March 21, 2018

New technologies take the lead on Korea’s Olympic high-speed line

Written by  David Briginshaw and Andy Tebay
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Korea’s latest high-speed line, the Gyeonggang line, has not only dramatically improved transport links to the northeast of the country, including the Winter Olympic venues, but helped to drive Korean railway technology forward, as Andy Tebay and David Briginshaw reveal.

THE 2018 Winter Olympic Games opened on February 9 in Pyeongchang, in the northeast of Korea’s mountainous Gangwon Province. Once considered fairly remote due to lack of transport options and long journey times, Korea’s Gyeonggang high-speed line, which opened on December 22 2017, has brought Pyeongchang and the east coast of the peninsula closer to the capital Seoul and the rest of Korea. During the PyeongChang Olympics, thousands of athletes, volunteers and spectators used the new service to reach competition venues and accommodation. 

The new 120.7km 250km/h line, which cost Won 3.75 trillion ($US 3.5bn) to build, runs from Gangneung to Wonju, where it connects with the existing 108.4km Joongang-Gyeongui Line to Seoul which was upgraded at a cost of Won 126.2bn.

GyeonggangWhile many assume the new line was built primarily for the Olympics, a feasibility study for the Gyeonggang Line was undertaken as early as 1996, and plans were only given the go-ahead in May 2010 - one year before Pyeongchang won its third bid to host the Winter Olympic games. With a fixed deadline to meet, Korea Rail Network Authority (KRNA) had the challenge of constructing the new high-speed railway to a timetable with no margin for error or delay. After designs were finalised in April 2012, a groundbreaking ceremony was held on June 2012 allowing construction to begin. Trial operation began on October 24 2017 and the line was finally opened on December 22 2017.

The new line has five stations: Manjong, Hoengseong, Dunnae, Pyeongchang, Jinbu and Gangneung, with the last three serving Olympic venues. “Initial plans included a new station in southern Gangneung, but the location was changed to a new site after reviewing accessibility to the Gangnam downtown area and Olympic venues such as the athletes’ village and press centre,” explains Mr Song Dong Chang, spokesperson for KRNA.

All five stations are fitted with solar panels to power lights and information displays, while ground heat exchangers power air-conditioning and heating in station concourses and offices. These two systems will generate around 15% of the total power needed at each station.

One of the major challenges KRNA faced was that 63% of the line from Wonju to Gangneung would be in tunnel. In all, there are 34 tunnels totalling 76km as well as 53 bridges with a combined length of 11km. The 250km/h maximum speed on the Gyeonggang Line enabled a tunnel cross-section of 65.7m2 with a 4.3m track centre, which is considerably less than on other Korean high-speed lines where the 300km/h maximum speed demands larger tunnels.

“We ran into conflicts with residents of the region in the process of carrying out construction in such a limited time period before the opening of the 2018 Winter Olympics and in harsh conditions presented by the numerous tunnels that needed to be constructed in a mountainous environment,” Song says. “But by choosing the right construction methods to match the terrain, and working with the local government to listen to residents’ constructive feedback, we were able to establish a plan to mitigate problems and successfully open the line on schedule.”

This included switching from cut-and-cover construction to the shield method using a tunnel boring machine (TBM) on one section in Gangneung after strong opposition from local merchants against the removal of 230 stores at three local markets in the path of the route. In addition, KRNA worked together with the city to create a flea market and park above the tunnel to improve the area for residents and sellers.

A plan to construct 70 new power pylons was another sensitive issue following resistance against building such pylons in other parts of country which have led to protests and unrest. Many residents were concerned about the electromagnetic waves and the potential for property prices to fall. As KRNA could not risk protests delaying the project, it worked with residents and investigated alternatives which led to the decision to place the high-voltage lines underground and not using pylons at all.

While Gangwon Province is well known for its picturesque landscapes and high mountains, this environment has proved a civil engineering challenge. From the design stage, the bridges underwent a thorough ground survey with foundations and bridge supports selected accordingly. Likewise, safe and effective designs for the bridges themselves were decided by taking into consideration several factors including roads, waterways, agricultural land and aesthetics.

Further ground inspections took place for the tunnels to determine the most appropriate construction methods, which resulted in the decision to use both the New Austrian Tunneling Method (NATM) and shield tunnel boring.

At 21.76km, the Daegwallyeong tunnel is both the longest on the line and the longest mountain tunnel in Korea. Work on the tunnel, which is located between Jinbu and Gangneung stations, began in June 2012 and involved 259,600 workers working round the clock using 110,900 items of machinery to excavate 1,910,000m3 of spoil. The double-track single-bore tunnel is 10.7m wide and 8.2m high. Tunnel breakthrough was finally made in November 2015 after 41 months.

As it takes 5min 30s for trains to pass through the tunnel it has a range of safety features. A four-track multi-function station has been built so that four trains can stop inside the tunnel simultaneously if necessary. The tunnel has six rescue points and four access tunnels protected by double-layer fire doors, which can be used for evacuation in the event of an emergency. Three of the access tunnels are fitted with a smoke exhaust system comprising fans and air ducts. In addition, the tunnel has 436 emergency exit signs alternating every 50m on each side, emergency exit lighting at 20m intervals, and fire extinguishers every 400m. In the event of a fire, the smoke exhaust and air supply automatically interface with the emergency exit signs to guide people to the nearest safe rescue point.

KRNA says the Gyeonggang Line is the world’s first 250km/h line to be equipped with a 4G LTE-based radio communication system optimised for rail. The LTE-R system has been developed in Korea and is used by traffic controllers, train drivers and maintenance staff. It features voice and video communication and high-capacity data transmission up to a maximum of 75Mbps. KRNA says that the ability to conduct multi-party video calls will facilitate information exchange during an emergency. LTE-R is also connected to Korea’s national disaster wireless communication network to enable a rapid response to emergencies. In addition, sensors are attached to railway assets which can transmit information via LTE-R to maintenance personnel.

Signalling is controlled from a CTC centre, and the line is equipped with electronic interlockings and automatic train protection (ATP) which continually monitors train speed according to operating conditions and automatically stops the train if necessary.

The Gyeonggang Line has a lot of safety features, including:

  • two dragging equipment detectors
  • 65 devices which will stop trains automatically if obstacles are detected on the track
  • a rail temperature sensor to detect rail buckling during high temperatures
  • 228 point heaters to melt snow and ice
  • two weather monitoring devices which will slow or stop trains during severe storms, and
  • earthquake sensors at six locations to provide early warning of seismic activity.

In addition, two track crossing call devices are installed on the line to warn maintenance staff of approaching trains, together with 55 train approach warning systems which are activated by staff prior to entering a tunnel.

KRNA has developed a Line Allocation System (KR LAS) to improve the efficiency of train operation on the new line. KR LAS is a computer program which calculates the departure and arrival times of trains to determine optimum track access allocation based on the needs of train operators and infrastructure availability. It includes a track access allocation system whereby operators can complete a track access request form in order to confirm their access rights.

KRNA says KR LAS will improve work efficiency, provide fair and reliable track access rights, enable a quick and accurate assessment of track access needs and facilitate timetable planning.

Korea has developed new designs of catenary and rail fastenings for the Gyeonggang Line, and KRNA says this is the first time a 250km/h catenary system and a rail fastening device for slab track have been designed in Korea using Korean technology and components. It says that by using its new rail fastening device, Won 15.1bn was saved in foreign currency. A non-exclusive licence for the fastening will be granted to any Korean company, and in particular SMEs, wishing to manufacture the fastening.

Trains

Korail purchased 15 KTX trains from Hyundai Rotem in a Won 494bn deal to operate on the Gyeonggang Line. Each train consists of two power cars, seven economy-class cars and one first-class coach. However, these trains will eventually be replaced by Hyundai Rotem’s new EMU-250 trains which Korail has ordered for its medium-speed lines. The first of these trains is expected to be delivered to Korail in 2020.

During the Olympics, Korail ran direct trains from Incheon Airport to Gangenueug as well as an intensive service from Seoul with a maximum of 51 trains per day in February.

Beyond the Olympics, the opening of the Gyeonggang Line is expected to stimulate Gangwon’s economy which in the past has remained fairly stagnant despite its proximity to the capital. Poor transport links were a major factor in this, and until the end of 2017, a trip by train from Seoul Cheongnyangni station to Gangneung took almost six hours.

Now, high-speed trains zip passengers from the capital to Gangneung in as little as 1h 26min. The service has already proven popular for local tourism prior to the Olympics, with 660,000 people using it to visit the region between December 22 and February 7. According to the city of Gangneung, sales at local markets and its Anmok coffee street have increased by 30%, while other surrounding areas have reported a 10-20% growth in revenue.

The Gyeonggang Line is only the beginning for new projects in the region, with a new 92km high-speed rail link from Chuncheon to the northern coastal city of Sokcho currently underway by the Ministry of Land, Infrastructure and Transport. The project was given the green light in mid-2016 after a preliminary feasibility study carried out by the government-run think-tank, the Korea Development Institute, concluded that the project was viable. This will connect with the Chuncheon - Seoul line to provide a second rail link to the northeast of Korea running parallel to and to the north of the Gyeonggang Line, which will finally end the region’s isolation.

 

New Korail CEO to merge HS operations

THE new CEO of Korail, Mr Oh Young-sik, who took office in February, has pledged to merge the high-speed services provided by Korail and Supreme Railways (SR). SR was set up in 2016 to break Korail’s monopoly on the operation of high-speed trains in Korea, but the current Korean government is against this.

“The merger with SR is a task we can’t delay anymore because of increasing public inconvenience,” Oh said during his inaugural speech on February 6. “Forcibly dividing short-distance railways and putting the operators up for competition will mar the effect of an ‘economy of scale’ and cause national inefficiency.”

SR began operation in December 2016 on the new 61.1km line from Suseo in the Gangnam business district of Seoul which connects with rest of the high-speed network. The line is mainly underground located in a 52.3km tunnel and has three stations.

SR provides services from Suseo to Busan and Mokpo. Its trains take 10 minutes less to reach Seoul due to the location of Suseo station on the southern side of the city compared with Korail’s city-centre terminal.

 

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