Welcome, visitor! [ Register | LoginRSS Feed

Post an Ad

Replacing your Standing Rigging

| Sail & Rigging | February 12, 2015

Rigging Inspection

cracked swage

There are no hard and fast times to replace your boats standing rigging, so regular inspection will help you know when to replace any stays. At the end of the season a thorough check leaves you time to make changes, while a quick check at the beginning of the season for clevis pins cotter pins etc. makes sure your rig is secure.

When inspecting your boats rigging check for;

    • Clevis & cotter pins
    • Cracks in swages and studs (see image)
    • Damage to wires (see image)
    • Damaged to turnbuckles

T Tterminal wire damage

During an inspection you find a shroud which has some issues. This observation becomes a concern and you inspect other parts of the rig and you see a couple of problems.

How do we go about fixing any problems.

    • Replace the wire part A
    • Replace the whole shroud B
    • Or Replace fittings



mearuring length

The answer is it depends on the damage. If the swage is cracked or the wire frayed, and the turnbuckle is OK, then you could just replace the wire. If the damage is local to the swage fitting or its cracked you could cut it off and replace with a swageless fitting with a extra long stud. For the DIY enthusiast this is a simple operation.

If just the turnbuckle is damaged this may be all that needs replacing. If the wire and the fitting is damaged the whole shroud should be replaced. This may be one shroud or the whole set of stays.

Whichever it is well look at how to do this.


Shroud Replacement (what you need to know)


Once you have figured out what you are replacing, the next step is how.

1;            Remove shrouds and give to Rigger

To do this it’s best to have the mast pulled during the winter or any downtime. If you remove the shrouds and send them to a rigger it’s almost unnecessary to do much more, as the rigger will be able to reproduce. If they have any questions they can ask for additional details.

2;            Measure rigging and order to swap out later

Measure rigging and order replacement for swapping out old for new at a later time. If you measure the rigging and send dimensions to a rigger for them to build replacements, this involves a lot more knowledge plus measuring in situ can be problematic.

3;            Replace yourself

Swageless fittings allows a boat owner to replace stays himself. You can replace one shroud at a time or if the mast is removed you can pull all the shrouds at one time.


Shroud details you need to know

    • Wire diameter
    • Clevis Pin diameter; these are sized to wire diameter.
    • Length of shroud (see measuring)
    • Terminal types; marine eye, fork, t terminal
    • Mast Tangs and backing plates
    • Turnbuckle stud thread diameter and hand right or left



Identify your Fittings

Main types of Sailboat Rigging Terminals

    1. Marine eye  / Marine jaw
    2. Stemball terminal
    3. T Ball Terminal
    4. Turnbuckles and studs

Top end

Marine eye, jaw, stemball and T Ball terminal

For these fittings you’ll need the tang type wire diameter plus the pin size

Tangs and backing plates; if you replacing shrouds make sure you have information on the existing mast tangs and plates so you can match to new fittings. Some T-Terminals are no longer made and new ones may have a different shape and the Gibb style T-ball may not fit into those backing plates.


Bottom end

marine eye, double jaw closed body turnbuckle, swaged stud, swaged open body turnbuckle

For these fittings you need wire diameter, clevis pin diameter, turnbuckle Stud diameter, and thread direction.

Note for a given wire size the thread could have 3 diameters. For example ¼ wire fittings can have a 3/8, 7/16 or ½ inch diameter.

If you have a turnbuckle stud at the bottom end you will need to know the wire diameter and the hand of the thread,

StaLok  Guide to Identify left or right hand threads



What sizes do you need; pin to pin dimensions, the wire size, terminal identification and terminal pin size are important. Some riggers use the pin centre as the definition of one end, other use the bearing point.

bearing points

bottom end bearing point


To measure a shroud, bang a nail into a suitable surface. Hang the shroud terminal on the nail and then hook the measuring tape on the same nail. Stretch out the shroud and tape, puling tight.


mearuring length

If you are making a whole new shroud you should measure the old stay and then when making the new one set the turnbuckle 2/3 open.

Turnbuckle 23 open

With the  turnbuckle 2/3 open, you have enough room to tighten the stay once the mast is stepped. Rigging stretches so the extra length to tighten the stay will be very beneficial. This 2/3 open is an Industry standard although some may set them at 1/2 open.


Replacing a terminal without replacing whole shroud


T Tterminal wire damage

One advantage of swageless terminals is they can be made by the DIY boater.

Advantages of swageless fittings

    • No need for specialized tools
    • Replace a shroud in the middle of an Ocean
    • You do not have access to a rigger
    • Replacing yourself DIY saves money

See this link for a full explanation of swageless fittings


In the example shown in the image (wire damage close to T Terminal), well show you how to fix this problem with swageless extra-long studs. Diagram A shows a normal swage above a extra long swageless fitting. The two lines show

Difference between normal swage and extra long swageless

where the wire ends inside the fittings. The distance between the two lines is how much can be gained by using a long swageless fitting. If you have the damage to wire and the damage is limited to 2 inches or less from the swage fitting then it’s possible to cut off the swage fitting and replace with a swageless fitting with a long stud.


Lets see how this works in practice with 1/4 inch wire. For this we need to look at the specs for normal and long fittings.

Navtec Norseman

The difference between c and b is what can be gained in length (diag B).

Specification Norseman fittings for ¼ inch wire; For 1/4 diameter wire with 1/2 inch thread; C = 5.71 inches, B = 3.27 inches

C-B = 2.44  inches which is the distance gained by using an extra long fitting.

Link to Noresman specs gives us the dimensions of B and C in the diagram B.




6178 total views, 1 today

Sailboat Standing Rigging

| Sail & Rigging | December 31, 2014

Swaged Rigging Terminals


swage machine

Sailboat rigging is simple in concept once you have a basic understanding. There are several parts which all work together to support a mast and sails. To make sure that your rig stays in one piece there are a few things you should know. Most mast failures occur from a simple loose cotter pin, frayed shroud or a cracked fitting. In this article we will be looking at Swaged Rigging Terminals, to help you understand what you may have and what other options are available.


Most sailboats rely on swage fittings at the terminals of wire shrouds. Swaging is the compression of the fitting onto the end of a wire by a roll swage machine. Therefore unless you have access to a swage machine you have to get a professional rigger to make them for you.

Swaging is different from Nicopress Type Swages which is the compression of a wire thimble over a wire to form an eye.

There are other wire terminals, swageless mechanical terminals, such as Noresman and Sta-Lok rigging terminals. These fittings can be installed by the DIY boat owner without any specialized tools.  We will look at these in another section in this sailboat rigging series.

Main types of Swage Sailboat Rigging Terminals

    1. Marine eye  / Marine jaw
    2. Stemball terminal
    3. T Ball Terminal
    4. Turnbuckles

Wire Terminals are normally made from Type 316 stainless steel.


1                   Swage Marine Eye


marine eye

These are the most common rigging terminals on sailboats. There are lots of sailboats with this setup of wire rigging with Marine eye ends attached to a stainless steel tang. Tangs are through bolted through the mast from one side to the other with compression tubes so the tightening won’t crush the mast wall. Now all you need to make is a set of wire shrouds with a marine eye at the top end. As well as Marine eyes and forks there are Aircraft eyes and forks. These are thinner than Marine eyes and often used for lifelines.


The picture above shows a simple single spreader rig, using Swaged Marine Eye’s with through bolted Tangs.

masthead Marine eye

The tang and eye fittings are the most popular seen on sailboats especially older ones. They are easy to make and inspect for maintenance. They can easily be made by a DIY boat Owner. Tangs can be bought from retail stores or specialized sellers like Rig Rite. Left is a Masthead Tang for marine Eye.




2       Swage Stemball Terminal

With this fitting the Stemball sits in a Cupel which itself sits in a tang, spreader base or spreader bar. The Stemball can articulate in the Cupels so the shroud can self-align. Here are three examples of Stemball terminals

A;    Swaged Stemball in Cast Spreader base

Stemball and cupel

The cast spreader base with integral shroud attachments were popular in the late 80’s and later. They proved to be quick and cheap to manufacture. However the problem with these mast fittings is the weakness in the spreader castings that attach to the mast. When these fail the whole mast is at risk, so it becomes a one point failure.

stemball thru cast spreader base800

The Stemball seats in a Cupel which sits in one of the two cutouts in the spreader base. Notice the T Ball terminal just in front of the spreader.

B;   Stemball in Spreader bar

A spreader through bar is a more modern use of spreaders and stemballs. The stemballs are fitted into a spreader bar which makes the Spreader bars structurally very secure. They take the load from the Spreaders and transfer through the mast without putting undue pressure on the mast wall. This is probably the strongest mast spreader shroud combination. It does require very accurate machining and needs professional Mast makers and Riggers to manufacture. This solution is more expensive but the lightest and is used mostly on racing sailboats.


thrubar stemballdetail

The above picture shows a rig with a Spreader through bar in which the Stemball is secured. The through bar has a hole for Stemball and Cupel. The second hole is for the Spreader Clevis pin. When assembling this type of set up you need to install the spreader through bar, push the shroud through the hole and then install the spreader over the bar and secure with the clevis pin. To remove the shrouds you need to remove the spreaders.

C;   Stemball Tang is fitted into the mast wall

More modern thinking using Stemball fittings for larger cruising boats. The Stemball Tang is fitted into the mast wall below the spreader. This approach is a little easier to build as the precise position of the shroud is not so important. However it not as structurally secure as the shroud is relying on the mast wall to transfer the load to the spreader, but can be built without specialized equipment or machining. Because the design is not as strong as the through bar solution the fittings and mast wall are larger and therefore heavier, but this is not a concern for most cruisers.

stemball mast wall

The Stemball fits into a Stemball Tang which mounts in a cutout in the mast Wall. In this case the wire fitting is inserted into the tang and then the complete assembly is pushed into the cutout. The tang is then screwed or riveted into place. The shroud cannot be removed without the tang also being removed. In the above picture the shrouds are discontinuous. The uppers and intermediates are terminated at the spreader. The upper shrouds join at the spreader tip with a Marine Eye and Fork and a Long Clevis pin. The diagonal shroud has a swaged turnbuckle and Fork.

3       Swage T Ball Terminal

Swaged shroud T terminal, sometimes called round T ball Terminals and even LollyPop’s. With the backing plate installed in the mast wall the round T ball is inserted into the mast plate at 90 degrees and then the wire and T ball is rotated inline. The black plug is inserted to secure the shroud in place. These are the easiest shroud fittings to install. However they are not quite as strong as some others. The weak point is the curved bearing point. However convenience is a big factor in using these fittings.tterminalplug

T Ball Terminals & Backing Plate

A  Smaller Gibb style T balls on a J80

Gibb T ball terminals are the first of this type. Now there are other T ball terminals like the Navtec ones seen below.

J80 T ball terminal DETAIL

T Terminals can be removed just by removing the plug and turning the shroud through 90 degrees.

B  Navtec style T Ball terminal on 42 foot cruiser

natec T ball terminal DETAIL

Navtec style T Ball terminal are newer and better for larger sailboats as the designs have bigger backing plates and the T Ball sits closer to the mast wall and not inside as with the Gibb Terminals. T Ball Terminals can be removed without removing the backing plate. The shroud is turned through 90 degrees so the T ball can be removed. There is a rubber plug that is inserted after the T ball has been installed so that the T ball cannot accidently fall out.


4          Swage Turnbuckles

Whatever the fittings you have at the mast or spreaders the bottom ends depend on the chainplates fitted to the deck and turnbuckle you will use. When setting up the turnbuckle it should be 2/3 open. That way you have enough room to tighten and half the amount to loosen when tuning the rig. This 2/3 open is an Industry standard and is you need a replacement shroud the rigger will set up the turnbuckle 2/3 open to the length you prescribe. The image below shows a boat with two examples of turnbuckle attachments. The chainplates seen are typical straps of stainless steel. Either on the side or through the deck. Turnbuckles to fit these chainplate should have a toggled bottom. This is important so the toggle can align with the line and load of the shroud. Without a toggle at the bottom end the turnbuckle bottom thread can bend drastically reducing strength.


A             Swaged threaded turnbuckle; this open turnbuckle body has a toggle at one end and a swaged stud at the other. The stud is swaged to your wire and is the recommended solution in this case. The fixed eye Turnbuckle on the other shrouds are prone to bending as they do not have toggles.

gibb swage Turnbuckle open

B             Marine eye to fit on double jaw fixed turnbuckle

fixed jaw turnbuckle erigging

The issue with this fixed jaw Turnbuckle is that there is no toggle. If the chainplate is not aligned up properly with the direction of the wire than the threaded part of the Turnbuckle (i.e. weakest link) can bend. Also as the rig moves in relation to the boat there is no give. A toggle lets the turnbuckle properly align at all times with the wire.   Now you understand the various Rigging Fittings what can we do to maintain then and how long should they last. To be continued.


Rigging Terminology

    • Clevis pin
    • Cotter pin
    • Marine eye, marine fork
    • Shrouds
    • Swage fittings
    • Swage studs
    • Swageless or Mechanical fittings
    • Tangs stainless mast
    • Threaded stud
    • Toggle
    • Turnbuckle open or closed, toggled, fixed, fixed eye jaw, fixed jaw,

15325 total views, 2 today

  • Boat Salvage Yards

    by on August 28, 2015 - 275 Comments

    This is a directory of Boat Salvage Yards by State in the US plus some overseas Businesses. These are Businesses which will come and help you dispose of a boat....

  • Conventional Stuffing box

    Stuffing Box Maintenance

    by on September 22, 2015 - 0 Comments

    Stuffing box maintenance You are getting water in the bilge and you track it down to the propeller shafts stuffing box (also called stern gland). The stuffing ...

  • Boat Donation Programs

    by on January 10, 2016 - 4 Comments

    at Donation programs take boats and use them in their in-house programs for a while before eventually selling them on. These Non Profit organizations will evalu...

  • Sailboat Standing Rigging

    by on December 31, 2014 - 0 Comments

    Swaged Rigging Terminals   Sailboat rigging is simple in concept once you have a basic understanding. There are several parts which all work togeth...

  • Selling Used Boat Equipment

    by on October 29, 2015 - 9 Comments

    Selling Used Boat Equipment? if you are one of the best places is UsedBoatEquipment.com. UsedBoatEquipment.com is a website for selling used equipment like a...

The Boatyard Categories