Rodkickers, Boomstruts

Rodkickers and Boomstruts are a practical, user-friendly concept for supporting the weight of the mainsail boom on a sailing yacht, preventing it from dropping to the deck.

The integral 2:1 wire purchase system runs from the bottom of the rod around the top sheave and culminates in a free end (made off with a stainless steel thimble eye) to which a kicking strap (or vang) tackle should be connected. The 180° turn in the wire part of the Rodkicker doubles the power of the vang, and by the same token, reduces the load by 50%. The Kicking Strap tackle is not supplied as part of the Rodkicker, but you should be able to use your existing kicking strap blocks and line (subject to an adjustment in length) because, due to the integral wire, they should be stronger than the Selden recommendation.

Universal, as well as Selden specific, boom and mast brackets are available if the rodkicker ends do not fit straight on to your existing kicking strap attachment points. The Jimmy Green Rigging Sales Team are on hand to help you find the correct part number.

A study of the Selden charts below confirms that their recommended specification for the blocks on a normal Kicking Strap is higher than those on a Rodkicker Tackle. The Selden recommendations are based on a combination of Yacht Length Overall and Righting Moment calculated at 30% of heel. Righting moment is a measure of a yacht's ability to carry sail and is approximately proportional to displacement. Selden use righting moment as a major factor in their recommended specifications right across the spectrum of rigging applications and hardware, so it is extremely useful to know the answer for your own yacht. You will need to enter your Beam in mm, Draft in mm, Displacement in kg, Ballast in kg, whether it has a bulb or wing keel and the number of crew members normally on the rail:

Selden Righting Moment Calculator

Select the correct Rodkicker size by Maximum Righting Moment in kNm (or Displacement in tonnes)

There are two sizing charts: 1. Fractional Rig and 2. Masthead Rig

Boom Height is denoted and measured as per XBH, see image below SWL = Selden Safe Working Load

There is more detailed Selden information on sizing including comprehensive charts on normal, hard and extra hard gas springs, see below.

Selden Rodkicker Information and Size Guide

If you are still uncertain which model and/or gas spring is best suited to your yacht, please contact the Jimmy Green Rigging Sales Team with your yacht details for a reassuring check by the Selden experts.