Slow Zone
Encyclopedia
A slow zone, in America, is an area where a train is forced to slow down for either structural, construction, power, signal, or track problems. Slow zones limit a train to about 10-35 MPH. Notification to train crews is referred to as a "slow order."
In the United Kingdom
the term "speed restriction" is used, either permanent (PSR), temporary (TSR) or emergency (ESR).
The last two are used where movement of the track is causing problems. PSR's are usually only for curves or switches and crossings (S&C). PSRs may also be imposed where signal spacing is short relative to braking distances.
As will be seen from the image, some PSRs are dual, allowing certain trains to pass at a higher speed, such as InterCity 125
(HST) and certain other classes.
In the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
the term "speed restriction" is used, either permanent (PSR), temporary (TSR) or emergency (ESR).
The last two are used where movement of the track is causing problems. PSR's are usually only for curves or switches and crossings (S&C). PSRs may also be imposed where signal spacing is short relative to braking distances.
As will be seen from the image, some PSRs are dual, allowing certain trains to pass at a higher speed, such as InterCity 125
InterCity 125
The InterCity 125 was the brand name of British Rail's High Speed Train fleet. The InterCity 125 train is made up of two power cars, one at each end of a fixed formation of Mark 3 carriages, and is capable of , making the train the fastest diesel-powered locomotive in regular service in the...
(HST) and certain other classes.