The U.S. Army Corps of Engineers, Rock Island District, has a requirement for steel cast horse boxes, quoin block and quoin stays for the bottom wicket gate structures at both Peoria and LaGrange Lock... The U.S. Army Corps of Engineers, Rock Island District, has a requirement for steel cast horse boxes, quoin block and quoin stays for the bottom wicket gate structures at both Peoria and LaGrange Lock and Dams.