Lot Essay
The 'Experiment' Class locomotive, introduced in 1882 and designed by Francis W. Webb, were the first class of compound locomotives to be built in quantity by the LNWR and the model represents one of the last batch to be built, in 1884. They represented the first major attempt by a British locomotive engineer to produce a working compound design and the thirty engines of the class were to prove harbingers of several hundred subsequent LNWR compounds to a number of different designs, the first examples of which displayed Webb's characteristic three-cylinder solution, viz: two outside high pressure cylinders exhausting into a single and much larger low pressure cylinder between the frames.
Posterity has not given Webb's three-cylinder compounds a very good reputation (or his subsequent four-cylinder types for that matter), but at the time of their introduction, there were several good reasons for Webb (who was a fine engineer) to proceed as he did. In 1878, highly influenced by the successful work of Anatole Mallet in France, Webb had rebuilt an old 2-2-2 simple expansion two-cylinder locomotive into compound form by simply reducing the size of the left-hand cylinder (which became the high pressure side), leaving the rest much as before. The engine, albeit less nominally powerful than before, was made much more economical in consequence and encouraged Webb to adopt an extensive programme of building new compound types.
Experiment itself, as its name implies, was a one-off trial engine in 1882. Based very much on the contemporary 2-4-0 simple engines of the day, it was followed by a further twenty-nine compounds during 1883-4 (of which Apollo was one) to a broadly identical design but with larger high pressure cylinders. These were at first called the 'Compound' Class after the name of the first of them, but when Experiment was itself rebuilt with the same larger cylinders, the whole series were generally named for the pioneer engine.
Webb's stated objectives for introducing the type were to improve economy and suppress the coupling rods, there being a strong feeling in contemporary locomotive engineering that the latter impeded free running of the machine. In the case of the 'Experiments', it was acheived by the simple expedient of having the outside cylinders drive the near pair of wheels and the inside cylinder the leading pair. The engines are therefore properly described as 2-2-2-0, albeit visually similar to a conventional 2-4-0. As things turned out, it would have been better to have fitted coupling rods, for there was a tendency for the two driven axles to behave somewhat independently, not to mention a proneness to slipping.
The reason for adopting two high pressure cylinders exhausting into one low pressure equivalent (as opposed to the more logical one high/two low pressure solution wherein all three could be made much the same size), is thought to have been of twofold origin. Firstly, it would enable easier starting using the two high pressure cylinders, prior to the third one coming into operation; while secondly, it was easier to fit a large single cylinder between the frames, not to mention simplifying the crank axle which could thus be made very strong. Whatever, Webb was to retain this arrangement on many more engines.
The 'Experiments' were followed between 1884 and 1888 by forty 'Dreadnoughts' of broadly identical conception but very much larger in absolute size and the 2-2-2-0 series was concluded by a further enlargement in the shape of the ten 'Teutonic' locomotives of 1889-90. Thereafter, Webb moved to even bigger 2-2-2-2 passenger types and an eight coupled 0-8-0 goods design (probably the best of them all) before adopting four-cylinder compound propulsion. By then, well over two hundred three-cylinder compounds were at work (including a handful of tank locomotives) and although not always accorded the best of subsequent reputations, they put up some creditable performances in their time.
This exceptional model, therefore, not only represents the first stage in what was to become a considerable evolutionary story in prototype terms, but also faithfully replicates every single moving part of the prototype, being of more than usual historical importance given that none of the originals have survived in preservation. It is modelled in the final state which these engines displayed, ie with replacement (stronger) smokebox door and other minor alterations, typical of those found during the lifespan of any steam locomotive class.
This model was awarded the J.N. Maskelyne Memorial Trophy (for the model locomotive, in any scale, which does most to promote the fidelity of design) and the H.C. Wheat Challenge Cup (awarded annually for the best '0' gauge model exhibited) at the Model Engineer Exhibition, Olympia, 1998/9.
Posterity has not given Webb's three-cylinder compounds a very good reputation (or his subsequent four-cylinder types for that matter), but at the time of their introduction, there were several good reasons for Webb (who was a fine engineer) to proceed as he did. In 1878, highly influenced by the successful work of Anatole Mallet in France, Webb had rebuilt an old 2-2-2 simple expansion two-cylinder locomotive into compound form by simply reducing the size of the left-hand cylinder (which became the high pressure side), leaving the rest much as before. The engine, albeit less nominally powerful than before, was made much more economical in consequence and encouraged Webb to adopt an extensive programme of building new compound types.
Experiment itself, as its name implies, was a one-off trial engine in 1882. Based very much on the contemporary 2-4-0 simple engines of the day, it was followed by a further twenty-nine compounds during 1883-4 (of which Apollo was one) to a broadly identical design but with larger high pressure cylinders. These were at first called the 'Compound' Class after the name of the first of them, but when Experiment was itself rebuilt with the same larger cylinders, the whole series were generally named for the pioneer engine.
Webb's stated objectives for introducing the type were to improve economy and suppress the coupling rods, there being a strong feeling in contemporary locomotive engineering that the latter impeded free running of the machine. In the case of the 'Experiments', it was acheived by the simple expedient of having the outside cylinders drive the near pair of wheels and the inside cylinder the leading pair. The engines are therefore properly described as 2-2-2-0, albeit visually similar to a conventional 2-4-0. As things turned out, it would have been better to have fitted coupling rods, for there was a tendency for the two driven axles to behave somewhat independently, not to mention a proneness to slipping.
The reason for adopting two high pressure cylinders exhausting into one low pressure equivalent (as opposed to the more logical one high/two low pressure solution wherein all three could be made much the same size), is thought to have been of twofold origin. Firstly, it would enable easier starting using the two high pressure cylinders, prior to the third one coming into operation; while secondly, it was easier to fit a large single cylinder between the frames, not to mention simplifying the crank axle which could thus be made very strong. Whatever, Webb was to retain this arrangement on many more engines.
The 'Experiments' were followed between 1884 and 1888 by forty 'Dreadnoughts' of broadly identical conception but very much larger in absolute size and the 2-2-2-0 series was concluded by a further enlargement in the shape of the ten 'Teutonic' locomotives of 1889-90. Thereafter, Webb moved to even bigger 2-2-2-2 passenger types and an eight coupled 0-8-0 goods design (probably the best of them all) before adopting four-cylinder compound propulsion. By then, well over two hundred three-cylinder compounds were at work (including a handful of tank locomotives) and although not always accorded the best of subsequent reputations, they put up some creditable performances in their time.
This exceptional model, therefore, not only represents the first stage in what was to become a considerable evolutionary story in prototype terms, but also faithfully replicates every single moving part of the prototype, being of more than usual historical importance given that none of the originals have survived in preservation. It is modelled in the final state which these engines displayed, ie with replacement (stronger) smokebox door and other minor alterations, typical of those found during the lifespan of any steam locomotive class.
This model was awarded the J.N. Maskelyne Memorial Trophy (for the model locomotive, in any scale, which does most to promote the fidelity of design) and the H.C. Wheat Challenge Cup (awarded annually for the best '0' gauge model exhibited) at the Model Engineer Exhibition, Olympia, 1998/9.