Zbornik radova Koridor 10 - Kirilo Savić

3rd International Scientific and Professional Conference
CORRIDOR 10 - a sustainable way of integrations
FIG. 11. Head checking (left) and squat rail defect (right) caused by rolling contact fatigue (photos
taken on the Belgrade Centre – New Belgrade section)
Special attention during maintenance should be paid to the condition of rail joints, tracks in the curve
(Dollevoet, 2010), as well as the tracks in the turnout zone, crossings and expansion devices. Every
noise increase on such sections points to irregularity of the track geometry, including the occurrence
of rail defects.
5.2 Maintenance of the wheel/rail contact surface
Testing shows that finer treatment of the wheel rolling surfaces can reduce noise emission in the
environment for 3 dB(A).
A frequent cause of unevenness on the wheel rims are damages occurring due to influence of the
brakes on the wheel. The level of damage is directly connected to the brake design, which is covered
by the expression (1). Disc brakes don’t damage the wheel rim, and thus they contribute to noise level
decrease of up to 11 dB(A) compared to the cast iron brake shoe. By discarding the additional shoe
brake, which was the cause of roughness of the wheel rim, TGV-Atlantic reduced noise in the
environment for 6 dB(A) with respect to TGV Sud-Est (Chiaramella, 1995). Similarly, but in respect to
freight cars, Swiss Railway expects to reduce the environmental noise pollution by 5 to 8 dB by
replacing shoe brakes affecting the wheel.
FIG. 13. Wheel tread surface condition: cast iron block brake (left), composite block
brake (center), disc brake (right)
5.3 Relation of the wheel and rail maintenance strategies
At even rail and wheel noise emission levels, total noise from both elements increases for 10log2=3.01
dB. Also, if noise induced by wheel and rail are the same, then reduction of noise emission on either
wheel or rail by 10 dB(A) will decrease total wheel/rail noise by only 2.6 dB(A) (Figure 12).
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