17§ M«. WILLIAM FAIBBAIRN ON THE 



The Accrington incline is composed of three gradients 

 and five curves, as follows :— 



On this incline the curves are — 



1. Bottom straight for 21 chains. 



2. Curve to the right, 50 chains radius, for ... 19^ „ 



3. Curve to the left, 50 chains radius, for 14 „ 



4. Curve to the left, 56 chains radius, for 41 „ 



5. Straight for 33 ,, 



6. Curve to the right, 40 chains radius, for ... 8 „ 



7. Curve to the right, 54 chains radius, for ... 23^ „ 



ToUl 160 = 2 milra. 



On a careful examination of the returns as indicated in 

 the above summary, very different results will be found to 

 those contained in the preceding Tables, as derived from 

 the goods trains. There the duty performed by the leading 

 and assistant engines bears nearly a direct comparison with 

 the single engine, both with respect to the weight carried and 

 the speed attained. In passenger trains, where the load is 

 light, and more within the power of the engine, the superi- 

 ority of the single engine is strikingly apparent, and will not 

 bear a comparison. It appears, when the load does not ex- 

 ceed 20 tons, the assistant engine is of little value ; and it is 

 only in monster trains, or in cases where the load exceeds 

 the maximum power of the engine, that the assistant 

 engine proves advantageous. In the experiments herein 

 recorded, we have for the mean of three trips a load of 23-^ 

 tons, drawn up an incline of nearly 1 in 40, by a single 

 engine, whose powers are represented by 353, at the rate 

 of 19*3 miles an hour; whereas, on a mean of 9 trips, with 

 two engines, where the maximum power is represented by 

 722-6, a load of 28*4 tons (little more than the other) is 

 carried the same distance, and to the same elevation, at the 

 rate of only 18*89, rather under 19 miles an hour. 



The result of these experiments is obvious. First ; that in 

 heavy trains, where the load approximates or exceeds the 



