Guide to rigging component identification and terminology

From Fractional or Masthead Sloops to Gaffs, Ketches and Schooners, there is tremendous variety in yacht rig design. For each rig category, there are also a myriad of variations to allow for yacht size and specific sailing demands. Happily, there is a relatively small range of wire termination types and components available on the market.

When replacing your standing rigging with Jimmy Green, it’s useful to be able to identify the parts you have so that suitable replacements can be identified and ordered with confidence. This guide will take you through the basic components and what to look for.

Swage, Swageless and Talurit

The picture below shows a swageless eye terminal (top), a Talurit eye (middle) turned around a stainless-steel ferrule, and a swage eye terminal (bottom). Swageless terminals are characterised by a short overall length and a relatively wide body diameter. Swages are slim and relatively long overall. Talurits feature a soft brown copper ferrule.

Termination types

On smaller yachts up to 30ft, a standard 1x19 wire can be bent around a stainless-steel thimble and Talurit pressed into position using a copper ferrule. This option is usually available for up to 6mm wire. Bigger sizes of wire are not flexible enough to turn around the tight radius of a thimble without deforming to the detriment of its strength. This is the most economical method for terminating wire, and it is ideal for outsized pins and mast studs.

Swaging is the most popular type of wire termination. The wire is inserted into the hollow terminal and pulled through a set of roller dies. Stainless steel is not particularly malleable, so the pressure required by the roller dies is exceptionally high, creating a solid bar of material. Once swaged, the terminal cannot be re-used or positionally adjusted.

Swageless terminals utilise mechanical compression to grip the outer strands of the wire onto a cone or wedge. These terminals only require hand tools to install and are quite DIY friendly for the practical-minded. They can also be completely disassembled and re-used (some models require inner cone replacement) providing great longevity. 

 Machined, Forged, Tapped and Formed

Swaged terminals are manufactured using 1 or more of the 4 processes listed above. A machined part is milled from a solid piece of material. These parts can be manufactured to very precise tolerances. They also create waste material which is usually recycled to create further parts. Machined parts often look a little chunkier than forged parts because the internal grain of the material remains parallel requiring some faces to be longer to retain strength.

Some Petersen Stainless terminals are manufactured using a process known as electrical upset forging. The electrical current used internally aligns the grain structure of the stainless steel. The result is a stronger, lighter fitting that is also more resistant to loading fatigue. The picture shows a forged eye (top) with relatively minimal material needed to form the eye. The Machined eye (bottom) is slightly larger for the same size wire.

Machined or forged

Some Swage and Swageless terminals are made of several components. These parts are sometimes tapped together like the strap toggles below. The Sta-lok terminal (3rd from left below) has a stud screwed into a tapped cross bar. This terminal utilises a stainless plate ‘formed’ over the bar to create the toggle.

Types of terminal

The picture below shows the most common rigging terminals used at Jimmy Green Marine. From left to right, Fixed Eye, Fixed Fork, Toggle Fork, T-terminal (sometimes called a shroud terminal or T-ball), Stud, Stemball (Elephants foot) and the toggle on the bottom of a rigging screw. The line denotes the measurement point used by riggers at Jimmy Green Marine.

Measurement points

If a rigging screw is supplied as part of a finished wire, the measurement will be made with the screw two thirds open as shown below.

2/3 open

T-terminal Types

T-Terminals or shroud terminals often provide the trickiest selection choice. There are universal fit t-terminals on the market such as the Sta-lok and OS/BSI varieties, however, it is recommended that you try to match the mast backing plate to the t-terminal of the same brand. The thickness and width of the head, as well as the angle of the bearing 'shoulders', are all critical factors in selecting the right one. From left to right below. Victory Flathead, Hamma spoon, Petersen shroud terminal, OS/BSI T-terminal, Sta-Lok T-terminal and Navtec T-terminal (now discontinued).

T-terminals

The Hamma Spoon and Petersen Shroud terminals are designed as direct replacements for the discontinued Navtec T-terminal. The picture below reveals the variation in thickness and head angle to the swage. 

T-terminal side

Rigging Screws

Jimmy Green Marine commonly supply 3 types of rigging screw for standing rigging. These are sometimes referred to as bottle screws or turnbuckles. The most popular choice is the Stalok version (middle) which utilises a chrome plated, forged bronze body. The most popular choice is the Sta-Lok version (middle) which utilises a chrome plated, forged bronze body. The slightly more expensive Petersen Stainless version is machined from aluminium bronze bar with the open centres offset drilled from both sides allowing this turnbuckle to be 20 % lighter than forged equivalents and equally strong. The Bluewave turnbuckle (top) is for racing enthusiasts who want to easily adjust settings on the water. This turnbuckle features calibration, one extra-long stud and a fold-out arm to facilitate easy adjustments. 

Rigging Screws

It is most common for standing rigging turnbuckles to use UNF threads. Metric threads are available. However, it is a good idea to switch to UNF if you are replacing a complete stay to make replacement components easier to procure. Imperial wire is also quite rare in Europe but is readily available in North America. Imperial components can be sourced but will generally attract a bespoke quote and much longer lead times. 

Overall, if you think you have a part that is not listed here, email a photo to the Jimmy Green Sales team and we will take a look. 

Published: Apr 5, 2019