The model is of mostly brass construction and (probably uniquely for the period), employs beautifully cast frames and stretchers rather than utilising the fabricated form which most large scale steam locomotive models display. Pattern making alone for such components denotes craftsmanship of a very high, not to mention expensive order, which is entirely compatible with the work which would be expected from the best instrument makers of the day (again see biographical footnote). The upper surface of the running plate is hand engraved in diamond pattern while all the (mostly brass) fabricate components are of equally fine quality. Here, mention perhaps might also be made of the perceptive detail work in the shape of dummy leather and horsehair front buffers, beautifully made safety chains and working air bleed valves, well observed wooden cylinder lagging, ivory valve handles and the change to 'Russian' iron for the characteristically shaped chimney and the smokebox wrapping plate.
The boiler is particuarly interesting in that it contains but twelve ½in. diameter fire tubes, rather than the many more smaller diameter tubes which an exact scale representation would be expected to feature. Like the brass firebox shell and the firebox itself (which has wet water legs), they are soft soldered in position and, in the case of the tubes, the soft solder appears quite new - a somewhat relative term since precise dates cannot be established. The pipe joints are flanged and fitted with 1/16in. bolts, except for the main steam and exhaust pipes which have large and anachronistic hexagon unions made from drawn hexagon shaped bar which was not available in 1864 - all of which features pose some interesting speculation.
The use of fewer larger tubes is very much in the more modern idiom for an effective 'working live steam' model and may well be a later modification, albeit incapable of being either proved or dated. But, given that both the smokebox and firebox show clear signs of the model having been steamed (smokebox door and ash pan are both removable, with care), there is no doubt that the model was intended to be workable from the outset, though with what success must remain forever shrouded in mystery!
Further supporting evidence of the original intention to steam the model are found in the use of steel for the connecting rods, 'Big Ends' made in what is best described as 'model' fashion (with dummy cotters) and with 'Little Ends' made in like manner but offset to the outside of the crossheads rather than forked to enclose the crossheads as per prototype. This latter feature may well be so as to allow for the wider than scale frame/wheel spacing, one of only two serious departures from prototype accuracy, the other being the smokebox door (see also next section - Prototype Notes).
The model is built to run on the scale equivalent of c.6ft. gauge track rather than 4ft. 8½in. This wider than 'correct to scale' gauge seems related to the fact that the model was intended to be working. The frames are set further apart than for a strict 1/12 interpretation of 4ft. 8½in. gauge and this, in turn, gives a smaller degree of lateral 'overhang' of the running plate outside the wheel faces, given that all other dimensions, including overall width, conform exactly to 1/12 scale parameters. However, during the 19th Century, there were wealthy patrons who ran working model railways to 6in. gauge, one well-recorded late 19th Century example from Manchester being of London and North Western models in a 90ft. x 30ft. room, using steam locomotives and costing over £10,000 at 19th Century prices! It is therefore quite feasible that the model was built originally for such a person. Moreover, it is also known that at the time, there was, rather surprisingly in view of the high accuracy of the rest of the model, a somewhat lesser regard for gauge fidelity than is currently the fashion.
The smokebox door itself is not of the correct pattern, being of complex 'curvilinear' octagonal shape. The explanation here may well be that since neither front elevations nor cross-sections appear on original official drawings of the type, the model maker relied on a degree of 'guesswork'. Furthermore, being an instrument maker, not an engineer (again see biographical note), it is reasonable to infer a wish to include an appropriate decorative element, provided that the door could be removed - which it can.
This model, though not identified by name or running number, undoubtedly depicts a development of the 'long boiler' locomotive type which represented the 4ft. 8½in. gauge in the well known 'gauge trials' of 1845, being a very accurate representation of one of the final batches which were built just after the trials themselves - see prototype notes, below. It is probably the only fine model of this type from the period in question and certainly the only one whose quality, size and fidelity to prototype permits a proper appreciation to be made of this most significant evolutionary type. It has no tender, but abrasion marks on the rear drawbeam suggest that a tender (of some sort or other) may once have been attached, supported by the fact that the functional engine-to-tender water feed pipes were presumably connected to some form of water supply. These pipes are additional indications which suggest that it was designed to be a working model, given that there are obvious signs of attempts having been made to steam it. A possible explanation of the omission could be that the tender may have been lost or damaged at an early stage, the model having been on static display during the whole of its recorded previous ownership. However, the model is a superbly accurate representation of one of the most significant pioneering British locomotive types of the pre-1850 era.
J.G.H. Warren -- A Century of Locomotive Building
Edward Talbot -- An Illustrated History of LNWR Engines
Gloria Clifton -- Directory of British Scientific Instrument Makers 1550-1851
Harmsworth Magazine 1898 (quoted in Model Railway News, June 1961)
E.L. Ahroms -- The Steam Locomotive 1825-1925
Robert Stephenson and Co. Official Drawings in the Science Museum Collection
THE MODEL ITSELF
For many years, this model (not unknown in the British context) was assumed to be of a Dutch prototype, largely, it is thought, because its modelled track gauge is a close scale equivalent to the notional two metre gauge of the Dutch broad gauge which was measured between rail centres and not, as customary, between the inside rail faces, lending credence to this view was the fact that its date of building coincided, more or less, with the demise of Dutch broad gauge, thereby inferring some form of valedictory role for the model.
However, though it is known that Robert Stephenson & Co. did indeed supply 'long boiler' types for the Dutch broad gauge, more recent research proves that these were mostly inside cylinder types with driving wheels between the carrying axles. Furthermore, the recorded list of imports from Stephenson and Co. for the Dutch broad gauge shows no examples of the type represented by this model.
On the other hand, contemporary drawings of the 'Great A' type for the York and North Midland Railway (as used in the aforementioned gauge trials), together with its later development for the LNWR in 1846-7 (most accurately represented by Robert Stephenson & Co. Drawing No. 102 at the Science Museum London) show such dimensional consistency (at 1/12 scale) with that of the model as to make it clear beyond all reasonable doubt that the model was intended to represent the important later LNWR development of the 1845 design used in those trials.
Careful measurement of the model against the original Stephenson drawing of 1846 reveals that, track gauge and smokebox apart, (both of which discrepancies are capable of rational explanation - see above), there is no single significant dimension which varies by more than one scale inch between model and prototype, nor do any of the important mechanical components show any meaningful variation between those used on the prototype and those depicted on the model.
The prototype engines were built in two batches for the Southern Division of the London and North Western Railway (newly incorporated under that name in 1846 as a corporate amalgamation of the London and Birmingham, Grand Junction and Liverpool and Manchester Railways, its three main components) during 1846-7. Their construction followed an impressive performance (by contemporary standards) of the 'long boiler' type in the famous gauge trials of 1845 which resulted in the adoption of 4ft. 8½in. as the standard gauge for railways. However, there was the feeling that a more developed version of this successful design might be worthwhile for the new LNWR and Stephenson and Co. were given the design remit. Of the sixteen examples built at the time, ten came from Jones, Potts and Co. in 1847 (with a few of their own 'company' stylistic variations) but the first six (nos. 153-8) came from Robert Stephenson & Co. itself in 1846, configured in exactly the same form as is shown by this model.
It is therefore believed that this fine model is the first truly accurate representation of a genuine LNWR locomotive (as opposed to its earlier constituent companies) and as such, its historical importance is evident. At this distance in time, it is impossible to determine why the model was built, though the fact that the class was withdrawn from service in the 1860s may be significant. Supportive evidence of its linkage with early LNWR history may also be found in the fact that it is finished in the early dark green livery of the LNWR, which preceded the more well known 'blackberry' black. It would not be possible (without risking damage to the model) to determine the exact age of the paintwork but what can be said is that the colour exactly matches the dark green shade which has been confirmed on the only known contemporary examples of the colour.
THE HISTORICAL SIGNIFICANCE OF THE STEPHENSON 'LONG BOILER' TYPE
The Stephenson 'long boiler', which first appeared in 1841, was not particularly 'long' in absolute terms, but was a significant evolutionary 'step along the way', so to speak, in terms of the development of mid-19th Century steam locomotives. The term was first used to distinguish the precise configuration of boiler on three-axle locomotives wherein two alternative positions of firebox were possible. The first, and in the British context far more common arrangement, was with the firebox between the second and third axles, whether the locomotive be in 2-2-2, 2-4-0, 0-4-2 or 0-6-0 configuration. By contrast, the 'long boiler' had the firebox to the rear of the third axle, no matter what the wheel arrangement may have been.
Now this position of firebox undoubtedly posed mechanical stability problems in terms of rear-end 'overhang', compared with the more conventional arrangement; but it had certain thermodynamic advantages (more fully exploited in Continental Europe than in the land of its birth, if truth be told) which were mostly to be found in slow speed work as the years went by. But at the time the 'A' Class were built, this restricting factor was not quite so obvious, so we need to look at its plus points in order to appraise the significance of this model.
In essence the 'long boiler' was an attempt by Robert Stephenson (a far better locomotive engineer than his more famous father George) to overcome the problem of incomplete extraction of heat from the fuel before combustion products were exhausted to atmosphere, often including a fair quota of unburnt fuel by way of cinders and sparks, largely because the restrictions of locomotive wheelbase at the time (itself conditioned by turntable size) forced boilers to be shorter than the ideal. A firebox placed behind the rear axle tended to overcome this problem, albeit at some cost in terms of stability as far as boiler length vis-a-vis chassis was concerned.
At the same time and by way of compensation, though not displayed in this model, cylinders were often placed ahead of the leading axle so as to redress the balance and it is a matter of fact that in Continental Europe, the 'long boiler' concept was of seminal importance in most subsequent locomotive design, quite often with four axles rather than three.
The use of long boiler engines in Britain was relatively short-lived except on the Stockton and Darlington and, to some extent, the Caledonian railways. Most of these had inside cylinders, but in Europe, outside cylinders were more common and the long boiler type formed the origin of most locomotive development on the European mainland. In the historical context, therefore, this model can be seen to have both international and British significance. In the latter case, however, what was of more long-term value in the design represented by this model, is the fact that although the long boiler itself was not widely adopted, this Robert Stephenson concept was to establish the use of the outside cylinders, inside frames and straight axles which were to become so dominant in the last years of British steam.
BIOGRAPHICAL NOTE ON THE MODEL MAKER
The model carries a maker's plate engraved 'J. Gardner, maker, 1864', a well known firm of scientific instrument makers from Somerset Place, New Road, Whitechapel, London. James Gardner himself worked from 1803-1836 (Somerset Place from 1834) but, numbered amongst his apprentices at that time was one William Gardner (not his son but maybe related in some other way) who worked in his own right at the same address from 1851 to 1859 and who was still noted as being at 56 New Road, Whitechapel in 1865. Given that the model probably took at least two years to make in view of its quality, it seems likely that it was largely the work of William Gardner but carries the name of the firm not the individual maker.
What is certain is that the method of construction is that of an instrument maker rather than what we would now call a 'model engineer'. This does not in any way betoken inferior quality but does offer a rational explanation for some of the observable variations from what we would now see as normal in the context of model engineering, eg. the rather more widespread use of brass and the less than exact representation of the 100 correct wheel tread/flange profile whose correct shape would be much more familiar to those of a purely 'railway' and/or engineering persuasion.
Records have not been found which indicate why or for whom the model was built or why it was made almost 20 years after the appearance of the prototype locomotive on which it is clearly based.