Baltimore and Ohio P-7

Baltimore and Ohio P-7
Type and origin Power type Steam Total produced 20
Specifications Configuration: ​  • Whyte 4-6-2 Gauge 4 ft 8+1⁄2 in (1,435 mm) Driver dia. 80 in (2,032 mm) Adhesive weight 201,000 lb (91,000 kg; 91 t) Loco weight 326,000 lb (148,000 kg; 148 t) Total weight 544,000 lb (247,000 kg; 247 t) Fuel type Coal Water cap. 11,000 US gal (42,000 L; 9,200 imp gal) Firebox: ​  • Grate area 70.3 sq ft (6.53 m2) Boiler pressure 230 psi (1.6 MPa) Cylinders 2 Cylinder size 27 in × 28 in (686 mm × 711 mm)
Performance figures Maximum speed 85 mph (137 km/h) Tractive effort 49,882 lbf (221.89 kN) Factor of adh. 4.03
Career Disposition One example, No. 5300, preserved.

The Baltimore and Ohio’s P-7 class was a class of 20 Pacific type locomotives built in 1927. Named for the first 21 Presidents of the United States, they were the prime motive power for the B&O’s top passenger trains for 30 years. One example, No. 5300, “President Washington”, has been preserved.

Design

The P7s were rather simple locomotives when built. Bearing a considerable resemblance to the Pennsylvania Railroad’s K4s, the two designs did differ in their style of firebox and boiler pressure. The engines produced an impressive 50,000 lbs. of starting tractive effort and could pull heavyweight passenger trains up to 80 miles an hour. Water scoops mounted on the underside of the tender allowed the locomotives to refill their 11,000-gallon tanks without stopping. The cabs of the locomotives were equipped with automatic train control, which improved safety by forcibly applying the brakes if the engineer failed to acknowledge an unfavorable signal.

The engines would receive upgrades over their 30-year careers and some locomotives received streamlined shrouds, but the class never saw a major rebuild.

B&O Pacifics

Class	Quantity	Road Numbers*	Build Year	Builder
P	35	2100-2134	1906	ALCO
P-1	10	2135-2144	1911	Baldwin
P-1a	30	2145-2175	1911	Baldwin
P-1c	30	5000-5009, 5035-5049, 5090-5094	1924	B&O
P-3	30	5100-5129	1913	Baldwin
P-4	10	5130-5139	1917	Baldwin
P-5	20, 10	5200-5229, 5230-5244	1919	Baldwin, ALCO
P-6	15	5230-5244	1923	Baldwin
P-7	20	5300-5319	1927	Baldwin
P-9	1	5320	1928	B&O

*The entries in this column are the numbers assigned to the locomotives when built. Some engines were renumbered before being retired.

Service

With the introduction of the P-7 class into its passenger fleet, the B&O sought to distinguish itself from its competitors, mainly the Pennsylvania Railroad. To accomplish this, instead of the usual simplistic black paint scheme, each of the P-7s would be adorned with names after the first 21 Presidents of the United States (a single locomotive, “President Adams”, symbolized both John Adams and John Quincy Adams).  Combined with a vibrant green paint scheme and gold trim, the railroad hoped to make the class more distinctive and memorable. The locomotives were put on display frequently for public relations, with the class making its debut performance at the Fair of the Iron Horse, which celebrated the railroad’s 100^th anniversary in 1927.

The locomotives were used throughout the B&O’s network in the eastern US, with their most famous efforts being the Royal Blue, a high-speed train connecting Washington DC and Jersey City. Also used between Baltimore and Philadelphia, the engines were used mainly in the Midwest leading up to their retirement.

Preservation

Being an early adopter of diesel power, the had B&O retired the P7s by the late 1950’s. In 1957, the President of the B&O Howard Simpson ordered the first P-7 built, No. 5300, to be saved from scrapping. The locomotive received a cosmetic restoration to its as-built appearance. Currently on static display at the Baltimore and Ohio Railroad Museum, it is the only pacific type locomotive built for the B&O to have been preserved.