ER9 electric trainset

For servicing suburban commuter lines, electrified on 25 kV, AC, the Railcar Manufacturing Plant of Riga produced ER9, then ER9p electric trainsets in the 1966-1975 period. The mass production of these trains had began in 1964.

Railcar types

Three types of cars were manufactured for these trains, which were motor, trailer, and cab-trailer. The minimal quantity of cars is four (2 motor & 2 cab-trailer cars). The maximal quantity was twelve (6 motor cars, 4 trailers, and 2 cab-trailers.) The trains could be controlled and/or operated only from cab cars.

Railcar boides

Cars' bodies were manufactured the same way like in ER2 electric trainset, by means of frameless construction. The separate parts of car body were redesigned, if compared with ER2 trains. It was caused by distinct equipment layout, and large weight of cars, due to the weight of AC transformers. Car entrances are capable both for high and low platforms. The cars have SA-3 auto-couplers. The bodies are supported by two double axed trolleys. The frames of trolleys are solidly welded, "jaw-like", and H-shaped. The boogies of trainsets up to ER9p-125, have N. E. Galakhov's elliptical amortizers in their central suspensions. Trolley frames are supported by 8 cylindrical springs installed in a coat of axle box balancers. The static deformation of amortizer is 105 mm. Starting with ER9p-126 trainset (1966,) the trolleys are supported on axles box through four sets of cylindrical springs, placed in two rows. The hydraulic amortizers are placed in the central suspension, like it was done is ER2 motor cars dated from 1966-1975. The static deformation remained the same (105 mm). The diameter of motor car wheels is 1050 mm, and of trailer car wheels is 950 mm.

Electric traction engines

Electric traction engines are installed on boogie frames, as in ER2 motor cars. The engine's shaft is connected with the minor gear train using a jaw clutch. The speed reduction couple's body is anchored on a pair of wheels through friction reducer made of rolls. From the side of minor gear train, the speed reduction couple is suspended from the trolley's frame.

Transmission

The transmission is one way, rigid, and straight-cogged. The ratio is 23:73 (1:3.17) Two braking cylinders are installed on every motor car's trolley. Brake shoes depress the wheel from both sides. The brakes feature electro-pneumatic control.

Transformer

Unit: OCR-1000/25 transformer Suspended: Under the body of a motor car Manufactured: At the Electric Technology plant of Tallinn The transformer has a core type, and is cooled by oil.

Composed on 4 coils:Primary, for 25 kV (normal power 965,000 volt-amperes),Traction coil: 7 outlets with regulating electrodes.Output voltage - 2208 V (During neutral position (not sure) )Normal Current 350 AHourly Current 530 A

Heating coil

power: 100 kV·Aoutput Voltage: 628 VSupplementary coilpower: 92 kV·Avoltage: 220 V.Transformer's mass is 3122 kg.

Pneumatic switch/circuit breaker

Unit: The main pneumatic switch (VOV25-4)Mounted: On the roof of motor carPurpose: to protect the high voltage circuits from short circuit currents and overloading.Manufactured by: High Voltage equipment plant of Nalchik.

Unit: UVP-1 Rectifier.Mounted: Under the body of motor carFeatures: Bridge scheme

Rectifying circuits

The unit has 30 VK2-200-6B rectifiers. Every bridge's arm has 3 parallel circuits, consisting of 10 rectifiers connected in series. The branchings have 3 parallel circuits, with 2 rectifiers connected in series. For even distribution of reverse voltage in serial circuits, the active resistors are connected in parallel with rectifiers in non-conducting period. The connection of rectifiers with same potential is realized by resistors.
*In motor cars so called "rectifier transfer," from one step of voltage to other is done. This feature allowed to exclude a division reactor from design. For this purpose rectifier branchings are connected in rectifier groups, which form a bridge arms. Every arm has 3 circuits connected in parallel, each of them has 4 rectifiers connected in series. that's why the total number of rectifiers in motor cars is 144. The normal value of rectified voltage is 1650 V, Current is 600 amperes. The unit weighs 580 kg.

Traction Motors

Unit: Electric Traction Engine (RT-51D)Installed: On motor carsVoltage: 825 V, directly from rectifiers.Power: 180 kW, 240 A (in case of 92.5% excitement )200 kW, 266 A (in case of 32% excitement)

Rotational frequency: 645 rpm (in case of 92.5% excitement)1140 rpm (in case of 32% excitement)

In case of pulse current, and 32% excitement the hourly power is 182 kW. The rotational frequency 2080 rpm.

Mass of Unit: 2000 kgThe motors are connected in series of two. These series are connected in parallel, and connected to the rectifier through general smoothing reactor.Besides high (92%) and low (32.5%) excitement levels, there is a medium level (53.5%)

Controlling train speed

Unit: KSP - 6B ControllerPurpose: Regulating the voltage on Electric traction Engines'clamps, as well as their excitement level.Composition: 18 contactors and leads. The system is developed by Professor L. M. ReshetovThe unit has 20 working positions.

Position 1: Maneuvering

The voltage from one traction coil segmentfollows to traction engines' clamps through startingresistor, and rectifier. The engines are working inhigh excitement mode.

Position 2

The circuit is the same, excluding the starting resistor.

subsequent positions (3 to 16)

the voltage on motor clamps isincreased, due to the serial connection of load to the traction coiloutput.

Position 17: The excitement level is brought down to 53.5%.Position 18: The same working mode as position 17.Position 19: The excitement level is brought down to 32%.

The main controller is controlled by Engineer's controller (1KU - 023). The unit has two handles.They are: Reversive - features Reverse, Drive, and Neutral positions.Main - features neutral, maneuvering, and 4 working positions.

Traction engines and most of electrical devices are manufactured by the Electric Equipment plant of Riga.

Unit: Phase SplittersPlaced: Under the body of Motor cars.Purpose: Converts single phase 220 V Current into3 phase. The produced current serves forpowering various supplementary machines.

Unit: Fan wheel.Placed: On splitter's rotor(?).Purpose: Cooling rectifiers, reactors, and transformers.The rotational frequency of the splitter is 1495 rpm.

Unit: Motor - Compressor.Composition: LOSV-72-6 Electric Motor, with EK1-V or EK-1Pcompressor. Performance 0.7, 0.6 and m³/min.Location: Under the body of attached and cab cars.

Unit: Alkaline, accumulator battery (90KN-55)Normal Voltage: 110 V. Charged by 220 V coil of the transformer, through silicon rectifier. The stabilized is in use for supporting the voltage.Location: Under the body of attached and cab cars.

The construction speed of the trainset is 130 km/h.Calculated acceleration up to 60 km /h is 0.8 m/s^2.

Weights: (On Earth)Motor Car - 59,000 kg 108 Seats;Attached Car - 37,000 kg 110 Seats;Cab Car - 39,000 kg 88 Seats;

Modifications to layout and construction

In process of manufacturing, a lot of changed were introduced in ER9p construction. Starting with ER9p-125 train, jaw clutch drive clutch is changed by rigid roll. Electric engines rotor rod is connected with minor cog wheel using rubber cord shell (like in ER2 motor cars)
*Starting with ER9p-230 trainset (1969), the UVP-1 rectifying unit is changed by UVP-3. It features 84 VKLD-200-8B avalanche rectifiers. Every bridge's arm has 3 parallel circuits, consisting of 6 rectifiers connected in series. The branchings have 3 parallel circuits, with 2 rectifiers connected in series. the connection resistors are absent in UVP-3, as well as devices reacting to rectifier fan-out. (?)
*Starting with ER9p-345 (1974) trainset Cab Trailers were released with more flat head. (As in ER2 electric trainsets trains numbered 1028 and up).

Modified versions of ER9

ER9P

Produced since 1961.In difference of ER9, the rectifiers were placed in car bodies not in passenger space compartments.

ER9M

Produced since 1976. In difference of ER9P, ER9M trainsets have high voltage compartment in their motor cars, where a high voltage bus is located. In ER9/ER9P it was done through the wall.
*Cushioned seats are installed instead of wooden ones. (Similarly with ER2 electric trainsets numbered 1112 and up.

ER9T

Produced since 1981. Differs from ER9M by natural air cooling of rectifiers.

ER9T

Produced since 1988 till the end of ER9 manufacturing by the plant in Riga. This modification has modernized boogies, traction engines and rheostatic brakes.

ER25 contract, for Bulgaria

Bulgaria Railways ordered ER25 trainsets from Railcar Manufacturing plant of Riga. The plant projected rheostatic braking system for these trains. ER9p-101 electric trainset was equipped with such a brake. This train was tested on experimental circle track of CNII of Railroad Ministry. The rheostatic braking was in use for lowering speed from 130 km/h down to 50 km/h. Then regular electro-pneumatic braking was in use. After that, the electric trainset entered Gorky Deport for a permanent use. It worked on common schedule with other ER9p electric trainsets.

In 1974 Tallinn Electrotechnical plant manufactured experimental UVP-5 rectifying units. They featured tablet avalanche rectifiers (12th class) with natural air cooling. One of these units was mounted in ER9P-32304 motor car, which were in use by Gorky Railroad.

Bibliography

V. A. Rakov, "Locomotives and MU rolling stock of Soviet Union Railroads 1966-1975".