Sleepers

MARCH 2015 Research, Planning & Coordination Department 2

THE SLEEPERS

SLEEPER TYPES

SLEEPER DEFECTS

THE SLEEPERS


INFO ABOUT SLEEPERS

SLEEPER TYPES CONCRETE SLEEPERS


• Concrete sleepers • Concrete sleeper is the most widely used type of sleeper

today. It is used on tracks and switches.



• 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.

• Approximate weight 250 kg



• B70 Concrete sleeper • This is used together with 60 E1 (UIC60) rails. Its technical

drawing is provided in Figure-2 below.

• Approximate weight 291 kg


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.


SLEEPER TYPES WOODEN SLEEPER


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.


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 cross-

section, 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.



Table 3: Limit values for distance between sleepers (mm)

(Deviation from the design value) (mm)

Operating speed of the

line, V

Side Tracks V<160 km/h V≥160 km/h Measures to be taken

AL

(Warning) ±60 ±50 ±40 Monitor

IL

(Maintenance)

±70 ±60 ±50

Correct sleeper tie spacing within 3

months.

IAL

(Intervention)

±80 ±70 ±60 Correct sleeper tie

spacing within 2 weeks.



• 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.



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)

Use of lateral resistance plate

R ≥ 400 No need. 300 ≤ R < 400 1 per 3 sleepers

250 ≤ R < 300 1 per 2 sleepers

R < 250 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)

Use of lateral resistance plate

R ≥ 300 No need. 270 ≤ R < 300 1 per 3 sleepers

250 ≤ R < 270 1 per 2 sleepers

R < 250 1 per each sleeper


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.


THE SLEEPERS SLEEPER DEFECTS

Picture 1 : Fracture Picture 2 : Abrasion

Picture 3 : Longitudinal crack

Sleepers

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