The Placer herald., 1860-03-31
Total by lower line 37GoI 72,4O5 5,G44Is IS,
Roadway and Structures.

In making up the cost of construction the width
of roadway has been assumed at II feet on top,
for embankments, with Il slope of to ) and for
excavnting width of Is feet at the surface of
the road. with slopes of to ncuttngs of mixed
rock and earth, and slopes OF to | in cuts of
solid rock.
The material of the upper or first Division is
the slate rock of the mining region, varying
greatly rs regards facility or difficulty Of work
ing 1t is occasionally traversed by veins of
quartz and strata of cement or conglomcrate.
Some of it requires blasting while other portions
are much decomposed and detached, and can be
removed with little more labor than ordinary
earth The earth covering the rock is the usual
red clay and gravel of the mining region
Some of the rock has been estimated as such at
81 per cubic yard for excavation. Where no Up-
portunity existed Of jnd dgng of the q ,antty or
quality of each kind Of material in cut, without
boring or prospecting eXi rcssly for the purpose,
it has been estimated us mixed. onelifth being
assumed to be rock. and the remainder earth or
detached rock and gravel. Should II closer in
specton prove that the proportion of rock or the
difficulty Of working it has been over estimated,
Il corresponding reduction may be made in the
price.
The second Division passes mainly through u
granite region, especially 50 below the Franklin
House. coarse granite sand and gravel covers
the surface. sometimes passing into cong glomerate;
and underneath these is often found a sort Of de-
caycd granite that can be removed without blast
ing Occasional bouldcrs and hedges Of granite
appear at the surface.
Grades.
In the location of this road have admitted no
grade sleeper than so feet to the mile. The pre-
iminary survey showed that grade OF 10 feet to
the mile might be obtained by crossing the Amor
icnn river above Folsom: but by raising the grade
to so feet was enabled to enter Auburn ut u
greater elevation, and also to descend into Big
Gulch, and join the Central Railroad at the north
end OF the bridge, thereby saving an expensive
structure Having concluded to adopt this maxi
mum, it was found that it enabled us to avoid
several deep cuts through the fiat SUBMITS ON the
central portion of the line, which could not have
been avoided if the 20 feet grade had been I'D
hercd to.
The several grades on the road are
or level grade 10.600 #. or POI ms. or lO.3 pr ct
pip # per mile 1880 " or 4.O7 d" or 2l.3 - -
1910" 400 or0.S9 /" or Is :" =
1l53. i" 1900 or OPS 90 or l.5 " "
1888. 1000 or 076 or 4. I" "
So 56.G5G "or 1913 or 56.2 :" "
The total elevation from the junction with the
Central Railroad to the head OF the upper line al
Auburn is 1888 feet, or to the head Of the lower
line is 979 feet.
No railroad has yet been actually constructed in the
mountainous regions of California. On the routes
that have been surveyed over the valley lands the
maximum grades are usually much less than 81
feet to the mile. But it will scarcely be possible
to penetrate far into the mining region, nor to
slrmount the Sierra Nevada, without resorting to
maximum grades not tolerated elsewhere than in
mountainous regions Grades Of so, 60, 70 and
so feet to the mile, and in some cases perhaps as
high as 80 or 100 it will be found economica and
probably absolutely necessary to admit. Sharp
curves, high bridging, deep rock cutting, and
tunnels, will also be characteristic of our noun
tain railroads. All these features are common to
the roads across the Aleghanies in Pennsyl ylvania
and Virginia. and some Of the mountainous dis
tricts of New York and New Eng land.
On the Baltimore and Ohio Railroad grade OF
| lG feet to the mile for II miles has been in use
for many years On the Pcnnsylvanl" Central
road there are grades of 95 feet for 81 miles,
Where curves occur on this grade, the grade is
reduced at the rate of OOPS per 100 feet per de-
gree of curvature. Passenger trains ascend ms
grade with velocity of "a miles per hour ana
descend at 20 miles per hour. The ascent when
there are more than three cars, IS Effected by lhe
aid of an additional engine The working load
of the heavy freight engines (welghing oo.ooo
pounds and on eight dryers) on the 10 ieet grade
is 1926 tons net or about 20S tons including tender
and cars.
On the Massachusetts Western road there IL
grade of s., feet to the mile for one mile and "A
half Engines of 20 tons draw 100 tons over tlls
grade. Passengers trains run up at about Is
miles per hour, without auxiliary power
These facts, deduced from the actual working oil
roads in daily use on the most important lines
! in the United Status will show what can be done
with the grades adopted for your road.
Grades much sleeper than those cited have been
successfully overcome by locomotives on several
Eastern roads but such grades have only been
resorted to for temporary purposes, anu ought no.
to be adopted as par. Of q permanent system We
ought to rpcollect that the Auburn road may pos
sibly become portion of the great transit route
across the Sierra, and its leading features ought
not to be such as TO unit it for that purpose,