turning the end of Blue mountain, thence seeking the low depression
at Cowan's gap in Tuscarora, would be too circuitous to compare
favorably with the bolder line from Shippensburg, already described.
But that line would encounter engineering difficulties of the
most formidable character; leaving out of view its objectionable
gradients, and considering it in reference to its cost, and the local
accommodations it would extend to a large portion of the State--at
present in a great measure deprived of the advantages of the State
improvements--(the strongest argument in favor of the route), it
will be found that equal accommodations could be extended to that
region with a _less_ expenditure of _capital_ by placing the main
stem of the road on the Juniata, and running a branch along one of
the comparatively level valleys that lie between most of the parallel
mountain ranges that we pass.
The facilities that railroads offer for extending their benefits to
remote districts by means of lateral lines constitute one of their
chief advantages over canals, and should prevent the error, too
frequently committed in locating leading routes, of turning from a
direct course to accommodate local interests to the injury of the
great object intended to be accomplished.
Other modifications of the Juniata route have been suggested, and
their merits fully considered, but, upon examination, all of them
tended to confirm our preference in favor of the river line.
These conclusions were communicated to the Board, and the general
route recommended having been adopted by them, I proceeded at once
to make arrangements to have the line surveyed throughout. For this
purpose three additional corps of engineers were organized--one for
Mr. Miller's division, under the immediate direction of Mr. G. W.
Leuffer, to operate on the summit and western slope of the mountain,
and two upon Mr. Foster's, the first of which was placed in charge
of Edward Tilghman, Esq., to whom was assigned the district between
Lewistown and the confluence of the Raystown branch and main Juniata
rivers.
The other corps was given in charge to S. W. Mifflin, Esq., a
gentleman of well-known professional skill and experience, to whom
we committed the surveys of the region from the Raystown branch to
the summit of the Alleghenies, embracing the most important and
difficult district upon the whole route to Pittsburg.
These parties did not take the field until the close of July, but
they prosecuted their examinations with so much energy and success
that we were enabled to determine the general line of the eastern
division in season to place the most difficult points upon it under
contract in November of last year.
While these arrangements were in progress, the parties previously
in the field were actively engaged in examining the country between
Harrisburg and Lewistown.
At the instance of a number of gentlemen from Perry county, a
line was tried up Little Juniata creek, leaving the Susquehanna
at Petersburg, thence near Bloomfield and along Sherman's valley
to Concord gap, where it passed the Tuscarora mountain, thence it
followed Tuscarora valley to Shade creek, and down that stream to
Augwick creek, along the valley of which it was carried to Drake's
ferry on the Juniata. The advantage promised for this route was a
considerable saving of distance. The result, however, demonstrated
that not only would we have had to encounter gradients running up
as high as sixty feet per mile, but the length of the line would be
increased four miles by its adoption. It was consequently abandoned.
After a careful examination of the country bordering on the
Susquehanna and Juniata rivers, a line has been located as far up as
Huntingdon, which is believed to be the best that can be obtained.
If the valleys of these streams had not been preoccupied by other
improvements, a route would have been selected differing somewhat in
its details from that adopted. Even for the short distance that we
are brought into close proximity with them, the cost of the grading
of the Road has been greatly enhanced by the confined ground we have
been forced upon.
The located line commences at the Harrisburg and Lancaster Railroad
depot; thence, passing through Harrisburg, it follows the sloping
ground between the canal and the capitol ridge four miles, when it
crosses the canal and, touching the point of Blue mountain, recrosses
and passes to the west side of the Susquehanna river by a bridge
3,660 feet in length, and 44 feet above low water at grade line,
which enables us to place the road on the top of the bridge. Thence
we pursue this bank of the river through the villages of Duncannon
and Petersburg to the Juniata, along the southern side of which it is
continued through Newport and Perrysville to a point a short distance
above Lewistown. Here the line crosses to the north side of the
river, and within a short distance recrosses, to save nearly a mile
of road, and one hundred and eighty degrees of curvature, together
with some difficult ground along the bluff shores on the south side
of the stream.
After regaining the southern side we follow the river slopes,
over favorable ground, to Mr. Harvey's, about seven miles above
Waynesburg, where the line again crosses to the north side, and
passing back of Newton Hamilton, cuts through the neck of land in the
great bend of that stream, 40 feet in depth at the summit and 3,100
feet in length at grade. Descending along the eastern slope of the
river, we once more cross it at Shaeffer's aqueduct, and continue
upon its southwestern bank through Jack's narrows, without meeting
any serious difficulties, and finally pass to its north side, along
which it is continued through Huntingdon to the Little Juniata, above
Petersburg. Above Huntingdon, a preliminary location has been carried
up the Little Juniata to Logan's narrows, at which point this stream
divides Bald Eagle and Brush mountains in its passage from Tuckahoe
valley.
Along the Little Juniata, from Dorsey's forge to the Narrows, the
line encounters much difficult ground, owing to the circuitous
character of the stream, and the high hills and mountains which bound
its course. To obtain a route with easy curves we are forced, within
this distance, to tunnel the point of Tussey's mountain, and to
cross the river twelve times. To follow the line recommended by Mr.
Schlatter through this region curves of 400 feet radius would have
had to be resorted to, which I deem wholly inadmissible upon a road
of the importance of that you have in view.
At Logan's Narrows we reach the valley that skirts the whole eastern
base of the Allegheny mountains. Here it becomes necessary to
determine the plan to be adopted to overcome the great barrier that
separates us from the West. If it is to be surmounted by a road, with
the gradients of the western division, the ascent must commence at
this point, and gradually wind its way to the summit, by an almost
continuous gradient, along the declivities of the mountains for
nearly thirty-two miles, crossing the several streams that issue
from it, by high bridges, and cutting through or tunneling their
dividing summits.
Mr. Schlatter, in his Report to the Canal Commissioners, estimates
the cost of grading the road, on this ascent, at $1,496,146, which I
consider too low for a line with the gradient he adopted, but with
the increased maximum grade found necessary on the western division,
and a somewhat lengthened line, it would probably prove sufficient.
Upon my first reconnoissance of this portion of the country it
occurred to me that its peculiar topographical features were lost
sight of in the adoption of this plan of ascent, which seemed to look
to the single object of obtaining a line with a particular gradient,
without regard to the magnitude of the obstacles to be overcome to
procure it; while, by pursuing a course from the Narrows, nearly in
a direct line to Sugar Run gap (which we shall hereafter show is
the best point to cross the mountain), the line would pass through
a beautiful valley over comparatively favorable ground, gradually
gaining elevation through its whole course, without exceeding the
maximum inclination required on the line below, until it reaches the
summit of the valley at Robinson's, a distance of fifteen miles. At
this point we attain an elevation of 1,174 feet above tide, leaving
but 980 feet to be overcome to reach the height found most suitable
for passing the mountain, which is attained by a continuous gradient
of 80 feet per mile, encountering no _very_ formidable difficulties.
A resort to a gradient of 80 or more feet per mile is by no means an
unusual expedient on leading railroads.
Upon the Western Railroad, in Massachusetts, their maximum gradient
is 83½ feet per mile. On the Baltimore & Ohio Railroad they now
have, between the waters of the Patapsco and Potomac, on each side
of Parr's ridge, gradients of 82 feet per mile, and from the greater
elevation of the Allegheny mountains at the place they must cross, it
is to be presumed that their gradients at that point will still be
increased to a higher rate.
Many other instances might be cited, some running up to 120 feet per
mile, but it seems unnecessary to extend the list. Theoretically,
the power necessary to overcome a given height is the same at all
inclinations of the plane of ascent, but in practice, it is to some
extent dependent upon the kind of power to be applied.
In the case under consideration, the locomotive steam engine will be
the medium used, where the power is carried with the train, and forms
part of the load to be moved, consequently, the cost of power on a
plane ascending 80 feet per mile is greater than upon one of a more
moderate inclination of equal height, by the difference between the
gravity of the engines required to carry the same load on both planes.
As a general principle this would be true when the lengths of the
roads to overcome the same height are equal, and it is necessary to
carry the locomotives, required for the high gradient, over the same
distance that they must run upon the low gradient.
But in one of these cases the maximum gradient due to the line below
Logan's Narrows is carried to within 12¼ miles of the summit of the
mountain--requiring extra power for that distance only--and in the
other it ends 32 miles from it.
To explain more fully the relative value of the maximum gradients
used on the different divisions of our Road, I have prepared the
following table:
Table headings:
Col A: Division of Road.
Col B: Maximum Gradient, ascending westwardly, per mile.
Col C: Maximum Gradient, ascending eastwardly, per mile.
Col D: Gross load of a 20 ton freight locomotive,
exclusive of engine, and a tender of 10 tons. Friction
8½ lbs. per T. Adhesion ½.
Col E: Load of merchandise for a 20 ton freight engine,
the cars being estimated at 4/10ths of their
weight and load.
Col F: Relative load of locomotive on each gradient,
level being unit.
Col G: Number of locomotives of equal power necessary to carry
the same load up each gradient.
====================+========+========+=======+=======+=======+=====
A | B | C | D | E | F | G
--------------------+--------+--------+-------+-------+-------+-----
From Harrisburg | { 16 | | 346.6 | 207.9 | 0.534 | 1.87
to Lewistown, | { | | | | |
60-7/10 miles | { | 8 | 454.3 | 272.6 | 0.697 | 1.42
--------------------+--------+--------+-------+-------+-------+-----
From Lewistown | { | | | | |
to foot of | { 21 | | 300.7 | 180.4 | 0.464 | 2.15
Allegheny Mts., | { | 10½ | 414.6 | 248.8 | 0.640 | 1.56
72 miles | { | | | | |
--------------------+--------+--------+-------+-------+-------+-----
From foot to summit | { | | | | |
of Allegheny | { 80 | | 105.6 | 63.4 | 0.163 | 6.13
Mountains, | { | Level | 648.0 | 388.8 | 1.000 | 1.00
12-3/10 miles | { | | | | |
--------------------+--------+--------|-------+-------+-------+-----
From summit to | { 47 | | 172.4 | 103.4 | 0.266 | 3.76
Pittsburg, 106 | { 50 | 50 | 163.7 | 98.2 | 0.252 | 3.95
miles | { 52.8 | 52.8 | 156.2 | 93.7 | 0.241 | 4.14
--------------------+--------+----------------+-------+-------------
It will be perceived from the foregoing table that three locomotives
are fully sufficient to transport the same load up the 80 feet
gradient that two will carry on the gradient of the western division,
and one on the eastern; hence the practical working of the road on
the two methods of ascent would be to run two locomotives with the
load brought from below from Logan's Narrows to the summit, say 31¾
miles, up the 50 feet gradient; while, on the other, the same engine
that brought the load from Harrisburg would continue with it to
Robinson's (15 miles), where it would accompany the two destined for
Pittsburg to the summit of the mountain and return.
In the first case the engines together will have traveled 63½ miles,
and, in the other, the three 51¾, leaving a difference in distance
to be traveled by the moving power due to each full train, from the
east, 11¾ miles in favor of the 80 feet gradient.
In practice it will therefore be seen--chiefly on account of
the actual distance saved--that transportation can be afforded
cheaper, in this case, on the 80 feet gradient than on the 50,
without bringing into the estimate the interest on $841,000 that
the latter would cost to obtain it more than the former. Under
these circumstances we did not hesitate when the choice of routes
was reduced to a selection between these two methods of overcoming
the mountain, to decide in favor of the line by Robinson's, which
has the additional advantage of bringing us within 6-1/3 miles of
Hollidaysburg, where a connection may be made with the Allegheny
Portage by a branch line, passing over favorable ground.
The distance from Harrisburg to Robinson's summit is 132-2/3 miles;
upon the whole of this line, the only extraordinary impediments
to the easy graduation of the road bed are the bridge over the
Susquehanna, a deep and long cut near Newton Hamilton, and a tunnel
1,200 feet in length through a point of Tussey's mountain, and in
this distance the maximum ascending gradient to Lewistown is 16 feet
per mile, and descending 8 feet. Thence, to Robinson's summit, they
are increased to 21 feet ascending, and 10-1/8 feet descending.
The descending gradients are generally so short that they will not be
found, in practice, to decrease the load going east much below what
is due to a fair _working_ load for a locomotive on a level.
The maximum ascending gradient above Lewistown is determined by the
deep cut near Newton Hamilton. The ascent of the Little Juniata
seems, however, to require--to obtain an economical line--the use
of this inclination, without much intermission, from Dorsey's forge
to Robinson's summit. Below Lewistown the gradients are fixed to
accommodate the increased trade that would fall upon the line between
that place and Harrisburg, without increasing the number of trains.
These low gradients insure to us the important advantages of a single
pair of drivers for the passenger engines, upon the eastern division,
and, with these rates of inclination, we are enabled to make the line
conform to the natural features of the country (above high water
mark) without decreasing the curvature below 955 feet radius, except
at the east end of the Susquehanna bridge, where a radius of 880 feet
has been admitted.
All of our efforts to save distance, by deviating, temporarily, from
the immediate valley of the river, involved either the use of high
gradients, not justified by the distance saved, or an increased
cost that was equally unwarranted. The beautiful valley of the
Kishacoquillas offered the greatest temptation to leave the river
route; but here we would have had to encounter gradients, in both
directions, of 26-4/10 feet per mile, a bridge over Mill creek, 1,200
feet long, 111 high; another over a small tributary of the Juniata,
850 feet long and 150 feet in height, together with several others,
or embankments of great magnitude, across ravines in the north
slope of the river hills. These difficulties, added to 342 feet of
additional elevation to be surmounted at the Allentown summit, so
greatly overbalanced the small increase of curvature and distance
(7/10 of a mile), by the river route, that it could not be adopted.
It was also ascertained that by the _use of the maximum gradients_
required on the valley route, the shortest line could have been
procured by the river, and at the least cost. A fact, conclusive in
itself, as to the proper route.
I deemed it unnecessary to make further instrumental examinations of
the Stone mountain route, feeling satisfied that even if a line could
be obtained in that direction which would approximate to an equality,
in an engineering point of view, with the route selected--which,
from a reconnoissance of a portion of the line and an examination
of the plots of Mr. Schlatter's surveys, I should consider _quite_
improbable--that its additional cost would entrench so much upon the
means of the Company as to place it entirely out of the question.
A line was traced from Huntingdon to the Frankstown branch of the
Juniata, below Williamsburg, across Tussey's mountain, by which a
saving of distance could have been made nearly equal to the Stone
mountain route, but its high gradients, cost, and the length of time
that it would require to build the road over it rendered it equally
objectionable. The valley of the Frankstown branch was also surveyed;
the route by it joining the Little Juniata line at Robinson's ridge,
but it proved both longer and more expensive than the latter. The
searching examinations made of the whole region offering any chance
for a more practicable route, on the north or south of the Juniata,
leaves no doubt upon my mind but that the best line has been procured
for the eastern division. Its comparatively easy curvature and low
gradients, adapted in their inclination to the direction of the
largest business, and extending from the eastern terminus of our
Road to the foot of the great barrier that divides us from the west,
give it advantages that are not equaled by any other route proposed,
between the east and west, and can not be too highly appreciated by
the Company.
Before determining the point to pass the mountain, a full examination
of its crest was made, from Cedar Swamp summit on the south, to
Three Springs Gap at the head of Moshannon creek on the north,
embracing a distance of 44 miles. The following table will show the
elevation, above tide, of each summit within that distance; also,
that at Emigh's Gap, on the northern route, and at the head waters of
Castleman's river on the southern:
_Tabular Statement of Depressions of Allegheny Mountain._
===================+=============================+================
| |
Name. | Waters Divided. | Authority.
| |
-------------------+-----------------------------+----------------
Summit of Chesa. & | |
Ohio Canal | Castleman's and Potomac | U. S. Engineers
Albright's Summit | do. do. |
Sand Patch do. | do. do. | J. Knight
Chambersburg and | |
Pittsburg Survey | | H. Hage
Cedar Swamp Gap | Raystown Branch of Juniata |
| and S. Fork of Conemaugh | S. H. Long
Bob's Creek do. | Raystown B. and Conemaugh | do.
Big Spring do. | Juniata and Conemaugh | do.
Laurel do. | do. do. | do.
Adams do. | do. do. | do.
Portage and Summit | Juniata and Clearfield | C. L. Schlatter
Sugar Run Gap | | S. H. Long
Burgoon's do. | do. do. | C. L. Schlatter
Kittanning do. | do. do. | do.
Dry do. | do. do. | do.
Hamer's do. |Little Juniata and Clearfield| do.
Schultz do. | do. do. | E. Miller
Cock Run do. | do. do. | do.
Maple do. | do. do. | do.
Bell's do. | do. do. | do.
Three Springs Gap | Little Juniata and Moshannon| do.
Emigh's do. | do. do. | C. L. Schlatter
-------------------+-----------------------------+----------------
{table continued}
===================+============+============+======
| Feet above | Feet below | Feet
Name. | Sugar Run | Sugar Run | above
| Gap. | Gap. | Tide.
-------------------+------------+------------+------
Summit of Chesa. & | | |
Ohio Canal | 476 | | 2739
Albright's Summit | 141 | | 2424
Sand Patch do. | 129 | | 2412
Chambersburg and | | |
Pittsburg Survey | 264 | | 2547
Cedar Swamp Gap | | |
| 160 | | 2443
Bob's Creek do. | 213 | | 2496
Big Spring do. | 314 | | 2597
Laurel do. | 222 | | 2505
Adams do. | 175 | | 2458
Portage and Summit | 41 | | 2324
Sugar Run Gap | 0 | | 2283
Burgoon's do. | 80 | | 2363
Kittanning do. | 75 | | 2358
Dry do. | 67 | | 2350
Hamer's do. | 177 | | 2460
Schultz do. | | 17 | 2266
Cock Run do. | | 55 | 2228
Maple do. | | 61 | 2222
Bell's do. | | 12 | 2271
Three Springs Gap | | 53 | 2230
Emigh's do. | | 240 | 2043
-------------------+------------+------------+-----
It will be perceived that the lowest point in the mountain, except
at Emigh's, is Maple Gap, from which issues Bell's Run (a branch of
the Little Juniata), on the east, and Sandy Run of Clearfield, on the
west. This point is 61 feet below Sugar Run Gap and could be further
reduced 150 feet by a tunnel 700 yards in length. If the ground had
been favorable beyond the summit, this route would probably have
offered the greatest advantages to cross the mountain, but it opens
westwardly upon the deep valley of Clearfield, a descent into which
would involve the necessity of a resort to as steep a gradient on
the west side of the mountain as that required on the east; and
the elevation thus lost would have to be regained by following up
the valley to Laurel Swamp or Munster summits, in the ridge that
separates Clearfield from the Conemaugh, which is here the true
backbone of the country.
Any attempt to carry a line along the west slope of the mountain, to
avoid the descent to Clearfield, would, from the rugged character of
the ground, prove impracticable, without a vast increase in its cost,
length and curvature. No other point offers equal advantages to cross
the mountain until we reach Sugar Run Gap, which is 41 feet below
the Portage Railroad summit, and may be reduced 120 feet more by a
tunnel 2,000 feet in length. Emigh's Gap, which is still lower than
Maple Gap, could not, on account of its gradual slope, be reduced by
a tunnel of moderate cost, and it is also too far north for a direct
route to Pittsburg. South of the Portage the Alleghenies become the
watershed of the Union, dividing the streams that flow into the gulf
from those that empty into the Atlantic. They here assume a more
elevated character than while separating only the tributaries of the
Susquehanna, affording no opportunity to pass them by a line adapted
to locomotive power--unless by a tunnel of immense extent--until we
reach Bob's Creek Gap. The accompanying profile, which exhibits the
crest line of the mountain (for 44 miles) will give a more definite
idea of the relative height of these summits.
The mountain on each side of Bob's Creek Gap rises to a considerable
height, making it appear, to a casual observer, a very deep
depression; and, from this circumstance, it has generally been
considered by the residents of the adjoining country to be the lowest
pass in the Alleghenies, and, as it falls off rapidly on either
side, it has also been supposed that it could be farther reduced by
a tunnel of moderate extent. The several surveys of the mountain,
however, prove it to be 212 feet higher than Sugar Run Gap, and, to
reduce it to a level with the surface of the ground at the latter
point, which is 120 feet above the grade of the adopted line, it
would require a tunnel 1¼ miles in length, to be constructed under
very disadvantageous local circumstances.
Cedar Swamp Gap, still farther south, is 53 feet lower than Bob's
Creek Gap, but it falls off on each side so gradually that it could
not be reduced conveniently more than 40 feet.