How to Use Climbing Descent STOP with Twin Ropes Safely & Efficiently

Mastering rappelling techniques is crucial for multi-pitch climbers. Using a Petzl STOP device with twin ropes offers significant advantages like redundancy and reduced rope drag, but requires specific knowledge. This guide ensures you do it correctly and safely.

Understanding Twin Ropes & STOP Compatibility:

• Twin Ropes: Designed to be used together as a single strand for both climbing and rappelling. They are thinner (typically 7-8mm) and lighter than single ropes.
• STOP Compatibility: The Petzl STOP (including STOP P, SIMPLE STOP) is explicitly approved for use with twin ropes, provided they meet the minimum diameter requirement (usually 7.7mm - ALWAYS CHECK YOUR DEVICE'S MANUAL).

Step-by-Step Usage Guide:

1. Prepare the Ropes: Ensure both twin ropes are clipped to the anchor point correctly and extend an equal distance below you. Tie stopper knots in the ends of both ropes and consider tying them together below the knots.
2. Thread the STOP:Hold the STOP with the handle facing down and the central slot accessible.Crucially: Pass both twin rope strands together through the central slot from the smooth side (usually marked "ROPE").Pull the ropes down and ensure they lie cleanly over the internal cam mechanism, exiting the bottom of the device. The ropes should not be separated or pass through different slots.
3. Attach to Harness:Clip a large, locking carabiner through the large central hole of the STOP.Securely attach this carabiner to your harness's belay loop (never just a gear loop). Lock the carabiner gate.
4. Pre-Descent Safety Checks:TEST BEFORE COMMITTING: Lean back gently on the system while holding the handle down (simulating descent). The ropes should feed smoothly.Release Test: Carefully release the handle. The STOP must immediately and securely lock the ropes, holding your weight. Perform this test close to the ground or while securely backed up.Visually confirm ropes are correctly threaded over the cam and not crossed.Double-check carabiner is locked and attached to the belay loop.Ensure stopper knots are tied and ropes are not tangled.
5. Controlled Descent:To descend: Grasp the ropes below the STOP firmly with your dominant hand (brake hand).Use your non-dominant hand to pull the STOP handle down towards your body.The cam disengages, allowing rope to feed through. Control your descent speed by modulating how far you pull the handle and applying friction with your brake hand below the device.Keep your brake hand ready to apply extra friction if needed.
6. Stopping:Simply release the handle. The internal cam will instantly re-engage and lock the ropes, stopping your descent.Maintain a firm grip on the ropes below the STOP until you are securely stopped or anchored again.

Critical Safety Considerations & Best Practices:

• Diameter is Paramount: Using ropes below the STOP's specified minimum diameter can cause catastrophic failure. Never exceed the maximum diameter either.
• Handle Clearance: Keep hands, clothing, and hair well clear of the moving handle and cam area during descent to avoid serious injury.
• Rope Management: Twins create more rope to manage. Use a rope bag if possible to prevent tangles. Be vigilant about potential snags.
• Heat Buildup: Rappelling generates friction heat. On long rappels, especially with thinner twins, descend slowly or in stages to prevent damaging ropes or the device. Gloves are essential.
• Partner Checks: Always have your partner visually double-check your setup (threading, carabiner, knots) before you leave the anchor.
• Know Your Gear: Read and understand the Petzl STOP manual specific to your model. Practice in a safe, controlled environment (like a ground anchor) before relying on it on a climb.
• Alternative Devices: While excellent for twins, consider if devices like an ATC Guide (in guide mode) or specific tube devices might be preferable for your specific rappel scenario.

Conclusion:

The Petzl STOP is a powerful tool for controlled rappels with twin ropes, offering smooth descent and reliable auto-locking. Success hinges on meticulous attention to threading (both strands together in the central slot), rigorous pre-rappel safety checks, understanding rope diameter limits, and maintaining constant control. By mastering these steps and prioritizing safety protocols, you leverage the benefits of twin ropes and the STOP device for efficient and secure descents on your alpine and multi-pitch adventures. Always prioritize practice and consultation of official manuals.