INTRODUCTION OFTHE LOCOMOTIVESAFETY TRUCK

_by John H. White_

Paper 24 pages 117-131, fromCONTRIBUTIONS FROM THE MUSEUMOF HISTORY AND TECHNOLOGY

UNITED STATES NATIONAL MUSEUMBulletin 228

Smithsonian InstitutionWashington, D. C. , 1961

Contributions fromThe Museum of History and Technology:Paper 24

Introduction ofThe Locomotive Safety Truck

_John H. White_

 INTRODUCTION OF THE LOCOMOTIVE SAFETY TRUCK

 _John H. White_

 _Pioneer railroading was dangerous. With increased speed and density of traffic came an increase in catastrophic wrecks that forced operators to take heed for the safety of their passengers and freight. This safety was painfully achieved through the slow process of improving equipment part by part. _

 _Antedating such spectacular post-Civil War advances as the steel rail, automatic coupler, and airbrake, was 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 much to reduce the all too numerous derailments that were a major cause of accidents. _

 The Author: _John H. White, is associate curator, in charge of land transportation, in the Smithsonian Institution's Museum of History and Technology, United States National Museum. _

American railroads of the early 19th century were cheaply and hastilybuilt. They were characterized by inferior roadbeds, steep grades, sharpcurves, and rough track. In spring, poor drainage and lack of ballastmight cause the track to sink into the soggy roadbed and produced anunstable path. In winter this same roadbed could freeze into a hard andunyielding pavement on which the rolling stock was pounded to pieces. 

In those pioneering times the demand for new roads left little capitalto improve or expand existing lines; therefore equipment was needed thatcould accommodate itself to the existing operating conditions. 

The first locomotives used in this country had been imported fromEngland. Designed for well-ballasted track with large-radius curves andgentle gradients, they all too frequently left the rails, and theunsuitability of the essentially rigid British design soon becameapparent. 

The challenge posed by the American roadbed was met by Americanmechanics. By the mid-1830's a distinctive American locomotive hadevolved that might best be described by the word "flexible. " The basicfeatures of its running gear were a bar frame and equalizing levers toprovide vertical relief and a leading truck to provide lateral relief. Of these devices the truck was probably the most important, and morereadily than any one component distinguished the American running gearfrom that used by the British before 1860. 

[Illustration: FIGURE 1. --Design drawing showing the 4-wheel leadingtruck, developed in 1831 by John B. Jervis, applied to the _BrotherJonathan_. This locomotive, one of the earliest to use a leading truck, was built in June 1832 by the West Point Foundry Association for theMohawk and Hudson Rail Road. The truck is attached to the locomotiveframe by a center pin, but the forward weight of the locomotive iscarried by a roller which bears on the frame of the truck. (_Smithsonian photo 36716-a_)]

It was John B. Jervis who is generally credited with first applying thetruck to the locomotive. His design, shown in figure 1, was developed in1831-32. Its merits quickly became apparent, and by 1835 it had beenuniversally recognized in this country. The truck successfully led thelocomotive around sharp curves, the resultant 3-point suspension enabledthe machine to traverse even the roughest of tracks, and, altogether, the design did far less damage to the lightly built U. S. Lines than didthe rigid, imported engines. [1]

The truck frame, fabricated from iron straps and castings, was attachedto the locomotive by a pin around which it might rotate. At first theweight was received by rollers or chafing pads mounted on the side beamsof the truck. However, the friction of these bearing surfaces and theirlocation at a considerable distance from the center pin combined torestrict the free movement of the truck. By the early 1850's the pointof bearing was transferred to the center plate, producing a truck thatturned more freely. [2]

[Illustration: FIGURE 2. --The 4-wheel Bissell truck as shown in thedrawing for British patent 1273, issued May 5, 1857. ]

[Illustration:

 A--Truck frame B--Equalizing lever C--Locomotive frame D--Double incline plane (_Centering device_) E--Truck bolster F--Swivel pin (_Pivot point_) _Drawn by J. H. White. June, 1960_

FIGURE 3. --Typical 4-wheel Bissell Safety truck of 1860. This drawing isbased on plate 69 of Alexander L. Holley's, _American and EuropeanRailway Practice in the Economical Generation of Steam_, New York, 1861. (_Smithsonian photo 46946_)]

For single axle engines this simple form of truck was entirelysatisfactory, but it proved less satisfactory for 4- and 6-coupledmachines. Also, as train speeds increased, so did the number ofderailments. Many of these could be traced to the inability of theengine to negotiate curves at speed. Levi Bissell, a New York inventorwho investigated this problem in the 1850's, correctly analyzed thedifficulty. He observed that when the engine was proceeding on straighttracks the leading truck tended to oscillate and chatter about thecenter pin, and he noted that it was this action that imparted a fearfulpitching motion to the locomotive at speed. The derailments were tracedto the action of the truck as the engine entered a curve. 

This action can be more easily understood from reference to Bissell'spatent drawing in figure 2. For example, let us say that an 8-wheelengine, fitted with a center-swing truck, enters a right-hand curve. Theleft truck wheels bear hard against the left rail. The drivers jamobliquely across the track, with the right front and left rear wheelsgrinding into the rails. As a result, the locomotive tends to leave thetrack in the direction of the arrow shown on the figure (bottomdrawing). It will be noted that the truck center pintle is in fact thefulcrum for this leverage. Under such strain the truck wheels areparticularly likely to leave the rails when they encounter anobstruction. Once derailed, the truck would then spin around on thedeadly center pin, throwing the locomotive over. 

In effect, then, the center pin of the conventional truck extended therigid wheelbase of the engine, and caused the truck to act much aswould a single set of leading wheels fitted rigidly to the engine framefar ahead of the front driving wheels. Bissell proposed to correct thefaults of the conventional truck by fitting the locomotives with hisinvention, the first practical safety truck to be patented. Since theprimary requirements were to keep the leading wheel axles at rightangles to the rails whether on a straight or curved track, and to allowthe driving axles to remain parallel, or nearly so, to the radial lineof the curve, he moved the center pin to a point behind the truck andjust in front of the forward driving axle. This shortened the wheelbaseof the engine and removed the danger of the pintle serving as a fulcrumbetween the truck and the driving wheels, thus allowing them to assume acomfortable position on a curve. 

[Illustration: FIGURE 4. --A 4-wheel safety truck fitted with A. F. Smith's swing-bolster centering device. Built by the Hinkley LocomotiveWorks. From Gustavus Weissenborn, _American Locomotive Engineering andRailway Mechanism_, New York, 1871, pl. 88. ]

Since the truck could assume the correct angle when entering curves, itwas claimed in the patent specification that, unless all four wheelswere simultaneously lifted off the track, the truck could pass over"quite a considerable obstruction. "[3] Bissell further claimed:

 In running on either a straight or curved track one of the truck wheels often breaks off, and the truck swivels around on its center pin in consequence, and throws the engine off the track, but with my device one wheel, or even the two wheels on the opposite sides diagonally of the truck might break off and still the truck would not run off, because its position is set and it has no axis of motion around which it could swing.... 

The other problem Bissell wished to correct was the oscillation andchatter of the leading truck. This was accomplished by a simplecentering device in the form of a pair of V-shaped double incline planes(D on fig. 3) situated at the center of the truck frame (A). The lowerplanes of the pair were fastened to the truck frame and the upper, castin the form of a bridge, were attached to the locomotive frame (C) by acenter plate. But while the portion of the locomotive's weight assignedto the leading wheels was borne at the center of the truck, as in theconventional design, the center plate was no longer the point ofrotation. On a straight track the V's would be at their bottom positionand thus prevent the truck from vibrating. [4] When the locomotiveentered a curve the planes allowed its forward weight to bearcontinuously on all four wheels, and at the same time controlled anyexaggerated swing caused by centrifugal force. 

The centering device is thus explained in the patent specification(figure numbers are omitted):

 I therefore obviate this difficulty [the oscillation of the truck] by providing two inclined planes ... Formed double as shown and of an angle proportioned to the weight of the forward part of the locomotive and the velocity of the same.... The position of the inclines is such that the blocks [V's] rest in the lowest part of the double inclines when the engine is on a straight track, and on coming onto a curve the inertia of the engine ... Is expended in going up the inclines, as the truck moves laterally toward the inner part of the curve; and on coming onto a straight line the blocks, descend to the bottom of the inclines and the engine is prevented from acquiring a sidewise or oscillating motion. 

[Illustration: FIGURE 5. --Detail drawing of the radius-bar truck, patented by William S. Hudson in 1864, as applied to the New JerseyRailroad and Transportation Company No. 44. From Gustavus Weissenborn, _American Locomotive Engineering and Railway Mechanism_, New York, 1871, pl. 8. ]

Bissell applied for a U. S. Patent on April 23, 1857. His petition wasinitially denied. A weary debate of several months duration followedbetween the patent examiner and Bissell's attorneys. 

During this time Bissell was busy promoting the application of his truckeven though he had no patent for protection. In May of 1857 he showed aworking model of his improvement to Gilbert M. Milligan, secretary ofthe Central Railroad Company of New Jersey. [5] Samuel L. Moore, mastermechanic of that railroad, also inspected the model. Both were soimpressed that it was decided to fit the device to the locomotive_Lebanon_, which at the time was undergoing repairs at the road'sElizabeth Port, New Jersey, shops. [6] Although the engine was less than18 months old, her tires were badly worn and she oscillated at highspeed. 

Early in June of that year a series of tests were held with the_Lebanon_. Moore said of these trials:[7]

 After the said invention of Bissell had been applied the engine was run out onto a curve which she turned apparently with nearly as much facility as she would travel on a straight line, and the forward part of the engine rose on the inclines as the truck entered the curve and remained fixed while running around said curve and then resumed its former position on entering a straight track, and the trial was pronounced by all who saw it as most satisfactory, even by those who before pronounced that it would be a failure. 

 At a subsequent trial under a full pressure of steam and a velocity of about thirty miles per hour the entering and leaving the curve was equally satisfactory, the same being accurately observed by a man located on the cow catcher. 

 ... The engine was run at its greatest possible velocity at least forty miles per hour on a straight track and the previous "shaking of the head" [oscillation] was found to be entirely overcome, and the engine run as steadily as a car would have done.... 

 At one of the trials a bar of iron 3/4 × 4 inches was spiked down across one of the _rails diagonally of the track_, ... And the employees of the company took the precaution to fill in around the track to facilitate getting the engine back again, supposing she must jump off; however on passing over slowly she still kept the track and the speed was increased until she passed over said bar ... While under a considerable speed. 

Messrs. Moore and Milligan heartily endorsed the truck as a completesuccess. Milligan predicted that[8] "the time is not far distant whenlocomotives will be considered incomplete and comparatively unsafewithout this improvement particularly on roads which have many curves. "

[Illustration: FIGURE 6. --The New Jersey Railroad and TransportationCompany _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 shopsof the road, under the direction of John Headden, were fitted with theHudson truck. Note that the radius bar is connected to the truck framejust behind the rear leading wheels. (_Smithsonian photo 46806-l_)]

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

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

In the same year the _American Railway Review_ noted that the truck wasin extensive use, stating:[10]

 ... The advantages of the arrangement are so obvious and its results so well established by practice in this country and Europe that a treatise on its principles will hardly be needed. 

 It is no longer an experiment; and the earlier it is applied to all engines, the better the running and repair accounts will look. 

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

[Illustration: FIGURE 7. --Bissell's 2-wheel truck of 1858 as shown by thedrawing for British patent 2751, issued December 1, 1858. ]

Smith's swing-bolster truck, with the heart pendant link, a laterrefinement, became the dominating form of centering devices and was usedwell into this century. It was to be superseded in more recent years bythe constant resistance and gear roller centering devices which, likeBissell's invention, depended on the double incline plane principle. 

The British-born engineer William S. Hudson, superintendent of theRogers Works and an early proponent of the Bissell truck, in 1864obtained a patent[14] for improving Bissell's safety truck. Hudsoncontended that since the Bissell arrangement had a fixed pivot point itcould traverse only one given radius accurately. He proposed to replacethe fixed pivot with a radius bar (see fig. 5) one end of which wasattached to the locomotive under the smoke-box and the other to rear ofthe truck frame, at the same point of attachment as in the Bissell plan. Thus, according to Hudson, the pivot point could move laterally so thatthe truck might more easily accommodate itself to a curve of any radius. He further claimed that a better distribution of weight was effected andthat the use of the radius bar relieved the center bearing casting ofmuch of the strain of propelling the truck. 

[Illustration: FIGURE 8. --A 2-wheel Bissell truck installed on thePennsylvania Railroad's _No. 91_. This engine originally an 0-8-0 WinansCamel built in February 1854, was rebuilt by John P. Laird in 1867, atwhich time the Bissell truck was added. Note that Hudson equalizinglever was not used. (_Smithsonian photo 46806-k_)]

The British journal _Engineering_, in an article otherwise friendly tothe inventor, expressed some skepticism as to the real merit of Hudson'sinvention. [15]

 If Mr. Hudson's truck, ... Be examined, it will be seen that the radius link serves no other purpose than that of carrying the truck along with the engine, and this could obviously be equally done by the pivot or central pin of the truck itself. 

It is probable that few builders other than Rogers made use of theHudson radial link. [16] One of these was John Headden, whose _GeneralDarcy_, shown in figure 6, was fitted with the Hudson truck. 

Thus, by 1860 there had been perfected and adopted a successful 4-wheelsafety truck for 4-4-0's and 4-6-0's used in general mixed and passengerservice. But as the decade advanced, the need grew for heavy freightengines that could be safely run at speed. Without a pilot truck, theleading driving axle of the freight engine was generally overloaded. While the application of a 4-wheel truck reduced this front-end overloadand permitted faster running it materially reduced the traction of thedrivers by bearing too great a portion of the total weight. This loss oftraction was of course highly undesirable and generally disqualified theuse of 4-wheel trucks for freight engines. What was needed was a truckwhich would guide the 0-6-0's and 0-8-0's around curves and yet leavethe greater portion of the weight on the drivers. The 2-wheel, or pony, truck met these requirements. [17]

[Illustration: FIGURE 9. --Running gear and truck designed by John L. Whetstone, as shown in the drawing for U. S. Patent 27850, issued April10, 1860. ]

Levi Bissell produced the basic patent for such a truck in 1857. ZerahColburn in September of that year had suggested to Bissell that hedevelop a 2-wheel truck. Such a device, he believed, would be wellreceived in Britain. [18] He was quite correct, as will shortly be seen. 

In nearly every respect Bissell's 2-wheel truck (see fig. 7) followedthe idea of the original patent for the 4-wheel truck, which he claimedas the basis for the present invention. The pintle was located behindthe truck axle, near the front driving-wheel axle, and the weight wascarried by incline planes that also served as the centering device. 

A study of the patent drawing in figure 7 reveals several interestingpoints. Note that the V's, and thus the point of bearing, are slightlyin front of the center line of the truck axle. It was suggested in thepatent specification that the V's might be placed to the front, rear, ordirectly over the axle, but in most actual applications they were placeddirectly over the axle. Note also that the locomotive shown on thefigure is obviously a standard high-wheel American type which hassuffered the rather awkward substitution of a pony truck for its regular4-wheel arrangement. It is probable that few if any American types wereso rebuilt. 

Bissell was granted U. S. Patent 21936 on November 2, 1858. Britishpatent 2751 was issued for the same device on December 1, 1858. A fewmonths later, in the summer of 1859, service tests of Bissell's new truckbegan in England. 

First known use of the truck was on the British Eastern Counties Railway_No. 248_, a rigid-frame 2-4-0 built by Kitson in 1855. The leadingwheels of the engine, as originally constructed, were attached to theframe in the same manner as the drivers and thus had no lateralfreedom. For the test the front pedestals, which held the journal boxesof the leading wheels, were cut off and a Bissell pony truck wassubstituted. About a year later Alexander L. Holley reported on thesuccess of the test. [19] The 248 had operated 17, 500 miles, at speeds upto 50 m. P. H. , safely and satisfactorily. The engine not only rode moresteadily but showed a remarkable reduction in flange wear. The road wasso pleased that by 1866 they had equipped 21 locomotives with Bisselltrucks. [20] Several other British lines followed the example of theEastern Counties Railway. 

[Illustration: FIGURE 10. --The Hudson-Bissell truck permitted theintroduction of Mogul and Consolidation type freight locomotives. Thisdrawing shows a typical installation for a Consolidation of the 1880's. Item A is the equalizing lever which connects the truck to the springsof the front driving wheels. From figures 891-3 in J. G. A. Meyer, _Modern Locomotive Construction_, New York, John Wiley, 1904, p. 543. ]

At first Bissell's 2-wheel truck received wider application in Europethan in this country, because most American roads, despite the interestin developing heavier freight locomotives, continued to depend upon the4-4-0 as a dual-purpose machine. It was not until after 1870, when Moguland Consolidation types appeared in greater numbers, that the 2-wheeltruck became common in the United States. 

The first use, known to the writer, of the Bissell pony in this countryoccurred in November or December of 1859 on the Memphis and CharlestonRailroad. D. H. Feger, master mechanic of the railroad reported, eightmonths later, that since the locomotive had been fitted with the Bisselltruck "she has never left the rail and previous to her having this truckshe was off the rail almost daily. "[21] In the same report Feger statedthat he planned to re-equip another locomotive in the same manner. 

[Illustration:

 ANTHRACITE COAL BURNING FREIGHT LOCOMOTIVE ROGERS LOCOMOTIVE & MACHINE WORKS

FIGURE 11. --The New Jersey Railroad and Transportation Company _No. 36_, built by the Rogers Locomotive and Machine Works in 1863, was one of thefirst locomotives to be equipped by this firm with a 2-wheel Bisselltruck. (_Smithsonian photo 46806-m_)]

The Baldwin Locomotive Works in December 1860 built a group of ratherawkward looking 2-6-0's for the Louisville and Nashville Railroad. Equipped with Bissell trucks, these were undoubtedly among the veryfirst new locomotives to be so built. The first consolidation type wasbuilt by Baldwin in 1866; it was equipped with a 2-wheel Bissell safetytruck. 

The Rogers Locomotive and Machine Works and the New Jersey Locomotiveand Machine Works, both of Paterson, New Jersey, in the early 1860'sbegan building Moguls; these are known to have had Bissell trucks. Otherbuilders followed their example, so that by the 1870's 2-wheel truckshad become relatively common. 

It should be noted that the 2-wheel truck was not an absolute successuntil it was equalized with the front driving axle. This arrangement wasperfected in 1864 by William S. Hudson, but before describing hisinvention it will be helpful to discuss several earlier attempts toequalize pony trucks with the drivers. 

In 1857 John P. Laird, then master mechanic of the Marietta andCincinnati Railroad, rebuilt an old Niles 8-wheeler into a curious 2-6-0on which only the two rear driving wheels were coupled. The front driverwas driven by a chain and sprocket, and the pilot wheels were equalizedwith the front driving axle. The success or failure of the arrangementhas not been definitely determined, but whatever the outcome, Lairdcontinued his experiments when he became superintendent of motive powerfor the Pennsylvania Railroad in 1862. He abandoned the chain drive fora more conventional arrangement of side rods, but the truck and his planof equalization were much the same as that tried earlier. Laird used twoequalizing levers, attached at one end to the front spring hangers andat the other to the truck, but in a way to allow the truck to swinghorizontally. The fulcrum for each lever was mounted on the underside ofthe front frame rail. A number of old 8-wheel Baldwin flexible-beamengines and several Winans' Camels were rebuilt in this way. One ofthese is shown in figure 8. Laird, however, eventually becamedissatisfied with his arrangement and re-equipped the engines withBissell trucks. 

[Illustration:

 LOCOMOTIVE ENGINE SAFETY TRUCK CO. OF NEW YORK. 

 Proprietors of the following Letters Patent granted to Levi Bissell, Aug. 4, 1857, Nov. 2, 1858 (extended Nov. 2, 1872); A. W. Smith, Feb. 11, 1862; D. R. Pratt. Oct. 16, 1860; W. S. Hudson, April 5, 18[digits missing] and May 10, 1864. 

 DRAWINGS FURNISHED AND LICENSES GRANTED ON APPLICATION. 

 A. F. SMITH, President. M. F. MOORE, Sec'y and Agent ALBERT BRIDGES. Treas. No 46 Cortlandt st. N. Y. 

FIGURE 12. --Notice of the Locomotive Safety Truck Company listing thepatents held by it. From _Railroad Gazette_, March 3, 1876. ]

John L. Whetstone on April 10, 1860, obtained U. S. Patent 27850, whichstrikingly anticipated the plan Hudson was to develop four yearslater. [22] Whetstone did not use a Bissell truck and was in fact moreconcerned in relieving the excess weight, often a 50% overload, from thefront axle of 0-6-0 locomotives and in distributing a portion of thatweight to a pony truck. His arrangement may be readily understood fromthe patent drawing in figure 9. Probably the best features of the designwas the transverse H-beam that connected the spring hangers to the truckframe, which in this case also served as the equalizing lever (note thatthe ball "C" acts as the fulcrum). 

Hudson made use of this same device but in a more practical manner. Hefound that while the Bissell pony truck could satisfactorily adjustitself laterally and could lead the locomotive around curves, it couldnot handle the varying loads imposed upon it by the rough trackagetypical of American railroads. At one moment an undue amount of weightwould fall upon the truck because the drivers were over a depression inthe roadbed. This condition overloaded the truck's springs and alsoresulted in a momentary loss of adhesion, causing the drivers to slip. Conversely, when the truck hit a depression too much weight was thrustupon the driving wheels, and broken springs or other damage mightresult. 

Hudson's ingenious remedy to this problem was simple and straightforward(see fig. 10). A heavy equalizing lever that connected the truck to thesprings of the front driving wheels was placed on the longitudinalcenterline of the locomotive, with the fulcrum under the cylindersaddle. Thus the truck and front driver reacted together to all theinequalities and shocks offered by the roadbed. 

In October of 1863, under Hudson's direction, two 2-6-0's equipped withBissell trucks were built at the Rogers Works for the New JerseyRailroad and Transportation Company. Probably some fault was found withthe suspension of these machines, numbered 35 and 36, for the next2-6-0, numbered 39, built for the New Jersey road was equipped withHudson's equalizer. This engine, completed in January 1865, is believedto be the first Mogul so equipped. [23]

The Locomotive Engine Safety Truck Company (see fig. 11) was formed inthe 1870's, with A. F. Smith as president, to exploit the patents ofBissell, Smith, and Hudson. For several years notices appeared in thecolumns of the _Railroad Gazette_ reporting suits by the Company againstvarious railroads and locomotive builders for unauthorized use of theirpatents. The _Gazette_ of May 29, 1875, carries a protest of the Companyagainst the Manchester Locomotive Works for unlicensed use of Smith'spatent of 1862. In the issue of August 28, 1875, is reported theCompany's success in establishing the validity of Smith's patent:

 Some important settlements for the use of the patent have lately been made with the company, one of them being with the Western Railroad Association, whose headquarters are at Chicago, which includes the principal western roads. Through this the company receives its royalty on several hundred locomotives. 

IN SUMMARY

It can be stated that Hudson's modification of the Bissell truck is ofunquestioned importance, for without the introduction of the equalizerit is doubtful if the 2-wheel pony truck would have been a completesuccess on American railroads. Bissell's 4-wheel truck was extensivelyemployed, but it did not enjoy the universal popularity of the 2-wheeltruck, and in the 1880's was eclipsed by other forms of 4-wheel safetytrucks. The Hudson-Bissell pony truck, however, survived in its basicform to recent times, when, in the late 1940's and early 1950's, thelast steam locomotives were constructed in this country. 

 1. Three-point suspension in a 4-2-0 was easily gained--the center plate of the truck and the two bearings of the driving wheel axle. On a 4-4-0 the center plate served as one point, while the fulcrum of each equalizing lever served as the other two points, thus providing the desirable and highly stable 3-point suspension. 

 2. _American Railroad Journal_, 1853, vol. 9, p. 427. 

 3. Connecting both truck axles with an equalizing lever so that they acted in sympathy with each other also did much to prevent derailments on rough trackage. 

 4. Bissell states in the patent specification that inclined planes had been previously applied to railroad car trucks. His claim rested on the application of this device to locomotive trucks. 

 5. From a sworn statement of G. M. Milligan dated July 2, 1857. This along with letters, petitions, receipts, and other such material quoted in this discussion are from the Patent Office papers housed in the National Archives, Washington, D. C. (hereafter referred to as Patent Office papers). 

 6. The _Lebanon_ was a 4-4-0, used in freight service, that had been built by the New Jersey Locomotive and Machine Company in December 1855. 

 7. Letter dated July 2, 1857, from S. L. Moore (Patent Office papers). 

 8. Statement cited in footnote 5. 

 9. Letter dated July 11, 1857, Charles Mason to Levi Bissell (Patent Office papers). 

 10. _American Railway Review_, February 9, 1860, vol. 2, p. 71. 

 11. U. S. Patent 34377, February 11, 1862. 

 12. Davenport & Bridges, car builders of Cambridge, Massachusetts, in 1841, obtained a U. S. Patent for a swing-beam truck. 

 13. Gustavus Weissenborn in his authoritative _American Locomotive Engineering and Railway Mechanism_ (New York, 1871, p. 131), stated that when in use the V's soon acquired a polished surface which seemed to defy wear. 

 14. U. S. Patent 42662, May 10, 1864. 

 15. _Engineering_, July 12, 1867, vol. 4, p. 29. 

 16. John Headden, master mechanic of the New Jersey Railroad and Transportation Company, built at the road's Jersey City shops several locomotives equipped with Hudson's variety of the Bissell truck. Headden, upon the death of Hudson, succeeded him in 1881 as superintendent of the Roger Works. 

 17. It is believed that Harrison, Winans and Eastwick made one of the first uses of a 2-wheel radial truck on a 2-6-0 built at the Alexandrovsky Arsenal, St. Petersburg, in 1844-46. The success or exact particulars of these machines is unknown. See John Jahn, _Die Dampflokomotive in Entwicklungsgeschichtlicher Darstellung Ihres Gesamtaufbaues_, Berlin, 1924, p. 239; Richard E. Peunoyer, "Messrs. Harrison, Winans & Eastwick, St. Petersburg, Russia, " _Railway and Locomotive Historical Society Bulletin_ no. 47, September 1938, p. 46; and Joseph Harrison, Jr. , _The Locomotive Engine, and Philadelphia's Share in its Early Improvements_, Philadelphia, 1872, p. 52. 

 18. Zerah Colburn, _Locomotive Engineering and the Mechanism of Railways_, ... , London, 1871, p. 99. Zerah Colburn (1832-1870) was one of the best informed and most vocal authorities on 19th-century American locomotive construction. He not only designed advanced machines while working at the New Jersey Locomotive Works but also advocated many reforms in locomotive design. He published the _Railroad Advocate_ in New York City for several years. In 1858 he became editor of _The Engineer_ and in 1866 founded the technical journal _Engineering_. 

 19. _American Railway Review_, June 8, 1860, vol. 2, p. 392. Holley was a well known authority on locomotive engineering and the author of several books on the subject. 

 20. _Engineering_ May 11, 1866, vol. 1, p. 313. By this time (1866), the Eastern Counties Railway had become part of the Great Eastern system. 

 21. _American Railway Review_ July 26, 1860, vol. 2, p. 38. 

 22. Whetstone was chief designer for Niles & Co. , a Cincinnati locomotive builder. His invention apparently did not receive a test, since the company closed shortly before the patent was granted. No other builder seemed interested. 

 23. Paul T. Warner, "Mogul Type Locomotives, " _Railway and Locomotive Historical Society Bulletin_ no. 100, April 1959. 

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