AKL 4: specifications, drawings and experience of operation

In the world of water-motor tourism and amateur shipbuilding abbreviation LAX It's long since been a mere set of letters, a symbol of reliability and affordability. ACL 4 This is a classic example of a flat-bottomed vessel that can be assembled on its own from plywood or aluminum, and it has become a kind of "people's" model, capturing the hearts of fishermen and hunters across the country for its simplicity and maintainability.

The four-metre length of the hull provides enough capacity for a crew of three to four, while maintaining an acceptable weight for transportation on the roof of a passenger car. makeshift This type of design allows the owner to make design changes during the design phase, tailoring the vessel to suit specific needs, and it's the flexibility of the configuration that has made this project so popular for years.

However, despite the seemingly primitive design, the creation of a quality vessel requires strict adherence to technology. Violation of angular connections or the use of substandard plywood can lead to loss of tightness at the first serious excitement. In this article, we will discuss in detail all aspects, from the choice of materials to the installation of attachments.

Design features and geometry of the body

The basis of the project is a flat-bottomed scheme with a straight forehead and a transom. This geometry, often called Kazanka in the broad sense, has maximum stability on standing water. Flat bottom This allows the vessel to easily go to the planing even when using low-power engines, although the comfort of running on the excitement suffers. The width of the hull usually varies between 140-150 cm, which is the optimal balance between stability and dimensions.

The on-board skin is made of whole sheets, which minimizes the number of docking seams. ACL 4 It has a zygomatic fracture that not only makes the structure rigid, but also acts as a splasher. Bulkheads divide the interior into compartments, ensuring that it is not sinkable. seamlessness It is more critical here than in rounded boats, since the flat bottom takes on all the energy of the impact on the wave.

The transboard requires a lot of design attention, and that's where the main traction load from the motor comes from. The keel-to-knee angle of the transom is usually 0 degrees relative to the vertical, but when you install the motor, you often need a pad to compensate for the differentiation. If you're planning to use powerful motors, the transom design needs to be reinforced with additional ones. ribs Or make it double with a polyurethane foam.

⚠️ Attention: The use of plywood below grade 2/2 or 2/3 for the underbody plating is unacceptable. Internal voids of the veneer can lead to instantaneous destruction of the side when hitting the fuel.

Selection of materials: plywood or aluminum?

The dilemma of material choice is faced by every boat modeler. FSF (moisture resistant) remains the most popular choice because of its availability and ease of processing, it is easy to saw, drill and glue. However, the wood requires constant maintenance: painting, impregnation with olifer and protection against rot. The life of a well-made plywood boat is 10-15 years, after which a major bulkhead is required.

Aluminum alloys, such as AMG5M or AMG61MThey offer a whole different level of durability, and a metal boat is not afraid of hitting rocks, it's not afraid of temperature changes and humidity, but working with metal requires a welding machine (preferably argon) and welding skills. Corrosion Aluminum in fresh water is minimal, but electrochemical destruction can develop in salt water or in contact with copper alloys (for example, a propeller).

Weight specifications also differ dramatically: plywood housing with a thickness of 6-8 mm will be heavier than aluminum analogue with a sheet thickness of 2-3 mm, if you do not use lightweight frames. aluminum You get a “perpetual” boat, but you have to be prepared for the more complex assembly process.

Assembly technology and necessary drawings

The assembly process begins with cutting the sheet material according to the patterns. Drawings of ACL 4 boat It's usually a roll-out of the sides, the bottom, the transom and the deck, and it's better to cut with an electric jigsaw with a saw-saw on wood or metal, leaving a small allowance for the seams, and the accuracy of the cut-outs directly affects the quality of the frame assembly.

The hull is assembled on a slipway or flat ground, first the rods and zygomatic stringers are assembled to form the vessel's skeleton, then the hull and bottom are attached to the frame, and the plywood is joined by a "silk and glue" method of gluing the seams with glass and epoxy glue. Aluminium parts are joined by welding or on rivets with mandatory sealing of the seams. thiocol or polyurethane sealants.

Special attention should be paid to the installation of a hinge bar and a nozzle. These elements take on side impacts. The inside of the case is treated with antiseptics (for wood) or primers. The final stage is painting. The bottom is better to use special anti-fouling or rubber paints that hide small irregularities.

Table of the main technical specifications

To understand the scale of the project and the requirements for motorization, we give an averaged data characteristic of the classical modification. ACL 4These parameters may vary depending on the thickness of the material and the density of the wood or grade of aluminum used.

With a capacity of 450 kg, three adults with a full suite of fishing gear are comfortably accommodated, and it is not recommended to exceed this limit, as flat-bottomed vessels are sensitive to overload and can draw water with splashes even when under a little excitement. Displacement An empty boat is usually around 100-120 kg for the plywood variant and slightly less for the aluminum variant.

Motorization and installation of equipment

Selection of engine ACL 4 The flat bottom creates high water resistance, so to go to plane with full load will require power of at least 5-6 hp The optimal choice will be engines with a capacity of 9.9 hp with the ability to "smother" up to 15-18 hp More powerful engines to put does not make sense due to limitations on the strength of the transom and the general hydrodynamics of the flat-bottom.

The motor is mounted on a hinged transom or a fixed board. lower unit Flat-bottomers have a large angle of trim on the nose when entering the plane, so the motor often has to be bullied higher or used linings, and improper installation will lead to yaw and squirming of the boat.

Inside the cockpit, it is advisable to install stringers for mounting cans (seats), banks must be removable to free up space for cargo, and you should also provide for handdukes in the bow for storing things that are protected from splashes. Affixing equipment, such as ducks for anchor and spinning holders, it is better to attach to a hinge bar, so as not to violate the tightness of the skin.

⚠️ Warning: Never leave a boat with an engine installed on the water unattended for a long time. lower unit or corrosive elements can cause loss of control or engine failure.

Operation, storage and security

Plywood vessels are designed to be dried after each outing, opening the drain plugs, and better stored indoors or under a tight awning, excluding direct sunlight that overdries the tar and leads to cracks. Aluminum boats are less demanding, but require periodic washing of salt and dirt, especially if operated in seawater.

Safety on the water is the number one priority. Flatboats They have high initial stability, but when rolling more than 20-25 degrees can be turned over dramatically, so sudden movement of passengers on the sides is prohibited, and the presence of life jackets is mandatory for all on board, regardless of their ability to swim.

In winter, plywood boats should be kept at plus temperature or allowed to breathe so that the condensate does not destroy the structure of the tree. Aluminum winters at all temperatures, but before conservation, it is worth lubricating the moving parts of the engine and mounting elements. Proper storage prolongs the life of the boat for decades.

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