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John H. White 



HARVftRO 

 jjNNEBSl-rt 



Pioneer railroading tvas dangerous. With increased speed 

 and density of traffic came an increase in catastrophic ivrecks 

 that forced operators to take heed for the safety of their passen- 

 gers and freight. This safety ivas painfully achieved through 

 the slow process of improving eq^uipment part by part. 



Antedating such spectacular post-Civil War advances as the 

 steel rail, automatic coupler, and airbrake, tvas the invention 

 of the safety truck for locomotives . Intended to lead the 

 bobbing, weaving locomotive around curves on the rough track 

 of the early roads, it did 7nuch to reduce the all too numerous 

 derailments that were a ftiajor cause of accidents. 



The Author: John H. White, is associate curator, in 

 charge of land transportation, in the Smithsonian Institution s 

 M.useurn of History and Technology, United States National 

 Museum. 



/|merican railroads of the early 19th century were 

 cheaply and hastily built. They were charac- 

 terized by inferior roadbeds, steep grades, sharp 

 curves, and rough track. In spring, poor drainage 

 and lack of ballast might cause the track to sink into 

 the soggy roadbed and produced an unstable path. 

 In winter this same roadbed could freeze into a hard 

 and unyielding pavement on which the rolling stock 

 was pounded to pieces. 



In those pioneering times the demand for new roads 

 left little capital to improve or expand existing lines; 

 therefore equipment was needed that could accom- 

 modate itself to the existing operating conditions. 



The first locomotives used in this country had been 

 imported from England. Designed for well-ballasted 

 track with large-radius curves and gentle gradients, 

 they all too frequently left the rails, and the unsuita- 



bility of the essentially rigid British design soon became 

 apparent. 



The challenge posed by the American roadbed was 

 met by American mechanics. By the mid-1 830's 

 a distinctive American locomotive had evolved that 

 might best be described by the word "flexible." 

 The basic features of its running gear were a bar 

 frame and equalizing levers to provide vertical relief 

 and a leading truck to provide lateral relief. Of 

 these devices the truck was probably the most im- 

 portant, and more readily than any one component 

 distinguished the American running gear from that 

 used by the British before 1860. 



It was John B. Jervis who is generally credited with 

 first applying the truck to the locomotive. His 

 design, shown in figure 1, was developed in 1831-32. 

 Its merits quickly became apparent, and by 1835 it 



118 



BULLETIN 228: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY 



