The Evansville daily journal. [volume] (Evansville, Ia. [i.e. Ind.]) 1848-1862, 1850-03-27
New YoRK, March 18th, 1850,

under your directions.
The enclosed tracing is rough copy ofthe
section you sent me, transferred as nearly as
possible from the paper pattern. This Sec
ton Of rail has been found to work we'll on
longitudinal bearings in the case of the Lon
don, and Croydon, and the Great Western of
England the latter being perhaps The best
Railroad in existence. The weight proposed
is the same as that used OF the former of these
roads and if recollect rightly. the same as
had been used on the Great Western, before
the introduction of the present enormous
machinery. The weight required for your
road depends of course on the weighf Of the
Engines, the speed, and other particulars
that you have omitted to state. The only
answer | can give you on this head is SIM
ply that on such Il superstructure as you de-
scribe, if proper provision be made for the
drainage of the road should consider your
/ As U rail as equal in vertical strength TO- at
all evenlsa Cobb rail on bearings thirty inches
apart. and as equal in lateral strength to
perhaps even a still heavier rail, supported at
the same intervals This difference of weight
! (12 lbs.) in the case of vertical strength is
very considerable in practice: after certain
point, increase Of metal yields a much higher
increase of strength, seeing that the upper
and lower web in one section, and the upper
web in all sections, being the same or nearly
so for all weights, an increase Of metal is an
increase chiefly Of depth-verical strength
varying as the square OF the depth a bar of
two inches deep will resist vertically as 4,
while bar of one inch deeper, or three inches
deep will resist as or to q times stronger.
You will observe by the dotted lines shown
on the tracing, that | apprehend a weakness
i'll the toes Of your rail- and as these must re-
ceve all the lateral shocks of the traffic Nth
q leverage they would, probably, by curling.
permit the rail to rock OH its base-the rail
would progress toward this shape --. and
though perhaps this progress might be very
t trihing-t would still tell very seriously OH
/ the stability and duration Of the track The
danger of the rail sinking into the bearer is
: also increased by losing an equality of resis-
lance at all points of the base and as the
same cause diminishes the resistance of the
! bearer one element of strength being there
fore reduced. the whole must become weaker
, vertically. For these reasons would sug-
gest an increase Of metal at the toes, be it
ever so littie-and as know no better place
n Of obtaining this increase, l would pair away
e as shown by the dotted lines, the necessary
: quantity from the under side of the upper
q web.
d should prefer spiking thro' the foot Of the
s rail, even tho obliged (if possible in this case,
i to counter-sink the heads at one side. AS the
# hook-headed spike cannot give as much sta,
- bility as a through-spike-I would recon
s. mend that at all events a through-spike be
used on the outside web of the base The
spikes had better be made to alternate thu;
5. -- on either side OF the foot, in order t.
ut increase the number of fixed points. The
= middle ofeach rail might be spiked down ad
D. vantageousIy with stronger spikes than the
Ii others with the view by making this IA 6xee
r point OF saving, al allevents these middle fast
IN enings from the loosening consequent on tht
81 expansion and contraction of the metal-th,
1e expansion and contraction being made,by thi
m means to take different directions on eithe
e. side of these stronger fastenings.
=, In reference 10 the superstructure woul,
suggest that in order to distribute the resi<
lance equally, the fewer knots you have i
the timber bearings next the rail. the better
Il, There can be very little danger of your roa
NJ sinking into the superstructure, and conse
Is quently amongst the other advantages OF sue
" system you effect great saving on that ez
OF pensive item of packing.'-
n In order TO secure this advantage more efet
tually you must provide for the drainage
the road this being one of the chief grount
'eS of objection to the continuous bearing. O
IT. binary ingenuity will suggest the best NEAR
lbs for this purpose, adapted to your particulf
OF road if the Youte furnish brush-wood, lay
1st er OF this under your tmbers will help out tt
ith drainage-if coarse gravel be convenient,
Try few inches of that around the timbers w
answer the purpose. Iwould impress on 20
TT generally, that the duration Of rail, timbe
ur- earthwork, plant, machinery, depends muC
tx more than is generally supposed on the drai
ry' age of a road.
Your superstructure is highly judicious
Oh a means of ultimate economy your rail
his altered is probably sufficiently strong Tor tt
gh road inasmuch as you will run it with the lig
v- Engines, used generally IN the West; and
the materials be selected with judgment, al