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THE SLEEPERS
MARCH 2015
Research, Planning & Coordination Department
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THE SLEEPERS
SLEEPER TYPES INFO ABOUT SLEEPERS SLEEPER DEFECTS
MARCH 2015
Research, Planning & Coordination Department
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SLEEPER TYPES CONCRETE SLEEPERS
• Concrete sleepers • Concrete sleeper is the most widely used type of sleeper today. It is used on tracks and switches.
MARCH 2015
Research, Planning & Coordination Department
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SLEEPER TYPES CONCRETE SLEEPERS
• Types of concrete sleepers • B58 Concrete sleeper • This is used together with 49 E1 (S49) rails. Its technical drawing is provided in Figure-1 below.
•
MARCH 2015
Approximate weight 250 kg
Research, Planning & Coordination Department
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SLEEPER TYPES CONCRETE SLEEPERS
• B70 Concrete sleeper • This is used together with 60 E1 (UIC60) rails. Its technical drawing is provided in Figure-2 below.
• MARCH 2015
Approximate weight 291 kg Research, Planning & Coordination Department
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SLEEPER TYPES WOODEN SLEEPER
• Wooden sleepers • It is used on any kind of rail, mainlines and switches. • Since wood is already flexible, forces from the rail are elastically transmitted to the ballast. • Three types of wooden sleepers are used on the line, namely line sleepers, switch sleepers and bridge sleepers. • Dimensions of standard wooden sleepers (line sleepers) are as follows: 2.60 – 2.70 m in length, 23 – 26 cm in width and 13 16 cm in height. • Flexible nature of wooden sleepers decrease the noise level of the lines compared to the lines where other types of sleepers (iron and concrete) are used. MARCH 2015
Research, Planning & Coordination Department
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SLEEPER TYPES WOODEN SLEEPER
MARCH 2015
Research, Planning & Coordination Department
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SLEEPER TYPES IRON SLEEPERS
• Iron sleepers • Iron sleepers are manufactured from mild steel. Because they have clawed heads, they resist lateral movements of the track. If the sleeper is not connected well to the rail, there may occur abrasion under vertical and lateral impacts on the surface where the rail foot seats.
• Due to decrease in sleeper section as a result of such abrasion, resistance at the relevant point decreases and cracks and fractures occur. Therefore, connections of sleepers must be perfect. MARCH 2015
Research, Planning & Coordination Department
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THE SLEEPERS INFO ABOUT SLEEPERS
• Distance between sleepers • The design value of the distance between sleepers should be 60
cm for lines with UIC 60 (60 E1) rails or rails of larger crosssection, and 62 cm for lines where other types of rails are used.
Shorter distances may also be used. However, for shorter distances, maintenance works would be difficult due to significantly increasing costs. • Maximum deviations for distances between concrete and wooden sleepers based on the design values on the next page. MARCH 2015
Research, Planning & Coordination Department
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THE SLEEPERS INFO ABOUT SLEEPERS
MARCH 2015
Research, Planning & Coordination Department
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THE SLEEPERS INFO ABOUT SLEEPERS Table 3: Limit values for distance between sleepers (mm) (Deviation from the design value) (mm)
Operating speed of the Side Tracks line, V AL
(Warning)
±60
V<160 km/h
±50
V≥160 km/h Measures to be taken
±40
Monitor
IL (Maintenan ce)
±70
±60
±50
Correct sleeper tie spacing within 3 months.
IAL (Interventio n)
±80
±70
±60
Correct sleeper tie spacing within 2 weeks.
MARCH 2015
Research, Planning & Coordination Department
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THE SLEEPERS INFO ABOUT SLEEPERS
• Mounting lateral resistance plates on sleepers to ensure lateral resistance of track at curves
• In case the length of rails used is longer than 72 meters, resistance plates should be used to ensure lateral resistance of the track.
• Lateral resistance plates are used as indicated in the table on the next page. MARCH 2015
Research, Planning & Coordination Department
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THE SLEEPERS INFO ABOUT SLEEPERS Table 4: Use of lateral resistance plates depending on rail length, curve radius and sleeper length
Lateral resistance plates to be used on curves with rails longer than 72 meters (for a sleeper length of 2.40 m)
Radius of Curve (R) (m) R ≥ 400 300 ≤ R < 400 250 ≤ R < 300 R < 250
Use of lateral resistance plate No need. 1 per 3 sleepers 1 per 2 sleepers 1 per each sleeper
Sleeper resistance plates to be used on curves with rails longer than 72 meters (for a sleeper length of 2.60 m) Radius of Curve (R) (m) R ≥ 300 270 ≤ R < 300 250 ≤ R < 270 R < 250 MARCH 2015
Use of lateral resistance plate
No need. 1 per 3 sleepers 1 per 2 sleepers 1 per each sleeper Research, Planning & Coordination Department
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THE SLEEPERS INFO ABOUT SLEEPERS
MARCH 2015
Research, Planning & Coordination Department
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THE SLEEPERS SLEEPER DEFECTS
Common sleeper defects are as follows:
– Surface defects (fractures, cracks, etc.) – Peeling, – Rough and sediment surfaces, – Abrasion due to tamping works, inappropriate ballast
use or shoulder settlements. MARCH 2015
Research, Planning & Coordination Department
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THE SLEEPERS SLEEPER DEFECTS
Picture 1 : Fracture
Picture 2 : Abrasion
Picture 3 : Longitudinal crack
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Research, Planning & Coordination Department
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