Indonesia's plans to unearth and export its vast coking coal resources could stumble over the need for large rail projects, meaning little relief for the tight global market for at least the next 5 years.

The government said that Central Kalimantan holds 1.4 billion tonnes of mostly high quality metallurgical coal reserves, but these are buried deep in the rugged mountains and forests of Indonesian Borneo.

Despite the difficulties, soaring prices for the steel making raw material mean the world’s top miners including BHP Billiton are still interested.

But regardless of how much is mined, a lack of funds and uncertainty over government rules could stymie the infrastructure needed to get the coal to ports and on board ships.

Low water levels in the key Barito River during the dry season from May to Sep can also limit coal barge trips to offshore loading facilities for up to 5 months a year.