B&O No. 3684

B&O No. 3684

Name: B&O No. 3684

Other Numbers: CSX No.6500

Railroad of Record: Baltimore & Ohio Railroad Type of Locomotive: GM-EMD model GP-40, 3000 hp, road freight locomotive Builder No. : 32644 Manufactured by: GM-EMD Date Built: November 1966

Status: Operational

Locomotive Weight: 139 tons

Prime Mover: EMD V-16, model 645E3 (two cycle), 3000 hp Starting Tractive Effort: 69,375 lbs.

The GP-40 was the first locomotive on the B&O with a 3000 horsepower engine and alternator. The GP-40s that were purchased by the B&O were equipped with the rate of change wheel slip, which was developed by B&O Chief Electrical Engineer, C.M. Machin. This system detected wheel slips by the rate of current flow to the traction motors, rather than by a predetermined voltage difference. The GP-40s had a narrow cab unit and all were geared for 65 miles per hour.

The No. 3684 was the very first of the 380 EMD model GP-40 locomotives placed in service by the B&O in November 1966. The B&O had the largest fleet of GP-40s in the country. They were versatile locomotives and could handle both manifest and heavy tonnage trains as well as hopper cars over poor mine trackage. The No. 3684 was later renumbered as CSX No. 6500 and repainted in CSX's blue and grey. In 1994, the B&O Railroad Museum returned the No. 3684 to its original B&O paint scheme. In 2006, it was restored once again by museum restoration staff.