Those of you in Mumbai will have noticed that our city is going topsy-turvy of late. Dug up roads, diversions, and loads and loads of construction everywhere! What’s going on? The city is literally going underground! Mumbai is getting its very own Metro System – a rapid underground network of trains.
Did you know that:
- there are over 160 subway systems on Earth?
- while excavating for the Paris metro, construction workers uncovered cannonballs, catacombs (cemeteries) full of human bones, and the foundations of historic buildings and very deep quarries from ancient Roman times? Eeeek!
Underground trains sound awesome, but isn’t that a lot of work? Yes! Engineers have to dig tunnels underground, and put in a sophisticated network of chutes and connectors.
But how do they know where to dig? That is really tricky stuff! Engineers and architects study blueprints (maps) of electrical lines, sewage lines and water lines that are underground. They then come up with a plan for where they will make tunnels so that they are least likely to cut through these important conduits. If they cut through these, then the area around them will not have water or electricity! Modern machines can dig tunnels below these obstacles and sometimes even below massive rivers. As you can imagine, waterproofing is a critical part of constructing subway tunnels. Also very important is a ventilation system to make sure there is circulation of fresh air reaching underground.
How are these trains powered, and who drives them? In the olden days, some subways used steam engines. Now, the trains, tunnel lights and station equipment all run on electricity. There are usually drivers for these trains, however some countries (Denmark) and cities (New York City) are trying to upgrade to automated, driverless trains.
Mapping a subway system is also super interesting. Initially, maps for the London Underground depicted the different train lines geographically and used a regular city map as a base. The main areas of the city therefore had stations drawn all bunched together which made reading the map quite tricky.
In 1931, a man called Harry Beck was working on making technical drawings. He got the brilliant idea of creating a full system map in colour. He realised that passengers didn’t really care about matching the exact geography to the location of the station – they just wanted to know how to get from one station to another and where to change trains. He used an electrical circuit diagram and devised the concept of an electrical schematic where all the stations were drawn almost equally spaced rather than with geographic accuracy. This was quite an ingenious idea at the time and has now been recognised as a classic.
Written by: Purnima Thacker, a keen art admirer, nature enthusiast, intellectual property lawyer and mum to a curious 8 year old.