Many inflatable boat owners are faced with the dilemma of how to install a more powerful engine if the standard transom does not withstand the load or is not designed structurally for heavy attachments. grazing-tree It's a design that shifts the engine's mounting point out of the normal position, spreading weight and improving the rideability of the craft, and it's not just a piece of plywood, it's an engineering element that requires accurate calculation and proper installation.
The use of such a design allows you to unload the stern part of the cylinders, which is especially important for boats with a flat bottom or low load capacity. The cinema of movement The boat is changing, the nose is less uplifted and the boat is more quickly planing, but improper installation can lead to serious consequences, up to the loss of the engine or leakage of the hull.
In this article, we will discuss in detail why you need a remote transom, what materials to use for its manufacture and how to avoid common installation errors, learn about the nuances of balancing and understand why sometimes it is better to sacrifice speed for safety.
Why do you need a snail and its benefits
The main function of the remote transom is to redistribute centre-up Inflatable vessels' regular transverses often have a power limit, usually up to 5-8 hp, and the installation of a more powerful unit causes the stern to overload, causing the boat to dig its nose or to fall on board when cornering.
By moving the engine mounting point back and slightly upwards, we effectively shift the engine. centre The boat-motor-passenger system, which compensates for the weight of the heavy engine and passengers sitting on the aft bank, is also often used to install electric motors that have an elongated leg and require a greater depth of immersion of the propeller.
Another advantage is the ability to install two engines or a combination of petrol and electric engines, in which case there is a catastrophic shortage of regular space, and the remote design provides the necessary area and rigidity for reliable fixation of equipment.
- 🚀 Improved hydrodynamics: the boat quickly enters the planing mode due to the optimal differentiation.
- ⚖️ Balancing: the ability to compensate for the weight of heavy batteries or passengers on the nose.
- 🔧 Universality: the possibility of installing long leg motors or dual power plant.
- 🛡️ Protection of the housing: reducing the load on the cylinders in the area of the standard transom, preventing their pressing.
⚠️ Attention: Installation of the remote transom changes the data-sheet specifications of the boat. Make sure that the total mass of the engine does not exceed the maximum permissible load specified by the manufacturer of the boat, otherwise there is a risk of destruction of the structure on the water.
Design features and types of remote transverses
Structurally, remote transoms are divided into several types depending on the method of attachment and material. transom reinforcementThis is a sling-and-belt system that is mounted on top of cylinders or to a standard transom, typically made of moisture-resistant plywood 12-18 mm thick and clad with fiberglass.
The second type is frame-frameThese are not water-sensitive or resistance-producing, but require very careful adjustment of the height of the motor installation. The height of the transom (h) must meet current standards, usually 381 mm (15 inches) or 508 mm (20 inches) from the lower unit cut to the bottom of the attachment point.
There are also specialized transes for electric motors, which are often smaller in height and reinforced in design to compensate for the lever created by the long leg of the motor. reinforced (triangular stiffness elements) which prevent the plane from bending under the weight of the engine.
When choosing a finished product or designing your own, it is important to consider the inclination angle of a lower unit. The standard angle is about 10-15 degrees from the vertical. If the transom is installed strictly vertically, and the motor is adjusted only within 5 degrees, the efficiency of the screw will decrease.
Materials and tools for self-manufacturing
If you're going to make a snail transom yourself, you're going to focus on the materials you're going to use. plywood The use of conventional construction plywood is unacceptable, as it will quickly dissipate under the influence of moisture and vibration.
To protect wood from water and mechanical damage, fiberglass is used. You will need fiberglass (density 200-300 g / sq.m) and epoxy resin with hardener. The alternative is to paint quality yacht enamel in several layers, but fiberglass provides better longevity and tightness.
The fasteners must be made of AISI 304 or AISI 316 stainless steel. The normal ferrous metal will rust in one season and the rust will flow onto the boat and clothing, and nylon belts with carabiners, soft linings of PVC fabric or foamed polyethylene will also be required to protect the cylinders.
| Material/Tool | Appointment | Requirements |
|---|---|---|
| FSF plywood 18 mm | The transom base | No knots, at least 3 layers. |
| Epoxy resin | Impregnation and gluing | Low-styrene |
| Glasswork | Reinforcement | Density of 200+ g/sq.m |
| Nylon belts | Boat anchorage | At least 200 kg |
| Fastening (bolts M8-M10) | Motor locking | Stainless steel AISI 316 |
When working with epoxy, be sure to use a respirator and gloves. Hardener fumes are toxic, and it is almost impossible to wash the resin from the skin after polymerization.
Step-by-step instructions for installing a remote transom
The installation process requires precision and consistency. First, you need to prepare the attachment site. If the transom is the consignment note, clean the top of the cylinders and the standard transom from sand and dirt. Put soft pads of foam material in the places where the belts contact the cylinders to avoid rubbing the fabric.
Then you put the transom in, and it's going to fit tightly to the support surface, and you're going to tighten the straps evenly, controlling the tension. Straining The belts can deform the cylinders, and the weak tension will lead to the backlash of the engine. The motor must be fixed rigidly, without the possibility of shifting left-right.
☑️ Verification of transone installation
After the physical installation, you need to adjust the height of the suspension of the motor. Antikavitation plate (horizontal plate above the screw) should be at the same level with the lower point of the bottom of the boat or be buried 1-2 cm If the plate is higher, air sucking and thrust loss will begin; if lower, water resistance will increase.
⚠️ Attention: Never run the engine out of water, even for a short time to check the mounting. A lack of water cooling will cause the pump to overheat instantly and jam, and vibration of the unfixed motor can damage the transom.
Balancing and impact on driving performance
Balancing correctly is a key to operating a remote-trans boat, and shifting the motor back creates an extra lever that can pick up the boat's nose. battery and passengers closer to the nose or install an additional loader in the bow.
The impact on performance can be both positive and negative. When you set the boat up properly, it becomes more stable on the course and easier to control. However, if the takeaway is too large, there is a "goat" effect - the boat starts to gallop on the waves, hitting the bottom hard, not only uncomfortable, but also dangerous for the driver's spine and structural integrity.
Particular attention should be paid centre-upIf the motor is not strictly mounted along the symmetry axis, the boat will be led aside even in direct gear, which forces you to constantly adjust the course, which increases fuel consumption and fatigue.
The optimal distance of the motor per transom is usually 30-50 cm Exceeding this value dramatically increases the lever of influence on the body and requires a serious rebalancing of the boat.
Safety and construction maintenance
The use of the remote transom imposes additional safety obligations: before each release, you must visually inspect the condition of the belts and their attachments. Tissue belts tend to stretch and rub, especially if they come into contact with sharp corners of the fittings.
Check the tightening of the engine mount bolts regularly. The vibration of the engine can weaken even well-twisted nuts. Use growers (spring washers) or a thread lock when assembly. Also monitor the condition of the wooden base: cracks in the lacquer coating or plywood swelling signals moisture entering the interior.
During winter storage, the remote transom is better dismantled and stored in a dry room at room temperature. Temperature changes and humidity can destroy the plywood adhesive layer. Metal elements should be preserved with lubrication.
- 🔍 Check your seat belts for any scuffs before each trip.
- 🔩 Check the tightening of the engine bolts after the first 10 minutes of engine operation.
- 🧼 Wash the transom with fresh water after use in salt water.
- 🛠️ Refresh the coating when microcracks appear.
⚠️ Attention: When driving at high speeds with a remote transom, you can not make sharp steering turns. The increased departure of the engine creates a huge inertial load on the mounting point, which can lead to the transom breakage or the breakdown of the lower unit.
Frequently Asked Questions (FAQ)
Can the motor be used more powerfully than the boat manufacturer recommends?
Technically, yes, the structure will, but it violates the rules of registration and safety, in the event of a rollover or accident, the insurance company will refuse payment, and the GIMS can write a fine for exceeding the permissible power, and the boat itself may not withstand the increased dynamic load on the bottom.
How to choose the height of the remote transom for an outboard motor?
The height of the transom (the distance from the top to the bottom) should correspond to the length of the lower unit of your motor. For the short leg (S), this is usually 381 mm, for the long leg (L) - 508 mm. It is best to try on the motor before final assembly or manufacture, as different manufacturers may have nuances in the geometry of the mounting.
Do I need to register a boat with a remote transom in GIMS?
The design of the transom itself is not subject to registration. The boat and the motor are registered. If after installing the transom you change the engine to a more powerful one, and the total power of all engines exceeds 8 hp (or 10 hp depending on current interpretations of the law, but it is worth focusing on 8 hp for peace of mind), registration is mandatory. It is also important that the weight of the equipped boat with the engine does not exceed 200 kg (taking into account the weight of the transom itself).
Why does a boat with a remote transom start to prowl on the course?
This can be caused by several reasons: improper centering on the sides (motor shifted left or right), damage to the lower unit, or too large engine departure, which increases the effect of the side wind and wave. It is also worth checking the condition of the screw - chips on the blades cause vibration and sideways.