Despite all of the things we see and learn during North Korea's military parades and missile tests, only a fraction of the real story gets told (and often a fair amount of obfuscation is mixed in as well). Public knowledge of their ballistic missile program is still extremely limited though new discoveries do come to light.
Not every missile or vehicle is openly shown, and there are many deployed weapons systems and other equipment that have never been disclosed. Likewise, the infrastructure and training programs for their Strategic Rocket Force is largely unknown. And, North Korea has a habit of doing things just unusual enough as to baffle experts around the world.
In comparison to the United States and Russia/USSR, they test rockets and fire missiles far less often before beginning to mass produce them and place them into service. Their ability to indigenously manufacture the vehicles needed to transport and launch their missiles (especially the more modern versions) has often been viewed as lacking, but somehow, they end up with the equipment they need. Sometimes this is accomplished by converting large trucks from China and elsewhere, but it seems that their domestic capabilities may now surpass the limited capabilities usually described in public intelligence reports.
Though this exact process is not fully understood, as WMD expert Melissa Hanham remarked in regard to the 11-axle transporter erector launcher (TEL) seen during the Workers' Party 75th anniversary parade in 2020, "It is also clear that they have built up their manufacturing sector to indigenously modify - and now potentially produce - their own missile launchers."
So, we are often left to dissect photos from state media, parse through the vague language of government and military officials, and use commercial satellite images to look for clues and try to learn what the DPRK doesn't want us to. That’s the purpose of this article, to use what is available to try and paint in some of the picture regarding North Korea’s TEL development.
One such little-known cog within North Korea's vast missile infrastructure are five (formerly six) unusual buildings that have been described as "clearstory cupolas". Their exact nature is not known, at least not publicly, but it is surmised that they play a role in both the development of new TEL designs and a role in the maintenance of deployed TELs, and in training their Strategic Rocket Force.
They take on two main designs, one is a modified section of roof of a larger, high-bay building and the other is a small building that is basically the modified roof section itself but placed on the ground as its own independent structure.
The most well-known of these little-discussed structures is the Jonchon TEL Assembly Plant that was written about in 38 North's "That Ain't My Truck", in which the authors hunt down the location of this special building after it was first shown in a state propaganda film.
Of the inventory of these formerly six (now five) buildings, two are located at known TEL/arms assembly factories, one was located at a missile-related facility, and three were built after 2011 at known missile operating bases stationing short range- and medium range- ballistic missiles.
The city of Jonchon has two of these facilities. The first is what was shown in the 2013 Korean Central TV program and discussed by 38 North. It is located at 40.645677° 126.432921°.
The following are models of the Jonchon TEL Facility.
Lastly, the particular nature and design of these clearstory cupola structures appear to make them unique to North Korea, as other experts have told me they weren't aware of any other country using buildings with this design in their missile programs.
It will take more research before their full purpose is known and how they interconnect with the rest of Pyongyang's missile program is understood, but at least we have a baseline of observations showing their locations, times of construction, and other important information that helps to build the picture.
--Jacob Bogle, 6/19/2021