Lot Essay
The so-called 'American' 4-4-0 type, denoting four carrying wheels ahead of four driven wheels (two axles in both cases), was the inevitable consequence of the particular circumstances surrounding the development of the steam railway (railroad) in North America during the nineteenth century. The ideal steam locomotive configuration had been established in 1829 by Robert Stephenson (not George, be it noted), when his famous 'Rocket' swept the field at the Rainhill trials in Britain, where considerable civil engineering was accepted as essential so as to achieve the much sought-after gentle track gradient and curvature. When more power was required, the addition of a third or fourth axle (to allow for greater boiler capacity and firebox length) did not therefore present too much of a problem and many hundreds of larger types began to appear, almost always with rigid plate frames. Elsewhere, especially North America, new lines often displayed much tighter curvature to avoid the higher cost of excavating a straighter route and in order to get the extra length to generate more power, greater wheelbase flexibility was needed and this led to the use of the flexible pivoting 'truck' (called a 'bogie' in Britain) mounted ahead of the main driven wheels, which later continued to be fixed to the main frames of the engine.
The first 4-4-0 patent was taken out in 1836; the first example appeared in 1837, and during the 1840's, engines began to appear in significant quantity. These were mostly developed from earlier 4-2-0 types and met with varying degrees of success. In them, the leading bogie acted as little more than a guide, the driving wheels still took most of the weight and the actual drive was usually to the rear axle (often using obsolete types of valve gear), all of which produced a frequently ungainly and not always satisfactory machine. But in due course, in 1852, a radical rethink, largely attributable to Thomas Rogers (whose chief designer William Hudson was an Englishman), gave rise to the classic outline and configuration of the 4-4-0 which became synonymous with North American railroads for well over a generation.
In the Rogers type (the familiar soubriquet 'American' does not seem to have been used until 1872), the drive was now taken to the leading axle and the driving wheelbase extended, thus allowing a deep round topped firebox to be fitted between the wheels, ahead of which was carried a wagon top or coned boiler. The simultaneous lengthening of the leading bogie, well separated from the driven wheels, allowed the cylinders to be brought down to a horizontal position and the connecting rods to be lengthened to seven or eight times as long as the crank throw, thus giving much lighter vertical thrusts at the slidebars. Furthermore, a general improvement in driving wheel springs (0ften of compensated beam type) produced, in conjunction with the central bogie pivot, a near-perfect three point suspension and consequential improvement in both ride quality and reduced track damage.
Coincidentally with these major changes came the almost universal adoption of the bar frame which had considerable technological advantages in the North American context compared with the more rigid European style plate frame, much of the success of the 'American' type, especially over more poorly aligned or maintained tracks, being attributable to this form of framing. However, although Rogers himself had also introduced the improved link motion valve gear into his own examples, it was some time before his imitators (and there were many) realised the true value of that particular feature, so it was not until the 1860's that these now familiar engines were all conceptually alike as near as made no odds.
For the most part, American 4-4-0s tended to come in two main sub-groups, best defined by their driving wheel size. The smaller wheeled engines (best used for heavier freight work and/or steep inclines) generally had wheels of about 5ft diameter (give or take an inch or two), while the so-called 'passenger' versions had approximately 6in. larger diameter wheels for higher speeds. There were of course some exceptions to this generalisation. Finally, and until well into the 1860's, many 4-4-0s were designed to burn wood and fitted with huge spark arresting chimneys. However some of the Eastern railroads preferred either anthracite or coal and by the 1870's, wood burning (which actually needed a different form of boiler draughting than coal or anthracite) was well into a decline across the whole continent.
The model in question represents Messrs Baldwin's interpretation of a coal burning 'passenger' example of the type (5ft 8in. diameter driving wheels) at perhaps the apogee of its evolution and styling.At that time, the type represented some 85 of all locomotives in service in North America and still accounted for some 60 of Baldwin's new production. By the 1880's, however, the classic American 4-4-0 was beginning to develop into something altogether more massive and the need for even larger engines than an enlarged 4-4-0 caused the latter to go into a rapid decline during that decade. But they had served North America well for some thirty-five years or more and it is difficult to overstate the importance of the type both in terms of operating the traffic and opening up the continent as the westward expansion took place. No other single general purpose locomotive ever enjoyed greater popularity and few of them proved to be as useful over such a long period.
The first 4-4-0 patent was taken out in 1836; the first example appeared in 1837, and during the 1840's, engines began to appear in significant quantity. These were mostly developed from earlier 4-2-0 types and met with varying degrees of success. In them, the leading bogie acted as little more than a guide, the driving wheels still took most of the weight and the actual drive was usually to the rear axle (often using obsolete types of valve gear), all of which produced a frequently ungainly and not always satisfactory machine. But in due course, in 1852, a radical rethink, largely attributable to Thomas Rogers (whose chief designer William Hudson was an Englishman), gave rise to the classic outline and configuration of the 4-4-0 which became synonymous with North American railroads for well over a generation.
In the Rogers type (the familiar soubriquet 'American' does not seem to have been used until 1872), the drive was now taken to the leading axle and the driving wheelbase extended, thus allowing a deep round topped firebox to be fitted between the wheels, ahead of which was carried a wagon top or coned boiler. The simultaneous lengthening of the leading bogie, well separated from the driven wheels, allowed the cylinders to be brought down to a horizontal position and the connecting rods to be lengthened to seven or eight times as long as the crank throw, thus giving much lighter vertical thrusts at the slidebars. Furthermore, a general improvement in driving wheel springs (0ften of compensated beam type) produced, in conjunction with the central bogie pivot, a near-perfect three point suspension and consequential improvement in both ride quality and reduced track damage.
Coincidentally with these major changes came the almost universal adoption of the bar frame which had considerable technological advantages in the North American context compared with the more rigid European style plate frame, much of the success of the 'American' type, especially over more poorly aligned or maintained tracks, being attributable to this form of framing. However, although Rogers himself had also introduced the improved link motion valve gear into his own examples, it was some time before his imitators (and there were many) realised the true value of that particular feature, so it was not until the 1860's that these now familiar engines were all conceptually alike as near as made no odds.
For the most part, American 4-4-0s tended to come in two main sub-groups, best defined by their driving wheel size. The smaller wheeled engines (best used for heavier freight work and/or steep inclines) generally had wheels of about 5ft diameter (give or take an inch or two), while the so-called 'passenger' versions had approximately 6in. larger diameter wheels for higher speeds. There were of course some exceptions to this generalisation. Finally, and until well into the 1860's, many 4-4-0s were designed to burn wood and fitted with huge spark arresting chimneys. However some of the Eastern railroads preferred either anthracite or coal and by the 1870's, wood burning (which actually needed a different form of boiler draughting than coal or anthracite) was well into a decline across the whole continent.
The model in question represents Messrs Baldwin's interpretation of a coal burning 'passenger' example of the type (5ft 8in. diameter driving wheels) at perhaps the apogee of its evolution and styling.At that time, the type represented some 85 of all locomotives in service in North America and still accounted for some 60 of Baldwin's new production. By the 1880's, however, the classic American 4-4-0 was beginning to develop into something altogether more massive and the need for even larger engines than an enlarged 4-4-0 caused the latter to go into a rapid decline during that decade. But they had served North America well for some thirty-five years or more and it is difficult to overstate the importance of the type both in terms of operating the traffic and opening up the continent as the westward expansion took place. No other single general purpose locomotive ever enjoyed greater popularity and few of them proved to be as useful over such a long period.