Dimensions of wooden railway sleepers. Reinforced concrete sleeper: dimensions

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Railway sleepers are the most important element of the construction of the corresponding highway. The stability of the infrastructure directly depends on their quality. In the Russian Federation, wooden and reinforced concrete structures are used. In relation to them, a number of important standards have been established that determine the size. What are their specifics?

Classification of wooden sleepers by type

The dimensions of a sleeper made of wood, in accordance with accepted state standards, should correlate with its type. There are several reasons for classifying the considered element of the railway track.

Among the most common is appointment. So, sleepers are divided into those intended for:

- main tracks of class 1, 2 or 3, provided that their traffic density exceeds 5 million tons / km per year, or operated at a train speed exceeding 100 km / h;

- main tracks of 3rd and 4th class, access (with intensive work), sorting, as well as receiving and departure - at the stations;

- any tracks related to class 5, including station tracks,classified as inactive, as well as others that are characterized by a shunting-export type of movement.

The specified types of tracks are built using, respectively, I, II and III types of sleepers. In relation to them, standardized indicators are thus established.

Moisture factor

The actual size of a railway sleeper made from wood may vary depending on the moisture content of the material. What does it mean? The fact is that the corresponding values are relevant for humidity not exceeding 22%. If this indicator is greater than the specified value, then the dimensions of the sleeper should be considered taking into account the necessary allowances for shrinkage. Its value depends on the type of wood - coniferous or deciduous. A similar requirement is also established for the cross sections of composite sleepers.

Permissible deviations in the dimensions of composite sleepers

The size of the sleeper may deviate from the norms fixed in state standards, within the allowable values. Regarding the length - it is 20 mm, thickness - 5 mm. There are also allowable deviations related to the width of the seams, the height of the sides, the distance between the bolts, as well as their vertical deviation from the axis of the sleeper.

Standardized sizes of wooden sleepers

Now let's consider, in fact, what the dimensions of a wooden sleeper (HD) can be, depending on the type.

For type I railroad elements, the values should be:

- thickness - 180 mm (deviation of 5mm);

- height of sawn sides - 150 mm;

- top plate width - 180-210 mm;

- bottom plate width - 250 mm (allowable deviation of 5 mm);

- length - 2750 mm (adjustment within 20 mm is allowed).

For type II sleepers, its dimensions must meet the following criteria:

- thickness - 160 mm (allowable deviation of 5 mm);

- height of sawn sides - 130 mm;

- top plate width - 180-210 mm;

- width of the bottom plate - 230 mm (deviation of 5 mm is allowed);

- length - 2750 mm (change within 20 mm is allowed).

In turn, type III sleepers must comply with the following indicators:

- Thickness - 150mm (5mm tolerance allowed);

- height of sawn sides - 105 mm;

- upper plate width - 140-190 mm;

- width of the bottom plate - 230 mm (deviation of 5 mm is allowed);

- length - 2750 mm (adjustment within 20 mm is allowed).

So, we have considered the requirements for the size of wooden railway sleepers, which are established by state standards. But in the structure of the railway track there is another important element of wood, used along with sleepers - transfer bars. We examine, in turn, the standards that are set by the state in relation to their sizes.

Sizes of transfer bars: criteria

Like the dimensions of the sleeper, the corresponding measurements for the beams are determined by their type. Reasons for classificationthere are also several elements of the railway track under consideration. Among the main ones, as in the case when the dimensions of the sleeper are determined, is the appointment.

So, bars can be used:

- on the main tracks of class 1, 2 or 3, characterized by a traffic density exceeding 50 million tons / km per year, as well as a train speed of more than 100 km / h;

- on the main tracks belonging to 2, 3 and 4 classes, access (with intensive work), as well as marshalling and transshipment, which are present at the stations;

- on tracks classified as class 5, including station tracks, classified as low-traffic access roads and others, characterized by movement of a shunting-export type.

The indicated paths correspond to I, II and III types of transfer bars.

As with sleepers, the moisture content matters. Thus, standardized dimensions of transfer beams, characterized by a moisture index of more than 22%, should be considered taking into account the necessary allowance for drying. As in the case of the standards that determine the dimensions of the sleeper, in this case it matters what kind of wood is used to make the beams - hardwood or softwood. In the first case, the necessary criteria are contained in GOST 6782.1-75, in the second, the provisions of GOST 6782.2.-75 are used.

Let's study, as in the case when we examined wooden sleepers, the dimensions of the bars in relation to their type.

Sizes of transfer bars by type

If we are talking about type I bars, then their characteristics should correspond to the followingvalues:

- thickness -180 mm (adjustment within 5 mm is allowed);

- upper plate width - 220 mm (broadened), 200 mm (wide);

- bottom plate width - 260 mm;

- sawn side height - 150 mm.

- the width of the timber for uncut elements - 300 mm;

Type II bars must have the following characteristics:

- thickness -160 mm (deviation within 5 mm is allowed);

- top plate width 220 mm (broadened), - 175 mm (normal);

- bottom plate width - 250 mm;

- sawn side height - 130mm.

- the width of the timber for uncut elements - 280 mm;

The following standards have been set for type III bars:

- thickness - 160 mm (deviation within 5 mm is allowed);

- top plate width - 200mm (wide), 175mm (normal);

- bottom plate width - 230 mm;

- sawn side height - 130 mm;

- the width of the beam on the uncut elements - 260 mm.

Length of bars: range of acceptable values

But what are the bar lengths? Unlike the standards governing the size of a wooden (railway) sleeper, when all values depend on the type of the corresponding element, they assume a fairly strict compliance with the established standards, in the case of beams, the length criteria are common to all their types. Moreover, the standards do not set a specific indicator, but an interval - from 3 to 5.5 meters with a gradation of 0.25 m with permitteddeviations within 20 mm.

Bridge bars: the specifics of standardization

So, we have considered what are the standards that regulate the size of a wooden sleeper (RW) and a beam that complements it in the structure of railway tracks. But there is another important component of the respective highways. We are talking about bridge beams. Just as the size of a railway sleeper is regulated, this indicator for the considered component of railway tracks is also fixed in state standards. Let's study this specificity in more detail.

The material for the manufacture of bridge beams is wood. Their size is correlated with one parameter - the size of the cross section, as well as the permissible deviation indicators. The main requirement for the bars is a rectangular shape. Corresponding elements of railway lines come with a section:

- 220x240mm;

- 220 x 260 mm.

Bridge bars of both types, however, must have the same length - 3250 mm. But in terms of standardization of limit deviations, the indicators may vary. So, for bars with a cross section of 220 by 240 mm, the maximum deviation can be: minus 2 mm (in thickness), 15 mm (in length). Regarding the second type of railway elements, the indicators are different. So, adjustments in thickness for bars with a section of 220 by 260 mm are not provided, as well as in length, but in width the corresponding value, which is set in the standard, is 3 mm.

It can be noted that, in agreement with the customer, bars with other sections can be manufactured - 220at 280 and 240 at 300 mm, having a length of 4.2 m.

As with the standards governing the size of a wooden (railway) sleeper, bridge beam lengths are set for products within a certain moisture level. In this case - 20%. If the bridge beams will have more moisture, then it is necessary to consider the size requirements, taking into account the necessary shrinkage allowances - in accordance with GOST 6782.1-75.

Reinforced concrete sleepers: classification

Reinforced concrete can be an alternative to wooden sleepers. These products are used on highways. Belong to the category of prestressed. They are used when laying rails of types P75, P65, and also P50. There are many reasons to classify reinforced concrete sleepers:

- according to the type of fastening with rails;

- according to the type of prestressing reinforcement;

- for electrical insulating characteristics;

- according to the level of workmanship.

In this case, we are interested in the first criterion - the method by which a reinforced concrete sleeper is attached to the rails. The dimensions of the product and its other most important characteristics are determined precisely on the basis of the characteristics of the corresponding mechanism. So, depending on the type of attachment to the rails, the sleepers are:

- type Ш1, designed for separate fastening using bolts by fixing the lining on the sleeper;

- type Ш2, designed for inseparable fastening using bolts by attaching to a sleeper notonly lining, but also rail;

- type Ш3, designed for inseparable fastening using bolts by direct attachment to the rail sleeper.

Reinforced concrete sleepers: dimensions and other parameters

The most important criterion that determines the required parameters of a reinforced concrete sleeper is its assignment to one of the above types.

So, if we are talking about a sleeper classified as Ш1, then it should have the following characteristics:

- required distance between the thrust edges - 2016 mm;

- the distance between the corresponding edges of one end of the product - 406 mm;

- product height in the rail section - 193 mm;

- product height in the middle section - 145 mm.

Sleeper type Sh2 must have the following characteristics:

- distance separating the thrust edges - 2016 mm;

- the distance between the corresponding edges of one end of the product - 406 mm;

- product height in the rail section - 193 mm;

- product height in the middle section - 145 mm.

A sleeper classified as Ш3 must comply with the following parameters:

- distance separating the thrust edges - 1966 mm;

- the distance between the corresponding edges of one end of the product - 359 mm;

- height in the rail section - 193 mm;

- height in the middle section - 145 mm.

These are the main characteristics that, according tostate standards, should have a reinforced concrete sleeper. Its dimensions in terms of length and width are most often fixed - respectively 2700 and 300 mm. Deviations comparable to those recorded for wooden products are not provided for in state standards for reinforced concrete elements. The size of a railway sleeper of the corresponding type does not assume variability in relation to humidity and other environmental factors.

Wooden and reinforced concrete sleepers: common points and key differences

What other fundamental differences can be noted between reinforced concrete and wooden elements? The first thing that differs, therefore, sleepers - dimensions. Weight is also a significant criterion for the dissimilarity of the respective products. The indicator for wooden sleepers is about 80-85 kg, reinforced concrete - about 270 kg. The scope of both those and others differs not so significantly. Wooden sleepers, the dimensions of which we examined in the first place? historically preceded reinforced concrete, but still have not lost their relevance. Moreover, they have a number of important advantages - low cost, ease of transportation, replacement and transportation, overload resistance.