ALCO and GE Switchers Withers. This heavily illustrated volume presents line-by-line listings of the Pennsylvania Railroad's Alco and GE switchers - including Alco's S-1 through S-4 switchers and T-6 transfer and General Electric's 44-ton switcher - as well as specifications for each locomotive and photographs of the switchers at work. 72 pages, 186 B&W photographs, 8½"x 11", softcover. #0R02692