Mao's swim

On July 16, 1966 it was reported that Mao Zedong swam in the Yangtze River at Wuhan. The reported event was a masterpiece by showing that Mao, then 73, was strong and was a force to be reckoned with. It helped provide further rapport with China’s youth, for his forthcoming Cultural Revolution. In some respects the reported facts about the swim was just too spectacular. I have tried to do some more studying of the actual event, mainly on the internet. Unfortunately, nothing emerged that can be traced directly back to the event. But I do want to share what I have learned,

First, here is some of the information that I have gathered from two sources listed below and others, from Google Earth’s view of Wuhan (attached).Swimming the Yangtze at Wuhan was an event that has been going on for some time; Mao swam at Wuhan at least twice previously. The distance swam has been reported as 10 miles, 15 km, and 30 li, all of which are approximately the same distance. The time in the water was 65 minutes much of which time he floated along rather than swim. The start of the swim was at the First Bridge, which Mao had dedicated some years earlier. The width of the Yangtze is approximately 1 km. A reported river current velocity, for one of the swimming events, after some period of rain was 2.06 m/s. The time for the 1500 meter men’s freestyle record is a bit over 14 minutes, which for steady swimming would require in excess of 140 minutes and super-human capability to swim 15 km.

With the above information in hand and without trying to be very scientific, I would like to try and make some sense out of Mao’s swim. Mao did not swim steadily for 15 km. Assuming that he allowed himself to be carried along by the current and using the 2.06 m/s velocity, he would have been carried about 8000m (8 km) in 65 minutes that would have required an additional 7 k m of swimming and which would probably be beyond the capability of a world champion swimmer. Therefore Mao was either in the water for more than 65 minutes or else he did not go for 15 km. If the water velocity had been greater than 2.06 m/s, a very dangerous current in excess of 5 m/s would have been required to carry him far downstream..

This exercise is not meant to denigrate Mao’s accomplishment and the very important historical importance of it. It is meant to better understand the physical aspects of the swim and to suggest that in the news release that perhaps the facts were stretched a bit.

Some of my sources are Times Asia and the official Wuhan Municipality website. Notice the small map of the Yangtze River, First Bridge and typical swim paths that are on the order of a couple of kilo meters. The small map can be compared from the Google Earth Wuhan image from which the river width was determined.