187. Item 3. Renewals Of Ties

The extra wear of ties on grades is considered by Wellington as being somewhat compensated by the improved drainage of the roadbed which is found on a track which is not quite level, the better drainage tending to increase the life of the ties. On this account Wellington made an allowance of 5% increase for class C and no increase for the other classes.

188. Item 4. Renewals Of Rails

Observations of rail wear on heavy grades show that the wear is much greater than on level tangents. The heavy grades of a mountain division of a road are usually operated with shorter trains or with the help of pusher-engines, and in such cases the proportion of engine tonnage to the total is much greater than on minor grades, and, since the engine has much greater effect on rail wear than an equal total tonnage of cars, partly on account of the use of sand and excess of engine tonnage, the grade will have a marked effect on rail wear. But such circumstances apply to ruling grades and very little, if at all, to minor grades. The use of sand on up grades and the possible skidding of wheels on down grades will wear the rails considerably. Even the slipping of the drivers, although sand is not used, will wear the rails. Wellington allows 10% increase for class C and 5% for class B.

189. Item 6. Roadway And Track

It is very plain that a large proportion of the subitems are absolutely unaffected by minor grades. In fact it is a little difficult to ascribe any definite increase to any subitem. Rail wear is somewhat increased and this will have some effect in increasing the track-work. Wellington allows 5% increase as a liberal estimate for class C, and makes no allowance for classes A and B. Items 2 and 5 are allowed the same.

190. Maintenance Of Equipment

It is evident that none of these items will be affected except repairs and renewals and depreciation of road engines and cars. The chief effect on these items will evidently be the repairs and renewals of wheels and brake-shoes. The draw-bars are also apt to suffer somewhat, on account of the increased work which they are required to do. It would appear that the extra stress on the locomotive mechanism will have some effect on locomotive repairs, and the expense of boiler repairs may be increased on account of the greater range of the demands on it. It would seem as if such effects would be quite large, but if the records of engine and car repairs on mountain divisions and on comparatively level divisions of the same road are examined and compared, there appears to be no such difference as might be expected. Considering the very small proportion of locomotive and car repairs which are affected at all by such circumstances, and also the very small percentage of these subitems which can be said to be affected by these two classes of minor grades, Wellington allows only an increase of 4% on each of these four items for class C and 1% for class B. This is reasonable in view of the 19% allowed for grades and curvature (Table XXIII) of which 13% was estimated for curves, leaving only 6% for all grades.

191. Conducting Transportation

It is apparent that the only items in conducting transportation which will be affected will be the four items of engine-supplies (82 to 85). As in Chapter XIII (Curvature. 159. General Objections To Curvature), since we are considering that the resistance is doubled, we will assume that there is an increase of 44% as the cost of the extra fuel used in climbing 26.4 feet, but the total cost of both rise and fall is to be considered. In class B, although steam is shut off; fuel will be wasted by mere radiation. On this account we will add 5%. For class C we must allow in addition the energy spent in applying the brakes, which we may assume as 5% more. Therefore we will allow 49% for class B and 54% for class C The other small items of supplies, 83, 84, and 85, will be estimated similarly. The items of general expense are evidently unaffected.

192. Estimate Of Cost Of One Foot Of Change Of Elevation

Collecting the above estimates we have Table XXVI, showing that the percentage of increase for operating grades of classes B or C will be 5.85% and 7.71% respectively on the average cost of a train-mile. On the basis of an average cost of $1.50 per train-mile, the additional cost for the 26.4 feet of rise and fall in one mile would be 8.77 c. and 11.56 c, or 0.33 c. and 0.44 c. per foot for the two classes respectively. For each train per day each way per year the value per foot of difference of elevation is For class B: 2 x 365 x $0.0033 = $2.41. For class C: 2 x 365 x $0.0044 = $3.21.

In assuming the number of trains running over a given grade the character of the trains must be carefully considered, since it will quite frequently happen that a hump or sag must be classified as belonging to class C, so far as heavy freight-trains are concerned, but may be classified as B or perhaps even A, the harmless class, for passenger-trains. The above values should likewise be modified when the trains are run only 313 days per year instead of 365.

Table XXVI. Effect On Operating Expenses Of 26.4 Feet Of Rise And Fall

Item number.

Item (abbreviated).

Normal average.

Class B.

Class C.

Per cent affected.

Cost per mile per cent.

Per cent affected.

Cost per mile, per cent.

2

Ballast...................

0.50

0

0

5

0.02

3

Ties.....................

3.10

0

0

5

0.15

4

Rails....................

0.92

5

0.05

10

0.09

5

Other track material.......

1.13

0

0

5

0.06

6

Roadway and track........

7.53

0

0

5

0.38

(All other items)..........

6.91

0

0

0

0

Maintenance of way.......

20.09

• • • • •

0.05

• • • • •

0.70

25-27,

Locomotives, passenger cars, freight-cars and work-cars .

21.24

1

0.21

4

0.85

31-36,

43-45

(All other items)..........

1.50

0

0

0

0

Maintenance of equipment..

22.74

0.21

0.85

53-60

Traffic...................

3.08

0

0

0

0

82-85

Fuel and other supplies for road engines.............

11.41

49

5.59

54

6.16

(All other items) ...............

39.03

0

0

0

0

Transportation ...................

50.44

5.59

6.16

106-116

General expenses..........

3.65

0

0

0

0

100.00

5.85

7.71