STATE GEOLOGIST. 109 
which, at best, could not make firm support, allowed the track to vibrate 
and undulate, shattering the street paving. Great opportunity was thus 
given for the entrance of storm water into the sub-foundation, making it 
still more unstable both for track and paving, until the street and track 
were both wrecks. To add to this, the rotting of the wooden ties required 
the continual tearing up of the streets in order to replace them and to keep | 
the track in sufficient repair so that traffic could. be maintained at all. 
Such conditions became unbearable in many of the important business 
streets of great cities, both to vehicle and railway traffic, and a remedy was 
sought. It is not necessary to follow the path of the search parties. It is 
sufficient to say that the remedy was found, as in many another search, 
in concrete. 
Concrete has been used in various ways as a foundation bed for 
wooden ties, as stringers beneath the rails only; as concrete ties on ordinary 
tamped earth beds or gravel beds, and as solid concrete road beds imbed- 
ding the rail directly within the mass of concrete. 
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Fig. 55.—Section of Track Showing Use of Concrete Ties, Pere Marquette Railway. 
t Figure 55 illustrates the form used on the Pere Marquette R. R., 
in Bay City, Michigan. A concrete foundation beneath the entire track 
is first laid, upon this, well made concrete blocks, 7 inches by g inches by 
360 inches are laid 33 inches center to center in a bed of cement mortar and 
then surrounded with concrete and the concrete is carried up to within 1 
inch of the base of the paving block. Upon the concrete block is placed 
a 3 inch white oak spiking block to which the rails, are spiked. Concrete 
is also filled in around the web of the rail sufficiently to leave flange way 
between the rail and the paving block. 
Fig. 56.—Street Railway Section 
Showing Concrete Rail Supports. 
In Minneapolis and St. Paul, * the rail is imbedded directly in the 
concrete as shown in Figure 56. ‘The rails are kept evenly spaced by metal 
+Hng. News, Aug: 28, 1902. 
*Hng. News, Feb. 26, 1908. 
