Rail transport operations

A rail transport or railroad system is a complex synergy of components which may be classified into two groups: extrinsic factors and intrinsic factors. Extrinsic factors concern the geography, present and historical, of a system, while intrinsic factors tend to be more technical in nature. Both must be taken into consideration when constructing, operating and managing a railroad system.

Contents

1 Background factors (feasibility) 2 Extrinsic factors 2.1 Physical geography 2.2 Human geography 2.3 Historical factors 3 Intrinsic factors 3.1 Permanent way and railroad construction 3.2 Types of rail system 3.3 Signalling 3.4 Types of vehicle 3.5 Passenger operations 3.6 Freight operations 3.7 Locomotive operations 3.8 Train composition and operations

Background factors (feasibility)

Each transport system represents a contribution to a country's infrastructure, and as such must make economic sense or eventually close. From this, each will have a particular role or roles to perform. These may change with time but they will affect the specifications of each particular system.

Extrinsic factors

Rail transport systems are built into the landscape, including both the physical geography (hills, valleys, etc) and the human geography (location of settlements). The rail transport system may in turn feedback into the human geography.

Physical geography

The permanent way of a system must pass through the geography and geology of its region. This may be flat or mountainous, may include obstacles such as water and mountains. These will determine in part the intrinsic nature of the system. The slope at which trains run needs also be calculated correctly. In this stage, it is decided where tunnels will pass.

Human geography

Rail transport systems affect the human geography. Large cities (such as Nairobi) may be founded by a railroad passing trough. Historically, when a station has been built outside the town or city it is intended to serve, that town has expanded to include the station, or buildings (especially Inns) sprung up near the station. The existence of a station may increase the number of commuters who live in a town or village and so cause it to become a dormitory town.

Historical factors

Rail transport systems are often used for purposes for which they were not designed, but have evolved into due to changes in the human geography. Politics can play a large part in decisions about railways, such as the Beeching Axe. Also in the UK, building or rebuilding a railway requires an Act of Parliament.

Intrinsic factors

Permanent way and railroad construction

Main articles: permanent way, railroad construction

The permanent way trails through the physical geography. The tracks' geometry is limited by the physical geography.

Types of rail system

• Regional rail and urban heavy rail, the most common types of rail system, has reasonably high speeds and high axle loadings.

• Light rail systems are designed for lower speeds and loadings and often have simplified specifications.

• High-speed rail is a rail system designed to withstand high speed trains.

• Monorails are sometimes used instead of light rail systems for commuter transport, etc.

• Maglev is a recent development with as yet only one real implementation.

• Cog railways are used to cross steep slopes on mountain railways.

Signalling

Main article: railway signalling

Railway signals are an aspect of railroad safety.

Types of vehicle

Main articles: trains, locomotives, railroad cars

Trains are pushed/pulled by one or more locomotive units. Two or more locomotives coupled in multiple traction ("twins") are frequently used in freight trains. Railroad cars or rolling stock consist of passenger cars, freight cars, maintenance cars and in America cabooses. Modern passenger trains sometimes are pushed/pulled by a tail and head unit, of which not both need to be motorised or running. Some passenger trains, mostly commuter trains or trains on quiet rural lines and metros consist of a multiple unit.

Passenger operations

Most public transport passenger operations happen in the train station and in the passenger car. The passenger buys a ticket, either in the station, or on the train at an higher fare. There are two ways of validating a ticket. In one case the passenger validates the ticket himself (by perforating it, for instance) and this is randomly checked by a ticket controller. A conductor checks all persons on the train, validates the ticket and devaluates it, so it can't be used again. Some passenger cars, especially in long distance high speed trains have a restaurant or bar. These need to be catered. In recent times, train catering has been diminished somewhat by vending machines in the train station or on the train.

Freight operations

Freight or cargo trains are loaded and unloaded in freight yards, by using cranes.

Locomotive operations

When inactive, locomotives are housed in a train depot. In engine facilities locomotives are cleaned, repaired, etc. Decommissioned locs are sometimes used to heat passenger cars and defrost railroad switches in winter. After this period, locomotives (and other rail vehicles) are turned into scrap or are left to rust in a train depot. Some end up in railway museums or are bought by railway preservation groups.

Steam locomotives are housed in a circular train depot, a roundhouse that surrounds a turntable.

Train composition and operations

Trains are composed in a classification yard. These large, uninviting structures are excellent locations for train spotting and graffiti sighting. Switcher or shunter locomotives help the composing.fr:Réseau ferroviaire