the requirements of Section 10 of the Rules for Building and Classing Bulk Carriers for Service on theGreat Lakes. The equipment tonnage is to be determined based on the particulars of the combinedunit.7.9 Guard RailsThe barge is to be consider
31、ed as a manned vessel and is to be provided with bulwarks and/or guardrails complying with the load line regulations of the Flag Administration (e.g. Part 45, Subsection Dof the Title 46 Code of Federal Regulations for US flag vessels).9 Still Water Bending Moment and Shear Forces9.1 ITB with Rigid
32、ConnectionStill water bending moment and shear force calculations are to be submitted for both the combinedunit and the barge by itself. The results of these calculations, for the anticipated loaded and ballastedconditions and loading/discharge sequences, are to be submitted in the form of curves sh
33、owing hullgirder bending moment and shear force values along the entire length of the combination or the entirelength of the barge alone, as appropriate.9.3 ITB with Articulated ConnectionStill-water bending moments and shear force calculations are to be submitted for the barge with andwithout the t
34、ug connected. The requirement to submit calculations with the tug connected will bewaived where the connection device is such that no vertical loadings are imposed by the tug on thebarge in any anticipated still-water conditions. The results of these calculations, for the anticipatedloaded and balla
35、st conditions and loading/discharge sequences, are to be submitted in the form ofcurves showing hull girder bending moments and shear force values along the entire length of thebarge.11 Structure in Way of Connection11.1 Connector LoadsFor classification purpose, the maximum lifetime connector loads
36、 are to be used for the design of theconnection system between the tug and barge. The maximum lifetime value is to be determined basedon a recognized prediction method for the long-term extreme value with an acceptable probabilitylevel. The design of the connector is to take into account the quasi-s
37、tatic loads, including thebuoyancy and propulsion forces, and the dynamic seaway loads, as well as the steering loads. Themethods of determining the maximum lifetime connector loads can be identified:6 ABSGUIDE FOR BUILDING AND CLASSING ITB COMBINATIONS INTENDED TO OPERATE ON THE GREAT LAKES .2002i)
38、 through a scale model test program covering a range of wave frequencies and headings so asto obtain the connector load response amplitude operators (RAOs) and then by analysis toidentify the worst heading and predict the long term extreme connector load for that heading,orii) by a motion response a
39、nalysis, using a suitable seakeeping analysis program that can handlemultiple bodies linked by articulation, in connection with a long term extreme analysis.The design calculation of the connector loads is to be documented and submitted for review.Fatigue strength is to be considered in the connecto
40、r design and the design life is not to be less thanthe design life for the main barge structure.11.3 Connector SpecificationSpecification of the connector system, including the load capacity and fatigue resistance, is to besubmitted for review together with the design load calculations for the conne
41、ctor loads in accordancewith 11.1 above.11.5 Structure in Way of ConnectionThe tug and barge supporting structure in way of the connection is to be analyzed for stressesresulting from the connector loads. The structural analysis is to follow acceptable engineering practiceand is to be submitted for
42、review. The connector loads applied are to be in accordance with the loadsdetermined from 11.1 above. In the case of notch type connections, an analysis of the barge wingwalls is to take into account torsional shear as well as primary and secondary shear and bendingstresses. The results of the struc
43、tural analysis are to be assessed for yielding and buckling failures.The allowable stresses for the structure will be subjected to special consideration depending on thederivation of the connector loads and method of analysis used. For a finite element based analysiswith the loads based on 11.1, the
44、 allowable value of Von Mises stress shall not exceed 85% of theyield strength. Special consideration is to be given to contour brackets or cutout details.Fatigue strength of details in highly stressed areas is to be assessed and the documented analysis is tobe submitted for review.Special construct
45、ion requirements will vary depending on the type of linkage proposed. In general,however, the structure in the bow of the tug and the stern of the barge is to be suitably reinforced bothin the athwartship and fore and aft directions with a system of webs, stringers, bulkheads, etc. towithstand the f
46、orces developed at these locations due to the connection and also to transmit theseforces into the main body of the vessels.13 Loading GuidanceA loading manual based on still water conditions is to be prepared in accordance with Appendix3-2-A2 of the Rules for Building and Classing Steel Vessels for
47、 tug-barge combinations and submittedfor review. The loading manual is to be in such a form that the effects on hull girder bending andshear along the length of the barge can be determined for any anticipated loaded and ballastedconditions and loading/discharge sequence. The approved loading manual
48、is to be furnished to andretained by the master of the tug for guidance.ABSGUIDE FOR BUILDING AND CLASSING ITB COMBINATIONS INTENDED TO OPERATE ON THE GREAT LAKES .2002 715 Life Saving Appliances and Equipment15.1 GeneralThe arrangements and installations of life saving appliances and equipment are
49、to comply with theapplicable requirements of the Flag Administration (e.g. the requirements of the Code of FederalRegulations 46 (46 CFR) for US flag vessels). The application of these requirements is specified in“Uninspected Towing Vessel Exam Checklist” issued by the US Coast Guard. See the introduction tothis Guide.)15.3 The TugFor towing vessels intended for dual mode operation, life saving appliances and equipment are to bearranged independently on board the tug. For towing vessels intended for pushing mode only, lifesaving appliances and equipment are to be arrang
