Wanderings – Page 4 – Akshat Rathi

10 reasons why digging a tunnel under London is an epic endeavour

August 2, 2014August 7, 2014 Akshat RathiLeave a comment

The BBC has a nice documentary on Crossrail, a £15 billion project to build a new 120-km train line passing through central London. I knew that this is a great engineering challenge, but I did not appreciate the scale of difficulty the engineers faced. You can watch the three one-hour episodes here (need UK access), or here’s the summary of the interesting points illustrated with pictures (credit: BBC, Wikipedia):

1. The project is using eight specially made tunnel-boring machines (shown below), each with a female name, such as Elizabeth, Mary and Victoria.

2. One of the biggest challenges has been tunnelling under Tottenham Court Road station. It is where the tunnel-boring machine needed to pass through very crowded space. The tunnellers have labelled it “the eye of the needle”. There the 900-tonne tunnel-boring machine has had to pass through a space where 30cm above it was a live escalator and 85 cm underneath was the active Northern Line.

3. When drilling under London, tunnellers need to ensure that all the buildings above ground remain as they were. This is tricky because during the operation, there is every possibility of disturbing the earth beneath some ancient buildings, causing them to tilt or, worse, crash down. To monitor the balance, they have installed laser sensors which measure any movement. When the building starts sinking, the alarms ring.

4. The building then needs to be brought back to its previous stable state, which is done by injecting grout just at the right place to fill up any spaces that are causing the sinking. To do that, they have created 22 massive shafts throughout London, which have small pipes originating from them spreading through the ground beneath as a spider web. Whenever there is a disturbance that the laser monitors spot, they insert a tube through the right pipe that goes under the building and pumps grout in that area, which we are assured stops the building from sinking. Some shafts operators spend 16 hours a day doing this.

5. The Thames river is the first river in the world to have a tunnel built underneath it. That first 400m tunnel, opened in 1843, needed 16 years of work to build. The design of the boring machine built then by Marc Isambard Brunel is still in use. In the modern version the actual digging work is done by robotic arms rather than people. The tunnel under the Thames near Woolwich of about the same length as the 1843 one took only 8 months.

6. Despite nearly two centuries of expertise boring under the tunnel, it’s still quite a challenge. One of those difficulties is a tunnel near the Custom House station. Where they had to block the river, drain the area and work on expanding an already existing tunnel to fit the wide Crossrail trains.

7. When tunnellers use the word “breakthrough” they are literally breaking through something. And when they use the phrase “seeing the light at the end of the tunnel”, they actually see light at the end of the tunnel.

8. The Crossrail’s Canary Wharf station (shown below) is going to cost £500 million. Similarly, the new Farringdon station’s cost is £440 million.

9. Station constructions have 22-week period allowed for archaeological investigation, if an opportunity shows up. In an old city, it almost always does. Shown here is the remain of someone who died from bubonic plague, or Black Death, in the 14th century. More than 20 other such bodies were found in the same spot near Farringdon station.

10. Underground trains form an almost perfect air seal, pushing all the air in front of it at the same speed as it travels. Each underground station has to build ventilation systems to accommodate the pressure such pushed air can create. So next time you see a ventilation shaft outside a station, remember that is built not built to keep you cool underground but to make sure the air pressure created by trains doesn’t break things.

The best hack for a healthy diet

July 31, 2014July 31, 2014 Akshat Rathi3 Comments

Summary: Eat anything you want, as long as you cook it yourself.

In less than a century, we have gone from fearing impending famines to worrying about controlling a global obesity crisis. Those most affected by this are urban-dwellers. If experts are asked to choose the biggest cause for the obesity epidemic, they blame the growing demand for processed and packaged food.

It is not hard to understand why. The aim of food corporations is to ensure that they sell as much as they can. To do that, through years of research in the “cravability” department, they have figured out the ingredients that make their products tempting to buyers—salt, sugar and fat—all of which they use in unhealthy amounts.

Given the scale of the problem, people have come up with many solutions to dealing with obesity. Most common among them is to diet. I’m not obese but I wanted to understand how difficult it is to go on a diet, so I tried the slow carb diet recommended by writer Tim Ferriss. I managed to lose 3.5kg in four weeks. Some of my friends have tried the 5:2 diet and have made it work too.

While fasting has benefits beyond keeping you healthy, there are easier ways to maintaining a healthy diet. The best hack I know to achieve this is to eat anything you want, as long as you cook it yourself.

The rationale is simple: when you choose to cook yourself, you will avoid making foods like french fries or chocolate brownies on an everyday basis, just because of the amount of effort that goes into making them. You will also use salt, sugar and fat in conservative amounts. The result is you will eat healthier food without having to set up strict rules around what you eat and when.

I used to think that cooking for one person is just an inefficient use of my time. But I’ve changed my mind. The amount of time you cook is actually a very good investment given the health benefits.

Implementation: It is impractical to think you will be able to cook every meal. So there are two tricks that might help you cook as many of your meals as possible. First, when you cook, make enough to last you two or three meals. Eating the same tasty food you cooked three times is not boring. Second, allow cheat days for when you have to or you choose to eat out. Relying on my slow carb algorithm, a rule of one cheat day a week is preferable.

Bonus: In 2010, I wrote a series of posts on tasty quick fix recipes. Their aim was to live up to my mum’s words: “There is always something you can make from whatever you have in the kitchen.” Since then I’ve come up with many more such recipes, and it’s time to revive that series.

This is a post in “the best hack series”, where the aim is to find small ideas that have a big impact in improving everyday life.

Image: chezmichelle, CC-BY-NC

The best hack for a to-do list

July 20, 2014 Akshat Rathi1 Comment

Summary: Every morning, put down on a to-do list only the three most important tasks.

For the office-goer of the 21st century, a to-do list is both a boon and a curse. While it can help get stuff done, it also creates a lot of anxiety. That is because, on most occasions, the list keeps growing without an end in sight.

What is needed is a way to ensure that you get enough stuff done and end the work day on a happy note. The best hack I know to achieve that is to make a simple tweak to building a to-do list. It is not an original idea, but its implementation has completely changed how I work.

Choose the three most important tasks (MITs) that need to be done that day, and put them down on a to-do list. Come what may, decide to do those three things before leaving work. If possible, do those them first in the morning.

Of course I do more than three things every day, but the idea is that I ensure doing the things that matter the most first. I leave work without lingering anxieties of incomplete tasks at hand.

The exercise is not as simple as than you’d think. The prime difficulty is the prioritisation of tasks. But once you start doing it, you realise through trial and error how to find those three MITs. And it is that which really changed how I work.

Bonus: There are two more tweaks that I’m trying to implement to this routine. First is to ensure that I leave work at a certain time. This is to respect Parkinson’s law that states that “work expands so as to fill the time available for its completion”.

Second is to choose one of those three MITs to be a task towards a long-term goal. On days when I have been able to do that, I feel I’ve accomplished more than what is needed of me at work, and I sleep a little better that night.

This is the first post in “the best hack series”, where the aim is to find small ideas that have a big impact in improving everyday life.

Image credit: naomi_pincher, CC-BY-NC-ND