Harken Ratchet and Ratchamatic Blocks

Harken Ratchet and Ratchamatic Blocks


For Harken blocks, there are three options:

- No ratchet, just a pulley or block

- Switched ratchet block - You can easily turn the ratchet on and off by flicking a small switch.

- Ratchamatic/Automatic ratchet block - the ratchet will automatically engage based on the load passing through the block.


Harken ratchet blocks hold a portion of the sheet's load, allowing you to trim and ease with complete control and allowing for faster trimming speeds. By only allowing the sheave to turn in the trimming direction, ratchets make it much easier to hand-hold higher loads. When you're holding or releasing the load, the faceted sheave grips the line, reducing fatigue and giving you more control. Additionally, since you don't need to maintain full control of the sheet while adjusting your grip, ratchets enable faster trimming.


What is Switchable Harken Ratchet Block

The switchable rachet block can be easily turned on and off. When the ratchet is engaged, releasing the line will cause friction over the ratchet sheave. As such, a ratchamatic block is ideal for an asymmetric spinnaker sheet on a smaller keelboat where the trimmer is holding the line while manually trimming the sail but later wants to release the line to allow the sail to run freely.


What is Automatic/Ratchamatic Harken Ratchet Block

Ratchamatic or an automatic switching ratchet block is set to a line load that engages the ratchet mechanism. That is used in a system where the line load is always going to be greater than what someone would want to hold for an extended period of time. However, when it comes to releasing the line, you want it to run as freely as possible.

Additionally, the automatic ratchet is very useful in boats with trapezes or racks, such as some skiffs or multihulls that have main sheet systems with ratchets in them. It's extremely difficult to get in off the wire or off the rack and come inboard to turn the ratchet off to ease out. An automatic ratchet would work well there.


The difference between a Ratchet Block and a Ratchamatic Block, is ― ratchet engages immediately when a predetermined load is reached. When the ratchet pawl is unloaded, it seamlessly disengages, allowing the sheet to run out instantly during mark roundings and jibes. The Ratchamatic allows lightly loaded sheets to run freely in both directions for fingertip control.


Available Products

40mm Harken switchable ratchet block

40mm Harken T2 automatic ratchet block

57mm Harken switchable ratchet block

57mm Harken T2 automatic ratchet block

57mm Harken automatic ratchet block

75mm Harken switchable ratchet block

75mm Harken automatic ratchet block