A report about the train was published in Bernama 28 Dec 2015. I will reproduce it here as the Bernama reports don't stay on their www.
Safety Factor Cited For Discontinuation Of Cave Train Service
KANGAR, Dec 28 (Bernama) -- Safety of the people has been cited as the primary reason for the discontinuation of the train service in Gua Kelam 2 (Cave of Darkness 2) in Kaki Bukit that ceased operation in 2013 after a three-year run.
Perlis Tourism Committee chairman Abdul Jamil Saad said today a study by the Department of Occupational Safety and Health and the Public Works Department found that the cave walls would not be able to withstand the level of the train vibrations.
He also said that the state government could not come up with the millions of ringgit that would be needed to strengthen the cave walls if the train service was to be resumed.
"The state government decided against resuming the train service due to the safety factor although it has helped to draw tourists to the cave," he told Bernama.
The service, then handled by the State Department of Forestry with the collaboration of the Tourism Ministry, involved a two-coach train carrying a maximum of 20 passengers per trip on a 400-metre journey every two hours per day.
Besides Gua Kelam 2, the Gua Kelam (Cave of Darkness) of 370-metre length that stretches into the Nakawan Range from Kaki Bukit town to Kampung Wang Kelian is also a major tourist draw.
It is odd that the train stopped running in 2013 yet this was only in the news at the very end of 2015.
It is also 'interesting' that one excuse/reason is "the cave walls would not be able to withstand the level of the train vibrations". I suspect this is just an excuse as there are trains in other caves around the world that don't affect the cave walls. Probably the oldest and most famous is the train at Postojna Cave in Slovenia. This train has been in operation for more than 140 years and covers 3.7 km.
The Gua Kelam 2 railway in 2010 -
