Skip to main content

Backstay Tensioner

Easy Upgrades: #1 of a seriesEvery fractionally rigged boat will have (or should have) a means of adjusting backstay tension. Its main purpose is to flatten and depower the mainsail in stronger winds, putting off the time at which a reef will be required. Because very few masthead-rigged boats are provided with backstay adjusters, cruising sailors regard them with the

Easy Upgrades: #1 of a series

Every fractionally rigged boat will have (or should have) a means of adjusting backstay tension. Its main purpose is to flatten and depower the mainsail in stronger winds, putting off the time at which a reef will be required. Because very few masthead-rigged boats are provided with backstay adjusters, cruising sailors regard them with the deepest suspicion–“just another thing to go wrong.” But on a masthead rig, backstay tension determines how much tension there is in the forestay, and therefore, how well the genoa sets.

In light winds, ease the backstay for a fuller, more powerful genoa; in stronger winds, tension the backstay to get the draft out of the genoa and improve the boat’s pointing ability and balance.

Few production boats have backstay adjusters fitted as standard, because of the cost, and because builders are worried that owners who do not know what they are doing would misuse the device and damage the boat or rig.

Installing a backstay adjuster need not be an expensive process, depending on the backstay arrangement. Masthead-rigged boats over 35 feet or so, with single backstays taken to a chainplate installed centrally on the transom, will require a hydraulic or mechanical adjuster. Mechanical adjusters are operated either by winch handle, wheels or flip-up handles; they’re simple and sturdy but they’re also slow to operate.

A typical self-contained hydraulic backstay adjuster like those made by Navtec is quick and easy to adjust, and usually has the advantage of a relief valve that will prevent the adjuster from overloading the rig. Both types of adjusters should have a scale or gauge installed so that the optimum settings can be noted and repeated. Backstay adjusters should be installed by professional riggers, as the penalties for poor installation can be severe.

On fractionally rigged (and some masthead-rigged) boats you will often see split backstays, with chainplates on the quarters. Usually, the twin backstays are joined to a single wire two or three meters up from the deck like an inverted Y. Replacing the tang with a sheave and one arm of the Y with a tackle is an easy and cost-effective process.

The sheave must be large in diameter and the tackle purchase should be 6:1, with good quality low-friction blocks. Measure it carefully, because it will probably need to be longer than you think—up to 3ft at full extension. A wire or Spectra strop should be installed between the backstay and the chainplate to ensure the mast won’t fall down if the tackle breaks or is accidentally released.

Another common method on boats under 30 feet is to rig a pincher tackle—a block on each arm of the Y attached to a 6:1 downhaul that draws the two together, thereby tensioning the backstay. These offer great purchase at light loads, but it decreases as the wires are drawn closer together; the longer the legs of the Y, and the closer together they are to begin with, the more efficient the tackle.

Related

Screen-Shot-2022-01-13-at-9.26.59-AM2048x

Video: Celestial Navigation Pt3

. In episode three of the Practical Celestial Navigation course, Andy Howe examines the theory behind celestial navigation, the celestial triangle and the celestial sphere, and why it is important to have a basic understanding of each. Topics introduced include zenith position, ...read more

01-LEAD-6.-After-2-years-ashore,-Nada-headsto-the-water-(3)

Sailing in the Time of Covid

In mid-August 2019, my wife, Terrie, and I laid up our Malö 46, Nada, in Falmouth, England, and flew home to Maine. We booked flights back to the UK for May 2020, anticipating a summer of cruising the Atlantic coasts of France and Spain. Then Covid struck. Remember that first ...read more

Ulysse Nardin promo photo

The Ocean Race Names Official Timekeeper

With just under one year before the start of The 2022-23 Ocean Race, Swiss watch manufacturer Ulysse Nardin has been named the official timekeeper of the race. The Ocean Race, formerly known as the Volvo Ocean Race and before that the Whitbread Round the World Race, announced ...read more

Arthur Daniel_RORC Maserati - RORC Transatlantic 2022 - Jan 15th -Social Media-4

Fast Finishes for the RORC Leaders

Over the weekend, the first finishers of the 2022 RORC Transat made landfall in Grenada, led by Giovanni Soldini’s Multi70 Maserati, which was awarded line honors with a corrected time of six days, 18 hours and 51 minutes. Maserati finished ahead of Peter Cunningham’s MOD70 ...read more

Background-02

Notice to Mariners: A Blog from the SAIL Editors

As a teenager, I stumbled across a copy of Derek Lundy’s Godforsaken Sea in the back room of a used bookshop. I had never heard of the Vendée Globe and frankly found all the boat-speak in the first 50 pages a little difficult to get through. But Lundy’s storytelling and the draw ...read more

Screen-Shot-2022-01-13-at-9.26.59-AM2048x

VIDEO: Celestial Navigation Episode 2

Celestial navigation is an invaluable tool for all kinds of sailors. In episode two of the celestial navigation series, learn the basic elements of navigation and the sight reduction process using declination and GHA to determine the Geographic Position and navigate using a ...read more

Film-poster-EP-2048

Cruising: Year of the Sea Shanty

Along with other timeless pursuits, like baking sourdough and gardening, singing sea shanties surged back into popularity during the recent lockdown, thanks, in part, to the app TikTok and its “duet” feature, which allows singers from around the world create music together. By ...read more

Book-Cover-9780712353700

Book Review: Sailor Song

Sailor Song is the ultimate guide to the music of working sailors during the 18th and 19th centuries. The book includes lyrics and sheet music for 50 of the most beloved sea songs with fascinating historical background on the adjoining page. Chapter introductions provide ...read more