bodyType

customContents

entityId

entityUuid

articlePageQuery

filter

article

articleBaseAdvertisingInfoArticle

articleListArticle

articleSeoArticle

hooksArticleAcknowledgementGateOverlayArticle

hooksTrackPageViewArticle

hooksContentInterestArticle

articleLinkingDataContent

hooksAmpRedirectArticle

articleSchemaContent

liveArticle

advertZone

sentiment

contentLock

topics

types

sections

paywallTypes

createdDate

publishedDate

sponsorType

urlAlias

moreOnThisArticles

commentCount

authorLocations

authors

corrections

displaySlideShow

multimediaEmbed

printHeadline

seriesContainer

articleSpeeches

socialHeadline

headline

images

flag

firstTopic

glossary

flattenTypeIds

image

relatedLinks

relatedNewsletters

__typename

sponsor

pdfFiles

seriesReverseOrder

series

disableOffPlatformContent

published

updatedDate

summary

subHeadline

body

keywords

readingTime

customTimezone

liveContents

Dannie Peng

The world’s “most difficult” railway project is taking shape in rugged southwestern China.
The line connecting Dali and border town Ruili in Yunnan province is the first to cut through the Hengduan Mountains, traversing some of the world’s most complex geological and topographical terrains.
Running along the country’s southwestern frontier for about 330km (205 miles), the railway is expected to boost China’s links with Southeast Asia.
The line is being built in two sections: Dali to Baoshan, and Baoshan to Ruili, a county-level city that serves as a major border crossing with Myanmar.
The first section broke ground in 2008 and was completed in 2022. The second half is now expected to be operational within five years, according to state media reports citing local officials.
Its completion will mark a milestone for global railway engineering.




The Dali to Baoshan section is a 133km journey that takes only about an hour. But it took tens of thousands of workers 14 years to complete it because of the complex terrain.
By comparison, building a similar railway line across flat, geologically stable terrain would only take about three years.
When the section entered operation in July 2022, its builder, China Railway Group – one of the world’s largest construction and engineering contractors – described how challenging the project had been.
The company said that the line passed through areas characterised by steep mountains, deep valleys, intense tectonic activity and unstable, fractured rock formations. The construction had to avoid major fault zones and cross four large rivers.
This required building numerous technically demanding bridges and tunnels to support the railway. In total, 34 bridges and 21 tunnels were constructed.
The 14.4km Dazhushan tunnel alone, which cuts through six geological fault lines, encountered “almost every major engineering risk associated with large-scale tunnel construction” and took 12 years to complete, according to the company.
One of the biggest challenges was massive groundwater inflows. Water gushing into the tunnels equalled the volume of 156,000 standard swimming pools, forcing workers to labour in submerged conditions for extended periods.
Construction of the second section, from Baoshan to Ruili, began in 2015. Engineers are now tackling the project’s final and most formidable obstacle: the Gaoligong Mountain Rail Tunnel, a 34.5km stretch poised to be the longest such tunnel in Asia.
According to a December post on the Yunnan provincial government’s social media account, builders working 765 metres (2,500 feet) below the surface in the heart of the Hengduan Mountains are contending with extreme geothermal heat, high-pressure water inflows and fragile surrounding rock – challenges it described as “world class” in their difficulty.
“[It is] the world’s most difficult railway to build,” the post said.
On February 11, state news agency China News Service reported that the tunnel – regarded as the “throat project” of the railway – had reached only around half of its planned progress after nine years of construction. However, work is expected to speed up following recent technical breakthroughs.
The Baoshan to Ruili section of the Dali-Ruili Railway was among “projects set to be completed and opened” during the latest five-year plan period from 2026 to 2030, provincial newspaper Ethnic Times reported this month citing an official briefing.
Gao Shangjie, a senior engineer with a local transport bureau, told reporters last month that advances in tunnelling technology had significantly improved construction speed.
If all went to plan, the tunnel would be complete and operational by 2028, China News Service said.
The railway will transform transport in Yunnan’s mountainous west, cutting travel time from provincial capital Kunming to Ruili to 4½ hours – half the current nine.
As a key section of the China-Myanmar international railway corridor, the Dali-Ruili line would also “open a more efficient route linking China with countries in South and Southeast Asia”, China News Service said.


China on track to finish world’s ‘most difficult’ railway project before 2030

Ras Al Khaimah eyes Chinese and Hong Kong investors as UAE-China ties deepen

China tightens rail approvals as Xi warns on overbuilding, waste and ‘operational’ trouble

China plans 19% high-speed rail expansion by 2030 amid global dominance in the sector

China Railway

A train seen during a trial run in 2022 on the Dali-Baoshan section of the railway line in Yunnan province. Photo: Xinhua

‘Time is ripe’: why China is eyeing another vast canal link to Southeast Asia

Construction continues on the Pinglu Canal in China’s southern Guangxi region in January. The canal is due to open before the end of 2026. Photo: Xinhua

China has invested US$10 billion to build the Pinglu Canal in the southern Guangxi region. It is also considering an even larger canal project further inland, which could cost more than US$20 billion. Photo: Weibo

A high-speed train leaves the Yichang North Railway Station in China’s Hubei province on December 26. Photo: Xinhua

News

China

Science

330km Dali-Ruili Railway is expected to transform transport in Yunnan’s mountainous west, and better link China to South and Southeast Asia


330km Dali-Ruili Railway is expected to transform transport in Yunnan’s mountainous west, and better link China to South and Southeast Asia.


Myanmar

Kunming

China on track to finish world’s ‘most difficult’ railway project before 2030

.css-1c6uqr6{color:inherit;font-weight:inherit;font-size:inherit;font-family:inherit;line-height:inherit;overflow-wrap:break-word;}330km Dali-Ruili Railway is expected to transform transport in Yunnan’s mountainous west, and better link China to South and Southeast Asia

330km Dali-Ruili Railway is expected to transform transport in Yunnan’s mountainous west, and better link China to South and Southeast Asia