of tests were held with the Lebanon. Moore said of these trials:⁷

Messrs. Moore and Milligan heartily endorsed the truck as a complete success. Milligan predicted that⁸ “the time is not far distant when locomotives will be considered incomplete and comparatively unsafe without this improvement particularly on roads which have many curves.”

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Figure 6.—The New Jersey Railroad and Transportation Company No. 12, built in 1868, was equipped with the radius bar truck, a modification by William S. Hudson of the original Bissell truck. The General Darcy and several other engines built at the Jersey City shops of the road, under the direction of John Headden, were fitted with the Hudson truck. Note that the radius bar is connected to the truck frame just behind the rear leading wheels. (Smithsonian photo 46806-l)

U.S. Patent Commissioner Charles Mason was so impressed by the evidence of the New Jersey trials, reinforced by the arguments of Bissell’s attorneys, that he agreed to grant a United States patent.⁹ It was issued as no. 17913 on August 4, 1857, and reissued October 18, 1864 as no. 1794. British patent 1273 had been issued earlier (May 5, 1857), and patents were also secured in France, Belgium, Austria, and Russia.

The Rogers Locomotive Works in 1858 was one of the earliest builders to apply the improved truck. By 1860 they had fitted many of their engines with it and were endorsing the device to prospective customers.

In the same year the American Railway Review noted that the truck was in extensive use, stating:¹⁰

The success of Bissell’s invention prompted others to perfect safety trucks for locomotives. Alba F. Smith came forward in 1862 with the simple substitution of swing links (fig. 4) for the incline planes.¹¹ A swing-bolster truck had been developed 20 years earlier for use on railroad cars,¹² and while Smith recognized this in his patent, he based his claim on the specific application of the idea to locomotive trucks. That the swing links succeeded the incline planes as a centering device was mainly because they [p125] were cheaper and simpler to construct, and not, as has been claimed, that the V’s wore out quickly.¹³

Figure 7.—Bissell’s 2-wheel truck of 1858 as shown by the drawing for British patent 2751, issued December 1, 1858.

Smith’s swing-bolster truck, with the heart pendant link, a later refinement, became the dominating form of centering devices and was used well into this century. It was to be superseded in more recent years by the constant resistance and gear roller centering devices which, like Bissell’s invention, depended on the double incline plane principle.

The British-born engineer William S. Hudson, superintendent of the Rogers Works and an early proponent of the Bissell truck, in 1864 obtained a patent¹⁴ for improving Bissell’s safety truck. Hudson contended that since the Bissell arrangement had a fixed pivot point it could traverse only one given radius accurately. He proposed to replace the fixed pivot with a radius bar (see fig. 5) one end of which was attached to the locomotive under the smoke-box and the other to rear of the truck frame, at the same point of attachment as in the Bissell plan. Thus, according to Hudson, the pivot point could move laterally so that the truck might more easily accommodate itself to a curve of any radius. He further claimed that a better distribution of weight was effected and that the use of the radius bar relieved the center bearing casting of much of the strain of propelling the truck.

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