On Railway Gradients. 



113 



result, I shall give a summary, deduced from experiments made 

 by a single engine, and by a leading and assisting engine, 

 combined : — 



GOODS 



TRAINS. 





Single Engine. 



Two Engines. 



No. of 

 Trips. 



Mean Load 

 in Tons. 



Speed. 

 Miles pr hour. 



No. of 

 Trips. 



Mean Load 

 in Tons. 



Speed. 

 Miles pr hour. 



196 



57.1 



5.73 



74 



117.2 



5.49 



The weight of the heaviest engine used was 26.25 tons, 

 tender 16.75 tons, 18 inches cylinder, two feet stroke, six five 

 feet wheels, all coupled. 



PASSENGER TRAINS. 



Single Engine. 



Two Engines. 



No. of 

 Trips. 



Mean Load 

 in Tons. 



Speed in 

 Miles pr hour. 



No. of 

 Trips. 



Mean Load 

 in Tons. 



Speed in 

 Miles pr hour. 



24 



23.26 



19.33 



99 



28.41 



18.89 



The heaviest leading engine used weighed 18.5 tons ; tender, 

 12.5 tons ; 15 inches cylinder ; 1 ft. 8 inches stroke ; 6.5-feet 

 6 inch wheels, four coupled 



The average weight of the assisting engine was 21.5 tons. 



The conclusions deducible from these experiments are, that, 

 where heavy trains have to be moved at low speeds, two engines 

 will perform a duty equal to that undertaken by one engine 

 with half the load ; but in the case of passenger trains, where 

 the power of one engine is equal to the efficient propulsion of 

 the train at a speed of (say) 20 miles per hour, the use of two 

 engines is rather disadvantageous than otherwise. 



This is conclusive evidence that the working of severe Gra- 

 dients has frequently been but imperfectly considered. The 

 following severe Gradients on British, European, and American 



