Concrete Wonders - Engineering Marvels of History

[K. A. Pital]

Okay, this is the obligatory introductory post.


Concrete Wonders is a series of posts to commemorate the opening of the History SubForum - dams and HEPS and other notable buildings which were massive engineering challenges, employing unique solutions. If there are Americans, Chinese and others who want to collaborate on the macro-engineering project, you're welcome to do so.

Contribution guidelines: look at the first entry for a rough idea on the volume and quality of contributions. A data sheet, construction history and details about unique engineering challenges and solutions employed would be very much appreciated. Other notable historical trivia about the building or place, or a person involved - welcome.

Issue #1: Chirkeysk HEPS

Issue #2. Sayano-Shushensk HEPS

Issue #3. Inguri HEPS


Planned coming issues so far: Ostankino. Don't know what's coming up next But there will be more dams that's for sure

Proposed member contributions so far: GURI Dam HEPS, Venezuela by Adrian Laguna. Hoover and Grand Coulee dams. Kiel canal (so far undetailed what are it's remarkable engineering solutions), Panama and Suez channels. Coliseum and Sophia Temple from olden times.

Take up your wanted article and PM me about it!

[K. A. Pital]

Issue #1. Chirkeysk H.E.P.S.



Click for wallpaper!


The perfect location for a game-designer is usually an engineering marvel which took lots of work to make

The Sulak river begins after the confluence of the Avarskoe Koysu river and the Andiyskoe Koysu river, which are begin in Caucasus mountain and flows into the Kaspiyskoe sea. The length of the river is 160 km, the square of watershed is 13400 km2, the grade is 331m, and average annual run-off is 5.58 km3.

Project of the unique dam and HEPS on Sulak was made by the famous Leningrad institute - NII "Lenhydroproject". HEPS construction started in 1963, ended in 1978.

It was the first such project in the USSR, and it remains the highest arch dam in Russia.

The Chirkeysk dam is 232,5 meter high and 338 m long, 6 to 30m thick. The Chirkeysk HEPS is a 1 Gigawatt HEPS and the 15th most powerful HEPS in Russia. It makes 2,47 terawatt-hours yearly.

Works amount:
The excavation of rock soil 2143 ths. m3
The embankment of soil 410 ths. m3
Rockfills, drains, filters 133 ths. m3
Concrete and reinforced concrete 1491 ths. m3
Metal construction and mechanisms 9,8 ths. T
Estimated construction cost in the prices of 1969 year - 207,4 million. rub
A. Construction of hydrotechnical buildings - 260,89 million. rub
The cost of storage - 10.9 million. rub
Constructive-wiring works - 215,87 million. rub
B. Cultural and house building - 18,7 million. rub
Capital investments in energy - 283 million. rub

Unit capital investments per 1 calculated kWt - 180 rub
per 1 kWt-hr - 7,3 kop

Schemes:

[(1) - more stats and schemes at Lenhydroproject]

Construction and trivia:
During the work on such a narrow and deep ravine (width at bottom 15m, at top 350m) for the first time in the Soviet Union the technology of "straight-surface fracture" was used for forming the bank cliffs. The quality of this fracturing done by HydroSpetsStroi on this construction site is referred to as exemplary even until today.


CAPTION: Construction of Chirkeysk HEPS was started like this... 1965. (Work on the foundation pit)

A smaller construction waterway tonnel was first made (seen up on the scheme):


Then, on 29 October 1967 a directed blast in mere seconds displaced 130,000 cubic meters of stone into the Sulak riverbed, forcing the river to flow into the construction tonnel. The blast was 37 tons TNT, with three slow-down stages with an 25m/s interval.

CAPTIONS: Sulak closed with direct blast. Foundation pit works at riverbanks.

On 28th February, 1970 the first concrete is laid in the dam foundation. During the construction of the deep cement hold in the foundation of the arch dam, on 14th May, 1970, the dam was in the epicentre of a Magnitude 9 earthquake in Dagestan. It did not suffer, but the left bank cliffs which should have been holding the arch dam became unstable. It was thus strenthened with concrete and very strong steel anchors. To do this, on 6 various levels three shafts were run, housing each 32 anchors, each under a 50-ton stress, in total the anchors numbering around 300. Their condition is controlled by engineers until this day. There are a total of 34 small anchor shafts, 40 to 98 meters deep.


CAPTION: Concrete strengthening of the unstable cliff massive.

During the creation of the deep concrete block in the base of the dam, for the first time in Soviet HEPS construction a fully-automated system of cementing control was used. The peak of cementing fell on 1972-1975, when during a single month up to 4,5 thousand metres of cracks were cemented.

The construction was done very fast, with concrete filled in by special cable cranes, then straightened by vibro-machines. The unique cable crane system - three cable cranes with a lift mass of 25 tons and a 205-meter rise, with cables as long as 500 meters thrown across the cliffs from one bank to the other, moving 8 cubic meter concrete-filled buckets. To mechanize the works, a tractor chassis vibromachine, a self-propelled cleaner machine to take off the concrete layering on everything around and a excavator-chassis manipulator to move the encasement. All this mechanization allowed to achieve a tempo of up to 12 m^3 of concrete per one man-workday. This method of concrete-laying was dubbed "chirkeysk laying" and marked by high awards in the USSR.

Finally the dam body was filled with 1,275 million m^3 of concrete, and the total amount of concrete laid is around 1,5 million m^3. That is equivalent to a concrete cube with a 110 m side.


CAPTIONS: Concrete is being delivered by cable-cranes and vibrated by machinery. Montage of waterways.

The waterways are huge metallic tubes 5 meters wide and 170 meters long. To strengthen and protect them from outside damage, they were encased into 1,5m thick concrete.

(courtesy: www.audi80.ru)

And so in 1974 the dam body was finished and it was launched in a festive opening ceremony, when in December it gave the first electricity. The date of launch was planned much earlier than the dam reservoir would get filled, and so around half the dam height, an auxillary entrance was made into the first waterway, which put water to the turbine. Later it was removed.


CAPTIONS: The dam is ready. The first hydrounit - ready! Launch!

From 1974 to 1976, all four hydrounits (waterway+turbine) were launched. Due to the narrow ravine, the hydroturbines were placed in chess order, which was also a unique solution for the time. Each turbine is 250 MWt.

CAPTIONS: Hydrounit stator shaft. The hydrounit rotor is delivered. Everyone is ready for the hydroplant launch...

In the HEPS, looking at wires and the dam (courtesy: www.audi80.ru)

A spare rotor - size demonstration (courtesy: www.audi80.ru)

The construction waterway tonnel was cut off, and thus the Chirkeysk reservoir began to fill up. During the fill up, the village Chirkey - the dam's namesake - was sunk. The villagers were moved to New Chirkey (Noviy Chirkey) on the riverbank. For the sinking of their village, they received new housing for free and huge compensations - even until now they legally used free electricity.


CAPTION: Chirkey village (sunk)

To drain excess water in the reservoir, a huge new drain tonnel was built, 10 meters wide and 700 meters long. Around 2400m3 of water can pass through it with a speed of 50 m/s.

CAPTIONS: Construction of the water drain tonnel /coating done now/. Waterways are finished.



The HEPS is almost finished. 01.06.1978, by A. Zybin.

There's also a 800m long automobile tonnel through the right bank cliffs to get to the powerplant. Over the dam on a mountain 500 meters higher, stays the city of Dubki (lit. Oaks). It is the city of hydroplant workers and builders, most of them still live and work there. It used to be a small town:

CAPTION: The town of the hydro-builders - DUBKI
A huge reservoir panorama from DUBKI

The explosive, drilling and cementing works done by HydroSpetsStroi have been marked by many VDNKH (All-Soviet Economy Exposition) awards. The collective of engineers and builders of the Chirkeysk HEPS for the following feats - strengthening an unstable cliff massive, arranging electric transmission from a narrow ravine's bottom, constructing the water drain end which allows to throw water off-bank, the waterways for turbines and the "chirkeysk concrete laying" method - were awarded the Premium of the Council of Ministers of the USSR.

On 9th of February, 1981 the hydrosystem was accepted into industrial exploitation.

15.08.1981, Somov Yuri.

SOURCE MATERIAL:
1. DAG SPETSHYDROSTROI webpage on Chirkeysk HEPS
2. ChirkeyskGESStrois (main construction company) webpage on Chirkeysk HEPS
3. LenHydroProject page on Chirkeysk HEPS
4. RIAN Image Library, "Chirkeysk HEPS"
5. A Chirkeysk HEPS visitor Alenok, who also borrowed most of the photos of construction from a private builder's album
6. Chirkeysk HEPS visitors from Audi80.ru website
7. OAO CDU-ES SOUTH page on the Chirkeysk HEPS

[Darth Wong]

Personally, I was always impressed by the Hoover Dam. While it may have been surpassed by other much larger and more impressive dams, it was done without the benefit of so much modern technology and machinery that we would use today. The blood and sweat and toil of ordinary men, so often unassisted by machinery, strikes me as a more profound accomplishment.

But if one is going to talk about concrete wonders, you really can't do it without mentioning the Roman Coliseum. After all, they actually invented concrete (and red bricks too) in order to build the thing, and it's still standing.

[K. A. Pital]

Personally, I was always impressed by the Hoover Dam.

I actually want someone to tackle that; I feel that an American would be best qualified. I even proposed for Volly do something useful and make a contribution as opposed to spamming about anarchism everywhere. So far he's been silent however.

[Fingolfin_Noldor]

The other concrete wonder that also deserves mentioning is the Hagia Sophia. Thousand years on since its construction (though the dome was reconstructed at least more than once), the structure still stands despite earthquakes and what not. A true testament to excellent Roman (though Byzantine) engineering.

[wjs7744]

I'm not sure how much is made of concrete, but I always found the Panama canal pretty impressive. Although I do remember seeing a documentary at one point that told how it was basically built on slave labour.

[Sea Skimmer]

But if one is going to talk about concrete wonders, you really can't do it without mentioning the Roman Coliseum. After all, they actually invented concrete (and red bricks too) in order to build the thing, and it's still standing.

They might have invented a new kind of concrete to build it, but concrete was hardly new, it was recently discovered that a good portion of the Egyptian pyramids were in fact poured concrete.

[Fingolfin_Noldor]

I'm not sure how much is made of concrete, but I always found the Panama canal pretty impressive. Although I do remember seeing a documentary at one point that told how it was basically built on slave labour.

You could throw in the Suez as well, though I understand that the Panama was more challenging in part because of wet soil conditions and the weather.

They might have invented a new kind of concrete to build it, but concrete was hardly new, it was recently discovered that a good portion of the Egyptian pyramids were in fact poured concrete.

There was this theory that Roman concrete was mixed with volcanic ash or something. The mixture allowed for strength and flexibility which allowed the Romans to build heck of a lot of stuff.

[MKSheppard]

That is an impressive post, sir. I commend you.

[Ma Deuce]

Personally, I was always impressed by the Hoover Dam.

For me, it's the Grand Coulee Dam, completed only six years after the Hoover, but is a far larger structure at nearly a mile long, and wider than the Great Pyramids at it's base. As far as I know, it is still the largest concrete structure in the United States. On the other hand, I understand an arch dam like the Hoover is much harder to engineer than a solid gravity dam.

[phongn]

I'm actually thinking of writing up the Grand Coulee and Hoover dams, but I may not be able to commit to the required time.

[PeZook]

If canals are allowed, I'll have to propose the Kiel canal. Few people know about it, but it's an important strategic resource, and had a big role to play in both world wars.

Then there's the Boston Tunnel, an undertaking which was completely insane when it was incepted, and only became slightly less so after introduction of various technological aids.

[K. A. Pital]

Issue #2. Sayano-Shushensk H.E.P.S.

7th most powerful in the world, 16th tallest concrete dam.

Click for wallpaper!

- The most powerful HEPS and electricity plant in Russia and the USSR - 6,4 GWt, makes 23,5 billion kWt-h yearly.
- The strongest and most stressed dam in the world - under 18 million tons of stress (Guiness Book of Records).
- The largest arch-gravity dam in Russia - 245m high, 1066m long, 110m wide at base and 25m wide at top.

The Yenisei River begins after confluence of big and small Yenisei, and flowing from south to north flows into the Yenisei gulf of the Kara Sea. The length of the river is 3487 km, the square of watershed is 2580 km2, the grade is 613 m, and average annual run-off is 610 m3.

Project of the dam and HEPS was made by the Leningrad NII "Lenhydroproject". HEPS construction started in 1966, ended in 1988.

Works amount:
The excavation of soft soil 3302 ths. m3
The excavation of rock soil 4351 ths. m3
The embankment of soft soil 3862 ths. m3
Rockfills, drains, filters 33 ths. m3
Concrete and reinforced concrete 9720 ths. m3
Metal construction and mechanisms 114,3 ths. T
Estimated construction cost in the prices of 1969 year 1243,6 million. roubles
Capital investments in energy 1009 million. rub
Unit capital investments per 1 calculated kWt 161 rub
per 1 kWt-hr 4,4 kop

Schemes:

[(1) - more stats and schemes at Lenhydroproject]

EXPO-70 (Osaka)
The dam and HEPS were the main exhibit on Osaka Expo-70 in the USSR pavillon. A scale model reflects a slightly different – more visually astonishing – project of the S-SH GES.

VDNKH
In 1982, commemorating the S-SH GES, another huge scale model was erected. You can see Italian delegates gazing.


Construction and trivia:


The writing «We're coming for you, Yenisei!»
1966 – in the Cheremushki town the 4th district where the management of «SayanGESStroi» resides is created. The administration is led by enginner Andrey Usachev.

Gagarin visits the building site. He leaves a shovel. G.T. Beregovoi with this shovel commemorating the start of river blocking – 11 October 1976. And the Yenisei river is blocked. Mere two years later, in December 1978, the first turbine goes online.
On 12 September, 1968 the first barricades are laid in the Karlov pit. On 1 October 1969 the administration of main superstructure construction is created, led by V.M. Evgrafov and chief engineer A.P. Dolmatov. In 1970 the first que pit is filled and on 17 October the first cubic meter of concrete is laid into the foundation. In 1975, A.G. Brusse rises to be the chief engineer of construction. The initiative for speeding up Sayano-Shushensk HEPS construction coming from Leningrad is supported by 43 enterprises in Krasnoyarsk, a creative cooperation council is created. S.I. Sadovsky becomes the chief of construction.

Construction site at night.
On 31th August, 1976, one million cubic meters of concrete are laid into the foundation. In 1978, Kosygin visits the HEPS and three million cubic meter landmark is reached, and on 18 December the first hydrounit is launched. On 23rd May next year during the spring water rise the powerhouse is overflown by water. By 4th July it's online again. 20 August, 1979 – 4 million cubic meters are laid. In winter, the second and third hydrounits are launched. 5 million cubic meters of concrete are reached in 1980. In October, on the Komsomol Day, the fourth turbine goes online and receives the name «Komsomolskaya», and in December the fifth is online. In 1981, the sixth one goes online ahead of schedule. In 1982, the HEPS becomes the seat of 60th Congress of the COMECON Electric Energy Commission which had the energy ministers of all COMECON nations. It was led by USSR energy and electrification minister P.S. Neporozhny (1910-1999) – in 2001, the station was given his name in honour.

One single brigade managed to lay 1,000,000 cubic meters of stone during construction. Overall during construction two brigades reached the 1,000,000 hallmark.
In 1984, 8 million cubic meters are laid, 7th and 8th units launched.

In 1985, the 9th and 10th units were launched and the Sayano-Shushensk HEPS became the most powerful HEPS in all of Eurasia. Next year, the final million m^3 of concrete were laid. In 1988, the HEPS is put into industrial exploitation by decree of the Council of Ministers.

An interesting fact: during the HEPS construction, alpinist builder crack teams were used, comprised of some of the best alpinist sportsmen in the Union. This practice started with the world's highest Nurek Dam in Tajik SSR, when alpinist units proved to be the only way to reach some of the locations. During one month of work, the HEPS builder alpinist crack team hanged 20,000 square meters of nets (with a total weight of 60-170 tons), drilled and anchored 1500 anchor shafts, used up around 5-6 thousand meters of wire to secure the nets. Each alpinist in the crack team made around 8-10 km up and down on the cliff on the average.

Saganenko Galina Iosifovna (30.11.1940) – a member of alpinist-engineer crack team. Mathematician, sociology PhD, Prof., graduated from mathetmatic-mechanical faculty of LGU (1963), a member of the Russian Academy of Sciences). First mountain climbing in 1964, last – 1987. Candidate for Sports Masters in Alpinism (1969). Candidate for Sports Masters in Cliff Climbing (1967) – 7 times the champion of Leningrad in cliff climbing contests, silver on the All-Union Competition (1970).

The generators were a challenge for Leningrad project engineers. Each 640MWt generator had a mass of 1860 tons and the stator was 14m in diameter.


The rotors were delivered to the HEPS by the north seas from Lenigrad:



Construction progress in photos (clickable for large panoramas):


SOURCE MATERIAL:
1. SH GES official website – with a photogallery in History too
2. An article about HEPS crack alpinist team
3. LenHydroProject page on Sayano-Shushensk HEPS
4. RIAN Image Library, "Sayano-Shushensk HEPS"
5. A visitor to the HEPS, great photos
6. Sayano-Shushensk HEPS article in USSR_INDUSTRY
7. Greycygnet's SHGES photoarchive

[K. A. Pital]

Issue #3. Inguri H.E.P.S.

Highest arch dam in the world and the fifth highest dam overall.

Click for wallpaper!

And click this little picture for a sense of scale


The Inguri river in Western Georgia starts from mountain ice shelfs and flows into the Black sea. The length of the river is 213 km, the square of watershed is 4060 km2, and average annual run-off is 170 m^3/sec.

Dam project made by the Hydroproject Institute. HEPS construction started in 1967, station entered industrial exploitation in 1978, site construction finished 1985.

The Inguri dam is 271,5 m meters high and 750 m long.
It's installed power is 1,3 GWt, it makes 4430 million kWt-hours yearly. It has 5 turbine units, each of which provide around 250 MWt.

The plant employs derivative-HES type engineering solution for power generation - the turbines are situated in a machine hall which is removed from the dam - a 15-km long waterway which is part open aqueducts, part tonnels that go through mountains giving extra 150m pressure, leads from the dam to the underground station which is deep inside a mountain - and the water falls into the river Erisckali.

This will later play an important part in historical events.

Works amount:
The excavation of rock soil ~3200 ths. m3
No exact money figures, but urban talk indicates 2-4 billion roubles.

Scheme:


Construction and trivia:
In 1965, the project of Inguri generators - some of the most complicated in the entire USSR hydro-industry, with internal stator cooling - was finished. Actual construction of Inguri HEPS started in 1967. In 1978, the first hydrounit was launched.

Inguri HEPS scale model, 03.01.1967. Construction of Inguri HEPS starts, 06.05.1967.


The workers of the Vedeneev Hydrotechnics Institute run a real-life test of strength on a copy model, evaluating possible higher stress points and failure risks. Leningrad, 01.12.1973.


HEPS builders return from workshift, 01.03.1978, 01.11.1978. The ultra-long cable cranes to raise concrete. 01.06.1977.


Alpinist crack team, 01.09.1977. On-site the leader of the crack alpinist team Negusi Akobia. 01.01.1977. The alpinist team works under the dam cap, 01.06.1977


Construction chief Mikhail Tsiskarishvili. 01.01.1977 Arch dam is being raised. 01.06.1977. Cable crane delivers concrete buckets to the dam body. 01.11.1978.


Waterways are mounted, and turbines are prepared for launch in the underground plant hall. The underground part of the waterway is constructed. 01.11.1978.


01.11.1978 >> 19.12.1982 >> 01.06.1985, dam finishing.

When Inguri started to run at full capacity in the end of 1970s, all smaller HES on Inguri were closed down since the station was more than adequate for supplying all of Georgia. But ten years later fate played a cruel joke on the inhabitants of Georgia.


One aqueduct part of the 15-km long waterway. 01.12.1985.

This mega-HEPS generates, by various accounts, 40 to 80% of Georgia's electricity [Georgian Energy Ministry and USAID; Russian CIS Trade and Investment System]. The rest (around 250MWt) Georgia buys from Russia.

Inguri and the recent history of Georgia
After the collapse of the USSR, Georgia entered a violent civil war. Inguri was the Georgian-Abkhazian natural border. Abkhazia seceded and the war ravaged both briges over Inguri, as well as parts of the mega-HES. After the war died down with the peacekeeper introduction, the HES was divided between Georgia and Abkhazia. Georgia controls the reservoir and the dam, but the station with electric turbines is deep in Abkhazia. Part of the electricity goes to Abkhazia thus, and they de-facto control the generators.

After the war in the 90s and 2000s, the station was run at 40-50% capacity (only 3 units top) and with frequent blackouts.

Georgia entered the night kinda like DPRK, leaving all Soviet urban centers - seaports - and the smaller towns and villages light-less.

Georgia, night-time light composites: 1993 and 2003.

The Russian trade ministry evaluated that Georgia has around 1 GWt of energy generating plants (including Inguri which makes up the bulk of it), but it requires twice as much - around 1,7 GWt (in Soviet times, it had around 1,8GWt). 70% of that is made by hydro-plants.

The sad and unfunny situation is that Inguri - both the dam and the turbines are in such bad condition because neither Georgia nor Abkhazia have any money to serve them properly - that they could barely afford one repair in what, 17 years? This is the source of constant blackouts.

Inguri dam is the "DMZ" between Abkhazia and Georgia and it is a border point, controlled vigilantly by soldiers from both sides.

Check out the pics:


SOURCE MATERIAL:
1. Large Soviet Encyclopedia 1970 edition, Articles "Underground Construction" and "Hydroenergetics"
2. Hydroprojects' "Foreign Objects" page
3. RIAN Image Library, "Inguri HEPS"
5. cyxymy about Inguri HES

[The Duchess of Zeon]

I'm actually thinking of writing up the Grand Coulee and Hoover dams, but I may not be able to commit to the required time.

I may do it instead, but I may focus on a less well known but still impressive project in the North Cascades instead, the Skagit River Dams: Gorge, Diablo, and Ross. They had to build a 50 mile long railroad simply to get to the site through untouched primeval forest, and to build the later of the two dams they had to build a funicular railroad to haul the friction railroad cars about eight hundred feet up an almost sheer slope. Here's Gorge Dam, the smallest of the three, and the Incline, as it's called, is over to the left:

[K. A. Pital]

That is cool. Is that an arch dam? How the hell is it protected from the water shock, there's water falling down everywhere it seems.

[The Duchess of Zeon]

That is cool. Is that an arch dam? :shock: How the hell is it protected from the water shock, there's water falling down everywhere it seems.

Yes, they have to do that to avoid the dam from bursting. Two of the dams on the Skagit are arch dams by necessity, considering the immensely rocky and high terrain of the area, and they have to be build with sluice gates capable of dumping that much water through them, because the nature of the Pacific Northwest is that our climate is a temperate rainforest, with extreme snow accumulation in the winter in the high mountains. When the snow melts it causes steady rises in rivers, not flash floods but over a period of 12 - 24 hours, which can rapidly swell resevoirs well beyond capacity. The dam is actually shaped like an S-curve due to the unique topography it was built in.

I misidentified the dam, since I was going on the last time I'd seen them, as a child, when I was traveling up there at the age of 13 (so I misremembered)--that's actually Diablo Dam. One of the reasons I misidentified it is because Lake Diablo has this beautiful, beautiful Azure colour in summer, and I didn't immediately associate the gray, muddied resevoir at floodstage with what I'd only remembered seeing when young when it was so placid and so uniquely coloured. Gorge is a 300ft gravity dam; Diablo and Ross are the arch dams. Construction on Gorge Dam began in 1921; the Pacific Northwest pioneered mass dam construction projects in the United States in many ways, and so this was a precursor to the great projects of FDR's era. Anyway, this is Diablo during the summer or fall when the Skagit isn't at flood stage:

here's the picture, you useless IE users.

[K. A. Pital]

Sweet project. When the water is going down I didn't notice the natural rocky slope. Must've been a pain in the ass building it in such narrow gorges.

That's more interesting than Hoover or Grand Coulee actually. Not as well known, that's why

[The Duchess of Zeon]

Sweet project. :) When the water is going down I didn't notice the natural rocky slope. Must've been a pain in the ass building it in such narrow gorges.

That's more interesting than Hoover or Grand Coulee actually. Not as well known, that's why ;)

Yes, it was a very impressive feat of engineering; here's a local news report on some river channel modification they did to restore full potential to the tailrace after a gravel bank was formed following the utterly massive 2006 fall storms and flooding. I think you might find it interesting.

[K. A. Pital]

If you'll have time to compose something about the construction of those things, you're welcome. The post structure is not that formal of course, but it would be nice to keep a unity of style

[wjs7744]

Then there's the Boston Tunnel, an undertaking which was completely insane when it was incepted, and only became slightly less so after introduction of various technological aids.

Well, if we're talking about tunnels what about the Channel Tunnel here in England? It's over 30 miles long.

[PeZook]

Well, if we're talking about tunnels what about the Channel Tunnel here in England? It's over 30 miles long.

Yeah, the Chunnel is awesome, but that crazy American wanted to dig a railway tunnel through the Apallachians by hand

[starslayer]

PeZook, do you mean the Hoosac Tunnel? A quick google search only turns up the Big Dig for a Boston tunnel.

Hoosac was an odd project, but its long history was mainly due to the fact that the first engineer misjudged the rock on the western side of the mountain. There, they ran into a large patch of rock with no stand-up time, not to mention a lot of water. This derailed the project until the route was resurveyed and a central shaft dug to pump the water out, at which point the tunnel finally moved to completion.

Also, most of the tunnel wasn't actually built by hand, IIRC. Nitroglycerin and pneumatic drills were coming into use around that time, so that the old hand techniques were replaced rapidly.

[Zor]

Stas, while this a very interesting thread, i would really apreciate it if you did a minor edit that removes the annoying format breaking.

Zor

[K. A. Pital]

Stas, while this a very interesting thread, i would really apreciate it if you did a minor edit that removes the annoying format breaking.

Zor

What, you're not 1024x768 screen? In that case pardon me. I only broke it due to the 800px wide images being hosted on a foreign server (and since I'm kinda short on my preferred image hosting space).

EDIT: hey... I think it's the Duchess, who unwittingly blew it up with a 1024px wide picture... I can't do much about it.