KTX-I

Korail
Industry	Rail transport
Founded	1963; 63 years ago
Headquarters	Seoul, South Korea
Area served	South Korea
Products	KTX-I high-speed train
Owner	Government of South Korea
Website	www.korail.com

The KTX-I, also known as the TGV-K or Korail Class 100000, represents South Korea's inaugural high-speed train, derived from the French SNCF TGV Réseau design. Its configuration consists of 20 cars, maximizing passenger capacity by excluding a dining car. The initial batch of 46 trainsets resulted from a technology transfer agreement; early units were assembled in France, while subsequent ones were manufactured domestically by Hyundai Rotem, marking a significant step forward in South Korea's high-speed rail production capabilities.

Managed by Korail, the KTX brand designates this model as KTX-I to differentiate it from later versions such as the KTX-Sancheon (previously called KTX-II). Since commencing service on April 1, 2004, the KTX-I has served as Korail’s flagship high-speed train, operating at a top scheduled speed of . Its operational dependability has progressively increased through ongoing maintenance improvements and incremental enhancements, maintaining its status as a vital component of South Korea’s growing high-speed rail network.

History

In 1991, South Korea initiated a bidding process to acquire and transfer essential high-speed rail technologies, encompassing catenary systems, signaling, and rolling stock for its new high-speed rail service. On August 26 of that year, consortia led by GEC-Alstom (the French manufacturer of the TGV), Siemens (Germany’s ICE producer), and Mitsubishi (Japan’s Shinkansen builder) submitted their preliminary proposals. Following five evaluation rounds, final bids from the French and German consortia were presented on June 15, 1993. The Korea High Speed Rail Construction Authority (KHSRCA) selected the consortium headed by GEC-Alstom as the preferred bidder on August 20, 1993, with the contract finalized on June 14, 1994.

The agreement with GEC-Alstom and its South Korean affiliate Eukorail covered the delivery of South Korea’s first high-speed trains—the KTX-I, modeled after the TGV Réseau. The first end car body was produced in January 1996; by December 1997, the initial complete trainset was assembled and tested in France before being transported to South Korea in March 1998. The maiden test run on Korean tracks took place in December 1999. Speeds reaching were attained by June 2000, with routine testing at this velocity commencing in November 2000 after all twelve Alstom-built trainsets had been delivered.

To satisfy contractual requirements stipulating that over half of the value added post-technology transfer be generated domestically, Hyundai Rotem constructed the remaining 34 out of the total 46 trainsets under license within South Korea. The first carbody manufactured locally was completed in October 1999; April 2002 saw the rollout of the first fully assembled Korean-built trainset, with all units delivered by December 2003.

Between January and April 1, 2004—the official start of commercial service—approximately 25 to 28 trains operated daily during intensive trial runs aimed at preparing infrastructure and staff for full-scale operations.

Technical details

Following the standard TGV design principles, the KTX-I is a permanently coupled trainset featuring two powered end cars positioned at each extremity of a series of articulated passenger coaches joined via Jacobs bogies. Based on the TGV Réseau platform, it comprises eighteen passenger cars—the longest monobloc TGV configuration to date. The two motorized bogies adjacent to the traction heads resemble those found on the TGV Sud-Est. Unlike European counterparts, the KTX-I operates using a supply voltage frequency of 60 Hz, includes rotating seats within First Class compartments, and excludes bar or restaurant cars. Although initial designs from 1993 proposed a "shovel nose" to improve aerodynamic performance in tunnels, the final exterior closely mirrors Spain’s AVE Class 100.

The trainsets incorporate pressure-sealed cabins to alleviate passenger discomfort during tunnel transitions. Their windows are triple-glazed with a thickness of . Seating offers a pitch of in Standard Class and in First Class. Onboard amenities include ceiling-mounted video screens, audio systems, telephones, and vending machines for passenger convenience.

Train composition

A KTX trainset consists of two power cars flanking 18 passenger coaches:

Coach Number	Type	Seating Capacity
Coach Number	Type	First Class	Standard Class	Restrooms
Power car
1	Standard Class	0	56	1
2	First Class with wheelchair accessibility	23 + 2	0	2
3	First Class	35		0
4	First Class	32		2
5	Standard Class	0	55	0
6			56	2
7			60	0
8			56	2
9			60	0
10			60	0
11			56	2
12			60	0
13			56	2
14			60	0
15			56	2
16			'Standard Class'	'60'	'0'

Service routes

KTX-I trains commenced commercial operations on April 1, 2004, initially serving two main corridors: Seoul to Busan via the Gyeongbu High-Speed Railway (HSR) and Seoul to Mokpo/Gwangju along the Honam Line, which combines high-speed and upgraded conventional tracks. Between June 2007 and October 2010, certain Gyeongbu KTX services were rerouted through Gimcheon and Gumi stations until a dedicated high-speed station became operational. Starting November 2010, the majority of Gyeongbu KTX trains transitioned to the newly opened Daegu–Busan HSR segment, while some continued using the conventional line to provide additional stops such as Suwon.

At launch, the KTX-I operated at a maximum speed of 300 km/h, which was raised to 305 km/h in November 2008 to better meet traveler expectations. Since 2006, some KTX-I trains have incorporated a moving cinema in the leading car as part of enhanced onboard amenities.

Technical challenges

Initial operational difficulties for KTX involved issues with rolling stock reliability, signalling systems, power supply irregularities, and track conditions. From the start through the fifth month of service, incident frequency dropped from 28 to 8 per month, with rolling stock-related problems decreasing from 18 to 5. Early failures were attributed to inexperienced personnel and inadequate maintenance routines. By the fifth year, failure rates had significantly improved.

In October 2006, questions were raised about the practice of using components from other trains as spare parts; Korail clarified that this was a common emergency procedure without compromising safety and affirmed that spare parts availability remained secure. Additionally, Korail launched a localisation initiative aimed at producing domestic substitutes for imported components, beginning with auxiliary inverters and brake cylinders.

On June 13, 2007 near Cheongdo, a detached damper on a KTX-I train caused ballast stones to strike several cars, resulting in two injuries and smoke inside the train; emergency braking was promptly applied. On November 3, 2007, a collision occurred at Busan Station when a KTX-I train struck a stationary train causing approximately 10 billion won in damages and minor injuries. Investigation revealed the driver had fallen asleep and disabled safety devices; furthermore, no station dispatcher was present. The driver received a fine of 10 million won. The railway union criticized single-driver operation combined with insufficient rest periods.

Passengers reported excessive noise when passing through tunnels; tests conducted in August 2005 demonstrated that enlarging mud flaps at articulated car joints by 43 mm reduced noise levels by 3–4 dB. Korail retrofitted all trains with these wider mud flaps by May 2006.

Evolution of successive models through localized innovation

Building on the technology transfer gained from the KTX-I project, South Korea's rail sector developed the prototype high-speed train HSR-350x. This advancement paved the way for Hyundai Rotem to secure contracts for the commercial high-speed train known as the KTX-II.

External links

Information on KTX-I (Korail)