B&R rig
The B&R rig is a variant of the Bermuda sailboat rig, designed and patented by Swedish aeronautical engineers Lars Bergström and Sven Ridder.[1] It employs swept spreaders that are usually angled aft, together with "stays" running diagonally downward from the tip of the spreaders to the attachment of the next pair of spreaders to the mast or to the intersection of the mast with the deck (so-called reverse-diagonal shrouds) that facilitates a pre-bend of the mast (curving aft) that is sometimes tuned into the rig before it is stepped onto the boat. Conventional shrouds thereby contribute to both lateral and longitudinal stability, unlike rigs with unswept spreaders.[2] A B&R rig can be a masthead or fractional rig depending on how stays are configured;[3] a backstay is optional.[4] Such rigs are employed in many of the models of at least one U.S. manufacturer and in many thousands of boats, worldwide.[4][5]
History
[edit]The earliest B&R rig was the result of wind tunnel tests and research by Lars Bergstrom and Sven Ridder at Sweden's Royal Institute of Technology.[6] The first generation, built around 1970, included a backstay and was used on many production boats. A patent application for the B&R rig was submitted in 1973 and was granted in 1975.[1] A second generation eliminated the backstay but used solid, deck-mounted struts to brace the lower mast section. In 1982 a second generation B&R rig with 2 forestays was incorporated into the 60 ft (18.3 m) "breakthrough" racing yacht Thursday's Child. On February 13, 1989 Thursday's Child beat the 135 year old clipper ship record sailing 15,000 mi (24,140 km) from New York to San Francisco.[7] A third generation B&R rig mounted the mast on a tripod of struts, had a single forestay and no backstay. In 1993 the third generation was incorporated into the all carbon/kevlar 68 ft (20.7 m) yacht Route 66.[6][8][9][10] The 60 ft (18.3 m) yacht Hunter's Child finished 2nd in the 1994-95 BOC Challenge using a second generation B&R rig. By 1997 more than 10,000 production sailboats were using the B&R rig.[4][11]
Tuning
[edit]Part of the design of the B&R rig involves inducing a "pre-bend" in the mast which provides some of the side-to-side and fore-and-aft stability of the rig.[2][3][4] The pre-bend is achieved by tensioning the reverse diagonals and certain other so called intermediate shrouds. Because the spreaders are swept back at approximately a 25° to 30° angle, this tensioning bows the mast. Balanced and proper tensioning keeps the bow and the mast aligned in the fore-aft direction and eliminates any curvature in the sideways direction. The pre-bend is generally set up on the ground before the mast is stepped (placed onto the boat). The mast is then stepped and all other standing rigging is attached to the boat and properly tensioned.[4][6][12]
Boat and yacht models incorporating B&R rigs
[edit]The majority of Hunter Marine's fleet incorporated the B&R rig. However, manufacturers on both sides of the Atlantic Ocean have employed B&R rigs in their boat designs.
Models with 1st Generation B&R rigs
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Models with 2nd Generation B&R rigs
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Models with 3rd Generation B&R rigs
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References
[edit]- ^ a b US 3862613, Bergstrom, Lars Rune & Sven-Olof Ridder, Georg, "Rigging System for Sailboat", issued 1975
- ^ a b Henderson, Richard (1991). Understanding Rigs and Rigging. Camden, ME: International Marine Publishing. pp. 91, 93. ISBN 0-87742-283-4.
- ^ a b Killing, Steve; Hunter, Douglas (1998). Yacht Design Explained: A Sailor's Guide to the Principles and Practice of Design. New York, NY: W. W. Norton & Company. p. 134. ISBN 9780393046465.
- ^ a b c d e f g h Bergstrom, Lars (May 1997). "What, No Backstay?!". Cruising World: 35–38 – via Google Books.
- ^ Hunter Sailboat B&R Rig Design. Hunter Marine. 2010.
- ^ a b c Bergstrom, Lars; Ridder, Sven Olof (28 Jan 1995). The Development of the B&R Rig, Structural Space Frame and Tripod Support System with Integrated Boom. Chesapeake Sailing Yacht Symposium. Annapolis, Maryland – via Sailing Yacht Research Foundation.
- ^ Byrne, Dan (13 Feb 1989). "Sloop Thursday's Child Sails Into Record Books". Los Angeles Times. Retrieved 11 June 2018.
- ^ "ROUTE 66". www.yachtroute66.com. Retrieved 2018-06-12.
- ^ Bergstrom, Lars (14 November 1994). Another New Approach to Cruising Sailboats - Fast, Safe, Long-Distance Cruisers (PDF). 13th International HISWA Symposium on Yacht Design and Yacht Construction (PDF). Amsterdam. pp. 20–29.
- ^ "Route 66 Specifications Document" (PDF). Yacht Route 66 home page. Retrieved 13 June 2018.
- ^ "The B&R Rig". Boat.com. Retrieved 10 June 2018.
- ^ "Tuning the B&R Rig" (PDF). HunterOwners.com. Retrieved 10 June 2018.
- ^ "Hunter 34 Boat Review". Practical Sailor. Archived from the original on 13 June 2018. Retrieved 13 Jun 2018.
- ^ "Hunter 42 brochure" (PDF). Retrieved 13 Jun 2018.
- ^ "Hunter Passage 42 brochure" (PDF). Jordan Yachts. 8 Mar 2010. Archived from the original on 19 October 2020. Retrieved 13 Jun 2018.
{{cite web}}: CS1 maint: bot: original URL status unknown (link) - ^ "Windex 92 brochure". Issuu Inc. 19 Mar 2010. Retrieved 13 Jun 2018.
- ^ "Hunter 420 brochure" (PDF). Marlow-Hunter. Retrieved 13 Jun 2018.
- ^ "Hunter 420". SailboatData.com. Retrieved 13 Jun 2018.
- ^ "Tailwind 38". SailboatData.com. Retrieved 13 Jun 2018.
- ^ "The B&R 23". Torkel Boats. Retrieved 13 Jun 2018.
External links
[edit]- The yacht Route 66 home page.
- Hunter Marine's video explaining the B&R Rig Design.