North Korea has started to build new railways to transport materials to a new missile base 2507114

In October last year before it shelled Yeonpyeong Island, the regime reportedly conducted an engine combustion test for the Taepodong-2 or an improved version of a long-range intercontinental ballistic missile in Tongchang-ri.

The Taepodong-2 is a designation used to indicate a North Korean two or three-stage ballistic missile design that is the successor to the Taepodong-1. Based on the size of the missile, the fuel composition, and the likely fuel capacity, it is estimated that a two stage variant would have a range of around 4,000 km and a three stage variant would be capable of reaching as far as 4,500 km, giving it potentially the longest range in the North Korean missile arsenal

A South Korean government source said the North is laying the tracks at the Tonchang-ri site, which is believed to have been completed early this year. The site is five times the size of the existing Taepodong missile test site in Musudan-ri in North Hamgyong Province.

Satellite images taken in January showed North Korea had completed a launch tower at the base, which was bigger and more advanced than the older Musudan-ri base on the east coast.

Analysts said the base at Tongchang-ri, whose construction was believed to be almost complete, was seen as vital to North Korea's quest for an intercontinental ballistic missile capable of striking the US.