The Class P 4 steam locomotives of the Palatine Railways were express train locomotives with a 2B1 (Atlantic) axle arrangement and a four-cylinder compound engine. A total of eleven locomotives were built by Maffei, numbers 286–291 in 1905 and 302–305 and 133 in 1906. They replaced the P 3.1 in express train service.

Palatine P 4
P 4 No. 290 von Frauendorfer
Type and origin
Power typeSteam
BuilderMaffei
Serial number2462–2467, 2515–2518, 2532
Build date1905–1906
Total produced11
Specifications
Configuration:
 • Whyte4-4-2
 • UIC2B1 n4v
Driver1st coupled axle
Gauge1,435 mm (4 ft 8+12 in)
Leading dia.960 mm (3 ft 1+34 in)
Driver dia.2,010 mm (6 ft 7+18 in)
Trailing dia.1,216 mm (3 ft 11+78 in)
Wheelbase:
 • Engine10,240 mm (33 ft 7+14 in)
 • Leading2,200 mm (7 ft 2+12 in)
 • Drivers2,150 mm (7 ft 34 in)
 • Tender5,000 mm (16 ft 4+34 in)
 • Tender bogie1,750 mm (5 ft 9 in)
 • incl. tender16,800 mm (55 ft 1+12 in)
Length:
 • Over buffers18,712 mm (61 ft 4+34 in)
Axle load16.5 tonnes (16.2 long tons; 18.2 short tons)
Adhesive weight33.0 tonnes (32.5 long tons; 36.4 short tons)
Service weight75.5 tonnes (74.3 long tons; 83.2 short tons) (loco only)
Tender type22 T 20
Fuel typeCoal
Fuel capacity6.5 tonnes (6.4 long tons; 7.2 short tons)
Water cap.20 m3 (4,400 imp gal; 5,300 US gal)
Firebox:
 • Grate area3.8 m2 (41 sq ft)
Boiler:
 • Pitch2,850 mm (9 ft 4+14 in)
 • Tube plates4,700 mm (15 ft 5 in)
 • Small tubes49 mm (1+1516 in) diameter, 280 off
Boiler pressure15 bar (15.3 kgf/cm2; 218 psi)
Heating surface:
 • Firebox13.8 m2 (149 sq ft)
 • Tubes167.5 m2 (1,803 sq ft)
 • Evaporative181.3 m2 (1,951 sq ft)
Superheater:
 • Heating area41.7 m2 (449 sq ft)
CylindersFour, compound
High-pressure cylinder360 mm × 640 mm (14+316 in × 25+316 in)
Low-pressure cylinder590 mm × 640 mm (23+14 in × 25+316 in)
Performance figures
Maximum speed120 km/h (75 mph)
Career
OperatorsPalatinate Railway
Numbers286–291, 302–305, 133
Retired1925

The locomotives were initially fitted with Pielock superheaters, but after a few years they had to be removed again due to corrosion damage. From then on the locomotives operated as wet steam engines.

The P 4 was one of the first locomotives in Germany with bar frames. It was based on the Bavarian class built in 1903, the S 2/5; up to the second coupling axle, both types were almost the same apart from details and minor dimensional deviations. However, the P 4 had, unlike the S 2/5, a wide firebox which was arranged completely behind the coupling wheels. For this reason, the distance between the coupling axle and the rear carrying axle had to be increased significantly and the carrying axle had to be designed to be radially adjustable. This and also the streamlined cab of the P 4 gave the locomotives a distinct appearance at the rear.

The P 4 was also closely related to other Bavarian locomotive types from Maffei: the engine was adopted almost unchanged for the high-speed locomotive of the S 2/6 built in 1906 - only the cylinder diameters were slightly enlarged - otherwise both locomotives had a lot in common. The family resemblance to the Class S 3/6 built from 1908 onwards is also unmistakable; the latter looks like an enlarged P 4 with a coupling axle added.

In the provisional reclassification plan by the Deutsche Reichsbahn all eleven locomotives were due to be reassigned numbers 14 151 to 14 161, but they were decommissioned before the redesignation.

Literature

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  • Schnabel, Heinz (1987). Eisenbahn-Fahrzeug-Archiv Band 2.5: Lokomotiven bayerischer Eisenbahnen (in German). Düsseldorf: Alba Publikation Alf Teloeken GmbH + Co KG. pp. 263–265, 385. ISBN 3-87094-105-7.
  • Wilhelm Reuter: Die Schönsten der Schiene – Die Geschichte der Atlantic. Transpress, Berlin 1993, ISBN 3-613-01512-9