DN Specifications

C. Mast

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IDNIYRA OFFICIAL SPECIFICATIONS

REVISED MAY 2022
Note: Dimensions are given in inches in the English System (except as noted) and in millimeters (MM) in the metric system.

C. Mast English   Metric  
1. Dimensions        
  Max Min Max Min
   a. Length overall (including hardware) 192 186 4876.8 4724.4
   b. The maximum fore and aft dimensions, excluding hardware: 4 101.6
   c. The minimum fore and aft dimensions, measured from full section above boom jaw area to a point located 127-1/2” (3238.5 mm) above the mast base: 3-1/2 88.9
   d. The minimum fore and aft dimensions, measured above a point located 127-1/2” (3238.5mm) above the mast base: 2 50.8
   e. The maximum side to side dimension, excluding hardware: 2-1/2 63.5
   f. The minimum side to side dimension, below a point located 127-1/2” (3238.5mm) above the mast base: 2 50.8
   g. The minimum side to side dimension, measured above a point located 127-1/2” (3238.5mm) above the mast base: 1-1/8 28.6
   h. The minimum depth of the boltrope tunnel from the outside trailing edge: 3/8 9.5

2. Materials: Aluminum; wood; carbon or glass fiber; adhesives; foam; fairing and finishing materials.

3. Other Specifications:

  1. Only one boltrope tunnel is permitted. The boltrope tunnel shall be substantially straight with the mast relaxed. Track is prohibited.
  2. Cross section profiles are optional. Mast may be solid or hollow.
  3. A halyard must be installed. An internal halyard is permitted.
  4. Devices which prevent or hinder movement of the boom on the mast are prohibited.
  5. The bottom of the mast must be fitted with a socket that will pivot freely on the mast step deck ball.
  6. The mast, without stays but complete with hardware and halyard used while sailing, may weigh no less than 15 lbs. (6.80 kg). Aluminum masts produced from a die existing prior to July1,1996 may weigh less than 15 lbs. (6.80 kg).
  7. When supported at one point in an approximate horizontal position, the mast, without stays but complete with hardware and halyard in sailing position, must balance at a point a minimum of 84 inches (2133.6 mm) from the mast base.
  8.  A removable internal reinforcement of allowable materials is allowed.This reinforcement may not be altered, turned or removed during a regatta.

INTERPRETATIONS OF THE OFFICIAL SPECIFICATIONS BY THE TECHNICAL COMMITTEE

Effective May 31, 2020

C. Mast
10/17/83: It is allowed to use a mast which is reinforced with carbon fibers from the inside as well as the outside.

10/17/83: It is allowed to reinforce an aluminum mast with a piece of wood from the inside.

7/01/96: Masts built prior to July 1, 1996, shall be considered legal if they meet prior specifications.

11/30/98: The minimum weight and balance point specifications (C.3.g and C.3.h) must be met with and without any removable internal reinforcement.

11/30/98: The mast must be one piece when used in a regatta.

02/15/2013: In specifications C.3.f. and C.3.g, the term “stays” includes all components and devices used to connect the cables to the mast hound at the height of the lower mast hound bolt, reference specification H.13., All components and devices used to connect the cables to the mast hound at the height of the lower mast hound bolt must be removed from the mast when determining the weight, C.3.f., and the balance point, C.3.g.