Dimensions of the larger of the two yachts


I have had requests for drawings of some of my boats. Mostly they are of generic design, based upon details gleaned from the web. All perform well and are well tried in various weather conditions. Having said that I had to carry out major ' Surgery ' on the larger of my Freelancer tugs as it developed a startling heel when put hard about ! For details see the page describing the boat.

The measurements here were taken with care. The author provides all dimensions freely in the best of faith. Acceptance of the details given rests entirely with anyone who choses to build this model. Beyond the provision of details the author can accept no responsibility.

As I work from sketches there are no drawings for the large Yacht. However I have set out at the bottom of this page the key dimensions of the boat from which, given a sheet of detail paper, a rule, compass and a thin, flexible knot-free batten, the lines and sections may be developed.

All dimensions are in mm. The deepest point of the fin has been taken as Datum for the dimensions of the Sheer line and the Keel line and their eventual location relative to the building board.

Here are a few notes to assist in preparing details:-

The details may require minor adjustment as the lines and sections are developed.

Deck plan dimensions are taken from the centreline of the boat to the Sheer line.

Keel-to-chine and Sheer line-to-Chine dimensions are measured as verticals flat on the panel i.e. they are the actual dimension of the inclined panels. These dimensions in conjunction with dimensions taken from the plot of the Sheer and Keel lines allow the frame details to be established. When cutting ply for panels an allowance should be made for trimming when in place on the frames.

The key lines drawing..........................

On a suitably sized sheet of paper draw the horizontal line of the Datum, vertical lines at the Station points and, at the top, the line representing a Building board ( allow space to access for parting the sheeted hull from the board ). On each station line from 1 to 10 mark the Keel point and the Sheer point with reference to the Datum. The position of the, mast step, fin and rudder can also be plotted.

(A 1200mm long, small section, knot-free batten is bent around these point to draw the ' smooth curves ' of the lines in elevation)

On the same sheet the deck plan can be established from the Centreline-to-Sheer dimensions.

The Frames drawings............................

On a separate sheet of paper or card draw the vertical Centreline. Then either side of the Centreline draw in the Datum line, Keel line and the Sheer line at the station being developed, also a line establishing the building board level which is common to all frames.

Using a compass, arcs are struck from the Centre line at the Keel level and the sheer line plotted from the Deck dimension, in each case using the appropriate panel width, to establish the Chine position at their intersection.

The details can then be used in fabricating the frames which include a deck beam at sheer level.


The frames can be constructed of ply (or stripwood with corner stiffeners ) The frames to be extended to a common height to permit attachment to the building board when turned through 180 degress.

Once the basic frames are set up on the building board at their staions, intermediate frames can be developed as required using the batten. Some frames will require fairing-off to provide full support for the sheeting panels At this stage final adjustment can be made to the cutouts for the Sheer, Chine and Keelson to ensure that these sit properly. In all cases allowance has to be made for the ply thickness selected for the deck and panels.

At this stage the sheeting can be test fitted. it is helpful in the final placement, if during the trial fit, pins are driven at key points and removed leaving small locating hole in the frames for the first few final fixings..then with the frames given a coat of adhesive the panel can simply be located in its intended location

Later, when the hull panelling is complete suitably shaped additions can be added to the deck beams which are integral with the frames to form the deck camber to the builders requirements.

The Prow and Stern before the first, and and after the last station can best be formed from hardwood blocks, rough-cut and shaped after fixing to maintain the curves of the hull. The stern can be shaped to the builders requirements *.

The amount of ballast required on the fin can be determined in a floatation test once priming and undercoat have been applied to the hull. Layers of lead flashing material ( later suitably coated ) can be applied as required. These can be taped in place and added or removed prior to final fixing to achieve an acceptable waterline.

The key dimensions of the model are given below:-

The station points* are established at 100mm centres, Station Number 1 being 10 mm from the Prow of the boat.

Station*.....Datum-Keel.......Datum-Sheer....Centreline-Sheer...Side panel..Bottom panel




3------------------205-------------------- 340---------------------130---------------------95-------------105








Stern aft of station 10-------------------- See comment Above*

Further dimensions :-

Prow to medium mast step position 410. Prow to Chine start 45 .Prow to leading edge of fin at keel 400. Fin length at keel 220. Fin thickness15. Datum to aft end of fin 10. Prow to rudder post 860. Rudder 70 x 50 x40

Ballast lower front corner is at Datum. Aft bottom corner to datum 10. Fore top edge to datum 55. Aft top edge to datum 55.

Mast height 1400. Section of mast at deck level 18 x 20. Section at top of mast 15 x 15. The mast was split and the sail groove machined prior to re-assembly.

Stays throughout are from stranded model aircraft control line wire. Builders without a lathe will have to purchase thebottle jacks for tensioningI the stays.

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