Self-build yacht project Natalie 800. Ballast fin, centerboard and rudder

In September 2001, on the Stugna website under the heading “Discussing an idea” there was a note by the yacht designer A. Nazarov (Sevastopol) about the proposed class of trailer cruise and racing yachts “T800”. The well-known yacht designer A. Taranenko (St. Petersburg), the author of the popular "Alekstars", actively supported the idea. Constructors and yachtsmen gradually joined in the development of the Class Rules. After a stormy exchange of ideas, a more or less final, 12th, edition of the Rules was born. Currently, the "T800" class is being legislatively consolidated, the Class Association is being created and it is included in the All-Russian competition calendar. We asked one of its creators to tell us about the new T800 class.

Main project ideas.

With today's uncertainty about the measurement and classification of cruising yachts in the CIS, yachtsmen, builders and designers are at a loss, while most are just waiting. The aging of the fleet of existing yachts, coupled with the lack of a clear strategy for the development of national classes and measurement rules, baffles yachtsmen - it is unclear what to buy or build: there is no clear perspective and the possibility of being “out of work” with a finished hull is scary ...

World experience shows that all attempts to “equalize the chances” and create handicap systems for cruising yachts are not very successful. It is unlikely that "absolutely fair measurement" is generally achievable in practice.

At the same time, cruiser yachtsmen should certainly meet at racing distances. Unfortunately, even in world practice, the policy of the official "sailing authorities" often does not contribute to the democratization and mass character of sailing, but is aimed at protecting the interests of specific manufacturers. Therefore, many yachtsmen and especially amateur shipbuilders often “drop out” from the racing process. Perhaps they should take the initiative into their own hands and propose the “rules of the game” themselves ...

One of the solutions and a very promising direction may be the cultivation of free (“open” - literally open) classes of yachts - such as the proposed “T800”. The advantages of free classes include the absence of any formulas and the simplicity of measurement, the conduct of races without a handicap, the broadest opportunities for improving the material part, a fairly long sporting life of ships, etc. It should be noted that in recent years the world has witnessed a truly rebirth of free classes - from “International 14” to modern “Mini 6.5” and “Open 60”.

The yacht of the “T800” class is seen as a small and relatively inexpensive, but rather fast, comfortable vessel for four people, suitable for transportation on a trailer behind a car to a place of rest or competition. The layout of the cabin should provide good habitability. Depending on the water area and the owner's preferences, these can be sailing dinghies, compromises or lifting bulb yachts.

“T800” can have water or solid ballast, various types of contours, sailing equipment, etc. The yacht must have reasonable safety and equipment requirements. It is important that the class will be best adapted to our conditions. But the main thing is that the “free class” status leaves room for the development of ships, for the technical creativity of yachtsmen, designers and amateur shipbuilders.

When developing the draft Rules, the authors largely focused on existing and popular yachts and the possibility of self-construction. With this in mind, a number of simplifying assumptions have been introduced into the Rules, which, nevertheless, should not worsen the driving performance and attractiveness of the boat.

The main provisions of the Rules.

There are two divisions - cruise and racing. The hull length should not exceed 8.0 m, width - 2.50 m, draft - 2.00 m, minimum weight - 1200 kg for cruising and 1000 kg for racing versions. An essential requirement is the ability to reduce the draft to 0.7 m for transportation on a trailer. Minimum freeboard restrictions have been introduced. The sail area is not standardized, but the dimensions of the mast are limited. The hull lines, the number and shape of keels, centerboards, rudders, etc. are not limited.

Layout of the cruising yacht: four berths, galley with stove and sink, latrine. The height in the cabin is at least 1.50 m on an area of ​​at least 0.75 m 2 with a length of 1.50 m and a width of at least 0.3 m. For the racing version, the height is at least 1.3 m on an area of ​​0.6 m 2 with a length of 1.30 m.

The rules regulate the ability to self-rectification: with a roll of 90 °, the yacht must independently recover with a load of 15 kg at the top of the mast. Tilting keels and masts, any movable ballast, trapezoids and the use of some expensive materials are prohibited. Requirements for equipment and supplies have also been developed. According to the author's idea, “T800” should fill the niche of rapidly aging “quarter” and “half-ton”.

The illustrations show some of our projects of yachts of the "T800" class.

In conclusion, I would like to immediately answer a number of possible questions:

- Why did we name this class of yachts T800?

First of all, because it is a trailer and its length is limited to 800 cm (which is required to transport a yacht behind a car). And, finally, which is especially pleasant, the name shows a certain continuity with the old Soviet "teshkas" (which, by the way, were also a free class).

- What is the real T800 fleet?

Taking into account the already built and still under construction yachts, the T800 fleet in Russia by the coming season will amount to more than 30 boats.

- Why is the minimum yacht weight limited?

First, to somehow equalize the chances of amateur-built plywood yachts with molded sandwiches. Secondly, to ensure sufficient strength and durability of the yachts.

- Why is the sail area not limited?

Sailing capacity will still have to be limited for design reasons, because the height of the mast, the length of the boom and bowsprit are limited. In addition, in practice the sail carrying ability is determined by the stability of the yacht.

- How much can a “T800” class boat cost if you build it yourself?

It depends on the region. In reality, the minimum cost of a wooden version will be about $ 3,000, depending on the quality of materials and components.

We hope that the appearance of "T800" will contribute to the development of sailing and yacht building in the CIS countries. We invite yachtsmen, shipbuilders, yacht designers to creative cooperation. It seems that by joint efforts it will be possible to create a truly "people's class" that will allow building and improving yachts of a new generation.

Yacht class T800 do it yourself

Cruise and racing trailer yacht "Cavalier 800" conceived and designed by us as a boat that can be built in the workshops of a yacht club or at home from available materials. In addition, since the T800 class is supposed to be free, options for modifying this project are provided in advance. We do not insist on the construction of a one-to-one boat according to the project, but we ask you to perceive the published drawings as a prototype and give the builders room for the flight of design ideas (of course, with proper technical justification).

A few words about the work that directly preceded the development of drawings. It was somewhat facilitated by the fact that earlier we had developed a project of a 5.9-meter cruiser "Pilgrim 590" similar in outline and design (Nazarov A., Kovalev M. "Pilgrim 590" - a family trailer cruise yacht - "Skipper" No. 6 - 2001. - P.12-15. And No. 1 - 2002. - P.13-15.). On the one hand, we wanted to provide a sufficiently high hydrodynamic characteristics of the boat to be able to successfully participate in races. At the same time, the contours should be sufficiently technological - for sheathing with plywood sheets, which is the most accessible in our conditions. It is known that in order to minimize the negative effect of the cheekbones, it is necessary to orient them along the streamlines and to avoid crossing the waterline by the cheekbones, including at running roll angles.

Basic data of the yacht "Cavalier 800"
Maximum length, m 8,00
Length at design waterline, m 8,00
Maximum width, m 2,50
Draft, m 0,63/2,00
Unladen weight, kg 1200
Sail area, m2:
- grotto 30,0
- staysail 13,5
- spinnaker 38
Dynamic characteristics:
- relative body length L / 3 √D SPL 7,52
- relative power-to-weight ratio √SA / 3 √D SPL 6,21

For a detailed study of the issue, with the help of specialists from the shipbuilding enterprise "AWL", a model of the hull was made on a scale of 1: 8 and towed in the seaworthy test laboratory of the Sevastopol National Technical University. In addition to measuring the towing resistance, the model was photographed and filmed.


At low relative speeds, as expected, the drag is slightly higher than that calculated for traditional "round bilge" contours. But at high Froude numbers due to the better separation of water from the cheekbones, the resistance of the Cavalier 800 hull is less.

Underwater video filming of the moving model was made with the help of the diving center "Union-Crimea". Viewing the video recordings for different speeds showed that the flow around the underwater part of the model with the "sorceresses" glued to the bottom occurs along the lines of the cheekbones. The slightly submerged transom used in the project has also proven to be effective. The materials of these design studies allowed us to improve the contours of the final version of the Cavalier 800.

Project concept

In developing this project, we set ourselves the goal of offering yachts a modern trailer cruise-racing yacht, economical and technologically advanced in amateur construction from plywood sheets. The yachtsman-racer will find in this project the necessary "base" to improve the driving performance for races in the "cruise" division (see the T800 class rules on the website www.kompanmarine.com).

For a family crew, the paramount qualities will be ease of management, a sufficiently high comfort, safety in operation on inland waters and in the coastal zone of the seas. The basic version of the Cavalier 800 is equipped with a centerboard, which makes shallow waters accessible. An outboard motor with a capacity of about 12 hp serves as a propulsion aid. with., hung on the transom. At the same time, let's make a reservation right away that the Cavalier 800 is a fairly fast boat, but still not an extreme boat. For fans of extreme sports, we can recommend the Pluto 800 project (see the KiYa magazine # 184).

The architecture of the hull and deck of the yacht "Cavalier 800"

The hull lines are multi-chine, with plating unfolding on a plane; a nose expanding above the waterline improves germination on a wave. The wide aft end with a slightly submerged transom, the longitudinal fullness coefficient C P = 0.57 and the center of magnitude position along the length L CB = 3.5% L WL are optimized for movement with high relative speeds.



Plasma ordinates table of the case

Frame numbers
0 1/2 1 2 3 4 5 6 7 8 9 10
Half-latitude from DP, mm
Keel 0 0 0 0 0 0 0 0 0 0 0 0
Ck1 5 13 27 78 153 214 246 256 255 234 195 144
Ck2 47 131 234 438 630 790 887 915 895 818 691 533
Ck3 96 209 344 598 817 984 1086 1120 1109 1051 955 835
LB 195 345 500 758 961 1108 1185 1214 1217 1186 1125 1041
Height from design waterline, mm
Keel -89 -138 -159 -183 -192 -196 -195 -190 -176 -138 -76 2
Ck1 -89 -138 -159 -183 -192 -196 -195 -190 -176 -138 -76 2
Ck2 140 121 99 58 21 -7 -25 -29 -19 6 43 86
Ck3 415 398 378 342 314 293 280 280 280 289 301 315
LB 970 956 940 909 883 862 848 836 826 816 808 800

The use of the superstructure "from side to side" allows you to get a more spacious cabin, simplify construction and significantly increase stability at high bank angles.

A spacious "two-tiered" self-draining cockpit with a length of 2.4 m is the main place of stay for the crew in good weather. The deck has an entrance hatch and a foreluck, used for working with sails.

We tried to pay attention to the design of the Cavalier's exterior. More aesthetic multi-chine contours, the faceted shape of the superstructure and modern contours of the windows were used. At the same time, the exterior of the yacht should not quickly become outdated, as is the case with "ultra-fashionable" boats.

General arrangement of the yacht "Cavalier 800"

The Cavalier 800 has an asymmetrical cabin layout. The effect of the spaciousness of the premises is enhanced by the spacious superstructure and large windows. A locker is fenced off in the forepeak part of the yacht; further - the bow cabin is actually an isolated bow berth. Further on the starboard side there is a bathroom, opposite - a wardrobe. In the saloon, on the starboard side, there is an L-shaped sofa and a table, on the left there is a galley and a navigator's table. The height in the cabin is 1.50 m. Along the sides of the cockpit there are coffin bunks, indispensable for resting on the move. The space under the cockpit is reserved for lockers. An insulated afterpeak locker is used to store the outboard motor, gas cylinder and skipper's equipment, accessible through the opening cockpit stern can.



1 - forepeak; 2 - double bed; 3 - wardrobe; 4 - latrine; 5 - galley; 6 - sofa; 7 - seat; 8 - chart table; 9 - bed; 10 - locker; 11 - gas cylinder compartment; 12 - storage compartment for the outboard motor; 13 - table; 14 - cockpit; 15 - podmast pillars.

Ballast fin, centerboard and rudder

The profiled centerboard is of the swivel type, it is flush retractable into the ballast fin fixed under the bottom. The hinged handlebar has a lifting arm.


Sailing rigs and deck equipment


Mast: mast - profile 130x80x2.5 mm, reduce to the top to 100x80x2.5 mm, AMg; boom - pipe 120x2 mm, AMg; bowsprit - pipe 80x2 mm, AMg; spreaders - pipe 28x3, AMg; standing rigging: main cables - cable 1x19, d = 5; medium cables - cable 1x19, d = 4; upper cables - cable 1x19, d = 4; forestay - cable 1x19, d = 5; backstay - cable 1x19, d = 4; backstays - cable 1x19, d = 4.

The mast is secured by fore- and backstays, backstays and shrouds carried to the stern. The project envisages: a mainsail with a large sickle, a twisted staysail, an asymmetric spinnaker on a retractable 1.5-meter bowsprit. We leave the detailing of deck equipment and sailing equipment to the discretion of the builder - an experienced yachtsman always has his own preferences ...

Structural drawings of the yacht "Cavalier 800"

Structurally, the building of the "Cavalier 800" is designed in the best traditions of domestic "unauthorized construction". A longitudinal set system with a large number of beams of the main direction - stringers - is used. Experience shows that the use of a longitudinal set system allows you to reduce the weight in comparison with the transverse one by about 30%, while reducing the complexity of the building. At the same time, the location of the frame frames and bulkheads is maximally coordinated with the layout of the boat, and the building elements at the same time ensure the strength of the vessel. There are fore A and aft P transoms, bulkheads and semi-bulkheads along frames B, F, H, L, N, frame frames D, J, M and flora C, E, G, I, K.

Constructive longitudinal section, body design
and deck structure


The body is sheathed with plywood sheets that unfold on a plane. The design was calculated according to the rules of the American Bureau of Shipping (ABS), which today is the generally accepted standard in yacht building.

Principal construction technology

The construction of the hull is carried out on the frame frames in the keel up position. A detailed description can be found in the superbly and easily written book by D. A. Kurbatov "15 projects of ships for amateur construction".

In short, the sequence of work is as follows:
- a welded building berth is made from rolled stock, installed and adjusted according to the level;
- using the plaza, frame frames are made;
- the frames are installed on the slipway, adjusted, the edges are milled;
- the keel beam is glued in place - on frames, from boards with a thickness of 10 mm;
- laminated stringers are installed, which are glued in place from two or three strips in thickness;
- the body is sheathed with 8 mm thick plywood sheets;
- the bottom is pasted over with fiberglass on epoxy resin in two or three layers, additional stripes are laid on the cheekbones, after which the body is puttied and prepared for painting;
- the hull is removed from the slipway and turned over to the position with the deck up;
- the most bulky elements of the internal furnishings are mounted;
- carlengs are installed (by analogy with stringers) (additional beams are visible on the given photos);
- the deck is sheathed with plywood sheets. Sheets of the superstructure can be assembled on wire clips, followed by gluing the seams with strips of fiberglass;
- the deck is pasted over with fiberglass, putty and prepared for painting;
- the hull is painted and the keel and deck equipment are installed.




1 - keel beam, laminated from oak, section at midship 200x40; 2 - knit (bow transom), pine, δ = 40 mm; 3 - old knit, pine, δ = 40 mm; 4 - bulkhead (shp. A), plywood, δ = 8 mm; 5 - frame A, 40x60; 6 - beams (shp. A), 40x60; 7 - bulkhead (shp. B), plywood, δ = 8 mm; 8 - frame B, 40x60; 9 - beams (shp. B), 40x60; 10 - bunk binding (sp. B), 20x30; 11 - bulkhead (sp. C), plywood, δ = 8 mm; 12 - frame C, 40x60; 13 - floor (sp. C), 40x80; 14 - bunk binding (sp. C), 20x30; 15 - bulkhead (sp. D), plywood, δ = 8 mm; 16 - frame D, 40x60; 17 - beams (sp. D), 40x60; 18 - floor (sp. D), 40x80; 19 - bunk binding (sp. D), 20x30; 20 - knit (shp. D), plywood, δ = 8 mm; 21 - bulkhead (sp. E), plywood, δ = 8 mm; 22 - frame E, 40x60; 23 - floor (sp. E), 40x80; 24 - bunk binding (sp. E), 20x30; 25 - bulkhead (sp. F), plywood, δ = 8 mm; 26 - frame F, 40x60; 27 - beams (sp. F), 40x60; 28 - floor (sp. F), 40x80; 29 - strapping (sh. F), 20x30; 30 - bulkhead (sp. G), plywood, δ = 8 mm; 31 - frame G, 40x60; 32 - floor (sp. G), 40x100; 33 - strapping (shp. G), 20x30; 34 - bulkhead (sp. H), plywood, δ = 8 mm; 35 - frame H, 40x60; 36 - beams (shp. H), 40x60; 37 - floor (sp. H), 40x100; 38 - harness (shp. H), 20x30; 39 - bulkhead (sp. I), plywood, δ = 8 mm; 40 - frame I, 40x60; 41 - floor (sp. I), 40x100; 42 - harness (shp. I), 20x30; 43 - bulkhead (sp. J), plywood, δ = 8 mm; 44 - frame (sp. J), 40x60; 45 - beams (sp. J), 40x60; 46 - floor (sp. J), 40x100; 47 - harness (sp. J), 20x30; 48 - knit (sp. J), plywood, δ = 8 mm; 49 - bulkhead (sp. K), plywood, δ = 8 mm; 50 - frame (sp. K), 40x60; 51 - floor (sp. K), 40x100; 52 - strapping (shp. K), 20x30; 53 - bulkhead (sp. L), plywood, δ = 8 mm; 54 - frame (sp. L), 40x60; 55 - beams (shp. L), 40x60; 56 - floor (sp. L), 40x100; 57 - strapping (shp. L), 20x30; 58 - knit (shp. L), plywood, δ = 8 mm; 59 - access hatch trim (sp. L), 20x40; 60 - bulkhead (frame M), plywood, δ = 8 mm; 61 - frame (frame M), 40x60; 62 - beams (sp. M), 40x60; 63 - floor (frame M), 40x100; 64 - strapping (sh. M), 20x30; 65 - knit (shp. M), plywood, δ = 8 mm; 66 - bulkhead (sp. N), plywood, δ = 8 mm; 67 - frame (sp. N), 40x60; 68 - beams (shp. N), 40x60; 69 - floor (sp. N), 40x100; 70 - strapping (shp. N), 20x30; 71 - transom sheathing (sp. P), plywood, δ = 8 mm; 72 - frame (sp. P), 40x60; 73 - beams (shp. P), 40x60; 74 - floor (sp. P), 40x100; 75 - stand (shp. P), 40x150; 76 - fenders laminated from oak, 50x30; 77 - laminated pine stringer, 40x25; 78 - laminated pine stringer, 45x30; 79 - laminated pine stringer, 45x30; 80 - laminated pine stringer, 45x25; 81 - laminated pine stringer, 50x30; 82 - bunk flooring, plywood, δ = 8 mm; 83 - payol, plywood, δ = 8 mm; 84 - toilet wall, plywood, δ = 8 mm; 85 - sofa wall, plywood, δ = 8 mm; 86 - sofa flooring, plywood, δ = 8 mm; 87 - cabinet wall, plywood, δ = 8 mm; 88 - pillers, steel δ = 50 mm; 89 - galley wall, plywood, δ = 8 mm; 90 - cushion wall, plywood, δ = 8 mm; 91 - galley tabletop, plywood, δ = 8 mm; 92 - sofa flooring, plywood, δ = 8 mm; 93 - sofa strapping, 20x30; 94 - bunk flooring, plywood, δ = 8 mm; 95 - longitudinal bulkhead, plywood, δ = 8 mm; 96 - rail, 40x25; 97 - bed carlengs, 20x30; 98 - afterpeak flooring, plywood, δ = 8 mm; 99 - rail, 50x25; 100 - rail, 40x25; 101 - longitudinal bulkhead, plywood, δ = 8 mm; 102 - bow transom decorator, styrofoam; 103 - bottom sheathing, plywood, δ = 10 mm; 104 - cheekbone 1, plywood, δ = 8 mm; 105 - cheekbone 2, plywood, δ = 8 mm; 106 - board, plywood, δ = 8 mm; 107 - deck planking, plywood, δ = 8 mm; 108 - superstructure coaming, plywood, δ = 8 mm; 109 - superstructure roof, plywood, δ = 8 mm; 110 - carlengs, 50x25; 111 - carlengs, 40x25; 112 - carlengs, 40x25; 113 - carlengs, 40x25; 114 - carlengs, 80x25; 115 - carlengs, 40x25; 116 - carlengs, 40x25; 117 - carlengs, 40x25; 118 - carlengs, 40x25; 119 - half-beams, 40x25; 120 - carlengs, 50x25; 121 - carlengs, 40x25; 122 - carlengs, 40x25; 123 - carlengs, 45x25; 124 - carlengs, 40x25; 125 - carlengs, 40x25; 126 - carlengs, 40x25; 127 - carlengs, 40x25; 128 - carlengs, 40x25; 129 - coaming strapping, 20x20; 130 - strapping of the aft compartment, 20x15; 131 - carlengs, 40x25; 132 - carlengs, 40x25; 133 - carlengs, 40x25.

Keel

The fin of the keel is either welded (assembled from vertical plates) or cast. The total weight of the fin (without centerboard) should be 300 kg. If necessary, additional internal ballast can be placed in the hull of the yacht "Cavalier 800".

Albert Nazarov, Maxim Kovalev, Dmitry Dolinsky.

 

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