Month: June 2020

Maintenance of Rolling Stock || Railway Engineering

Maintenance of Rolling Stock

The rolling stock includes locomotives, coaches, and wagons. The rolling stock must be maintained in perfect order. The following are some important points that should care during the process of maintenance.

1. The worn-out portions of the rolling stock should be replaced from time to time.

2. The various parts of the rolling stock must be washed or cleaned every day.

3. The lubrication of all reciprocating parts and bearings should be carried out.

4. The axles which have already completed the running length of 3,220,00 km should be changed by a new one

5. Locomotive boilers must be carefully maintained and renewed every 15 years.

6. The useful life of a passenger train is considered as 30 years. After 30 years, it is to be dismantled and reassembled, even though it is not worn out.

Railway Water Columns

Bearing Plates in Railway

Tools Used for Railway Track Maintenance

Kolkata Metro – India’s First Underground Metro

Kolkata Metro

Kolkata Metro is the first metro in India. Kolkata was the capital of India till 1911 under British rule. This is a very beautiful and well-known city in India, also known as the ‘City of Joy’. Kolkata is the first city in India where the first underground railway construction was thought, because of the increase in the number of road users.

It has the surface area for roads as only 6% as compared to 25 % for Delhi and even 30 % for other cities in India. Therefore, the lack of surface area for new road construction was the most important reason which forced to think about the construction of the Kolkata Metro Rail.

The Kolkata Metro work started from the year of 1972. The rail route was made to connect Dum Dum and Tollygunge, a distance of around 16.45 km. There are 17 stations in between the route, out of 17 stations, 15 stations are underground and two end stations Dum Dum and Tollygunge are at the ground level.

The trains have a maximum running speed of 80 km per hour, with an average running speed of 30 km per hour. The frequency of availability of the train at the station is less than 2 minutes during peak hours. It is estimated that nearly 5 to 7 lakh passengers are carried daily for a 16.45 km length route. The total time taken to travel 16.45 km is only 33 minutes, which would be challenging to achieve by any other surface-based system.

Kolkata Metro is also the fifth metro in Asia. It increased its route length around 4 km on October 24, 1984, including five stations in between Esplanade and Bhowanipore.

Further, on November 12, 1984, they include another 2 km route length in the North between Dum Dum and Belgachhia. The passenger service was extended up to Tollygunge on April 28, 1986, covering a distance of about 8 km. The metro railway line was fully commissioned for public use on September 26, 1995.

Kolkata Metro faced some serious problems because it was the first underground railway construction project of its kind taken up in India without any experience and definite knowledge.

Delay in the construction of the Kolkata Metro and the increase in construction cost were taken place mainly due to the combined effect of the following three problems

(i) Complex subsoil conditions,
(ii) Inadequate flow of funds, and
(iii) Land acquisition problems.

Important Features

The following are the important features of Kolkata Metro:

1. All trains have automatic over-speed protection with a cab signaling system.

2. All trains have a uniform class of accommodation.

Read More:

Types of Rail

Types of Railway Platforms

Railway Gauge

How is a Wagon Stopped in a Hump Yard?

Stopping of a separate wagon or group of wagons in hump yards is carried out as follows:

1. Somebody runs along the wagon and applies the wagon’s brake at the point where it needs to be stopped.

2. Retarders may be employed to stop the moving wagons. These are blocks or bars which are fixed on either side of the rails. The retarders are operated automatically and when operated, they press against the sides of wheels of the moving wagons. The moving wagons are thus brought to a stop.

3. Skids may be placed on the rails. A moving wagon will drag the skid and the friction thus developed will prevent the further movement of the wagon. This method is adopted in India.

However, the action of hump yards is a little uncertain because the rate of movement of wagons depends on some factors such as:

a) The climatic condition
b) Different types of axle-boxes; and
c) The weight of wagons.

Read More:

Objectives of Railway Signalling

Types of Railway Platforms

Ash Pits in Railway

Function & Properties of Soil as a Road Material

Function of Soil as a Road Material

The soil as Roads subgrade has the following function:

Function & Properties of Soil as a Road Material

1. Soil is an essential component in the road construction which is used as subgrade material.

2. It acts as an integral part of the road pavement.

3. It ensures the stability and durability of the road under adverse conditions.

4. It facilitates proper drainage for rainwater percolating through the road pavement.

5. It helps to overcome some critical defects on roads like waves, corrugation, rutting in blacktop pavement, and cracking of cement concrete pavement by providing proper subgrade stability and durability.

Properties of Soil as a Road Material

The properties of soil as a road material are as follows:

1. The soil subgrade should remain stable in adverse conditions.

2. It should have permanent strength.

3. It should be incompressible.

4. It should have proper drainage properties to evade excessive retention of moisture.

5. It should be easily compatible which ensures higher dry density(dry density of soil) and strength under particular types and amounts of compaction.

6. It should have minimum variation in volume under adverse conditions of weather and groundwater. The minimum change in volume will ensure minimum variation in differential strength and differential expansion.

Read More:

Method of Providing Superelevation

Spoil Bank

Foundation on Sloping Ground Method

Foundation on Sloping Ground

If the structure is to be constructed on sloping land, it will be expensive to build the structure at the same level. Because, the amount of earth requirement is very high, which becomes most of the time impossible due to lack of earth or more excavation cost and for high construction expenditure. The work can be economized by providing a stepped foundation.

In case of a stepped foundation, at first, the foundation trench is excavated in steps. The depth of each excavated step should not be more than the thickness of the concrete bed block which is to be provided under the foundation. Deth of each step should be multiple of even number of masonry courses.

The overlap between two layers of the foundation concrete should be equal to the thickness of the concrete bed or twice the depth of the step, whichever is greater.

A minimum foundation depth of about 80 cm should be provided at all points, this is essential from the point of view of protecting the foundation from weathering effects.

If the foundation is situated in soil or in rocks, the depth of the foundation should not be less than 1 m and 0.6 m respectively.

Read More:

Types of Foundation Settlement

9 objects of the Foundation

Method of Brick Flat Soling in Foundation Trenches

How Can You Get Good Natural Ventilation in Buildings?

First, it should be remembered that natural ventilation is mostly effective for small houses, not for large buildings. The natural ventilation system works by providing windows, doors, small openings, and ventilators in the proper location of any house. The following points should be considered to achieve good natural ventilation in buildings.

1. Inlet openings (means the opening which receives air from the atmosphere) should be located in such a way that all the portion of the room is evenly ventilated. The inlet opening should be located in the direction of wind blows and at a low level.

2. Outlet opening (which helps warm air to blow out from the rooms) should be located near the ceiling in the side walls of the room. Sometimes the outlet may be located in the roof, in this case, the area of the inlet openings should be larger than the area of the outlet.

3. The height of the room also affects the ventilation. More room height gives better ventilation as compared to a short room height.

4. Ventilation through windows can be improved by using deflectors, radiators, exhaust ducts, etc.

5. It should ensure that trees, partitions, adjacent buildings, or other obstructions do not obstruct the portion of the inlet and outlet opening. Because, it prevents the flow of winds through the opening, and reduces the rate of ventilation.

6. Long narrow rooms should be ventilated by providing openings in short walls instead of long walls.

Natural Ventilation in Buildings by providing Long narrow rooms

7. If the wind direction is variable, then the opening should be provided in all directions of the wind.

8. If gas or fuel is to be burnt in the room, then extra ventilation should be provided by providing extra windows or a large size of the outlet opening.

Read More:

Purpose of Ventilation in Buildings

Method of Ventilation of House Drains

Method of Ventilation of Sewer

5 Objects of Air Conditioning