Railroads in America have built both passenger and freight cars entirely of steel for a considerable while. The reason for this was partly because of the increasing scarcity of wood and the superiority of steel vehicles in collision, but chiefly owing to the fireproof qualities of such construction.

Although actually the first steel passenger vehicle was designed and built in England for a local electric railway, it only has been in comparatively recent times that English and European railways have oriented themselves towards the all-steel passenger car.

Meanwhile American practice with its long experience of steel cars has realised that enormous sums have been expended annually in the upkeep of such vehicles, chiefly in combating corrosion. This matter has assumed such importance that several years ago a high executive engineer of the Pennsylvania R.R. gave evidence before a Committee of the U.S. Congress in support of the Muscle Shoals project, and submitted as his reason that this development would cheapen the cost of aluminium and render possible the construction of freight cars from aluminium-manganese alloy and thereby practically eliminate the heavy annual corrosion charges.

In consequence, it is not surprising to observe a growing tendency to employ aluminium and aluminium alloys in modern car construction for such purposes as side plating, roofs, doors, interior parts, etc., and vehicles are now in operation which make use of such materials for framing, underframes and bogie truck frames as well. For over a decade the Pennsylvania system has had more than two thousand cars in service having cast aluminium doors, and recently the same railroad has put into service on its Paoli electric lines steel frame cars having duralumin side panels and roofs, as well as other cast and fabricated aluminium alloy parts to the extent of nine tons per car, which represents a saving of at least double this weight. Further, the latest dining car stock is equipped exclusively with aluminium furniture because of its proven increased durability.

There seems to be no sufficient reason why British and other railways should not profit by the experience of American roads and start investigation of non-ferrous car construction without first going through the all-steel phase of the art. Of course, it may be contended that with the commercialisation of stainless steel, there is no necessity for resorting to non-ferrous construction, but although something may be achieved in the reduction of corrosion charges absolutely none of the contributary advantages of aluminium can be realised by the use of the former material. The most important of these, perhaps, is that of lightness, which is of greater consequences in electric railway operation where rapid acceleration, deceleration and heavy power draughts are the rule. Another case where this feature will be of utility is in the case of steam operation where limitation of axle loads, clearances or draw-bar strength prevent the use of larger locomotives. In either of these cases, reduced dead weight will mean increased ability for handling paying loads and possibly, also, increased useful life of existing motive power units. In connection with the former condition, it was stated at the time of the inauguration of the electrified suburban lines of the Illinois Central R.R. at Chicago, that the employment of aluminium in their new cars only for roofs, upperworks and doors, would result in a reduction of 250 dollars in the annual power bill of each car operated.

On the Manchester-Bury electric lines of the L.M. and S. Railway, steel frame aluminium sheathed cars has been used exclusively for over ten years while similarly equipped wood frame cars have been in use on the Southport lines for a much longer page 39 period. Since the merger of the L and Y. Railway into the West Coast System, the practice has been continued, and also has been extended to main line stock. Apart from the usual asvantages of such censtruction, one which was not foreseen at the inception was that, when being shopped, these cars could be put through at a considerably greater rate, thereby practically doubling the shop capacity and reducing charges. This accrued chiefly from the facility with which paint solvents could be used when removing old paint, and also because a much reduced quantity of paint was required to obtain the same degree of finish as in the case of either wood or steel panelled cars.

While perhaps not of direct concern to the railway man, the tramcar shown in Fig. 1 is of considerable instruction as a pointer towards possible developments in his own field. This vehicle actually is an “all-aluminium” car, for not only are the sheating, interior fittings, ventilators, etc., of aluminium, but also the whole superstructure, underframe, and bogie truck frames. The underframe is built up from aluminium alloy structural shapes and forgings which yield tensiles from 60,000 to 85,000lb per square inch, depending upon the alloy used, while the truck frames and body framing make use of similar materials. These cars, compared with previous all-steel cars of identical design and dimensions showed a total weight reduction, including electrical equipment, of from 41,140lb. to 30,300lbs., or about 26 per cent. This was obtained by an increased construction cost of 10 per cent. In extended operation, power consumption has been reduced by 20 per cent., and the Cleveland Railway Co. considers this to be a sufficient justification for the adoption of the all-aluminium car as standard. These cars have shown an actual cash saving per annum in power alone of 500 dollars per car, and it was predicted at the last A.E.R.A. Convention that the widespread adoption of such vehicles would follow. In average cities, operating between 300 and 1000 cars, this power saving alone would increase earnings from 150,000 dollars to 500,000 dollars per annum.

More recently some all-aluminium multipleunits cars have been built for the Berlin local railways, which are now in process of electrification, and it is reasonable to suppose that the satisfactory results obtained at Cleveland will be repeated on this system.

The construction is not confined to railway vehicles as will be seen by reference to Fig. 2, which shows a small bus constructed in duralumin in England, and it may be remarked in passing that the new six-wheel top-covered London bus has a body made entirely from the same material.

From the foregoing brief review, it will be seen that aluminium is definitely taking a place in the transportation field, a sphere heretofore considered to be peculiarly for wood, ferrous and cuprous metals. It is not realised generally that there are opportunities for the employment of aluminium high tensile alloys for certain locomotive parts, and ordinary alloys in cast or fabricated forms often may be used with advantage to replace brass and other cuprous materials in general railway and engineering construction work. It appears safe to say that although the progress of aluminium during the three and one-half decades of its commercial existence has been rapid, its field of application will be broadened to a much greater degree in the next ten years.