The reference for locomotives and railcars
Bavarian BB I and Palatinate Railways G 4II
Germany | 1896 | 3 produced
Die Lokomotive, December 1906

The BB I was a single Mallet locomotive with a 0-4-4-0 wheel arrangement, which was primarily used to push freight trains on the steep ramps in Franconia. The locomotive built by Maffei was originally intended for the Swedish-Norwegian railways, but was then taken over by the Bavarian State Railways. The Pfalzbahn also procured two identical locomotives in 1896 and designated them as class G 4II.

In contrast to the BB II, which was later built in series, it was a tender locomotive, and it was also much heavier with an axle load of 14 tonnes. The rest of the structural design was similar, with vertical connecting pipes from the steam dome to the high-pressure cylinders in the middle and the low-pressure cylinders in the front. Like other four-axle Mallet locomotives, the machine was notable for its rough running and strong tendency to slip, which is why no more were procured. The same observations were also made at the Pfalzbahn with the two identical machines, whereupon these were only used in part to test new braking systems.

Both operators decided to use eight-coupled locomotives again in the future, as these did not have the weaknesses of the Mallets, despite the somewhat poorer curve running properties. The Reichsbahn number 55 7101 was reserved for a single remaining BB I, but this was no longer taken over due to the decommissioning in 1923. The Palatinate machine, which was still in use up to this point, suffered the same fate.

Axle config0-4-4-0 (Four Coupled Mallet) 
Gauge4 ft 8 1/2 in (Standard gauge)
Dimensions and Weights
Length55 ft 8 15/16 in
Wheelbase19 ft 4 11/16 in
Fixed wheelbase5 ft 8 1/8 in
Service weight122,577 lbs
Adhesive weight122,577 lbs
Axle load31,306 lbs
Water capacity3,646 us gal
Fuel capacity12,125 lbs (coal)
Power sourcesteam
Estimated power671 hp (500 kW)
Optimal speed14 mph
Top speed40 mph
Starting effort30,365 lbf
with start valve36,438 lbf
Power Plant
Driver diameter52.8 in
Boiler pressure203 psi
Expansion typecompound
Cylindersfour, HP: 16 5/16 x 24 13/16 in
and LP: 25 x 24 13/16 in
Grate area22.3 sq ft
Evaporative heating area1,324 sq ft
Total heating area1,324 sq ft
Calculated Values
steam locomotive
last changed: 04/2022

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