Rig Tuning, Part 2—Understanding Rake and Bend

In Part 1 we got the mast upright so it was not leaning over to one side or the other.

Now let’s set the fore and aft rake and bend. But before we set off on that long and winding road, we need to make sure we really understand the theory of tuning. That's what this chapter is about.

Yeah, I know, we would all much rather I just wrote a step-by-step guide. I get that, particularly since it would be easier on me, too, but there are just too many variables to come at tuning that way.

(Part 1 was a teaser to get you hooked, before we got to the boring theory...I'm so devious.)

Rather, each of us must clearly understand how all the different factors interact before we start twiddling turnbuckles.

That said, once we deal with the theory, we will go on to a step-by-step guide. And, by combining that with this theory, each of us will be able to deal with pretty much any tuning situation. Surely better than monkey read, monkey tune?

Let's do it:

  1. Six Reasons To Leave The Cockpit Often
  2. Don’t Forget About The Sails
  3. Your Mainsail Is Your Friend
  4. Hoisting the Mainsail Made Easy—Simplicity in Action
  5. Reefs: How Many and How Deep
  6. Reefing Made Easy
  7. Reefing From The Cockpit 2.0—Thinking Things Through
  8. Reefing Questions and Answers
  9. A Dangerous Myth about Reefing
  10. Mainsail Handling Made Easy with Lazyjacks
  11. Topping Lift Tips and a Hack
  12. 12 Reasons The Cutter Is A Great Offshore Voyaging Rig
  13. Cutter Rig—Should You Buy or Convert?
  14. Cutter Rig—Optimizing and/or Converting
  15. Cruising Rigs—Sloop, Cutter, or Solent?
  16. Sailboat Deck Layouts
  17. The Case For Roller-Furling Headsails
  18. UV Protection For Roller Furling Sails
  19. In-Mast, In-Boom, or Slab Reefing—Convenience and Reliability
  20. In-Mast, In-Boom, or Slab Reefing —Performance, Cost and Safety
  21. The Case For Hank On Headsails
  22. Making Life Easier—Roller Reefing/Furling
  23. Making Life Easier—Storm Jib
  24. Gennaker Furlers Come Of Age
  25. Swept-Back Spreaders—We Just Don’t Get It!
  26. Q&A: Staysail Stay: Roller Furling And Fixed Vs Hanks And Removable
  27. Rigid Vangs
  28. Rigging a Proper Preventer, Part 1
  29. Rigging a Proper Preventer—Part 2
  30. Amidships “Preventers”—A Bad Idea That Can Kill
  31. Keeping The Boom Under Control—Boom Brakes
  32. Downwind Sailing, Tips and Tricks
  33. Downwind Sailing—Poling Out The Jib
  34. Setting and Striking a Spinnaker Made Easy and Safe
  35. Ten Tips To Fix Weather Helm
  36. Running Rigging Recommendations—Part 1
  37. Running Rigging Recommendations—Part 2
  38. Two Dangerous Rigging Mistakes
  39. Rig Tuning, Part 1—Preparation
  40. Rig Tuning, Part 2—Understanding Rake and Bend
  41. Rig Tuning, Part 3—6 Steps to a Great Tune
  42. Rig Tuning, Part 4—Mast Blocking, Stay Tension, and Spreaders
  43. Rig Tuning, Part 5—Sailing Tune
  44. 12 Great Rigging Hacks
  45. 9 Tips To Make Unstepping a Sailboat Mast Easier
  46. Cruising Sailboat Spar Inspection
  47. Cruising Sailboat Standing Rigging Inspection
  48. Cruising Sailboat Running Rigging Inspection
  49. Cruising Sailboat Rig Wiring and Lighting Inspection
  50. Cruising Sailboat Roller Furler and Track Inspection
  51. Download Cruising Sailboat Rig Checklist
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Eric Klem

Hi John,

Good explanation of rake and bend. One note on rake is that boat trim really matters. An awful lot of boats are down by the stern and only get worse with people in the cockpit. On our own boat, we had to relocate batteries and a few other items to get the fore and aft trim right and then we run very little rake, just enough that it looks right.

Even weirder looking to me than a boat with no or negative rake is a schooner or ketch with equal or decreasing rake as you go aft. Many of the older schooners used rake for a totally different purpose (mitigating bad slatting) but that is an aside.

I am seeing an increasing number of boats around us that have masthead geometries that are setup so that as you increase backstay tension, you also increase bend but that may be out of the scope of what you want to cover.

Eric

RDE

In one of the sillier projects of my long and disastrous career, I was hired by an American/Hong Kong consortium to convert an aluminum 12 meter into the only 24 passenger USCG certified America’s Cup boat on the planet. We bought the boat, two masts, and a container full of sails for about the cost of an new Catalina and then had it shipped from Long Island NY to Seattle in the middle of the winter. I got a call from the truck driver from somewhere in North Dakota where he had gotten jammed up trying to maneuver the 90 foot masts into a place to purchase trip permits. Once out of that town he hit upon the perfect solution. He just drove non-stop to Seattle with no permits but a lot of Mother’s little helpers. (a la Grace Slick/ Jefferson Airplane)

As I was unpacking the container I came across a giant hydraulic cylinder about 3″ in diameter & 6′ long.. Turns out that it was used to change the mast rake by moving the butt while underway. Standard sailing procedure involved throwing the mast head forward about 6′ on every downwind leg.

Among the other oddities of the rig was the mast weight rule. Since they had to weigh 1,000 pounds, the masts were chemically etched to reduce weight and then ballasted with lead in the base. Peculiar to the NYYC team, they had reduced the weight of the masthead lock to the point where it regularly jammed, requiring that a crew member be sent aloft to beat on it with a hammer before sail changes. Their other solution was to spray the sail track with silicone, thus ensuring that the Australian sand in the air was captured for posterity.

Fun with boats.

RDE

Hi John,
In that same era that you describe, the 6 meter Worlds were held in Seattle. We were out spectating when the wind returned to it’s normal summer force of zero. We towed Turner back to the dock but didn’t even get a thank-you to say nothing of a beer.

On my conversion of NYYC 42 I built a custom full batten mainsail system using Harken traveler track because ball bearing systems that large hadn’t been developed yet. Cut out the mid deck and welded in two 12 passenger longitudinal seats. Adapted hydraulic motors to all winches. Powered it with a 70hp Suzzie similar to the Beta you have in MC.

In principle you could singlehand the boat once it was done, the only problem being that by that stage in 12 meter development they had reduced the size of the rudder to the point where you had to tack the boat using the main to assist the rudder. Perhaps throwing the mast back and forth was part of race maneuvering as well! LOL

We may laugh at the silly products of Rules, but on the other hand back then no one would have thought of racing in the Southern Ocean on flush deck open cockpit boats that are continually swept by waves like the current Volvo boats.

Marc Dacey

John, some queries: how do these parameters change for deck-stepped masts; how do two backstays affect the issue (save for counting identical turns), and how do running backs, which are eased or tensioned according to point of sail and/or conditions, affect pre-bend and rake in the sense that they aren’t always in use?