The case for a train to Koh Samui

A combined road/rail bridge could put an end to Samui Airport’s stranglehold on the island.

Numerous new railway proposals in Thailand have been made over the years. Some of them are now being built (such as the railway to Chiang Rai), while some of them are too radical to be true (such as this Hanoi – Luang Prabang – Chiang Mai line).

One line that hasn’t been proposed is a railway to Koh Samui. At this point, you might be thinking how a railway is supposed to get to an island that is 17 km off the mainland? Read on, and you will discover that not only is this possible, but there is not much that needs to be done in addition to what is already being planned.

This article will also show that a train to Koh Samui doesn’t even rank among the radical infrastructure ideas that have been proposed in Thailand.

How to build a railway to Koh Samui

This is what is needed to build a railway line to Koh Samui.

The Koh Samui Bridge

Koh Samui is the second-largest island in Thailand (after Phuket), and there is a plan to build a bridge to the island from the mainland. This road bridge would be about 17 km in length, making it the longest over-sea bridge in Thailand.

The bridge is about to undergo a feasibility study, so it would be a matter of turning the bridge into a combined road/rail bridge. Ideally, there would be a space reserved in the middle of the bridge for a railway. It would only need to be a single track as there would be no need for a double track over such a short distance.

Another option, if they don’t want to make the bridge wider or if it’s too late to change the plan, is to run the railway on the road, like the First Thai–Lao Friendship Bridge. Traffic in one direction would have to be closed while the train crosses, but if it was scheduled, then vehicle traffic would know then to cross the bridge.

[Nong Khai to Thanaleng shuttle train crossing the Mekong River.]

Mainland railway

On the mainland side, a railway extension from Surat Thani to the ferry port at Don Sak has already been proposed, so this is not a new proposal on my behalf. With that extension already proposed, this could be extended across the bridge.

Island railway

On the Koh Samui side, the station would have to be near the bridge landing point. It would then be up to Koh Samui if they wanted to push the railway further into the island. This would be the most difficult part because the land is already built up and the terrain would require tunnels. Perhaps a long-term vision would be to create an urban railway to Chaweng to reduce traffic on the busy east coast.

Why a train to Koh Samui is not as radical as it sounds

A more ridiculous idea is a second Samui Airport

Koh Samui is served by Koh Samui Airport, which is privately owned by Bangkok Airways. This airport feels more like a resort than an airport, and for other airlines, it’s expensive to use. Thai Airways stopped flying there, and AirAsia prefers to fly to Surat Thani, where bus and ferry transfers await.

[Samui Airport]

Tourism bodies of Koh Samui have often complained about the expensive landing fees, and there was a proposal to build a second airport to get around the monopoly held by Bangkok Airways.

Building a second airport on an island the size of Koh Samui would be a ridiculous idea. Perhaps the proposal was a bluff to make Samui Airport reconsider its landing fees. Either way, a train line sharing space with vehicle traffic on a bridge that is already being planned is a more sensible idea than building a second airport.

There are longer and more complex rail bridges in the world

If the Koh Samui bridge is built, it will only be about half the length of the longest bridge in Southeast Asia. 

Compared to other railway bridges, the world’s longest cross-sea high-speed railway bridge is being built in China, which will be 29.16 km.

As for road and rail bridges, the longest road and rail bridge in Europe is the Øresund Bridge. While this is “only” about 8 km, it has the added complexity of being a combined bridge and tunnel system.

Thailand has proposed an even more ambitious bridge project

The Samui bridge is the longest proposed bridge that could be built, but the longest proposed bridge is across the Bay of Bangkok. At 50 km long, that would be the new longest bridge in SE Asia.

The train could end the Samui Airport monopoly and become a tourist attraction in itself

Getting the train to Koh Samui would become a tourist attraction in itself and provide another alternative to domestic flights.

If the train is connected to the current metre-gauge railway, you could get an overnight train from Bangkok and wake up on Samui, without the extra bus and ferry transfer combo.

If Thailand ends up building a high-speed train to the south, you could get from Bangkok to Samui in a matter of hours, which would make flying to Samui from Bangkok obsolete.