Speed, Comfort and Safety.

What is the highest speed at which a single rail-car can run with safety on a well-laid track? (asks the “Railway Gazette”). This question must have been asked whenever it was realised that practically all the diesel or petrol-engined units that have run at over 90 m.p.h. have been of the articulated type with two, three or six vehicles. Yet the highest speed recorded, 143 m.p.h., was made by the Krackenberg car, a six-wheeler without even the supposed advantage of the double-bogie layout. From there we pass down to the 119.5 m.p.h. of the Etat Bugatti, the only other single unit vehicle which has appreciably exceeded the hundred mark. It has been reported that this vehicle has since attained 125 m.p.h. on the same stretch, viz., between Paris and Le Mans. The Burlington Zephyr. U.P.R.R., City of Portland, and the Flying Hamburger, with respective maxima of 112, 112, and 110 m.p.h., are all articulated trains, and we must go down to the 100.2 m.p.h. of the Breda-A.E.C. car on the Italian State Railways before we come to another single-unit running alone. Of the range of articulated trains, the Nord triple-car units have run at 98 m.p.h., the Dutch triple-car sets at 90 m.p.h., the Belgian twin-unit at 88 m.p.h.; both the Flying Yankee on the Boston and Maine railroad and the Comet on the New York, New Haven and Hartford railroad have exceeded the hundred mark. Apparently the Danish “Lyntog” Diesel trains are limited by permanent-way conditions, for so far as we are aware they have not exceeded 85 m.p.h. The top speed attained with safety is not as a rule a matter of careful streamlining and the provision of adequate power; it is more particularly dependent upon the suspension, and definite knowledge on this subject for super-speed railway vehicles is not yet in an advanced state. Moreover, the top speed which may be attained without derailment is by no means the maximum which can be attained in conjunction with comfort.