Among the top 5 crane manufacturers in the world, China's Dalian Crane Factory ranks first. Of course, China's electrical facilities are slightly insufficient, but the structure designed by China is unmatched by any crane company in the world. If you write a thesis You can take a look at the development history of China's cranes. It will be beneficial to you. You can also ask Mr. He from the China Crane Equipment Network. He is currently studying these things!