The legendary Soviet Ob M remains one of the most recognizable symbols of domestic water tourism, despite the solid age of the structure. aluminum-boat The hull was designed as a versatile means of transport on rivers and reservoirs, able to withstand the harsh conditions of Siberia and the Far East, which is why the specifications of the hull still attract keen interest from fishermen and hunters looking for reliable and maintainable equipment.
The main feature of the model is its modular design, which allows you to transport a boat on the trunk of a passenger car. Many aqueous motorists value it for its simplicity and the ability to independently operate. recovery But when you buy a boat today, it's important to understand not only its benefits, but also the real technical limitations of the age of the metal and the structure.
In this article, we will take a closer look at the passport details, the real size and nuances of operation you will have to face, you will learn why this boat is still popular and what to look for when buying a used one. A critical parameter for safety is the bottom thickness, which often thins due to corrosion.
History of creation and design features
The boat was developed in the 1960s at the Chkalov Aviation Plant in Novosibirsk, where aircraft hull technology was adapted for civil shipping, and engineers were able to create a robust design made of the AMG5 aluminum-manganese alloy, which is highly corrosive and weldable, originally conceived as a replacement for wooden boats that quickly fell into disrepair and required constant maintenance.
The design of the body is made according to rivet-technologyThis solution was the standard for aviation at the time, and it was tight and vibrating, allowing the boat to withstand impacts on ice and rocks in shallow water. Unlike today's welded counterparts, the Ob M is easier to repair in the field, because the damaged skin can be replaced without sophisticated equipment.
Why the rivet?
The riveted joints have a unique property: when vibrating and impacting, they do not crack like welded seams, but only slightly spread out, which allows you to quickly tighten or replace the rivet.
The design has focused on seaworthiness, the elongated bow and the keeled bottom, which is a very rare thing for boats of this class. sink-board reinforced, which allows you to install outboard motors up to 30 hp, although the passport often indicated more modest values.
Overall dimensions and weight parameters
For owners planning to transport a boat on the roof, the exact dimensions are crucial. The Ob M is a small boat, but it is larger than modern inflatables, with a total hull length of 4,500 mm, which allows a crew of four with a full set of equipment to comfortably accommodate.
The midwive is 1,600 mm wide and 700 mm high. This ratio provides good stability, but creates sailing in strong side winds. An empty boat without motor and equipment weighs about 190 kg, making it a task for strong-minded and body people to climb to the roof of the Zhiguli or Muscovite. Often, special adaptations or the help of several people were required to load it.
It is important to take into account that the real weight may differ from the passport due to the accumulated over the years of operation of cargo, water in niches and installed improvements. Load capacity The model is officially declared at 400 kg, but experienced water engines recommend not to exceed the load of 350 kg to maintain driving performance.
Technical specifications of the body and engine
The basis of the durability of the Ob is the hull material, a 2 mm thick AMg5 alloy, which allows the vessel to maintain rigidity even when fully loaded. The table below shows the main technical parameters that will help you assess the suitability of the boat for your tasks.
| Parameter | Meaning | Note |
|---|---|---|
| Longest length | 4,500 mm | No attachments. |
| largest width | 1600 mm | Midel-spangout. |
| Height of board | 700 mm | Midle. |
| Load capacity | 400 kg | Including crew weight |
| Engine power | 30 hp. | Recommended |
The engine compartment is designed to accommodate Soviet-made outboard motors such as the Whirlwind or Neptune, and modern imported engines are also suitable, but may require overhang due to the differing geometry of the lower unit. Tranza It is made of a thicker sheet and reinforced with a bar, which allows you to withstand the vibrations of powerful engines.
When choosing an engine, it is worth considering that the Ob M is a rather heavy boat, and to get on plane with full load, you will need a motor with a capacity of at least 15-18 hp At low power, the boat behaves like a displacement vessel, which saves fuel, but reduces the speed of movement.
To improve the output for planing, install transax plates or hydrofoil on the lower unit engine - this will reduce yaw and improve driving performance.
Internal layout and habitability
The interior of the boat is divided into several functional areas, with a closed trunk in the bow, which is sealed and can be used to store things that are not afraid of moisture, or as an emergency compartment for unsinkability, and often a detachable tent was installed above the trunk, turning the nose into a makeshift tent.
The central part is occupied by a cockpit with three transom cans, the central bank serves as a seat for the helmsman and has a cutout under the rummule, the design of the cans allows you to remove them if necessary to increase the space available or for overnight stays in the boat, spreading sleeping bags on the floor.
⚠️ Warning: When sleeping in a boat, be sure to arrange ventilation. Aluminum cools quickly at night, forming condensation, and in an enclosed space with an awning it can be stuffy.
The aft section, under the aft can, often housed fuel tanks and gearboxes, and some owners installed larger stationary tanks than standard 20-liter canisters. ergonomics The cabin is designed for fishing in a sitting position, which is convenient for long transitions.
Operation and maintenance
Despite its reliability, the boat requires regular maintenance, especially if it is stored on water or in the open air. The main enemy of the aluminum hull is electrochemical corrosion, which occurs when contact with other metals in salty or polluted water. zinc protectorsIf they're installed.
Every year, before navigating, it is recommended to inspect the bottom for cracks and weakened rivets. Pay special attention to the zygomatic guides and the keel section, who take the main blows. If you find a leak, do not rush to brew the hole - for AMG5 you need special wire and skills, it is better to use cold welding or epoxy compounds for aluminum.
☑️ Annual preparation for the season
Keeping the boat upside down under the canopy is best, so that there is no moisture or snow inside, and if you can't, make sure to cover the cockpit with a breathable awning that lets water vapor through but delays rainfall, which will prevent mold from forming on the wooden elements and corrosion of the metal.
Comparison with modern analogues and modifications
There are many aluminum boats on the market today, such as the Crimea, the Salute, or modern models from the Master and Aqua. However, the Ob M beats many of them in seaworthiness and the volume of internal space. Modern Kazankas are often narrower and lighter, making them less stable on large water, but more convenient for transportation.
There are several modifications to the Obi, including the improved design version of the M and the chopped-down version of the Ob-3, which is considered the middle ground between an open boat and a comfortable boat, and is devoid of heavy logging, which reduces sailing and weight, but retains the ability to install an awning to protect against rain.
⚠️ Warning: When buying a used boat, be sure to check the gradient. 70s boats may have hidden corrosion under layers of paint that you can't see on a surface inspection.
Many owners are doing the same. tuning With its more powerful motors, modern sonars and navigation, the ease of processing aluminum allows for additional shelves, brackets and even fiberglass inserts, making the boat virtually immortal in skilled hands.
The main advantage of the Ob M over modern analogues is the combination of a large volume of the cockpit and the possibility of transportation on the roof of a passenger car without disassembly.
Frequently Asked Questions (FAQ)
Can I install a 40 hp engine on the Ob M boat?
Formally, the passport allows up to 30 hp, but the reinforced transom often withstands 40-horsepower engines. However, installing a more powerful engine can lead to a stern overweight and reduced safety, especially when fully loaded.
What is the maximum speed of the boat OBM?
With an engine of 20-25 hp and two passengers, the boat develops a speed of about 35-40 km / h When fully loaded, the speed drops to 25-30 km / h, since the boat is heavy and has significant water resistance.
Do I need to register the boat OB M in GIMS?
Yes, the weight of the boat (190 kg) and the engine power (more than 8 hp) exceed the limits exempt from registration.
How to fix the leak in the aluminum case?
For temporary repairs, epoxy compounds with aluminum powder will be suitable. Major repairs require argon welding or patching from the same AMg5 alloy. A normal steel patch will cause severe corrosion.