Original plan was to bring in 33 experts. So far 17 experts came according to NBC Indonesia.

Tunnel 2 is in Mekargalih area, Jatiluhur, Purwakarta. First tunnel construction in clay shale geology.  Clay shale tunnelling has risk for movement of the embankment construction and the road above it. Therefore experts from China came.

https://www.cnbcindonesia.com/news/20220114120144-4-307342/pembangunan-kereta-cepat-molor-begini-fakta-faktanya