Motor boats are the most common means of transportation in small water bodies, as well as in coastal areas of the seas and oceans. The convenience of this type of transport lies in the fact that the vehicle itself is relatively inexpensive, and, moreover, does not require large expenditures on fuel or components. The boat can freely deliver several people to the right place in the shortest possible time, and even a child can master its management. Most often, such vehicles are used for boat trips, patrolling the territory, as well as for fishing.
The boat "MKM" is one of the most prominent representatives of this category of transport. The thing is that it successfully combines several very valuable technical qualities that are in demand among domestic customers. It is worth noting that today on the market you can find a large number of defective or fake products. So it’s worth buying only those boats that have been certified, and even better, contact the branded distributors of these products.
Technical characteristics of the boat "MKM"
In short, all the data about this vehicle can be presented in the following form:
- the greatest length is 410 centimeters;
- maximum width - 152 centimeters;
- side height in the almond - 57 centimeters;
- the deadrise angle of the bottom in the transom is 2 degrees;
- estimated weight together with equipment and supplies - 150 kilograms;
- load capacity - 400 kilograms;
- passenger capacity - 4 people;
- maximum power of the installed motor - 25 Horse power;
- maximum speed with the most powerful engine and full load - 32 kilometers per hour.
Useful improvements boat "MKM" General description of the boat
This model of motor boats began to be produced in the sixties of the last century. As a basis for it, an older sample was taken - the MK29 motor boat.
By the way, MKM inherited a large number of details and features from this model. Particularly the outlines. The main reason for the creation of such boats was the moral and physical obsolescence of the Kazanka boat models, which could only work with motors with a power not exceeding 12 horsepower.
Nevertheless, the arrangement of the MKM for a more powerful engine created its own difficulties. In particular, there was a problem of movement on an undulating water surface. This boat can only be used in almost complete calm, as oncoming waves hitting the bow with force will splash almost everything inside, and, in particular, the cockpit. Of course, passengers will also be far from being in the most comfortable conditions.
Boat hull MKM
The hull of the boat is entirely made of duralumin alloy, and has a thickness not exceeding one millimeter. The design itself, as was customary in those years when it was only being developed, was made by means of rivets. Among the characteristics of the MKM boat, one cannot fail to note the bottom, which was characterized by a flat deadrise with a corresponding indicator not exceeding two degrees. Of course, this has a very negative effect on the stability of the swimming facility. 
A significant drawback of the boat are also extremely low cheekbones. They provide little to no splash protection, which is why many owners try to fix this problem on their own. Additional intakes are installed near the sides, which act as spray deflectors.
However, it is worth noting the undeniable advantage of the boats of this model. They have incredible stability when stationary, which is a very important factor in user comfort during operation.
The fact that the sides converge in the stern from above contributes to this in the best possible way. In addition, the blocks providing buoyancy are located in two places of the MKM boat.
Seaworthiness of the boat "MKM"
The use of the motor boat "MKM" is significantly limited by the height of the wave on the water surface. If this indicator exceeds 30 centimeters, this means that operation is not recommended, as this may be unsafe. Of course, this narrows the range of cases and situations when you can go to sea on this boat, or swim on a wide river or a large lake.
In addition, if the required amount of horsepower is even slightly exceeded, the boat may begin to behave completely inappropriately, and at the same time all safety indicators will significantly decrease. That is why the main area of operation of this kind of equipment is short-term walks along the coastal zone and small reservoirs, as well as parking fishing in these smallest reservoirs. In addition, she showed herself well on small rivers.
With the advent of 20-horsepower outboard motors, the question arose of the need to replace the then almost only motor boat Kazanka: it was still produced in large series, but it was no longer suitable for operation with such motors. As a replacement, shipbuilders offered a metal version of the previously popular MK-29 plywood motor boat designed by E. E. Kloss. The theoretical drawing was completely borrowed from this project, the hull design was copied from the Kazanka - and this is how the wider and high-sided (it would seem - and more seaworthy!) MKM appeared, for the construction of which in 1967-1969. seven factories took over at once!
Soon, after the modernization and the corresponding increase in the price of the Kazanka with boules - the MD model was already sold at a price of 400 rubles, the MKM became the cheapest motorboat: the retail price of most of the boats was 370 rubles. (Note that some builders not adapted to the large-scale production of boats were forced to sell the MKM at a higher price - up to 450 rubles; while the expensive boat did not differ more high quality manufacturing, nor any additions to the equipment.)
What can be said about the contours of the "MKM"? Its theoretical drawing () was developed almost 20 years ago with the expectation of operating mainly with the 10-strong Moscow, under which the MK-29, which had a light, 70-kilogram hull, developed top speed up to 30 km/h. With a load of 3-4 people, the boat was in transition to planing mode, therefore, in order to improve its hydrodynamic qualities, it was necessary to increase the width of the bottom and limit the deadrise angle to a minimum value (at the transom - 4 °). The bending of the bottom down at the transom also contributed to the entry into gliding and the reduction of the running trim. Thanks to this bend, the value of which is the same on the "MK-29" and "MKM" and is 8 mm, the aft section of the bottom is located at a greater angle of attack to the oncoming water flow than the middle of the hull; a significant lifting force is created here, which raises the stern and “puts” the bow of the boat on the water.
But what was good for the 10-strong Moscow turned out to be significant shortcomings when installing twice as powerful "Whirlwind" and "Mskva-25" on the same boat. It is well known that a boat with a wide and flat bottom is planing at a minimum angle of attack, and the effect of the bottom bend also acts on the MKM. Therefore, when meeting even with a small wave, clouds of spray break out from under the low-lowered cheekbone of this boat and fall on the heads of the passengers and the driver of the boat. Attempts to raise the bow - to increase the running trim to the stern, giving the boat a stern load, do not give an effect. It is not uncommon to see how the MKM is driven by sitting on the very transom and lowering their legs into the engine compartment. And the reader of the Petrushko collection from the city of Novochebok-sarsk tried to improve the seaworthiness of the boat by loading the engine compartment to the top with wet sand; against the wave, the boat, indeed, went better, but its speed fell by almost half.
V.V. Borodenko from Saratov made an outrigger bracket behind the transom of his MKM, on which he hung two Neptunes, installed longitudinal steps and zygomatic splash guards, moved the boat control post to the stern and placed 4 fuel canisters here. And all this taken together could not "tear off the bow" of the boat from the water, significantly improve it driving performance on the wave.
It goes without saying that attempts to equip the MKM with a remote control with a steering wheel in the bow of the cockpit - near the windshield, further exacerbated the existing drawback. The boat not only did not float on the oncoming wave, but crashed into it, losing its course. It is not surprising that, despite the large width and significant stability of the MKM, from time to time there are cases of capsizing of boats of this type: after all, it is enough to make a sharp movement with the tiller on a passing or side wave ...
Needless to say about strong blows that a flat-bottomed boat gets when going against a wave, about an uncomfortable engine compartment, a lack of an awning and a fragile windshield, about a hopelessly outdated design. It is very good that by now the production of MKM has been discontinued at five plants, but two enterprises continue to produce this far from perfect model this year.
Well, what to do with tens of thousands of "MKM", which are already in personal use?
If we leave aside the irreparable shortcomings inherent in the MKM, like any boat with a flat bottom of low deadrise, then we can say that the “root of evil” is the bend of the bottom at the transom. Therefore, first of all, it is necessary either to get rid of this limb, or to neutralize its effect.
To eliminate the bending of the bottom, it is necessary to expand the rivet seams that fasten the bottom and side skin along the cheekbone, as well as to the bottom stringers and keel, starting from the transom to the second frame from the stern. The lower edge of the transom, together with the bent flange, should be cut off by 8 mm, and the edge of the engine compartment bulkhead by 3 mm. Accordingly, it is necessary to cut the edge of the side sheets adjacent to the cheekbone, then upset the bottom stringers flush with the new surface of the bottom, and rivet the knit at the transom.
Having assembled the set on temporary M4 bolts, press the skin sheets against it and check the contours of the bottom. To do this, attach a rail 1.5-2 m long with a verified straight edge or a steel ruler to the bottom. Over the entire surface, 1.5 m from the transom, the rail or ruler should fit snugly against the skin. Now you can adjust the cheekbones and the keel profile, drill all the rivet holes to d = 4.2 mm, put a sealing tape and rivet the seams again, but with rivets of a larger diameter.
This work takes a lot of time, but judging by the fact that many amateurs even manage to lengthen their duralumin boats on their own, which is much more difficult, it can well be done at home. You can read about how to properly rivet and paint an duralumin boat in the book “300 Tips on Boats, Boats and Motors” (“Shipbuilding”, 1975).
The second way to increase the running trim of the boat is to install a transverse step or bow hydrofoil.
The dimensions and installation diagram of the transverse redan are indicated on the sketch. Redan can be made from a sheet of duralumin or other aluminum alloy with a thickness of 1-1.5 mm. Having cut out both halves of the redan, give it a slight concavity by knocking out a sheet with a wooden mallet in the sand or “rolling” around the pipe. The nose edge of the sheet must be sharpened until the edge fits snugly against the skin. Planks supporting the stern edge of the redan and connecting both parts of it on the keel can be made of hard wood, textolite or light alloy.
Before installation, redan sheets must be carefully primed with inside and paint - the space between the skin of the boat and the redan freely communicates with sea water. Mounting screws must be galvanized steel or stainless steel; the use of non-ferrous metal fasteners will cause corrosion of the sheets. It is recommended to strengthen the fastening of the bow edge to the bottom by gluing with epoxy glue.
A similar redan can be made solid - from foam or wood, glued to the sheathing metal cleaned to a shine with epoxy glue. Outside, such a redan after processing must be pasted over with a couple of layers of fiberglass.
The arrow-shaped redan should take about 90% of the total weight of the boat on the move; this must be taken into account when loading it. The redan position shown in the sketch is designed to accommodate the driver in front of the cockpit.
It should be noted that the above recommendations were not tested on the MKM boat, but they were well tested and gave positive results on similar boats. Therefore, if the effect of installing a redan turns out to be excessive - the trim will be too great or the boat will begin to dolphin when not fully loaded (or controlled by the tiller of the motor), do not be surprised and do not despair. To begin with, move the fuel canisters forward, try to load the nose trunk, put the passenger on the nose seat.
If these simple measures do not help, you will have to install transom plates with an adjustable attack angle (see the mentioned book “300 Tips”). By increasing the angle of attack of the plates, it will be possible to redistribute the load between the plates and the transverse step, achieving the optimal trim for any case of boat loading and weather conditions.
Another useful addition to the serial "MKM" - zygomatic splash guards mounted on the sides at a length of 1.95 m from the stem. They can be made from a strip of 1.5X40 light alloy, fixed to the body with a solid duralumin square 20X20 or short pieces cut from it. The surface of the splash guards should be sloped downwards at an angle of about 10° to the horizontal in order to more effectively deflect splashes.
The above recommendations should significantly reduce the splashing of the MKM boat on the move, improve its germination on the oncoming wave. An even more effective measure would be to install a nasal hydrofoil (see the article by L. L. Heifets “Boat on one wing” in), however, the manufacture and refinement of such a device is a matter that is incomparably more complicated, not to mention the fact that operating a boat on wing is not possible in every water area.
A useful piece of equipment is an awning that protects the cockpit of the boat from splashing in fresh weather. If the boat is controlled by the tiller, it is not necessary to make the awning high and cover the entire cockpit.
Approximate dimensions of a comfortable awning are shown in the sketch. The arches of the awning are hinged towards the nose and placed in front of the windshield. On the move, the aft canopy 4 twists into a roll and is suspended from the arc 3 on ribbons, leaving the cockpit in the stern free to control the boat. In the parking lot, the cockpit can be closed completely, and the height under the awning is sufficient for accommodation on the floorboards for the night. Details are given in the book "300 Tips".
We were given the task of designing and building an duralumin boat for large-scale production and sale to the public, designed for an outboard motor with a power of up to 25 hp. from.
This boat should replace the widespread, but already outdated Kazanka. Recall that some other boats were also developed from the same material, but they turned out to be too complex in design and did not go into mass production. It should also be taken into account that the design of the Kazanka, as well as a number of new boats, was created for the development of large enterprises with rich experience in working with duralumin, powerful press facilities and sets of dies, and most importantly, capable of heat treatment of bent parts. Even shipyards, let alone individual teams of amateurs, often do not have such opportunities.
When developing the working drawings of the MKM boat (modernized metal boat), we counted on a wide range of amateurs, and not just on the industry. In order for the boat to be built at home, there are no complex-shaped parts in its design that require heat treatment during bending.
Basic data of the boat "MKM"
We did not specifically deal with the development of any special new forms of contours, and the following considerations were used as the basis for the choice of dimensions. We interviewed many motorboat owners and came to the conclusion that the vast majority of trips are related to fishing and hunting, and there are no more than three or four people on board. With the most popular engines "Moskva" and "Veterok" and a load of four people, the speeds of various boats are almost the same (14-16 km / h), so considerations are not so much propulsion as safety and ease of navigation. In particular, the possibility of overnight stay on the boat plays a significant role.
Recently, descriptions of a variety of boats have been published in the press, but they were all made of plywood or boards, so we could not find a suitable duralumin boat. The plywood boat "MK-29" was taken as a basis, the description of which was given in the first issue of the collection, therefore the theoretical drawing and the table of ordinates are not given here.
The contours of the hull are planing with sharp chine, with a rather high chin to reduce shocks on the wave. Branches of flora sp. 1 and 2 have a bulge for a better fit of the skin.
To install the motor in the transom, a cutout is made up to a height of 380 mm. The aft compartment from the impenetrable bulkhead on sp. 6 to the transom is used to store the outboard motor and its accessories. In the parking lot, this compartment is closed by sliding covers from the sides to the DP (on deck and on the transom).
In the aft part of the cockpit, in which there are three transverse banks, there is a sealed buoyancy compartment with a volume of 90 liters. In the bow from the impenetrable bulkhead to sp. 1 there is a bow sealed compartment with a volume of 168 liters. This is enough to ensure the unsinkability of a flooded boat with a motor and floating passengers holding on to it.
Compartment between bulkheads on sp. 1 and 2 is designed to store personal belongings of passengers.
The windshield is made easily removable so that it can be removed not only in preparation for winter, but also for passing under low bridges and all kinds of obstacles. To remove the glass, you need to give 20 screws.
The awning device was not designed, since everyone can make it at their own discretion and taste from auxiliary materials. At the same time, factories can produce awning devices for the distribution network separately. Remote control was not provided, since the industry will soon produce them along with motors.
The boat is adapted for rowing; subkeys are located between sp. 2 and 3.
The hull of the boat is made of duralumin D16AT. The bottom and deck have a thickness of 1.5 mm, sides 1 mm. Barrel-head rivets are used to reduce drag.
The test results of the MKM boat are described in
The MKM boat began to be produced in 1968, with the aim of replacing the legendary Kazanka, which was considered insufficiently safe at high speeds.
The technical characteristics of the MKM boat largely repeated the characteristics of its predecessor, however, new model had higher stability, improved hull strength and a high side.
Thanks to this, MKM with a 9.9 hp engine. showed itself at high speeds much more confidently than Kazanka.
Specifications:
The main part of the hull consists of a riveted duralumin base, the thickness of the sheathing material is 1mm.
The model is equipped with three transverse beams, protective glass.
2 seats located on the bow, complemented by folding backrests. The bow has a lockable trunk. Approximately at the middle of the length of the MKM there are oarlocks to insert the oars.
The use of MKM is possible with maximum height waves up to 0.25 meters and distance from the coast no more than 1 kilometer.
This motorboat is ideal for fishermen, hunters and hobbyists. water recreation. When temporarily parked, the outboard can be stowed in a storage compartment and tightly closed with a lid.
The boat is quite maneuverable, easy to manage and easily passes the allowable wave. And the size of the MKM boat allows you to transport it without any problems.
Video and photo of the boat MKM
