KUANTAN: The 665km East Coast Rail Link (ECRL), a mega-rail project launched in 2017, is designed with the monsoon season and future flooding in mind.
Scheduled for completion in December 2026, the RM50 billion project will traverse Kelantan, Terengganu and Pahang to the Klang Valley. It will cut travel time between the east and west coasts from eight hours to four hours.
Two interesting features are the elevated super major bridges and major bridges.
Malaysia Rail Link Sdn Bhd infra head of construction Noor Azlan Salleh said they were built based on the 100-year average recurrence interval flood level.
"Based on the calculations and requirements by the authorities, we build elevated railway tracks in flood-prone areas to ensure train services will not be disrupted during floods.
"For instance, we recorded 3m-high floodwaters in our site here, which did not affect the project (with a pier height of between 6m and 14m). The project can withstand floods and train operations will not be affected."
He said this during a visit to the 3.88km Sungai Kuantan super major bridge construction site in the Kampung Padang area.
In Pahang, there are 71 bridges covering a distance of 45km.
When flood water rises above the rails, trains are forced to slow down to prevent damage and there are instances of floods disrupting rail services.
To differentiate between major bridges and super major bridges, ECRL Section 6 Work Zone 1 chief engineer Han Tian Jie said major bridges would have a cumulative distance longer than 300m and super major bridges were more than 500m in length.
Section 6 covers 144.1km of the 665km ECRL alignment, with four major stations, 18 tunnels and 41 bridges.
Citing Sungai Kuantan, he said it had a 100-year reduced level of 9.27m and projected the highest flood level of 6.16m.
"The rail level in the river area is 19.843m, which is higher than the projected flood level.
"Bridges provide a better discharge of flood water as constructing subgrade in flood-prone and swampy areas is not ideal. This is because the subgrade water discharge speed is slower than bridges."
In transport engineering, subgrade is the native material underneath a constructed road, pavement or railway track.