CMAA SPECIFICATION NO. 70-2015 - SPECIFICATIONS FOR TOP RUNNING BRIDGE AND GANTRY TYPE MULTIPLE GIRDER ELECTRIC OVERHEAD TRAVELING CRANES

This Specification has been developed by the Crane Manufacturers Association of America, Inc. (CMAA), an organization of leading electric overhead traveling crane manufacturers in the United States, for the purpose of promoting standardization and providing a basis for equipment selection. The use of this Specification should not limit the ingenuity of the individual manufacturer but should provide guidelines for technical procedure. In addition to Specifications, the publication contains information which could be helpful to the purchasers and users of cranes and to the engineering and architectural professions. While much of this information must be of a general nature, it may be checked with individual manufacturers, and comparisons may be made, leading to the selection of the proper equipment. Table of Contents 70-1 General Specifications 1.1 Scope 1.2 Building Design Consideration 1.3 Clearance 1.4 Crane Runway 1.5 Runway Conductors 1.6 Rated Capacity 1.7 Design Stresses 1.8 General 1.9 Painting 1.10 Assembly and Preparation for shipment 1.11 Testing 1.12 Drawings and Manuals 1.13 Erection 1.14 Lubrication 1.15 Inspection Maintenance and Crane Operator Training 70-2 Crane Classifications 2.1 General 2.2 Class A (Standby or Infrequent Service) 2.3 Class B (light Service) 2.4 Class C (Moderate Service) 2.5 Class D (Heavy Service) 2.6 Class E (Severe Service) 2.7 Class F (continuous Severe Service) 2.8 Crane Service Class in Terms of Load Class and Load Cycles 70-3 Structural Design 3.1 Material 3.2 Welding 3.3 Structure 3.4 Allowable Stresses 3.5 Design Requirements 3.6 Bridge End Truck 3.7 Footwalks and Handrails 3.8 Operator's Cab 3.9 Trolley Frames 3.10 Bridge Rails 3.11 End Ties 3.12 Structural Bolting 3.13 Gantry Cranes 70-4 Mechanical Design 4.1 Mean Effective Load 4.2 Load Blocks 4.3 Overload Limit Device 4.4 Hoisting Ropes 4.5 Sheaves 4.6 Drum 4.7 Gearing 4.8 Bearings 4.9 Brakes 4.10 Bridge Drives 4.11 Shafting 4.12 Couplings 4.13 Wheels 4.14 Bumpers 4.15 Stops 70-5 Electrical Equipment 5.1 General 5.2 Motors--AC and DC 5.3 Brakes 5.4 Controllers, Alternating and Direct Current 5.5 Resistors 5.6 Protection Safety Features 5.7 Master Switches 5.8 Floor Operated Pendant Pushbutton Stations 5.9 Limit Switches 5.10 Installtion 5.11 Bridge Conductor Systems 5.12 Runway Conductor Systems 5.13 Voltage Drop 5.14 Inverters (variable Frequency Drives) 5.15 Remote Control 5.16 Collision Avoidance 5.17 Weigh Scale System 70-6 Crane Inquiry Data Sheet 70-7 Glossary 70-8 Index