Metal shoring towers support formwork for cast-in-place concrete structures and serve as erection bents for precast concrete members. Much faster to erect than single-pole shoring systems, they are modular assemblies of single- or multi-tiered pairs of end frames connected by pivoted diagonal cross braces. Many combinations of end-frame and cross-brace dimensions are possible. Shoring tower components also include adjustable screw jacks, base plates and top plates (or U-heads), pinned connectors between frames of multi-tier towers, and extension legs. General principles of shoring tower layout for standard, intermediate-strength, and heavy-duty systems are given. These include guidelines for joist spacing, stringer span, stringer orientation, and cross-brace locations between frames. Special guidelines are given for developing the full capacity of heavy-duty shoring towers. Shoring tower safety tips are included.