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Concrete Crossties
Special Trackwork and Construction
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Concrete Crossties
Crossovers and Turnout Track, Special Applications
for Concrete Crossties
 Although,
precast, prestressed concrete crossties have been installed by transit
systems and railroads for many years, turnouts and crossovers are
commonly assembled on wood ties because of the complexity of the special
trackwork. Recently, installations of concrete tie turnouts have been
undertaken to determine the economic and technical benefits that might
arise.
Canadian National Rail installed the first concrete tie turnout
in North America in 1984, and in 1986 Calgary Transit installed
their first crossover on concrete ties. In 1995, the New Jersey
Transit Corp. installed concrete turnout ties on the Kearny Connection
Project, amounting to the largest all-concrete tie interlocking
installation in the U.S. The construction of track, high-speed turnouts,
and new interlockings allows for maximum operating flexibility and
speeds up to 80 mph.
In general, each concrete switch or turnout tie is specifically
designed for precise fit. Extremely tight tolerances during manufacturing
provide excellent geometry for traffic flow through either the tangent
or turnout side of switch. Accurate geometry and alignment are maintained
during operations. The higher track modulus provided by concrete
switch ties is better able to withstand heavy loads and frequent
switching. Typically, installation procedures include pre-assembly,
splitting into panels of multiple crosstie lengths, and reassembly
at the site.
Construction with Concrete Crossties
 Concrete
crossties can accommodate any commercial rail fastening system.
Production rates of a mile a day or better can be achieved when
laying new track. Dimensional consistency allows for smooth placement
and accurate track alignment during installation, leading to shorter
construction times. Concrete ties can be spaced 25% to 50% farther
apart than wood. This means fewer ties are required per mile, reducing
the cost of other track components.
A variety of common track machinery is available for installation.
Individual ties can be placed with existing maintenance-of-way equipment
with only minor adjustments. Large-scale replacement is not expected
for 50-plus years. When finally necessary, disposal will require
no special environmental preparation. There are no chemicals to
leach into the soil and the water table as with timber ties.
Crossing North America
To date, over 20 transit and passenger rail systems have installed
or are installing concrete crossties. The results have been longer
material and component lives, smoother ride, increased allowable
train speeds, and overall lower maintenance. All of which demonstrates
that concrete ties are beneficial in all areas of North America,
from the Canadian provinces to the four corners of the United States,
coast to coast, border to border.
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