Pere Marquette classes N to N2
For use in front of fast freight trains, the Pere Marquette also chose the 2-8-4 “Berkshire” wheel arrangement in the late 1930s. It was able to develop great power at speeds of up to 70 mph thanks to the large firebox above the bogie. Of a total of 466 square feet in the firebox, 122 were made up of thermosiphons and water pipes. This allowed 26 by 34 inch cylinders to be operated with 69 inch wheels.
The first delivery from 1937 included 15 class N locomotives. The last five of these had a booster in the bogie. In the years 1941 and 1944 twelve more N1 and N2 each followed. When the Pere Marquette was merged into the Chesapeake & Ohio in 1947, the N1 and N2 classes became the N-1 and N-2 and the N class became the N-3. The two newer series, which had not yet been paid for by the C&O, kept the color scheme and the old numbers.
From 1951 the locomotives were also used on routes other than those originally operated by the Pere Marquette. The first series was scrapped by 1954. The use of the newer machines ended in 1958 and a total of 13 units were stored until 1961, as payments were still outstanding.
Numbers 1223 and 1225 are still preserved today, both of which belong to class N1. The 1225 is the only still functional Pere Marquette locomotive today. It has been used intermittently since 1985 and formed the basis for the locomotive in the book and film “The Polar Express”. Today it is used almost every year around Christmas time on the “North Pole Express” in Michigan.
Technical data
General
- Built
- 1937, 1941, 1944
- Manufacturers
- Lima
- Wheel arrangement
- 2-8-4 (Berkshire)
- Gauge
- 1,435 mm (Standard gauge)
Dimensions and weights
- Length
- 31.00 m
- Wheelbase
- 12.80 m
- Total wheelbase
- 26.89 m
- Service mass
- 200.7 t
- Adhesion mass
- 125.9 t
- Total mass
- 365.6 t
- Rigid wheelbase
- 5.55 m
- Axle load
- 31.5 t
- Water capacity
- 83,279 l
- Fuel capacity
- 20 t (coal)
Boiler
- Grate area
- 8.389 m²
- Firebox surface
- 43.293 m²
- Tube heating surface
- 400.505 m²
- Evaporative heating surface
- 443.798 m²
- Superheater surface
- 179.489 m²
- Total heating surface
- 623.3 m²
Power plant
- Driver diameter
- 1,753 mm
- Boiler pressure
- 16.9 bar
- Expansion type
- simple expansion
- Cylinders
- two, 660 x 864 mm
Power
- Power source
- steam
- Estimated power
- 3,356 kW (4,563 PS)
- Top speed
- 113 km/h
- Starting effort
- 308.6 kN
Calculated values
- Factor of adhesion
- 1 : 4.00
- Optimal speed
- 66 km/h
- Power-to-weight ratio
- 16.7 kW/t
- Heating Surface Equivalent
- 1,019.2 m²
- Cylinder volume/HSE
- 1 : 580.46
- Adhesive weight/Total
- 1 : 1.59
- Tractive force/Heating surface
- 1 : 10.34
- Grate area/Heating surface
- 1 : 74.30
- Firebox/Tube surface
- 1 : 9.25
- Total/Superheater
- 1 : 2.47