Transactions of the American Society of Civil Engineers, Vol. LXX, Dec. 1910 | Page 4

Louisiana & Texas |Newell Tilton, Asst. Supt.
|1880 2| " |Long Island |S. Spencer, Gen. Supt. |1878 3| " |Atchison,
Topeka & Santa Fe |J. D. Burr, Asst. Engr. |1879 4| " |Chillan &
Talcahuana |J. E. Martin, Local Supt. |1879 5| " |Chicago, Burlington &
Quincy|H. B. Stone |1880 6| " |Chicago, Burlington & Quincy| " |1880
7| " |Chicago, Burlington & Quincy| " |1880 8| " |St. Louis & San
Francisco |C. W. Rogers, Gen. Mgr. |1879 9|Pa. R.R |Cumberland
Valley. | |1910 10| | | |1910 11|Baldwin.|Atchison, Topeka & Santa Fe |J.
D. Burr, Asst. Engr. |1879 12| " |Missouri Pacific |John Hewitt, Supt. M.
P. |1880 13| " |Western Maryland |D. Holtz, M. of Mach'y. |1878 14| "
|Atchison, Topeka & Santa Fe |J. D. Burr, Asst. Engr. |1879 15| "
|Virginian Ry. | |1910 16| |Pennsylvania | |1910 17|Baldwin.|Virginian
Ry. | |1910 18| " |Lehigh Valley, Wyoming Div. |A. Mitchell, Div. Supt.
|1871 19| " |Great Northern |Grafton Greenough. |1908 20| " |Great
Northern |Grafton Greenough. |1908 21| " |Baltimore & Ohio |F. E.
Blaser, Div. Supt. |1910 22| " |Central of N. J. |W. W. Stearns,
Asst.Gen.Supt.|1880 23| " |Great Northern |Grafton Greenough. |1908
24| " |Great Northern |Grafton Greenough. |1906
===================================================
=========================
===================================================
=========================== |Source of Data. |Remarks.
--+-----------------------------------------+---------------------------------
1|Baldwin Catalogue, 1881, p. 134 | 2| " " 1881, " 72 |10 miles per hour.
3| " " 1881, " 115 | 8 " " " | | Stops and starts on grade. 4| " " 1881, " 100
| 5| " " 1881, " 116 |Stops and starts at any point | | on grade. 6| " " 1881,
" 116 | 7| " " 1881, " 116 | 8| " " 1881, " 87 | 9| | 10|Trautwine's Pocket
Book, Ed. 1882, p. 412|Empty cars; many curves and | | reversions.
11|Baldwin Catalogue, 1881, p. 114 | 12| " " 1881, " 112 | 13| " " 1881,
" 86 |12 miles per hour. 14| " " 1881, " 114 | 8 " " " 15|Engineering
News, Jan. 13, 1910. | 16|Trautwine's Pocket Book, Ed. 1882, p. 412|
17|Engineering News, Jan. 13, 1910. |Road locomotive and helper.

18|Baldwin Catalogue, 1881, p. 112 | 19|Baldwin Loco. Wks. Record,
No. 65, p. 29| 20|Baldwin Loco. Wks. Record, No. 65, p. 29| 21| |Very
crooked line. Uncompensated. 22|Baldwin Catalogue, 1881, p. 113 |
23|Baldwin Loco. Wks. Record, No. 65, p. 29| 24|Baldwin Loco. Wks.
Record, No. 65, p. 29|
===================================================
===========================
In proportioning grade resistance for any line, therefore, a locomotive
may be counted on to utilize 24.3% of the weight on the drivers for a
distance of 5 miles on a 0.002 grade without any assistance from
momentum, and, in the event of an unexpected stop, should be able, as
soon as a full head of steam is built up, to start the train and carry it
over the grade. This is probably a maximum, considering the condition
of the equipment of this Virginian Railway, as previously mentioned.
Treating Item 14 in the same way, a distance of 2,310 ft. is accounted
for by momentum, leaving, say, 5.5 miles for the steam, or the length of
a 0.02 grade on which a locomotive may be loaded on a basis of
tractive power equal to 24.2% of the weight on the drivers.
From these figures it may be concluded that on lines having grades
from 12 to 15 or more miles in length, grades of 3 to 5 miles in length
may be inserted having rates 50% in excess of that of the long grades,
without decreasing the capacity of the line. This statement, of course, is
general in its bearings, each case being subject to its especial
limitations, and subject to detailed calculations.
It may be noted that the velocity of 60 ft. per sec., assumed at the foot
of the grade, is probably higher than should be expected in practice; it
insures, on the other hand, that quite enough has been allowed for
momentum, and that the results are conservative.
Arguments like the foregoing are always more or less treacherous;
being based on statistics, they are naturally subject to material
modifications in the presence of a larger array of data, therefore,
material assistance in reaching practical conclusions can be given by
the presentation of additional data.

DISCUSSION
C. D. PURDON, M. AM. SOC. C. E. (by letter).--Some years ago the
writer, in making studies for grade revision, found that the tractive
power of a locomotive up grade becomes less as the length of the grade
increases, and in some unknown proportion. This was a practical
confirmation of the saying of locomotive engineers, that the engine
"got tired" on long grades. On a well-known Western railroad, with
which the writer is familiar, experiments were made for the purpose