North Korea appears to be preparing to test a vertical launch tube used in submarine-launched ballistic missiles in an indication the communist nation is forging ahead with SLBM development, a U.S. research institute said.
  

"Commercial satellite imagery indicates that North Korea is continuing the development of a submarine-launched ballistic missile at the Sinpo South Shipyard, including planning for a test of the vertical launch tube intended to fire the weapon," Joseph Bermudez Jr., an expert on North Korea's military, said in an article contributed to 38 North.
  

Satellite imagery taken on Sept. 21 showed that a launch superstructure has been erected at a vertical launch stand built at the east coast shipyard. Such a structure is erected to conduct tests of the stabilization and fire-control systems and for ejection, or "pop up," tests of the launch tube, he said.
  

"These developments may account for a CNN report on October 9 -- the eve of the 70th anniversary of the Workers' Party of Korea -- that US officials believed the DPRK (North Korea) might conduct an SLBM test soon," the expert said.
  

Satellite imagery also showed that the ongoing modernization program at the construction halls and machine shops underway at the shipyard since June 2014 appears to be nearing completion, Bermudez said, adding that the shipyard is the primary site for building submarines in the North and the construction suggests the country is about to embark on a new program.
  

"Given what appears to be a strong commitment to its submarine program, indicated by the pace of development of its SLBM and associated submarine and the nearly complete modernization effort at Sinpo South Shipyard, the DPRK is likely planning to commence the production of new submarines in the next 12-24 months," he said.
  

In May, North Korea claimed it successfully carried out an SLBM test underwater, renewing tensions on the Korean Peninsula amid concern that the North's SLBM capability, if fully developed, would pose a serious threat because its mobile nature would make it very difficult to detect preparations for a launch.
  

But experts said it was believed to be not a full-scale test, but an "ejection" test conducted in an early stage of developing SLBM capabilities. U.S. officials said the North also exaggerated progress and is many years away from developing an SLBM. (Yonhap)