Photo: Wood Pipe Load
A photo from The History of Sanitary Sewers website:
Notice the tree sapling cribbing.
Caption from the site: "Substitute materials used in WWII: a shipment of 1,488 feet of 18-inch, 24-inch, 30-inch and 36-inch wooden pipe on one flat car. [Looks like a gondola car to me.] Weight 70,020 pounds. An equal footage of reinforced concrete pipe weighs 455,412 pounds and requires over ten cars. These pipes, used in place of corrugated iron or reinforced concrete pipes, were made of sections cut from short lengths of wood. Locking of adjacent rings with hardwood dowel pins produced a flexible structure. About 100,000 feet of these wooden pipes were installed in 1942 in drainage culverts, storm sewers and conduits, under highways and at army camps, naval stations, airfields and ordnance plants. Photo date 1943."
The History of Sanitary Sewers website: https://www.sewerhistory.org/