iE305 Series: 120 km/h, Local Design & The Rise of Indonesia's Railway Industry

KRL iE305 – The first electric commuter train entirely designed and manufactured by Indonesian workers. (Image: INKA / Speedo Science)

The KRL iE305 series is not merely a commuter train—it is a symbol of Indonesia's railway engineering independence. Produced by PT INKA (Industri Kereta Api) in Madiun, East Java, the iE305 is the first electric multiple unit (EMU) entirely designed and manufactured by Indonesian workers. With a top speed of 120 km/h, advanced safety systems, and a capacity of over 1,200 passengers per trainset, the iE305 represents a leap forward for Indonesia's railway industry. Developed in partnership with KAI Commuter, this train is now serving the Jakarta metropolitan area, replacing aging Japanese rolling stock with locally built technology. This is the engineering story of Indonesia's new national pride.

1. Overview: Indonesia's First Locally Designed EMU

• What: Electric Multiple Unit (EMU) commuter train, first fully designed and produced in Indonesia
• Who: PT INKA (Madiun) & PT KAI Commuter (operator)
• When: First unit completed December 2024; operational testing March 2025; full deployment 2025-2026
• Where: Manufactured at INKA Madiun and Banyuwangi facilities; operates in Jakarta metropolitan area
• Why: To reduce dependence on imported rolling stock and build domestic railway manufacturing capability
• How: Stainless steel carbody, IGBT-VVVF traction system, regenerative braking, and locally developed bogies

"The iE305 is proof that Indonesian engineers can build world-class trains," said a PT INKA executive. "For decades, we relied on imported trains from Japan. Now, we have our own design, our own technology, and our own pride. This is the beginning of a new era for Indonesian railway manufacturing." [Source: PT INKA]

2. iE305 Series Performance Metrics

• Maximum Speed: 120 km/h (75 mph)
• Operating Speed: 100-110 km/h (operational limit on Jabodetabek network)
• Acceleration: 1.0 m/s² (0-60 km/h in approximately 17 seconds)
• Deceleration: 1.1 m/s² (service brake), 1.3 m/s² (emergency brake)
• Carbody Material: Stainless steel (corrosion-resistant, lightweight)
• Carbody Width: 2,950 mm (9.7 feet)
• Carbody Length: 20,000 mm per car (65.6 feet)
• Trainset Configuration: 4-car or 8-car formations
• Passenger Capacity: 300-350 passengers per car (including standing) — 1,200+ per 4-car trainset
• Seating Capacity: 80-100 seats per car (depending on configuration)
• Traction System: IGBT-VVVF (Insulated Gate Bipolar Transistor - Variable Voltage Variable Frequency)
• Traction Motors: 8 x 200 kW per 4-car trainset (1,600 kW total)
• Power Supply: 1,500 V DC overhead catenary

Analysis: The iE305's 120 km/h top speed matches the operational limits of the existing Jakarta commuter network infrastructure. While not a high-speed train by global standards, it represents a significant upgrade in acceleration and energy efficiency compared to the aging Japanese 203 and 205 series trains it replaces. The regenerative braking system recovers energy during deceleration, reducing overall power consumption by approximately 20%.

3. The INKA Madiun Factory: Indonesia's Railway Manufacturing Hub

• Location: Madiun, East Java (main facility) and Banyuwangi, East Java (assembly)
• Established: 1981 as state-owned enterprise (Persero)
• Workforce: 5,000+ employees across both facilities
• Production Capacity: 500-600 passenger cars per year
• Products: Commuter trains, locomotives, diesel multiple units (DMU), passenger coaches, freight wagons, LRT vehicles
• Export Markets: Bangladesh, Philippines, Thailand, Australia, Mongolia
• Technology Partners: Bombardier (Canada), Nippon Sharyo (Japan), CRRC (China)

"INKA is not just a train manufacturer—it is the heart of Indonesia's railway industry," said a factory manager. "We have built trains for Jakarta, Surabaya, Palembang, and even for export. The iE305 is our masterpiece: the first train designed entirely by our own engineers." [Source: PT INKA]

4. Engineering Insight: The Locally Developed Bogie System

One of the most critical components of the iE305 is its bogie system—the undercarriage that houses wheels, suspension, and brakes. For the iE305, INKA engineers developed a bogie specifically designed for Jakarta's unique track conditions.

• Bogie Type: Bolsterless air-sprung bogie (optimized for passenger comfort)
• Suspension: Primary coil springs + secondary air springs (adjustable)
• Wheel Diameter: 860 mm (new), 780 mm (worn)
• Axle Load: 14 tons (compatible with existing track infrastructure)
• Track Gauge: 1,067 mm (Cape gauge, same as Japanese commuter lines)
• Local Content: 60% locally manufactured components (target 80% by 2027)

Why this matters: Bogies are the most mechanically complex component of any train. Developing them locally required years of research, testing, and certification. The iE305's bogie system is now being considered for export to other Southeast Asian railways using the same 1,067 mm gauge.

5. Passenger Experience & Interior Design

• Seating: Longitudinal bench seats (optimized for high-capacity standing) with priority seating for elderly, disabled, and pregnant women
• Air Conditioning: Ducted HVAC with 24°C set temperature (adjustable by driver)
• Lighting: Full LED interior lighting with dimming capability
• Passenger Information: Digital route maps, next station displays, and automated announcements (Indonesian and English)
• Accessibility: Wide door openings (1,300 mm), dedicated wheelchair spaces, and audible door chimes
• Safety Features: CCTV monitoring, emergency intercoms, fire suppression system
• Windows: Laminated safety glass with UV protection

Insight: The iE305's interior was designed specifically for Jakarta's commuter culture—where peak-hour standing is the norm. Wide aisles, multiple handrails, and optimized standing space accommodate up to 350 passengers per car, making it one of the highest-capacity trains in Southeast Asia.

6. Comparison: iE305 vs Japan's 205 Series (Legacy Fleet)

Specification	iE305 (INKA)	205 Series (Japan)	203 Series (Japan)
Top Speed	120 km/h	110 km/h	100 km/h
Acceleration	1.0 m/s²	0.8 m/s²	0.8 m/s²
Traction System	IGBT-VVVF	Chopper control (GTO)	Chopper control (GTO)
Regenerative Braking	✅ Yes	❌ No	❌ No
Door Width	1,300 mm	1,100 mm	1,100 mm
Passenger Info System	Digital displays	Static maps only	Static maps only
CCTV	✅ Yes (every car)	❌ No (retrofitted)	❌ No (retrofitted)

↔️ Swipe the table to the right to view all comparison data.

Context: The iE305 is a generational leap over the Japanese-built 203 and 205 series trains that have dominated Jakarta's commuter network for decades. With higher top speed, faster acceleration, regenerative braking, and modern passenger amenities, the iE305 significantly improves service quality and energy efficiency. Most importantly, it demonstrates Indonesia's capability to build its own trains.

7. The Road to 120 km/h: Testing and Certification

• Static Testing: Completed at INKA Madiun facility (December 2024)
• Dynamic Testing: Solo Jebres–Lempuyangan line (March 2025) — first run at 120 km/h
• Certification: Passed Ministry of Transportation safety tests (April 2025)
• Public Debut: Jakarta commuter line (August 2025)
• Current Deployment: 16 trainsets (64 cars) in service, 8 more under production

"The test run from Solo to Lempuyangan at 120 km/h was a historic moment," said a test engineer. "For the first time, an Indonesian-designed train reached that speed on Indonesian tracks. It was smooth, stable, and quiet. We knew then that we had succeeded." [Source: PT INKA Testing Division]

8. Why It Matters

The iE305 series matters for three reasons. First, it ends Indonesia's dependence on imported commuter trains—a market dominated by Japanese manufacturers for over 40 years. Second, it builds domestic engineering capability, with INKA now able to design and manufacture complex railway systems without foreign partners. Third, it positions Indonesia as a potential railway exporter to other Southeast Asian nations with similar 1,067 mm gauge networks.

For Jakarta's 1.2 million daily commuter rail passengers, the iE305 means more reliable service, better acceleration, and modern amenities. For Indonesia's manufacturing sector, it proves that high-technology products can be built locally. And for the global railway industry, it signals the emergence of a new player in the rolling stock market.

9. Frequently Asked Questions (FAQ)

What is the top speed of the KRL iE305?

The iE305 has a maximum design speed of 120 km/h (75 mph), which matches the operational limits of the Jakarta commuter rail network.

Who manufactures the iE305?

The iE305 is manufactured by PT INKA (Industri Kereta Api) at its facilities in Madiun and Banyuwangi, East Java, Indonesia.

Is the iE305 fully designed in Indonesia?

Yes. The iE305 is the first electric commuter train entirely designed by Indonesian engineers at PT INKA, with 100% local design input.

How many iE305 trains are in service?

As of March 2026, 16 trainsets (64 cars) are in service on the Jakarta commuter network, with 8 more trainsets under production.

What is the capacity of the iE305?

Each 4-car trainset can carry over 1,200 passengers (including standing). Each car accommodates 300-350 passengers.

Does the iE305 have regenerative braking?

Yes. The iE305 uses IGBT-VVVF traction control with regenerative braking, recovering energy during deceleration and reducing power consumption by approximately 20%.

What is the track gauge of the iE305?

The iE305 uses 1,067 mm (Cape gauge), the same as Japan's commuter rail network and Indonesia's existing lines.

Does INKA export trains?

Yes. INKA has exported trains to Bangladesh, the Philippines, Thailand, Australia, and Mongolia. The iE305 technology may be offered for export in the future.

10. The Future: 160 km/h and Beyond

The iE305 is just the beginning. INKA is now developing next-generation trains capable of 160 km/h and higher. This includes lightweight aluminum carbody designs, advanced bogies for higher speeds, and trains optimized for Indonesia's planned high-speed rail network extensions.

"We are not stopping at 120 km/h," said a senior INKA engineer. "Our engineers are already working on trains that can run at 160 km/h, then 200 km/h. The iE305 is our first step—proof that Indonesian workers can build world-class trains. The next step is to build the fastest trains in Southeast Asia."

For Indonesia's railway industry, the iE305 represents a turning point. After decades of importing technology from Japan, Europe, and China, the nation now has the capability to design and build its own trains. The engineers who designed the iE305 are now training the next generation. The factories that built it are expanding. And the railways that operate it are becoming more reliable every day.

This is the story of Indonesia's railway independence—and it starts in Madiun.

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Sources: PT INKA, KAI Commuter, Ministry of Transportation Republic of Indonesia, Railway Gazette, Speedo Science Database