1. Introduction to Tubular Structures. Attributes of Tubes. Architectural and Structural Forms. The Need for an Integrated Approach. Author's Viewpoint for this Monograph. Tubulars as Structural Members. Simple Welded Joints. 2. Conceptual Basis for the Design Rules. Definitions. Failure modes of tubular connections. General procedures for analysis and design. Design simplifications. Stresses in welds. 3. Static Strength of Circular Section Joints. Early work on T-, Y-, and K-connections. Lessons from field failures. Overcoming the beta paradox. Empirical punching shear design equation. Understanding the sources of reserve strength. Further evolution of the A.W.S. code. Final form. Design charts. 4. Fatigue Design. Levels of analysis. Hot spot stress. Stress concentration factors (SCF). S-N curves. Comparisons with international rules and data. 5. Tubular Connections Involving Non-Circular Sections. Box connections - existing A.W.S. rules. Box connections - proposed new rules. Hybrid connections. Special topics. Fatigue box connections. 6. Special Topics for Circular Section Joints. Overlapping connections. Multi-planar connections. Grouted connections. Internally stiffened tubular connections. 7. Fatigue Size and Profile Effects. Fracture toughness. Lamellar tearing. Role of redundancy. Non-destructive inspection criteria. 8. Construction System. Material selection. Tube manufacture. Connection layout. Welded joint design. Welder and procedure qualification. Prefabrication. Assembly. Inspection. Appendices. 1. Symbols and notation. 2. Design revisions, tubular structures. 3. Notch toughness task group, proposed revisions for AWS D1.1. Index.