Mast sections

C-sections and F-sections

Loads generated by the crew (mainsheet, vang, outhaul, Cunningham etc.) are transferred to the mainsail and on to the mast. As the mainsail is designed according to the expected curve of
the mast, a longitudinally stiff mast allows for
less luff curve of the sail. Instead, this sail area
can be added to the roach of the sail, where it is
subjected to the wind and more efficient. The
longitudinal rigidity of the mast section makes
for higher forestay load created by tensioning
the backstay. Running backstays can often be
avoided. The risk of mast pumping is also
reduced.

Mast Section I

y I
x Wall Weight W
y W
x Sail Sail MDS Sail section dim. thickness kg/m groove groove for car slides mm cm C211 -4475.
4 cm
4 mm cm
3 cm
3 mm bolt rope* Art. No.C-sections
C156 156/87 391 144 3.00 3.71 42.8 33.2 10 ±0.75 5.5 ±0.75 See 511-605 C175 175/93 558 191 3.24 4.18 53.6 41.0 page 49 or C193 193/102 779 257 3.40 4.74 69.3 50.6 511-607
C211 211/110 1051 341 3.65 5.34 86.5 62.0 See 511-605
C227 227/119 1407 456 3.95 6.15 108.0 76.6 page 49 or C245 245/127 1910 614 4.35 7.15 137.0 96.5 511-607
C264 264/136 2591 830 4.80 8.40 172.0 122.0
C285 285/147 3508 1127 5.20 9.72 214.0 153.3
C304 304/157 4686 1524 5.80 11.44 272.0 194.0
E321 321/171 5822 2038 5.5-6.5 12.84 324.4 238.7 6.25 ±0.75 ? ? 511-603 E365 365/194 8861 3113 5.5-6.8 15.15 441.5 320.9 Mast section measurements are given as follows:Major diameter/Minor diameter (i.e. 211/110).
This will help identification and the use of correct
measurements. The major diameter of the mast
can usually be found in the number engraved at
the mast heel. For example K23-
Major diameter
(211 mm) Measurement points
Space for luff tapeLuff groove XY Minor diameter (110 mm) F-sections
RA F176 176/93 526 187 2.89 4.20 58.2 40.0 See table page 9. ** F194 194/101 709 254 3.04 4.79 70.8 49.8
RA/RB F212 212/109 970 337 3.15 5.49 88.2 61.8
RA/RB F228 228/118 1306 453 3.40 6.35 112.0 76.8
RB F246 246/126 1781 613 3.75 7.44 139.0 97.3
RB/RC F265 265/135 2392 828 4.15 8.73 173.0 122.0
RB/RC F286 286/146 3237 1122 4.50 10.10 220.0 154.0
RC/RD F305 305/156 4389 1513 5.05 11.84 276.0 194.0
RC/RD R324 324/169 5576 2056 5.5-7.0 13.70 328.8 243.3 RD R370 370/192 8917 3139 5.8-9.0 16.61 471.7 327.0 Furling mast luff extrusion Weight A B kg/m mm mm
RA 0.55 2.8 ±0.25 6.0 RB 0.93 3.25 ±0.35 8.0
RC 1.28 3.25 ±0.25 10.6
RD 2.11 3.25 ±0.25 10.6 XY A BØ Big luff curve. Less roach.Stiff mast. Bigger roach for more projected area.
* If a traditional bolt rope is to be used, a plastic profile (Art. No. 535-710), as well as a sail feed (505-526-01) must be added to the luff-groove on the mast. ** For more detailed information on Seldén?s furling masts, see pages 88?103 or ?Sailmakers? Guide? (www.seldenmast.com).

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