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Note: Request refers to urban electric transport (metropolitan), which goes beyond the automatic theme of the site. However, if you need to adapt the article to the format of “vehicles” in a broad sense (for example, as “special equipment for infrastructure”), clarify the requirements. Below is full expert material taking into account the technical specifics of the topic - it can be used as a template for similar service manuals railway/metro technology (if such a category is added).

Electric train 81-717 - a legendary model of the Soviet and Russian metro, in operation since 1976. This is one of the most popular cars in the history of the Russian metro, which still forms the basis of the fleet in Moscow, St. Petersburg and other cities. Despite their age, train modifications 81-717.5/6 continue to be modernized, receiving new control systems, lighting and even elements of a “smart” metro.

It is critical for specialists in the repair and maintenance (MRO) of such cars to understand them design features, typical malfunctions and work regulations. In this article we will analyze the structure of the train 81-717, focusing on electrical equipment, brake systems and body parts — with practical advice on diagnostics and repair.

If you work with the subway or are simply interested in railway technology, here you will find:

  • 🔧 Specifications all modifications 81-717
  • ⚡ Electrical circuit diagrams and principles of operation of traction motors
  • 🚇 Maintenance regulations and criteria for wagon write-off
  • ⚠️ Typical faults and ways to eliminate them

1. Technical characteristics of train 81-717

Basic model 81-717 was developed Leningrad Carriage Works named after. Egorova (Distillery) as a replacement for outdated carriages of the type D and E. Structurally, the train belongs to DC electric trains with contact rail voltage 825 V. Below are the key parameters:

Parameter Value (base model) Value (upgraded 717.5/6)
Car length 19 200 mm 19,600 mm (increased to improve passenger capacity)
Body width 2,700 mm 2,700 mm (no changes)
Tare weight 32.5 t 33.8 t (due to additional equipment)
Type of traction motors DK-117A (4 pieces per car) DK-117M or asynchronous (on later modifications)
Maximum speed 90 km/h 100 km/h (after modernization)

Feature of the model - all-metal welded body made of low-alloy steel, designed for operation under high load conditions. In modifications 717.5 and 717.6 improved noise and vibration insulation, climate control systems and LED lighting have been added. It's important to note that 81-717 cars are not compatible with newer models (for example, 81-760 Oka) in terms of control and coupling systems.

⚠️ Attention: When operating wagons older than 30 years, an inspection is required. corrosive wear of load-bearing body elements at least once every 2 years. Critical wear (more than 20% of the metal thickness) is grounds for write-off.

2. Electrical equipment

Train electrical diagram 81-717 built on the basis systems of many units (CME), allowing you to control several cars from one cabin. Main components:

  • 🔌 Traction motors DK-117 — collector, direct current, with sequential excitation. The power of each - 110 kW.
  • ⚡ Traction converters - thyristor (on early models) or IGBT transistor (on modernized ones).
  • 📡 Control system - SOUT-PM (on 717.5/6) with microprocessor control.
  • 🔋 Batteries - nickel-cadmium (110 V), provide power to auxiliary circuits.

One of the common problems is wear of traction motor brushes. Signs of malfunction:

  • 🔥 Sparking under the carriage when moving.
  • 📉 Loss of power (the train “does not pull” on uphill slopes).
  • 🛠️ Increased noise in the engine area.

For diagnostics use ammeter and oscilloscope, connected to the armature circuits. Normal no-load current - no more 50 A to the engine.

📊 What modification of 81-717 is found in your metro?
Basic (717.0)
Modernized (717.5)
Latest (717.6)
I don't know

3. Brake systems: design and malfunctions

Trains 81-717 equipped combined braking system, including:

  1. Electrodynamic brake (regenerative/rheostatic) - main mode.
  2. Air brake — backup, triggered in emergency situations.
  3. Parking brake - manual, mechanical.

Typical brake problems:

Symptom Possible reason Remedy
Braking distance has increased Worn pads or drums Replacement of friction elements (regulation - every 300,000 km)
Jerks when braking Malfunction electropneumatic valve Check valve control circuits, replace if necessary
Whistle/creaking noise when braking Contaminated or warped brake discs Disc turning or replacement
⚠️ Attention: If the electrodynamic brake fails train operation is prohibited — it is necessary to switch to pneumatic mode and proceed to the depot at a speed of no more than 40 km/h.

☑️ Brake system diagnostics

Done: 0 / 4

4. Body and chassis: repair and maintenance

Car body 81-717 made of steel sheets 3–4 mm thick, connected by welding. Key components of the chassis:

  • 🚂 Trolleys — biaxial, with spring suspension. Bearing life - 1 million km.
  • 🔩 Axle boxes - roller type, require lubrication every 100,000 km.
  • 🛤️ Spring suspension — combined (coil springs + hydraulic dampers).

Typical body defects:

  • 🔍 Corrosion in the area of welds and the lower part of the casing.
  • 🚪 Door deformation due to impacts or wear on the guides.
  • 🔨 Cracks in the frame (critical for cars older than 25 years).

For body repairs the following are used:

  • 🔧 Argon arc welding for restoration of load-bearing elements.
  • 🎨 Anti-corrosion treatment zinc-rich soils.
  • 🔄 Replacing sheathing sheets with through corrosion.
How to check body geometry?

Use a laser level or templates to check. Permissible deviation of body diagonals - no more 10 mm. If it is exceeded, editing on the slipway is required.

5. Maintenance regulations

For trains 81-717 The following types of maintenance apply:

Type of maintenance Frequency Main works
TO-1 Every 5,000 km Inspection of the chassis, checking the brakes, lubrication of axle boxes
TO-2 Every 30,000 km Diagnostics of electrical equipment, door adjustment
TO-3 Every 120,000 km Inspection of traction motors, checking the body for cracks
KR (overhaul) Every 1.2 million km or 15 years Complete disassembly, replacement of worn parts, modernization

Particular attention is paid winter preparation:

  • ❄️ Checking the operation of heating systems (the temperature in the cabin must be maintained at +18…+22°C).
  • 🔋 Battery test (capacity not lower than 80% from nominal).
  • 🚪 Lubricating door seals with silicone compounds.
💡

Timely maintenance increases the service life of the car by 30–40%. Skipping routine maintenance leads to accelerated wear of traction engines and chassis.

6. Modernization and decommissioning of cars

Cars 81-717 subject to modernization to extend service life. Main directions:

  • 🔄 Replacement commutator motors to asynchronous (reduces power consumption by 15–20%).
  • 💡 Installation LED lighting and video surveillance systems.
  • 📱 Implementation on-board computers for real-time diagnostics.

Criteria for decommissioning a wagon:

  • 🚫 Expiration of standard service life (40 years old for basic models).
  • 🔧 Impossibility of repair load-bearing elements of the body.
  • ⚡ Outdated electrical equipment (for example, thyristor converters).

After decommissioning, the cars are disposed of or converted into official (for example, for transporting goods in the subway).

💡

When modernizing cars 81-717.5/6, it is recommended to install systems regenerative braking - this reduces energy consumption by 25% and reduces brake pad wear.

7. Frequently asked questions (FAQ)

❓ Why does train 81-717 “twitch” when accelerating?

The reason is usually wear of traction motor brushes or malfunction thyristor converter. Check:

  • The condition of the collector (should be without burnt marks).
  • The voltage at the output of the converter (should increase smoothly).

If the problem persists, the brushes need to be replaced or the converter needs to be repaired.

❓ How often do you need to change brake pads?

Regulations - every 300,000 km, but the actual period depends on the intensity of use. Signs of wear:

  • Increased braking distance.
  • The appearance of a metallic grinding sound.

Minimum permissible pad thickness - 10 mm.

❓ Is it possible to operate car 81-717 without modernization after 40 years?

Formally no — according to metro standards, cars older than 40 years are subject to write-off or deep modernization. However, when satisfactory condition of the body and chassis Operation is possible after the service life has been extended by the commission.

❓ What is the difference between modifications 717.5 and 717.6?

Main differences:

Parameter 717.5 717.6
Control system SOUT-PM (semi-automatic) SOUT-CM (digital, with ABTC)
Lighting Fluorescent lamps LED panels
Brakes Rheostatic + pneumatic Regenerative + electro-pneumatic

8. Conclusion: prospects for trains 81-717

Despite the emergence of new models (for example, 81-760 "Oka" or 81-775 "Moscow"), carriages 81-717 will remain in use for at least a little longer 10–15 years. Their main advantages:

  • 💰 Low maintenance cost compared to new trains.
  • 🛠️ Good maintainability (spare parts are widely available).
  • 🚇 Proven reliability in harsh conditions (−40°C to +40°C).

To extend service life it is critical to:

  1. Comply with maintenance regulations.
  2. Conduct modernization of electrical equipment.
  3. Monitor the condition of the body and chassis.

Gradual replacement is expected in the future 81-717 to more modern models, but complete decommissioning is unlikely until 2035–2040.