57mm Ratchamatic® HTE Block — Swivel

Harken 57mm Ratchamatic® HTE Block — Swivel

The Carbo Ratchamatic® is a load-sensing ratchet block that rolls freely in both directions under low loads and automatically engages the ratchet as loads increase. Shifting between ratchet and light-air modes is seamless, making it an ideal choice for sailors who need precise control across a range of wind conditions.

The HTE (high-threshold engage) version of the 57 mm Carbo Ratchamatic block was engineered with a stiffer internal spring to delay the point where the ratchet engages, allowing the block to run free more of the time. The ratchet function engages at higher loads to allow the old kite sheet to run free for crisper gybes. Once the load threshold is met, the ratchet automatically engages to provide the necessary holding power for heavy-air trimming.

The sideplates are constructed from high-strength, UV-stabilized composite material, making the block significantly lighter and stronger than comparable stainless steel alternatives. An eight-facet machined aluminum sheave provides consistent 10:1 holding power once engaged. The swivel attachment enables smooth articulation and versatile deck positioning.

Key Features

• High-Threshold Engagement (HTE): Stiffer internal spring delays ratchet activation for crisper gybes and a free-running lazy sheet
• Load-sensing performance: Seamlessly transitions from free-spinning light-air mode to high-grip ratchet mode as breeze increases
• 10:1 holding power with standard grip sheave once ratchet is engaged
• Durable Carbo construction with high-strength, UV-stabilized composite sideplates
• 57 mm sheave diameter accommodates lines up to 10 mm (3/8 in)
• Swivel mounting for versatile installation and optimal lead angles
• Popular applications include asymmetrical spinnakers, J/70 and Melges 24 kite sheets, mainsheet systems on performance dinghies, and sportboat control systems