RT

Right twist, or RT, describes the direction in which strands spiral around the core of a rope, cable, or wire bundle. When viewed from above, the strands wind upward from left to right, following the slope of a forward slash. This is the dominant lay direction in industrial rope and wire because it matches the natural twist imparted by most conventional machinery and feels intuitive to human operators handling the material.

RT is distinguished from LT (left twist), where strands spiral upward from right to left. In practice, RT dominates steel wire rope for hoisting, synthetic rope for rigging, and power transmission cables. The choice between RT and LT affects how the rope behaves under load and how it spools onto drums or reels. RT rope tends to unwind naturally when unsupported and spins counterclockwise when freely suspended under tension, which can matter for safety-critical applications like crane rigging.

Why the distinction matters

Mixed lay directions in a single assembly create internal stress and kinking. A rope handler or rigger must verify the lay direction of replacement rope before installing it on existing drums or pulleys designed for a specific direction. Spooling RT rope onto a drum wound with LT rope, or vice versa, can cause the material to bunch, cross over itself, and fail prematurely. Wire rope for boom-hoist systems on mobile cranes typically specifies RT to match the drum.

The name stems from the visual appearance: standing above the rope and looking down along its length, right-hand strands spiral away to the right. Some regions and older texts call this "clockwise lay" or "right-handed lay." The term is abbreviated RT in engineering drawings, load charts, and rope catalogs to save space and eliminate ambiguity.