Harken 40mm Twing Block
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Harken 40mm Twing Block
The Harken 40mm Twing Block (Part No. 2699) is a compact, low-friction Carbo Air snatch block engineered for fast, single-handed operation on dinghies, sport boats, and small keelboats. Part of Harken's proven Carbo Air series, it combines lightweight composite construction with high working loads to deliver reliable, effortless trimming in all conditions.
The opening sideplate is spring-biased to fold open when unlatched, allowing the block to be clipped onto a loaded sheet with just one hand — even while wearing sailing gloves. A locking mechanism automatically re-engages when the cheeks are closed, keeping the block securely rigged under load. The becket or fixing point is designed as a rotating sleeve, enabling the trim line to be rigged as either a 1:1 (splice or knot to the roller at the pivot base) or 2:1 (control line around the roller) purchase system for versatile up-down control. Sideplates and sheave are constructed from UV-stabilized carbo composite for durability and long-term resistance to sun exposure.
The block accepts sheet lines up to 12 mm in diameter and up-down control lines up to 10 mm. With a maximum working load of 275 kg (606 lb) and a breaking load of 825 kg (1818 lb), it provides a substantial safety margin for demanding racing applications. Weighing just 86 g (3 oz) and measuring 89 mm (3-1/2 in) in length, it adds minimal weight to any setup. For maintenance, clean with a mild detergent and water solution; do not apply lubricants to the sheave; flush thoroughly with fresh water after use in salt water.
Key Features
- Opening sideplate for easy rigging and removal from a loaded sheet
- Spring-biased to open when unlatched — true one-handed operation
- Roller at pivot base supports 1:1 or 2:1 up-down control rigging
- Rotating sleeve becket/fixing point for versatile purchase configurations
- UV-stabilized Carbo Air composite sideplates and sheave
- Lightweight at 86 g (3 oz) with 40 mm sheave diameter
- Maximum working load: 275 kg (606 lb); breaking load: 825 kg (1818 lb)
- Accepts sheet lines up to 12 mm and control lines up to 10 mm
- Suitable for dinghies, sport boats, and small keelboats
- Ideal for spinnaker sheet/guy control and code zero sheet up-down control
