--- title: Trains and the Underground — a lesson of Mova's school · trees and pragmatics description: «Trains and the Underground», a lesson of the technology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: A train is a long chain of carriages or wagons rolling on two steel rails. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Technology](https://md.mova.elamur.ai/free/en/corpora/school/technology/) / Trains and the Underground # Trains and the Underground Lesson 21 of the technology course of Mova's primary school: 20 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/technology/21-trains-and-the-underground/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/0/) — A train is a long chain of carriages or wagons rolling on two steel rails. - [1](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/1/) — The rails steer the wheels, so the driver can only make the train go faster or slower; a train can never swerve round anything on the line. - [2](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/2/) — Steel wheels on smooth steel rails roll with very little friction, the rubbing that slows things down. - [3](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/3/) — That is why one locomotive, the engine that pulls the train, can pull a whole line of heavy wagons, and also why a fast train needs a very long way to stop. - [5](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/5/) — That is why you always wait behind the yellow line. - [6](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/6/) — To keep trains apart, the line is cut into sections, and a signal shows red while a train is in the section ahead. - [7](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/7/) — Under big cities, electric trains run in tunnels called the Underground, the Tube, the metro or the subway. - [8](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/8/) — Electric trains take their power from overhead wires or from a third rail beside the track; diesel trains carry their own engine. - [9](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/9/) — Because steel wheels roll so easily on steel rails, a fast train can need more than a kilometre to stop. - [10](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/10/) — Rails are fixed to sleepers laid on a bed of stones; at a level crossing, lights flash and barriers close the road before a train comes, and a second train may follow the first. - [11](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/11/) — A live third rail or an overhead wire can kill without any train in sight; overhead wires in Britain carry about 25,000 volts, and the electricity can jump to someone who only comes close. - [12](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/12/) — The London Underground opened in 1863 and was the first underground railway in the world. - [13](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/13/) — A signal shows red when a train is in the section ahead; modern signalling can stop a train automatically if it passes a red signal. - [14](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/14/) — Ticket barriers read paper tickets, cards or phones and then open; the gates close fast, so nobody should squeeze through behind someone else. - [16](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/16/) — Japan's Shinkansen bullet trains began in 1964 and are famous for running on time. - [17](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/17/) — In the cab the driver controls the speed with a lever and watches the signals; a safety pedal or button must be pressed regularly, or the train stops by itself. - [19](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/19/) — London's Docklands Light Railway has run with no driver in a cab since 1987; computers drive it between stations. - [20](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/20/) — Platform screen doors are glass walls along the platform whose doors open only when the train's doors line up with them, so nobody can fall onto the track. - [21](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/21/) — A freight train is a long line of wagons pulled by a strong locomotive, carrying coal, containers, cars or stone; one freight train can take dozens of lorries off the road. - [22](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/22/) — A usual passenger carriage runs on 8 wheels: two sets of 4 wheels, one set near each end. - ← previous: [Buses, trams, lorries and traffic lights](https://md.mova.elamur.ai/free/en/corpora/school/technology/20-buses-trams-lorries-and-traffic-lights/) - next →: [Why planes fly](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/) - ↑ back to [Technology](https://md.mova.elamur.ai/free/en/corpora/school/technology/)