Twin Tension Skate Block in Tower Rescue
When precision, control, and redundancy matter most, the twin tension skate block system stands out as one of the most refined vertical rescue techniques. This blog walks through a full scenario utilizing this method, focusing on streamlined rigging, dynamic lowering, and the critical importance of redundancy at height.
A Real-World Rescue Scenario
The operation begins with a compliant but incapacitated climber—suspended on a tower, either from fall arrest gear or work positioning equipment. The objective: safely transition the patient from suspension to a controlled lower using a twin tension skate block.
System Overview
The rescue setup uses two identical tensioned lines—each with a descent control device such as the Petzl ID or CMC MPD. These lines are arranged in a skate block configuration to evenly distribute load. Rather than relying on a traditional main and belay format, the twin tension approach ensures shared load management and mitigates swing fall risks.
- One Rescuer Deployment: A single trained rescuer climbs with both ropes—main and belay—secured in a bag carry configuration.
- Anchor Setup: Anchors are established 6 to 10 feet above the patient. Each line is attached to separate anchor slings for redundancy and proper tension matching.
- Patient Assessment and Connection: Before applying load, the rescuer thoroughly checks the victim’s harness and condition. Once confirmed, the rescuer connects both tensioned lines to the patient’s sternal D-ring.
Lifting Methods
To lift the patient slightly for transition:
- Inline MA System: Using devices like Petzl IDs or MPDs, a quick 3:1 mechanical advantage can be rigged inline to raise the patient.
- Dynamic Anchor: A mini 4:1 haul system between the anchor and descent control device offers precision lifting—especially helpful with rack systems.
- Vectoring: With angle advantage, rescuers can manually vector the lines downfield to generate a controlled lift.
These lifting options offer flexibility depending on gear availability and tower height constraints.
Why Twin Tension Skate Block?
Traditional skate block systems pair one mainline with a separate belay. If the main fails, a belay high on the tower can result in catastrophic swing. In contrast, the twin tension approach provides:
- Shared Load: Lines bear equal or near-equal weight (50/50 or 60/40 split)
- Automatic Backup: Should one line fail, the second immediately takes the load
- Smoother Edge Transitions: Better control at the tower lip or over obstructions
Transition and Lower
Once both systems are tensioned and the rescuer confirms that all slack is removed, they disconnect the patient from their original suspension system. With ground operators managing the descent, the patient is lowered in a stable, redundant twin-line system—eliminating sharp swings or single-point failure risks.
Summary
The twin tension skate block is more than a method—it’s a commitment to elevated safety. In high-angle tower rescues, it offers:
- Clean rigging for small teams
- Better anchor load distribution
- Reduced swing fall potential
- Seamless patient transitions from suspension to controlled descent
Whether for training or live rescue operations, incorporating this technique ensures your team is ready for the complexity and risks of vertical work.
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