Notes about trains and railways

These are notes on important but little-know information about railway engineering that is not found in most textbooks about railway engineering. E.g.: Derailment containment.

1 Track

Track supports the weight of the train and guides it. All types of track are support structures for steel rails.

1.1 Gauge

1.2 Axle load rating

Typical axle load ratings as of 2023:

1.3 Ballasted track

1.3.1 Sleepers

1.4 Slab track

1.4.1 Types of slab track

1.5 Directly-attached track

Occasionally in bridges rail is fastened directly to a grider under the rail that runs through the length of the bridge without gaps.

1.6 Rail

See also:

1.7 Derailment containment systems

Types of derailment containment systems

Source for the types: Functionality Analysis of Derailment Containment Provisions through Full-Scale Testing—I: Collision Load and Change in the Center of Gravity

Railway containment systems keep the rail vehicles close to the track in case of derailment. This reduces the damage to both the train and the surroinding infrastructure.

All track should be protected by derailment containment. However, mediocre practice usually limits it to bridges. Derailments are especially problematic on bridges because the train can fall over the sides or hit and damage structural elements. The latter also applies to tracks under bridges.

1.8 Switches

1.9 Track on bridges

1.10 Tramway track

2 Electrification

3 Rail vehicles

Greater Freighter wagon in Australia

Greater Freigher wagons in Australia (the 3 wagons after single passenger wagon) Source.

US-American bogie name Axle load Wheel diameter
100 ton 319 kN (32.5 t) 914 mm
125 ton 350 kN (35.7 t) 965 mm

3.1 Couplers

Type F couplers.

Type F couplers (source).

Scharfenberg coupler.

Scharfenberg coupler (source).

3.2 Bogies

3.3 Loading gauge

Loading gauges are given as width × height. This refers to the maximum width and height. Note that the loading gauge is usually not rectangular, but instead it tapers near the top (for tunnels) and the bottom (for platforms). Also, there is some clearance between the top of the rail and lowest allowed part of vehicle body.

Region Max. width (mm) Max. height (mm)
North America 3251 6172
Russia and ex-USSR 3400 5300
India 3660 ?

4 Shunting

Shunting is also known as switching, classification and marshalling.

All current methods involve a shunting bowl.


4.1 Innovative shunting methods

5 Train logistics


6 Ultra-broad gauge railways

There are railways built with a much broader gauge for specific applications. For example: The Krasnoyarsk ship lift with a gauge of 9 m.

7 Differences between countries

Region Length Speed Electrified? Typical axle load Containers
North America Very long, ~2 km Varies widely, from walking speed to ~90 km/h Generally not electrified 319 kN (32.5 t) Double stack well cars
Western Europe Short, ≤ 780 m. Fast Mostly electrified 221 kN (22.5 t) Single stack flat cars
Russia and ex-USSR Long, 1.5 km. Fast Mostly electrified 230 kN (23.5 t) Single stack flat cars
India Medium, 1 km. Fast Significant electrification ? Double stack flat cars

8 Technical specification of railway companies for private track

9 Railways compared to other forms of transports

9.1 Conventional railways compared to maglev

10 Rail modeling

10.1 Vendors

11 Details

Details relevant to rail modeling.

11.1 TTX series