Select a rope rescue system, enter load weight and efficiency — get haul force, rope multiplier, and system notes. Covers Z-Rig, Piggyback Z, C-Rig, Drop C, and custom MA.
| System | TMA | AMA @78% | Haul Force (200 lb) | Best Use |
|---|---|---|---|---|
| Z-Rig | 3:1 | 2.3:1 | ~86 lb | Standard haul, most rescues |
| C-Rig | 4:1 | 3.1:1 | ~65 lb | Heavier loads, confined space |
| Drop C (6:1) | 6:1 | 4.7:1 | ~43 lb | Very heavy loads, limited haulers |
| Piggyback Z (9:1) | 9:1 | 7.0:1 | ~29 lb | Max advantage, complex setup |
| 5:1 Compound | 5:1 | 3.9:1 | ~51 lb | Litter hauls, mid-range advantage |
The Z-Rig is the most common rope rescue mechanical advantage system. Two pulleys and the load anchor create a Z shape. Pull 3 feet of rope to move the load 1 foot. Quick to build, easy to reset, and sufficient for most single-victim rescues with 2–3 haulers on a 200 lb load.
A 3:1 Z-Rig attached to the haul strand of another 3:1 Z-Rig. Theoretical advantage is 3 × 3 = 9:1. Practical advantage is lower due to compounding friction. Used when very heavy loads or very few haulers require maximum mechanical advantage. Setup is complex and rope consumption is high.
A 4:1 compound system using three pulleys. The rope runs from anchor through two traveling pulleys to the haul point. More efficient rope use than a Piggyback Z for a similar result, but slightly more complex to build correctly. Common in confined space and low-angle rescue.
A 6:1 compound system, effectively a 3:1 pulling through a 2:1. Provides high advantage with manageable rope consumption. Useful for heavy patient packaging, litter rescues on steep terrain, or when hauler count is limited.
⚠️ Disclaimer: This tool is for training and planning purposes only. Do not rely on these calculations as the sole basis for live fireground operations. Always defer to your department's SOPs. Read full operational disclaimer.
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