Classic Machines ScrapersClassic machines: The Caterpillar 631A scraperCharles FairbairnMarch 24, 2016August 8, 2017 by Charles FairbairnMarch 24, 2016August 8, 2017 A direct descendent of the 1950s DW21, the 631A was introduced in 1960 and was the second of Caterpillar’s new ‘600’ series motor scrapers to
