Handing Over the Country to 1949

Hardcore science popularization vlogger Jiang Fan receives a mysterious watch that plunges him into a white void with a ticking 72-hour countdown. When he opens his eyes, he finds himself in the war-torn Anshan Iron and Steel Works of 1949, a nation desperately needing reconstruction. Expecting to just coast for three days and return home, Jiang instead finds himself escorted straight to headquarters due to his modern attire, fluent English, and blueprint-reading skills. Amid the smoke-filled conference room, over a dozen leaders fix their piercing gazes upon him. "Young man, you study machinery? Perfect. We have a technical problem that has been plaguing us for days." What? They want him to solve high-tech engineering crises for the 1949 Anshan Iron and Steel Works?!