User talk:Helmbuddy

The Steersman

The Steersman is a self-steering device for sailing boats. It was invented by Robert Chicken UK Patent No. GB2390350 (yr. 2001). It consists of two swinging platforms fitted on to the cockpit coamings either side of the boat. The jib sheet winches are moved from their normal position and re-bolted down on to the top of these platforms.



With the sails set, the leeward jib sheet is cleated to the winch in the normal way, and the wind pressure in the jib, transmitted through the jib sheet, swings the platform forward. To balance this movement, a shock cord spring tensioned between the platform and a point at the stern of the boat, keeps the platform in a central neutral position. Once set, any slight changes in wind strength or direction, causes the platform to swing forwards or backwards, and a simple linkage then transmits this movement to the helm to keep the boat on course. The pressure in the sails can vary hugely depending on the wind strength and the direction that the boat is travelling relative to the wind. To accommodate this, the spring is arranged in a ‘block-and-tackle’ form with a double block fitted to the stern of the boat, and a single block clipped to the platform. The fixed end, and tail end are also attached to the platform; the fixed end is clipped, and the tail end passes through a jamb cleat for fine adjustment. With this in place, the maximum spring tension is now made up of four lengths of shock cord. For a lower wind pressure in the jib, the fixed end, and the single block can be re-clipped to an attachment point on the base of the platform. This then gives a range of spring strengths from one to four shock cord lengths. And, for very light winds, a single lighter length of shock cord is used instead. Fine tuning is achieved by adjusting the tail end as it passes through the jamb cleat on the platform. The benefit of this design over a windvane system is that it is far more sensitive because it uses the larger jib area to sense any changes in the wind. This also has the benefit that it can operate in higher wind strengths, because a jib can be reefed down, a windvane cannot. Its position in the cockpit area also leaves the stern of the boat clear for other purposes such as dinghy davits, stern ladders etc. In 2012, this invention won the Haven Academy Award in the UK. The chairman of the judging committee was Sir Robin knox-Johnston, the first person to complete a circumnavigation non-stop, single handed.

Here are some links showing the Steersman in action:

https://www.youtube.com/watch?v=0aZmG1yC4uU&ab_channel=TheSteersman https://www.youtube.com/watch?v=A3IRecpbW_k&ab_channel=HavenKnox-Johnston https://www.youtube.com/watch?v=uoUjpwKug2k&ab_channel=RobertChicken https://www.youtube.com/watch?v=1pHNeOf-sts&ab_channel=TheSteersman https://www.youtube.com/watch?v=XPys_TvSE48&ab_channel=HavenKnox-Johnston https://www.youtube.com/watch?v=lGEwxEOQYIc&ab_channel=TVmarine

The Steersman
The Steersman is a self-steering device for sailing boats. It was invented by Robert Chicken UK Patent No. GB2390350 (yr. 2001). It consists of two swinging platforms fitted on to the cockpit coamings either side of the boat. The jib sheet winches are moved from their normal position and re-bolted down on to the top of these platforms.

With the sails set, the leeward jib sheet is cleated to the winch in the normal way, and the wind pressure in the jib, transmitted through the jib sheet, swings the platform forward. To balance this movement, a shock cord spring tensioned between the platform and a point at the stern of the boat, keeps the platform in a central neutral position. Once set, any slight changes in wind strength or direction, causes the platform to swing forwards or backwards, and a simple linkage then transmits this movement to the helm to keep the boat on course. The pressure in the sails can vary hugely depending on the wind strength and the direction that the boat is travelling relative to the wind. To accommodate this, the spring is arranged in a ‘block-and-tackle’ form with a double block fitted to the stern of the boat, and a single block clipped to the platform. The fixed end, and tail end are also attached to the platform; the fixed end is clipped, and the tail end passes through a jamb cleat for fine adjustment. With this in place, the maximum spring tension is now made up of four lengths of shock cord. For a lower wind pressure in the jib, the fixed end, and the single block can be re-clipped to an attachment point on the base of the platform. This then gives a range of spring strengths from one to four shock cord lengths. And, for very light winds, a single lighter length of shock cord is used instead. Fine tuning is achieved by adjusting the tail end as it passes through the jamb cleat on the platform. The benefit of this design over a windvane system is that it is far more sensitive because it uses the larger jib area to sense any changes in the wind. This also has the benefit that it can operate in higher wind strengths, because a jib can be reefed down, a windvane cannot. Its position in the cockpit area also leaves the stern of the boat clear for other purposes such as dinghy davits, stern ladders etc. In 2012, this invention won the Haven Academy Award in the UK. The chairman of the judging committee was Sir Robin knox-Johnston, the first person to complete a circumnavigation non-stop, single handed.

Here are some links showing the Steersman in action:

https://www.youtube.com/watch?v=0aZmG1yC4uU&ab_channel=TheSteersman https://www.youtube.com/watch?v=A3IRecpbW_k&ab_channel=HavenKnox-Johnston https://www.youtube.com/watch?v=uoUjpwKug2k&ab_channel=RobertChicken https://www.youtube.com/watch?v=1pHNeOf-sts&ab_channel=TheSteersman https://www.youtube.com/watch?v=XPys_TvSE48&ab_channel=HavenKnox-Johnston https://www.youtube.com/watch?v=lGEwxEOQYIc&ab_channel=TVmarine Helmbuddy (talk) 18:30, 17 August 2022 (UTC)