Transporting the car on locomotive traction (towing by train) is a rare but extremely important scenario for equipment owners, trucking companies and even the military. Unlike the usual movement on its own, here the efficiency (coefficient of efficiency) depends not only on the characteristics of the machine, but also on the parameters of the locomotive, type of coupling, track profile and even weather conditions. Why does this issue cause so much controversy? Because the real efficiency of such movement may differ from theoretical calculations by 2–3 times - and this is not an exaggeration.

Many people mistakenly believe that towing by train is always more energy efficient than moving independently. In practice, everything depends on car mass relative to composition, type of rolling stock (platform, wagon, specialized transporter) and even on how exactly the vehicle is secured. For example, Volvo FH16 weighing 20 tons on the platform will give a load on the locomotive 5–7 times less than its own weight when moving on wheels, but at the same time friction losses in carriage bearings and aerodynamic drag of the train can consume up to 40% of energy. Next, we will look at exactly how efficiency is calculated under such conditions and what influences it.

To begin with, it’s worth clarifying: by “efficiency of a locomotive-hauled car” we mean the ratio of the useful work of moving the machine to the expended energy of the locomotive. This is not the same as the efficiency of a car engine or even the efficiency of a train itself. This takes into account:

  • 🔹 Rolling resistance car wheels (if they are not blocked)
  • 🔹 Aerodynamic drag machines and composition
  • 🔹 Locomotive transmission losses (up to 15% for electric locomotives)
  • 🔹 Mass and inertia the car itself relative to the composition
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1. Theoretical efficiency: formulas and basic principles

To estimate the efficiency of a car when towed by a train, a modified formula from railway mechanics: 

Efficiency_auto = (F_thrust  S) / (E_locomotive  k)

where:

  • F_thrust - traction force per vehicle (N)
  • S — distance traveled (m)
  • E_locomotive — energy expended by the locomotive (J)
  • k — load distribution coefficient (0.1–0.5 depending on the position of the vehicle in the composition)

In practice real efficiency rarely exceeds 30–35% even for ideal conditions (flat track, minimal aerodynamic drag, optimal loading of wagons). For comparison: the efficiency of the same Volvo FH16 when driving on the highway at cruising speed reaches 40–42%, and a diesel locomotive 2TE116 - total 28–32% (taking into account losses in the transmission and overcoming the resistance of the train).

Key point: a car on a platform is not a “passive load”. Even if its wheels are locked, the wheel bearings and tire deformation create additional resistance. For example, for Kamaz 6520 with a load of 15 tons, rolling losses will be ~1.5 kN at a speed of 80 km/h - this is equivalent additional 10–12 kW of power, which the locomotive must compensate for.

⚠️ Attention: When towing a car with unlocked wheels (for example, on specialized conveyors with roller ramps) efficiency drops by 15–20% due to friction in the bearings and possible slippage.

2. Comparison with the classical movement: which is more effective?

To understand whether locomotive traction is beneficial, let’s compare it with the independent movement of a car using the same parameters:

Parameter Self driving (diesel truck) Towing by train (electric locomotive + platform)
Efficiency, % 38–42 25–30
Energy consumption per 1 t km, kWh 0.8–1.2 1.1–1.5
Maximum speed, km/h 90–110 80–120 (limited by infrastructure)
Weather influence (rain, snow) Efficiency reduction by 5–10% Efficiency reduction by 12–18%

As can be seen from the table, independent movement is more profitable in terms of efficiency, but only if we are talking about single car. During transportation groups of cars (5+ units) or over distances over 1000 km locomotive traction begins to benefit due to:

  • 🚂 Scale: the energy to overcome the resistance of the train is distributed to all cars
  • 💰 Fuel savings: An electric locomotive is cheaper to operate than a diesel truck
  • 🛠️ Reduced wear: car mileage does not increase, there is no load on the engine and transmission

However, there is a downside: strict size restrictions (height up to 4.5 m, width up to 3.2 m) and the need for special equipment for loading/unloading. For example, for transportation Mercedes Actros with trailer required low loader flat car, the rental of which will cost 3–5 thousand rubles per day.

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If you are planning regular car transportation by train, order individual fastenings for the car model. This will reduce the risk of damage and speed up loading by 30–40%.

3. Factors that kill efficiency: top 5 mistakes when towing

Even with ideal calculations, efficiency can collapse due to errors. Here are the most critical ones:

  1. Incorrect weight distribution in the composition. If the car is located at the rear of the train, it accounts for up to 40% extra dashes when braking/accelerating. Optimal position - second third of the lineup.
  2. Ignoring aerodynamics. Open platforms increase air resistance by 15–20%. Use canvas covers or shelter containers.
  3. Overloading the car. Exceeding the norm by 1 ton reduces efficiency by 3–5%. For MAZ 5336 maximum laden weight - 22 tons (otherwise permission from Russian Railways will be required).
  4. Lack of lubrication in the hubs. Forgot to lubricate the bearings before loading? Friction losses will increase by 2 times.
  5. Incorrect coupling. A rigid mount (without shock absorbers) transmits up to 70% vibration, which leads to microdamage and increased resistance.

The point about the coupling is especially critical. For example, when transporting Scania R470 on a platform with chain fastenings (without rubber dampers) Efficiency drops by 8–12% due to additional loads on the frame.

Carefully secure the steering wheel (use a belt or zip ties)|

Check tire pressure (optimally 3.5–4.0 bar)|

Lubricate the wheel bearings (Lithol or equivalent)|

Install shock-absorbing pads under the mounts|

Close air ducts and cracks (to reduce aerodynamic drag)-->

4. Practical calculations: example for a truck

Let's consider a real case: transportation Kamaz 65115 (weight 18 tons) on the model platform 13-401 as part of a train with an electric locomotive VL80S. Initial data:

  • Distance: 1200 km (Moscow - Yekaterinburg)
  • Speed: 70 km/h (average)
  • Train weight: 3000 tons
  • Locomotive energy consumption: 4.5 kWh/t km

Step 1: Calculate the energy spent on movement Kamaz: 

E_total = 3000 t  1200 km  4.5 kWh/t km = 16,200,000 kWh

E_on_auto = E_total  (vehicle_weight / vehicle_weight)  k = 16 200 000  (18/3000)  1.2 = 1,166,400 kWh

where k=1.2 — coefficient of additional losses (aerodynamics, friction in fastenings).

Step 2: Compare with independent movement. For Kamaz 65115 diesel consumption - 25 l/100 km, specific heat of combustion of diesel fuel - 10 kWh/l. Then: 

E_self = (1200 km / 100)  25 l  10 kWh/l = 30,000 kWh

Conclusion: In this case, locomotive traction 38 times less effective on energy costs! But this doesn't take into account:

  • 💸 Fuel cost vs. electricity (diesel is 3–4 times more expensive)
  • 👷 Car wear and tear (mileage does not increase when towing)
  • ⏱️ Time (the train goes without stops for refueling/rest)
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Locomotive towing is beneficial only when mass transport (5+ cars) or on distances over 1500 km, where savings on logistics cover efficiency losses.

5. How to increase efficiency: technical tricks

Efficiency can be optimized at several levels:

1. Composition optimization:

  • 🔧 Use carriages with roller gangways - they reduce rolling resistance by 20–25%.
  • 🌡️ Control the temperature of carriage bearings (optimally 40–60°C). Overheating higher 80°C increases losses by 10%.

2. Preparing the car:

  • 🚗 Remove mirrors, antennas, spoilers - this will reduce aerodynamic drag by 5–7%.
  • 🔋 Turn off all electrical consumers (for example, ECU, immobilizer) to avoid draining the battery.

3. Route and speed:

  • 🗺️ Choose paths with a minimum number of slopes (losses on climbs reach 15%).
  • ⚡ Optimal speed for an electric locomotive - 60–80 km/h. Exceeding up to 100 km/h reduces efficiency by 8–12%.

For road trains (for example, Scania R730 with a trailer) gives an additional effect grouping vehicles by weight: heavy cars are placed closer to the locomotive, light ones - in the tail. This reduces inertial loads during braking.

Why can't you tow a car with an automatic transmission in neutral?

When towing in neutral automatic transmission torque converter there is no lubrication, which leads to overheating and failure of the clutches. Maximum allowable distance - 50 km at speeds up to 30 km/h. Mandatory for long-distance transport disconnect the driveshaft or use a tow truck with the drive wheels lifted.

Apart from technical aspects, the efficiency of locomotive towing depends on regulatory requirements and tariffs. The following rules apply in Russia:

  • 📄 To transport a car on Russian Railways you need agreement with the rolling stock operator (cost - from 15 thousand rubles. per car).
  • 🚫 It is prohibited to tow a car with fuel/oil leaks (fine up to 50 thousand rubles.).
  • ⚖️ The weight of the car should not exceed 24 tons (otherwise you will need a special carriage).

Economic feasibility is determined break-even point. For example, for transportation Man TGS from Moscow to Novosibirsk (3300 km):

  • 🚛 On your own: 3300 km 30 l/100 km 50 rub/l = 495,000 rub. + wear
  • 🚆 By train: 2 carriages 18,000 rub/day 5 days = 180,000 rub. + loading (RUB 30,000).

The benefit is obvious, but only if:

  • 📦 Transportable car group (from 3 units).
  • 🛣️ The route passes through mountain regions (for example, the Urals), where the fuel consumption of a truck increases by 30–40%.
⚠️ Attention: During transportation foreign cars with electronic systems (for example, Volvo FH with AdBlue) be sure to turn it off ECU from the battery. Vibrations along the way can cause false errors in the control unit, which will lead to failure to start after unloading.

7. Alternatives to locomotive towing: which is more efficient?

In some cases, other transportation methods may be more profitable:

Method Efficiency, % Cost (per 1000 km), rub. Limitations
Locomotive traction 25–30 50 000–70 000 Dimensions, loading time
Car transporter (trailer) 35–40 80 000–120 000 Height up to 4 m, speed up to 90 km/h
Sea container ship 45–50 30 000–50 000 Only for international transport
Air transportation 20–25 500 000+ Weight up to 5 tons, cost

The optimal choice depends on distance and urgency:

  • 🌍 Up to 500 km: better use car transporter (faster and without overload).
  • 🚆 500–3000 km: locomotive traction wins on price.
  • ✈️ Over 3000 km: consider sea containers (for example, from Vladivostok to Moscow).

For special equipment (excavators, cranes) often used combined method: disassembly into modules + transportation to open carriages followed by on-site assembly. This reduces dimensions and increases efficiency by 10–15%.

FAQ: Frequently asked questions about the efficiency of locomotive-hauled vehicles

Is it possible to tow a car with an automatic transmission on a platform without disconnecting the driveshaft?

No. in neutral position torque converter The automatic transmission does not receive lubrication, which leads to overheating and failure after 50–100 km. Be sure to disconnect the driveshaft or use a tow truck with a lift on the drive axle.

Which locomotive is the most efficient for towing a car?

Optimal for transporting cars electric locomotives (for example, EP20 or VL85) with efficiency 30–32%. Diesel trains (eg TEP70) have efficiency 25–28%, but they win in non-electrified areas. For maximum effectiveness, choose formulations with regenerative braking - it returns up to 10% energy when descending.

How many cars can be transported in one carriage?

Depends on the type of car:

  • 🚗 Platform 13-401: 2 passenger cars (for example, Toyota Camry) or 1 truck (GAZon Next).
  • 🚛 Special wagon for equipment: up to 4 auto types Ford Transit.
  • 🚜 Transport car: 1 unit of special equipment (for example, JCB 3CX).

Exceeding the norm leads to a fine up to 100 thousand rubles. and suspension of transportation.

Does the time of year affect efficiency?

Yes, and very significantly:

  • ❄️ Winter: Efficiency drops by 12–18% due to:
    • Increased air resistance (cold air density is higher)
    • Freezing of grease in carriage bearings
    • Icing of rails (requires additional energy for adhesion)
  • ☀️ Summer: Efficiency is maximum, but at +30°C there is a risk overheating of brake systems composition increases.

Optimal time for transportation - spring/autumn (temperature +5…+15°C).

Is it possible to transport electric cars (eg Tesla) by train?

Yes, but with mandatory precautions:

  • 🔋 Battery charge must be no more than 50% (to avoid fire).
  • 🛑 Disable all systems (Autopilot, Sentry Mode).
  • 🌡️ Monitor the battery temperature (optimally 10–25°C). When overheating higher 40°C required carriage ventilation.

Russian Railways demands safety declaration for lithium batteries with a capacity above 100 kWh.