THE FAIRLIE ENGINE.

Evening Star, Volume VIII, Issue 2205, 1 June 1870, Page 2

THE FAIRLIE ENGINE.

In Wales lately, there has been given a series of experiments with the Fairlie engine, with a view to asccrteiniiig whether or not the engine increased the carrying capa* city of a railway or diminished the cost of working it. These experiments were instituted for a Russian commission which had been scut to England to inspect the actual working of the system, with a view to i; s adaptation in Russia,, and were made in the presence of a commission appointed by the Indian Government, Captain Tyler, the represeatativc of the Board of Trade, Mr Pehl, chief engineer of railways, and representative of the Norwegian Government, the Duke of Sutherland, and other distinguished per. sonages. The party proceeded to Portmadoc, the terminus of the line known as the Festiniog Railway, of 2ft gauge (really only Ift Him), which was the principal object of the iuve-ligation. It is a single line, 13] miles in length, with a branch of one mile connecting the slate quarries of Festiniog with the quays of Portmadoc. The terminus at Festiniog has 7OOffc elevation above that at Portmadoc, the average gradient being 1 in 92, which is enough to secure the desemt of the trains on the'return journey from Festiniog to Portmadoc by the impetus of gravitation. The line runs through a rude rocky country, and has to adapt itself to an endless variety of curves along the contour of the hills, so that a train of any length has frequently to wriggle in serpentine fashion along two or three reverse curves, some of them sharp enough the radius being chains. On these curves the cant or superelevation of the outer rails is never more than 3iu. With the view above stated, two engines were put on their trial—one, tho Little Wonder, on the Festiniog Railway, of 2ft gauge, in North Wales ; the other, the Progress, on the ordinary gauge of 4ft in South Wales.

We now proceed to state what were the experiments with the Fairlie engine, both on the narrow and on the broad gauge. The Little Wonder is an eight-wheeled doublebogie engine of four cylinders 8 3 16in. in diameter, with a stroke of 13in. The diameter of its wheels is 2ft. 4iu.; its average steam pressure is 1501b.; its weight is 19A tons; its total length is 27ft.; its total wheel-base is 19ft., and the wheel-base of each bogie, which practically has alone to be considered, is sft. This engine was first of all made to carry from Portmadoc to Festiniog a train made up of 90 slatewaggons, weighing 57Atons > seven passenger carriages and vans, weighing 13 A tons ; and 57 passengers, weighidg four tons- in all, 75 tons. Add to this its own weight, and we have a total load of 944 tons. The weight, it will be seen, was considerable, if we take into account thg size of fac endue, the narrowness of the gauge, the steepnesi of thb gradients, and the sharpness and multitude of the curves. Bat the chief point of interest in this experiment had reference to the length of the train, which was Ss4ft. —nearly the cixth part of a mile. A train of such a length on such a line had to run often upon two or three reverse curves, some of them with a radins as short as If chains, and it curled and doubled upon itself as it would among the Welsh hills so that the passengers in the front carriages could, sitting in their seats, make signals to the passengers in the hindmost ones. The engine, being in full gear, took this very long train up thp ijills and in and out the curves at an average speed of 14.1 miles fpf hour, and at a maximum speed of 264 miles, Let us here add by way of parenthesis, in order not to refer to it again, that some days afterwards a similar train of 140 empty and seven loaded waggons, weighing in all 101 tons, and measuring in length, 1,323 ft. — that is, a quarter of a mile—a tram so long, iu fact, that there were parts of the road on which it had to run on no less than five reverse curves —was by the same engine hauled up the hills at an average speed of 124 miles, and a maximum of 164. Now, what was the result observed in wriggling along these curves ? It was generally observed (we now quote almost verbatim from the protocol signed by the chief witnesses) that even on curves of If chains radius, and at maximuni speed, there was very little perceptible oscillotion or'movement on the cpghie qr iq tbq carriages, and bo no means such as is felt on comparatively easy curves on ordinary railways. Nor must this remarkable point bo forgotten—a fact almost incredible, but yet certified by competent witnesses—that the oscillation diminished as the speed increased. The speed, let it be added, is naturally less ou a narrow gauge than on abroad one. Captain Tyler, the Government inspector of railways, was at first so doubtful of the safety of a high speed on a railway of such narrow gauge and snob wild curves as that at Festiniog that he insisted on limiting the company to a maximum speed of 12 miles an hour. Since then, however, his doubts have been so completely diopersed that he lias removed all restrictions as to the rate of speed ; and as a matter of fact the Little Wonder, when necessary, works up to 30 and 35 miles an hour. Next followed some trials as to the comparative powers of the two classes of engines used, and the Welsh Pony was selected to represent the pqiumou type of engine. J ill is engine was found' to he nb|e'to carry nearly 74 tons up a gra lient of 1 iii 85. The Little Wonder ascended the same gradient with a total load of 3Q6 tpqs, Op the 14th of February, the Progress left the Three Cocks dilution, outlie Mid Wales Railway, with a train 732 ft. long, and weighing 326 tons, including the engine, and proceeded up several gradients and on reverse curves. The gradionts were 1 in 75, 1 in 162, and 1 in 90. The total distance run was 14 miles, from Three Cocks to Builth, which was done in about an hour, including stoppages. On the same day the engine was taken to some still more severe gradients on the Brecon and Merthyr Railway. At the cQiiclilsion of these remarkable experiments Mr Fairlie was warmly congratulated by the commissioner and the either members of his distinguished party on tha complete success of his system, which, now that it has been made thus generally known, will doubtless soon meet with general application. There is but one opinion of the engineers of the lines examined— Mr Broughton and Mr Hensbaw—as to the effect of the Fairlie engine upon the rails. It does far more work than any ordinary engine, and y it is far less destructive to the permanent way.