Allen Brothers 30mm Dynamic Tii-On Block (A2030Tii)
The Allen Brothers A2030Tii is a 30mm single Dynamic block designed for soft attachment using rope or soft shackles. Featuring a stainless steel head loop, it provides a strong, reliable and low-profile solution for modern rigging systems where weight, alignment, and efficiency are critical.
With a maximum rope diameter of 8mm, it is ideal for fast-running control lines on dinghies and performance yachts.
Tii-On Soft Attachment System
The defining feature of the A2030Tii is its stainless steel head loop, designed specifically for soft attachment.
This offers:
- High strength with minimal cheek separation under load
- Improved reliability compared to traditional soft-attach designs
- Consistent block orientation when loaded
- Compatibility with Dyneema® lashings or soft shackles
The result is a lighter, more efficient connection that allows the block to align naturally under load, reducing side-loading and improving overall system performance.
Available with or without a soft shackle, the A2030Tii integrates easily into modern rope-based rigging setups.
Dynamic Bearing System for Low Friction Performance
At the core of the block is Allen’s patented Dynamic bearing system:
- Twin rows of stainless steel ball bearings
- Stainless steel bearing rail
- Acetal sheave
This configuration ensures smooth, low-friction sheave rotation, even under continuous adjustment. Compared to systems using plastic bearing races, the stainless-steel rail improves load distribution and long-term durability.
Ideal for:
- Cunningham and outhaul systems
- Kicker / vang cascades
- Traveller controls
- Lightweight performance setups
Integrated Becket for Compact Systems
The large central rivet acts as a rope-friendly becket, allowing:
- Direct line termination within the block
- Cleaner, more compact cascade systems
- Reduced need for additional hardware
This is particularly useful in multi-part purchase systems where efficiency and simplicity are key.
Correct Installation for Maximum Strength
Tii-On blocks rely on correct attachment to achieve full strength and performance.
For best results:
- The attachment line should be fed around the central axle and through the head loop
- A crossed or through-threaded configuration is recommended wherever possible
- When using a soft shackle, crossing the load path helps keep the block cheeks compressed
- Non-crossed attachment methods should only be used in lower load applications
This ensures the load is correctly distributed through the block, maintaining strength and alignment under load.
A Modern Solution for Soft-Attach Rigging
The A2030Tii combines the proven low-friction performance of the Dynamic range with a purpose-built soft attachment system.
For sailors moving towards Dyneema® lashings and lightweight rigging solutions, it offers a strong, efficient and highly adaptable block for modern control line systems.
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