MINORITY REPORT ON ECONOMICS OF RAILWAY

LOCATION.

To the Members of the American Railway Engineering Association:

The undersigned cannot agree with that portion of the report concerning the foot-ton method of calculating the fuel consumed referred to in Conclusions 12 and 13 (Bulletin 173).

The fuel consumed per indicated horsepower of work varies from about 7.7 lbs. with locomotives working full stroke to about 4.75 lbs. at its maximum efficiency at about 3.6 times the speed that it can maintain full cutoff.

The indicated horsepower at maximum efficiency is also over 60 per cent. more than at full cutoff.

With these two facts in view it appears that the amount of coal per 1,000 foot-tons will vary widely. Another factor, however, enters into the work done by the locomotive, and it may or may not be a considerable percentage of the total work. This factor is the power exerted in accelerating trains which will vary from less than 1 per cent. of the total power used on heavy gradients to more than 20 per cent, on level grades, depending on the distance between stops.

No notice is taken of this factor in the method set down in the report of the Committee, and yet it is liable to add considerably to the total foot-pounds.

In the following table the simplest cases are taken, of three stations ten miles apart on a tangent.

The train starting at one end of the line and working at its maximum power on level and ascending grades, but stopping at both the other stations, using brakes for the last 1,500 ft. of stop. There is one exception to this: on descending grades, the train accelerates by gravity to 35 M.P.H., then is held at this speed to the foot of the grade, and then drifts to within 1,500 ft. of station where brakes are applied.

The four separate cases are as follows:

(1) A level grade the entire distance.

(2) A level grade for one-half mile.

9 miles of ascending 0.4 per cent. grade.

A level grade for one mile with station stop in it.

9 miles of descending 0.4 per cent. grade.

One-half mile of level grade.

(3) Same as (2), except 0.7 per cent. grades are used instead

(4)

of 0.4 per cent.

Same as (2), except 1.0 per cent. grades are used instead of 0.4 per cent.

There is no question which of the above would be the most economical to operate. The whole idea of using the above is to illustrate the fallacy of using the foot-ton method in calculating fuel.

As tables covering the distances used in acceleration and retardation on the various gradients had been worked out for a consolidation locomotive in the article "Locomotive Fuel Consumption and the Speed Diagram," pp. 3 to 20, Part 2, Vol. 14, American Railway Engineering Association Proceedings, the same engine and train are considered here.

The first part of the table shows the time engine is working and time drifting, estimated very quickly with the use of the tables.

The coal used is estimated on the average fired by hand in a freight locomotive per hour while engine is working. Also the average used while drifting as per table, page 6, of above article.

This method of getting the fuel consumed has been tested in many cases on divisions varying from those of a water grade to those having 1.0 per cent. gradients, and the calculated fuel agreed quite closely to the actual fuel used.

Next appears the foot-tons resistance on level and ascending grades, according to the method proposed by the Committee.

The balance of the table is self-explanatory.

As the same stops are made in each case, the fuel used while locomotive is standing need not be considered.

Above equivalent to H.P. of work...... 651.53

Pounds coal per 1,000 foot-tons work... 6.20

5.88

6.57

8.03

ing

Foot-tons grade resistance.

Total foot-tons resistance......487,634 537,492 748,339 959,185

758.44 649.77 521.03

.487,634 256,364 256,364 256,364 281,128 491,975 702,821

By the table we find that the coal used per 1,000 foot-tons varies from 6.20 to 8.03 lbs. Taking the difference in foot-tons and the coal used for the various lines, we can get still wider results as follows:

It is rightly claimed that we cannot be exact, owing to variables that enter into consideration of the subject, but we can be more exact than the foot-ton method of calculating the coal, as there is absolutely nothing to use as a base per 1,000 foot-tons. The above shows that you can figure it from various angles and get a maximum of over six times the minimum. The simplest method and the one of greatest accuracy is by calculating the time of engine working and the time drifting and multiply this by the fuel consumed per hour working and drifting.

In the second paragraph of Conclusion 9 of this year's report it is proposed to plat a speed diagram of the line. To do this the economical thing to do is work up tables, such as are shown on pp. 16 to 19 of the article on "Fuel Consumption," for the assumed train on the maximum grade. This can be worked up in a diagram for convenience of fieldmen. In order to expedite the work, time diagrams can be worked up covering the time consumed on the various grades in passing from one speed to another. With the speed diagram, however, it is simple to calculate the time.

Furnish the Locating Engineer a set of the tables or a diagram cov ering the information contained therein, and in comparing two alternate locations it is a small job to get very approximately the difference in coal used. He cannot get it by the foot-ton method except by chance. As has

been shown, it is not a question of getting the average of minor variables, but trying to get an average of something which may vary over 500 per cent., depending on the way the thing is figured. There is no average.

With the above points in view the undersigned recommend the following changes in the conclusions as shown in the report:

Insert in Conclusion 12, after the first paragraph:

"The above method must be understood to not take into account the resistance due to accelerating trains. This may or may not be a considerable part of the total resistance, depending on the rate of grades and the distance between stops."

The next to the last sentence in Conclusion 12 should be changed to read:

"In comparing different locations, the resistance under average conditions should be used."

Conclusion 13, cut out the last sentence and insert:

"It should be understood that the first method does not give information as to actual fuel consumed.

Respectfully submitted,

A. K. SHURTLEFF,

MAURICE COBURN,
J. DEN. MACOMB, JR.

To the Members of the American Railway Engineering Association: The subjects assigned by the Board of Direction for investigation and report are as follows:

(a) Make critical examination of the subject-matter in the Manual, and submit definite recommendations for changes.

(1) Recommend standard rail sections.

(2) Continue investigations of rail failures and deduce conclusions therefrom.

(3) Continue special investigation of rails.

(4) Present specifications for material in rail joints.

Meetings were held during the year as follows: Atlantic City, June 30; present, 15. Chicago, October 13; present, 15. New York, December 4; present, 20. Buffalo, January 5; present, 15.

Sub-Committee meetings were held as follows:

Sub-Committee "A": Pittsburgh, September 4; present, 5. Chicago, November 10; present, 4.

New York,

Sub-Committee "B": New York, January 15; present, 7. New York, August 21; present, 8. Chicago, November 20; present, 8. Buffalo, January 4; present, 7.

December 4; present,

-.

The subjects assigned will be considered in order as assigned.

(1) STANDARD RAIL SECTIONS.

This subject was assigned to Sub-Committee "B," R. Trimble, Chairman, and as a result of their investigations and the action of your main Committee, the following report is submitted:

"The present A.R.A. sections 'A' and 'B' were adopted in 1908. We were instructed by the American Railway Association to study these sections, and submit a single type for standard.