Turnbuckle or Deadeye

When you re-rig your yacht with synthetic standing rigging, you need to ask yourself if you want to keep your turnbuckles or not?

This question is ultimately up to the owner to decide. Each has their pros and cons, and you need to be willing to accept the limitations of each.

Turnbuckles are the standard method for tensioning standing rigging. Turnbuckles hold two screws, one has Left Handed threads, the other Right Handed threads. As you turn the turnbuckle, the threads will simultaneously pull in or push out. When they pull in, they will make the stay shorter and add tension in the process.

The reason turnbuckles work so well is thanks to the mechanical advantage they offer. Turnbuckles use a few simple machines to achieve their purposes, first is the inclined plane. The threads on the screw are actually an inclined plane, and as you turn the turnbuckle, you are moving along that incline. If your turnbuckle screws are 20 threads per inch, that means that 20 rotations will advance the screw 1 inch.

The turnbuckle also gets to take advantage of leverage in the form of a wrench or rod that can be used to manipulate the turnbuckle. The leverage gained by the rod multiplies the mechanical advantage of the incline plane in the screws, allowing the turnbuckle to tension the standing rigging to extraordinary levels!

Lastly, turnbuckles are compact. All this mechanical advantage is packed into a small machine which lives just above the chainplate. They are quick and easy to use and hold securely. As you can imagine, such a strong and powerful machine would have an equally qualified price to match, and they do. Turnbuckles are on the expensive side, and have a recommended service life of 10 years. After 10 years, they should be replaced, and the cost of doing so can be rather impacting. The minimum number of turnbuckles on a single spreader sloop rig is 8:

  1. Headstay
  2. Backstay
  3. Port Cap Shroud
  4. Starboard Cap Shroud
  5. Port Forward Lower Shroud
  6. Port Aft Lower Shroud
  7. Starboard Forward Lower Shroud
  8. Starboard Aft Lower Shroud

Additional stays from a second spreader, split backstay, or cutter rig will add turnbuckles and cost to the equation. When I re-rigged Wisdom, we had 11 stays to replace. The total cost for the materials (including extra line for spare stays) was $4,400. 11 turnbuckles would have added $1,100 to the cost, making the process of re-rigging much more expensive!

What could go wrong with a simple turnbuckle? A few things actually. Turnbuckles are typically made of stainless steel and bronze. The bronze components will last a very long time and show little damage from corrosion and stress. The stainless steel components will suffer from corrosion, both external and crevice. Crevice corrosion will lead to catastrophic failures with very little warning. While most of the turnbuckle can be inspected with ease, the section of threads inside the turnbuckle will prove very difficult to inspect. Yearly disassembly and inspection is recommended to evaluate for crevice corrosion, which then necessitates a yearly re-tune of the standing rigging. 

Turnbuckles offer a quick and easy way to tune your rigging with a few simple tools and a basic knowledge of rig tuning. Their only trade-offs are their ability to corrode and price.

The alternative to turnbuckles are deadeyes. Deadeyes use lashings to form a block and tackle setup at the bottom of the stay to achieve the necessary tension needed to tune the rigging. Deadeyes consume 4 feet of dyneema, making them rather economical by comparison. For example, a small deadeye made of 3mm dyneema would cost $6.40, while a large deadeye made of 9mm dyneema would cost $24.20; significantly cheaper than a turnbuckle.

As always, there is a trade-off. Deadeyes are much more time consuming and complicated to adjust when compared to turnbuckles. A small boat with turnbuckle rigging can be tuned in around 20 minutes, and under an hour for a mid-sized yacht. Deadeyes take nearly 20 minutes per stay and require advanced knowledge of knots and pulley systems.

While deadeyes may seem complicated and time consuming to adjust, they are not that bad. Standing rigging doesn't need to be adjusted all the time. I recommend a spring time tune up, which is a one time thing for the year, and not such an ordeal when lumped in with all the other spring time commissioning rituals.

Being how deadeyes are made of synthetic fibers, they will not suffer from corrosion of any kind. They are also very easy to inspect visually as any damage that occurs would occur on the surface of the rope and will be easily seen upon closer investigation. Pretty much, slight fuzziness is to be expected as the outer fibers degrade from UV exposure while the inner fibers remain unharmed; serious chafe will cause serious wear on the deadeye. If the chafe is severe, the dyneema grommet can always be replaced.

Deadeyes offer an inexpensive method to tension your standing rigging without any concerns of corrosion, but at the cost of more time consumed in tuning of the rigging. Turnbuckles offer quick and easy rigging adjustments but at a higher cost and with the risk of corrosion leading to failure.