Design 176 – Selestra 51
15.5m' Cruising Ketch

176
Other Drawings:

Gen. Arr. (with Magnify Tool).
Interior Plan & Profile.
Deck Plan.
Sail Plan.

Specification
LOA 15.500 m 50' 10¼"
LWL 13.568 m 44' 6"
Beam 4.400 m 14' 5½"
Draft, deep keel 2.200 m 7' 2½"
Draft, stub keel, c/b up 1.400 m 4' 7"
Draft, stub keel, c/b down 2.720 m 8' 11"
Displacement on dwl 18100 kg 39,904 lbs
Ballast 7000 kg 15,432 lbs
I 18.125 m 59' 5½"
J 5.540 m 18' 2"
P 16.310 m 53' 6"
E 5.775 m 18' 11½"
Py 10.025 m 32' 10¾"
Ey 3.790 m 12' 5¼"
Mainsail 41.100 m² 507.0 ft²
100% foretriangle 50.200 m² 540.3 ft²
Mizzen 19.000 m² 204.5 ft²
135% Genoa 68.400 m² 736.3 ft²
Mizzen staysail 44.500 m² 479.0 ft²
Engine 81 kw 110 hp
EU Category A - Ocean
The Selestra 51 is the first of new range of powerful classic modern cruising yachts envisaged primarily for construction in aluminium alloy, taking full advantage of our long experience of both designing and building in this material. The designs would also be suitable for cold-moulded wood/epoxy construction.

In aluminium alloy the Selestra class is built on well-spaced fabricated ring frames, the principal web components for which can easily be CNC cut, with the flanges naturally formed without rolling. A typical frame for the Selestra 51 is shown below – a larger image is here.

176 Selestra 51

Longitudinal T-section stringers are fairly closely spaced, running through the frames and naturally formed on the job. This system provides and extremely strong substructure, with relatively small panel areas, and will result in a very fair hull, requiring a minimum of filling and fairing if the hull is to be painted.

Plating is in diagonal strips, typically about 400mm to 500mm (16" - 20") wide, which will lay naturally around the hull without rolling or wheeling, and with little edge fitting required.

For yachts from about 10m (33') up, aluminium alloy really comes into its own with the best strength/weight ratio of all materials apart from exotic fibres. It is lighter and cleaner to handle than steel and used correctly in the right grades it doesn't corrode in a marine environment. It doesn't require painting, unless that is preferred, which pretty well produces the ultimate in a maintenance-free hull.

It can be cut with normal woodworking machinery and power tools (table saw, bandsaw, circular saw, router etc.). And it can be filed and drilled with ease. It does require good welding techniques and the correct welding equipment – for yacht work, almost exclusively MiG welding is used. Other than that, no specialist machinery is generally required.

The interior layout of the Selestra 51 is shown below; click the image for a larger version, together with a profile view.

176 Selestra 51

The detailed and accurate plans together with true step-by-step building instructions lead you through the building process simply and easily. Nothing is missed out. The plans are fully dimensioned. No scaling or lofting is required. You can trust the plans and instructions to be professional, practical, clear and detailed – just follow them and you will be successful. No other information is needed. Professional technical support throughout the build, is available by email, via the forum or by regular mail. More plan info