69
votes
Why are so many metros underground? Isn't that more expensive than an elevated system?
In Moscow, under former mayor Yuriy Luzhkov, it was built a line (Butovo line) which is mostly elevated. I think the practice was not considered quite successful as a result.
There are many drawbacks:
...
- 32.7k
57
votes
Why are so many metros underground? Isn't that more expensive than an elevated system?
This is mostly about urban planning, and how much change the local government can or will be able to make to the existing streets.
In London, the central parts of the city (Westminster and the City) ...
- 3,312
45
votes
Did ancient peoples ever hide their treasure behind puzzles?
One man's lock is another man's puzzle.
Combination locks have been used since at least ancient Rome. Whether the lock uses numbers or letters (or other symbols), the combination to be entered may be ...
- 4,062
43
votes
Did ancient peoples ever hide their treasure behind puzzles?
The Copper Scroll
The Copper Scroll is a Dead Sea scroll found in 1952, unique in that it is of copper (with a little tin), has a list of 63 or 64 locations of treasure with "obscure hints of the ...
- 108k
40
votes
Accepted
Why did Jodrell Bank assist the Soviet Union to collect data from their spacecraft in the mid 1960's?
SHORT ANSWER
Jodrell Bank's first 'coup', tracking Sputnik 1 in 1957 (without Soviet assistance), put it in the news and helped secure funding. It also led to a congratulatory telegram from the ...
- 108k
36
votes
Why was Panama Railroad in poor condition when US decided to build Panama Canal in 1904?
I have a book at home, The Path Between the Seas (also from McCullough), that talks about that railroad extensively. I'll try to consult it when I get home to polish this answer up, but my memory of ...
- 121k
31
votes
Why are so many metros underground? Isn't that more expensive than an elevated system?
For New York, the answer is related to real estate value.
In New York City, the construction of the metro was performed by real estate developers. The idea was to build homes, then connect them to ...
- 7,491
16
votes
Why was Panama Railroad in poor condition when US decided to build Panama Canal in 1904?
It lost its appeal after 1867, and, after bankruptcy of the French, deteriorated quickly.
Remember that is a railroad built across the jungle (just its construction took 5,000 to 10,000 deaths for 76 ...
- 1,065
13
votes
How long did it take a typical capital warship to ramp up to flank speed?
TL;DR: that is difficult to say. Mainly due to technological limitations and fluid dynamics, and as such there is a correlation between output of the engines (or reactors) and the current speed of the ...
- 1,014
12
votes
In what year did Charles Proteus Steinmetz fix Ford's Generator for the famed $10,000 invoice?
It would have been somewhere between 1917 and 1923, and thus the amount on that check would be the rough equivalent of getting a check for $150k-$200k today. Assuming the story is true at all, of ...
- 121k
11
votes
Accepted
Would every Roman army have dedicated engineers?
As the comment above indicates, the Roman army before Julius Caesar's time seems to have had a dedicated engineer corps, but this group would also be expected to fight if necessary. From Julius ...
- 319
11
votes
Why are so many metros underground? Isn't that more expensive than an elevated system?
Noise, vibrations, and visual impact drop the value of the nearest houses, and decrease quality of life for its inhabitants. The maintenance of an elevated system is expensive, not only economically ...
10
votes
Why are so many metros underground? Isn't that more expensive than an elevated system?
Quite often subway lines are built to relieve traffic pressure on areas where there is no room to add more roads, including the towers needed to allow for the creation of elevated roads or railways.
...
- 11.3k
10
votes
Why did Chicago and other cities choose an L (elevated metro) when most others chose underground subways?
I don't know about other cities, but Chicago appears to have had many troubles with its underground terrain, to the point that, to build their sewer system (once these things became "fashionable" :-)),...
- 12.7k
9
votes
Why did Chicago and other cities choose an L (elevated metro) when most others chose underground subways?
Based on my knowledge of geology, adding to @sjuan76's answer:
The geological map linked by Sjuan76 shows that most of the area underneath Chicago city is, as he says, beach ridges, sands, and gravel....
- 286
8
votes
Where is (or was) the biggest medieval drawbridge?
The purpose of the drawbridge was to deny access to the castle gate. As such, spanning large distances was not usually necessary, at least by the drawbridge itself. The still-operational drawbridges ...
- 40.5k
8
votes
Why did the steam locomotive take so long?
The steam engine was invented around the start of the 1700s
Thomas Newcomen's 1712 atmospheric engine — itself an improvement on Thomas Savery's 1698 steam powered pump, known for being prone to ...
7
votes
Accepted
When were public roads cleaned electromagnetically?
Well, the truck was definitely real, not an artists concept sketch. An image gallery at the Nevada Department of Transportation website shows the following picture:
The caption simply labels it as an ...
- 40.5k
7
votes
Why are so many metros underground? Isn't that more expensive than an elevated system?
I can add that Washington DC is still expanding its Metro and the expansion is not underground. The newest line is the Silver Line, and as it goes through Tysons Corner it's almost entirely elevated. ...
- 171
6
votes
How close did the French come to digging a canal across the Isthmus of Kra in the 1880s?
tl; dr
How close did the French actually come to succeeding at getting the project underway?
The project never came close to getting underway. The route chosen for the survey proved to be ...
- 77.2k
6
votes
Why did the steam locomotive take so long?
As the adage goes, necessity is the mother of invention. If there isn't a perceived idea, it doesn't get invented. Things get designed to solve a particular problem. There is also the issue of the ...
- 2,872
6
votes
Accepted
Are the dimensions of bricks used in Sumerian monuments like the great Ziggurat of Ur the same as in the Indus Valley Civilization?
Page 88 of the reference given above by @T.E.D. gives:
The author further observes, on the following page, that:
The most suitable brick shape that can improve the way of joining the structure to ...
- 72.4k
5
votes
Are steam engines still in regular use anywhere in the world?
A large variety of preserved and rebuilt steam locomotives are still used on well over a hundred heritage railways in the UK, some well over 10 miles in length. See the list of British Heritage and ...
- 51
5
votes
How advanced were the people of Indus valley civilization in engineering?
It would be hard to compare with other contemporary civilisation at the time viz Egyptian or Sumerian as not much written information available of that time. However, archealogical finding suggests ...
- 512
4
votes
Why did Jodrell Bank assist the Soviet Union to collect data from their spacecraft in the mid 1960's?
Alla Masevich writes in the memoirs under the name "Stars and Satellites in My Life":
In fact for Lovell such request was an important reason for advertizing of the telescope. For the first time ...
- 141
4
votes
Why did Jodrell Bank assist the Soviet Union to collect data from their spacecraft in the mid 1960's?
As can be gathered by the other answers, it's a complex topic. The University of Manchester website gives some extra information.
Firstly, the Soviets were probably annoyed that no-one outside of the ...
- 2,872
4
votes
How long did it take a typical capital warship to ramp up to flank speed?
A major limiting factor on rate of acceleration of an oil fired steam ship is how quickly the boilers can be brought to full pressure.
Large ships, such as battleships and aircraft carriers, have ...
- 3,421
4
votes
Why are so many metros underground? Isn't that more expensive than an elevated system?
There is a city Chongqing in central China, there are two big rivers & lots of rocky mountains so for some districts it was too difficult/too expensive to build underground metro (or "...
- 141
4
votes
Why are so many metros underground? Isn't that more expensive than an elevated system?
In Berlin, Germany, there is - as said before - a mixture of underground and overground services. The reason here for not using underground in some areas is the consistency of the soil / kind of ...
- 41
Only top scored, non community-wiki answers of a minimum length are eligible