common in sections of Europe. The usual substitute materials are steel, concrete, and reinforced
Figure 3.3. Curvature of Crossties.
a. Steel ties have the advantage of long life and reduced labor and maintenance. The
most serious drawback to their use is that they become twisted in wrecks or track destruction,
causing removal difficulties. Breakage and rust necessitate many renewals. Steel ties cause
excessive insulation problems on lines depending on track circuits for signaling, and they are
noisy and expensive.
b. Concrete and reinforced concrete ties have the same general advantages as steel ties.
However, they are far too heavy for ease in handling, lack the resiliency needed to withstand the
shocks of rail traffic, are easily crushed in derailments, and cause short-circuit problems in track-