Shipman 28

Sailboat specifications

The Shipman 28 is a 28’11” (8.8m) cruising sailboat designed by Olle Enderlein (Sweden). She was built between 1969 and 1979 by Shipman Sweden AB (Sweden) and Albin Marine (Sweden).

Shipman 28's main features

Model: Shipman 28
Hull type: Monohull
Category: Cruising sailboat
Sailboat builder: Shipman Sweden AB
&
Albin Marine
Sailboat designer: Olle Enderlein
Country: Sweden
Construction: Hull and deck: GRP (glass reinforced polyester)
Number of hulls built: About 1000
First built hull: 1969
Last built hull: 1979
Appendages: Keel : fin without bulb
Helm: Single tiller
Rudder: Single rudder on skeg
Unsinkable: No
Trailerable: No
Standard public price ex. VAT (indicative only): N/A €

Shipman 28's main dimensions

Hull length: 28’ 11”8.8 m
Waterline length: 23’ 6”7.15 m
Beam (width): 8’ 6”2.6 m
Draft: 5’ 1”1.55 m
Mast height from D_WL: 35’ 1”10.7 m
Light displacement (M_LC): 6173 lb2800 kg
Ballast weight: 2668 lb1210 kg

Shipman 28's rig and sails

Upwind sail area: 461 ft²42.8 m²
Downwind sail area: 821 ft²76.3 m²
Mainsail area: 175 ft²16.3 m²
Genoa area: 285 ft²26.5 m²
Jib area: 132 ft²12.3 m²
Stormjib area: 58 ft²5.4 m²
Symmetric spinnaker area: 646 ft²60 m²
I iFore triangle height (from mast foot to fore stay top attachment): 35’ 1”10.7 m
J iFore triangle base (from mast foot to bottom of forestay): 10’ 8”3.25 m
P iMainsail hoist measurement (from tack to head): 31’ 10”9.7 m
E iMainsail foot measurement (from tack to clew): 10’ 2”3.1 m
Rigging type: Sloop Marconi masthead
Mast configuration: Deck stepped mast
Rotating spars: No
Number of levels of spreaders: 1
Spreaders angle: 0 °
Spars construction: Aluminum spars
Standing rigging: 1x19 strand wire continuous

Shipman 28's performances

Upwind sail area to displacement iThe ratio sail area to displacement is obtained by dividing the sail area by the boat's displaced volume to the power two-thirds. The ratio sail area to displacement can be used to compare the relative sail plan of different sailboats no matter what their size. Upwind: under 18 the ratio indicates a cruise oriented sailboat with limited performances especially in light wind, while over 25 it indicates a fast sailboat.: 232 ft²/T21.54 m²/T
Downwind sail area to displacement iThe ratio sail area to displacement is obtained by dividing the sail area by the boat's displaced volume to the power two-thirds. The ratio sail area to displacement can be used to compare the relative sail plan of different sailboats no matter what their size.: 413 ft²/T38.41 m²/T
Displacement-length ratio (DLR) iThe Displacement Length Ratio (DLR) is a figure that points out the boat's weight compared to its waterline length. The DLR is obtained by dividing the boat's displacement in tons by the cube of one one-hundredth of the waterline length (in feet). The DLR can be used to compare the relative mass of different sailboats no matter what their length: a DLR less than 180 is indicative of a really light sailboat (race boat made for planning), while a DLR greater than 300 is indicative of a heavy cruising sailboat.: 217
Ballast ratio iThe Ballast ratio is an indicator of stability; it is obtained by dividing the boat's displacement by the mass of the ballast. Since the stability depends also of the hull shapes and the position of the center of gravity, only the boats with similar ballast arrangements and hull shapes should be compared. The higher the ballast ratio is, the greater is the stability.: 43 %
Critical hull speed iAs a ship moves in the water, it creates standing waves that oppose its movement. This effect increases dramatically the resistance when the boat reaches a speed-length ratio (speed-length ratio is the ratio between the speed in knots and the square root of the waterline length in feet) of about 1.2 (corresponding to a Froude Number of 0.35) . This very sharp rise in resistance, between speed-length ratio of 1.2 to 1.5, is insurmountable for heavy sailboats and so becomes an apparent barrier. This leads to the concept of "hull speed". The hull speed is obtained by multiplying the square root of the waterline length (in feet) by 1.34.: 6.49 knots