Harken 75mm Double Block — Swivel is a high-load, high-efficiency solution designed for powerful purchase systems in demanding sailing applications. Part of the trusted Carbo Air range, this block delivers exceptional strength, smooth performance and reliability in a compact, lightweight design.
The double sheave configuration provides increased mechanical advantage, making it ideal for control lines and trimming systems where additional power is required. The large 75mm sheaves efficiently handle thicker lines, reducing friction and improving performance under load, while the swivel head ensures optimal alignment in dynamic conditions.
Built as a companion to Harken Big Boat blocks, this Carbo Air Double Block offers impressive working loads, making it suitable for sheets, vangs and high-load control systems on dinghies, keelboats and small yachts.
Specifications
Length: 152 mm / 6 in
Weight: 402 g / 14.2 oz
Sheave Diameter: 75 mm / 2 15/16 in
Maximum Line Diameter: 14 mm / 9/16 in
Maximum Working Load: 1100 kg / 2426 lb
Breaking Load: 2722 kg / 6000 lb
Shackle Pin Diameter: 8 mm / 5/16 in
Key Features
- Double sheave design for increased mechanical advantage
- Large 75mm sheaves for efficient handling of thicker lines
- Low-friction Carbo Air construction for smooth performance
- Swivel head for optimal alignment under changing loads
- High working load capacity for demanding sailing systems
- Lightweight yet strong construction
- Compact, durable design for marine environments
- Ideal for sheets, vangs and high-load control systems
- Suitable for dinghies, keelboats and small yachts
- Reliable performance for racing and cruising use





