【History of Haichuan Chemical】--Blueprints drawn line by line with a pen 45 years ago; take a look at the differences compared to modern CAD

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This post was last edited by HaiChuanLaoYu on 2026-5-9 at 11:24. Drawings created by drawing lines one by one; understanding development through history – history is the best teacher. This series of posts will continue to be updated. [HaiChuan Chemical Industry History] Summary post – Understanding development through history! Constantly being updated! https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5718076 (Source: Haichuan Chemical Industry Forum (Hua Haichuan Liu hcbbs)). Everyone is welcome to participate in the discussion. --------------------------------------------------------- The attached diagram is a design blueprint for a wastewater treatment plant at a printing and dyeing factory from the 1980s. Now we are already used to turning on our computers, opening CAD, and using the mouse to view various drawings. I’ve long since gradually forgotten all those various drawings. Many people have never seen the drawings from that era, which were created by drawing lines one by one with a pen. What many people don’t know even more is how difficult drawing was in that era; just one wrong line could mean having to start over from scratch. Compared to being able to make arbitrary changes on a computer these days, the difficulty level is not in the same league at all. If the line is drawn wrong, just click the mouse and you can start over!