DRY-LAND DREDGING 249 



banks of the ditch can be sloped as the ditch is excavated with 

 this machine. 



The Fairbanks Steam Shovel Co., of Marion, O., manufactures a 

 ditching machine known as a "walking dredge." Such a machine 

 is meant for ditch work where there is not enough water to float a 

 boat. The machinery is placed on a timber hull that reaches over 

 the constructed ditch. The boom is operated by a turntable, and 

 attached to the boom is the scraper-like shovel, with a capacity of 

 from 1 to 2 cu.yds. The long scraper arm reaches down into the 

 ditch, and the bucket or scraper is rilled by means of a drag line 

 from the engine. The scraper has two bails and two lines on it. 

 The second bail keeps the bucket in an upright position while being 

 loaded, and by releasing the line the bucket is dumped. The 

 machine is named from the method of moving it over the 

 ground. 



Another type of walking dredge has been used in Minnesota on 

 drainage work. This machine has a second boom, known as the 

 walking beam, suspended from the boom. The scraper or bucket 

 is attached to this second boom, and instead of working toward 

 the machine, it works away from the dredge when loading. This 

 is done by means of a chain attached to the walking arm, and the 

 load is released by a chain on the other side of the arm. The follow- 

 ing description is taken from the bulletin of the Northeastern Experi- 

 ment Farm of the University of Minnesota. 



"The peculiarity of this machine is the method of moving. 

 Under each corner is a timber platform the shape of a stoneboat, 

 called a foot. Each of these corner feet is 6 ft. wide, 8 ft. long and 

 4 in. thick. They are joined together transversely by a light timber. 

 This requires them both to move in the same direction, the direction 

 being controlled by a chain which runs from each corner foot to 

 a drum that is operated by the cranesman. Near the outside of 

 each corner foot there is a knife made of iron, J in. thick by 6 in. 

 wide and 6 ft. long, which prevents the foot slipping sidewise. 

 Midway of the machine on either side is a center foot 6 ft. wide, 

 14 ft. long and 6 in. thick. On the under side a 6X6 in. timber 

 is bolted crosswise, to prevent slipping back. This foot is attached 

 to a heavy triangle frame, free to move longitudinally between 

 the double side frame of the hull. A chain, the end of which is 

 attached to the side timbers of the hull, passes over two pulleys 

 in this triangular frame and then passes along the hull to the back 



