Consider the 'grand-daddy' of all tunnel 'day-lighting' projects - the Southern Rwy.'s gradual elimination of all but 1 tunnel on the former 'Rathole' division of the Cincinnatti, New Orleans & Texas Pacific / Cincinnatti Southern line, which is described in this article from the Southern's "Ties" magazine titled "90 Years to "Daylight" ": http://southern.railfan.net/ties/1963/63-8/daylight.html
See also the messages on the forum about "Abandoned Rathole Tunnels" at this link: http://www.jreb.org/ns/index.php?topic=91.0
Finally, here's a link to a recent Steve Schmollinger photo of the Kings Mountain Cut, which bypassed one of the early 'Rathole' tunnels (No. 1 ?) as part of the early 1960's improvements. M-O-W people on other railroads that have cuts and tunnels to maintain have been known to cry ( ) when they see photos of cuts like this one - and the few new tunnels have almost as impressive overhead clearances:
http://www.railpictures.net/viewphoto.php?id=342451
- Paul North.
Murphy Siding Page 73 of the January issue of Trains Magazine shows a Westbound BNSF Railway stack train fololwing the Flathead River through tunnel #4 in West Glacier, Montana. The tunnel appears to be as long as, say, 6 or 7 railcars. The amount of rock above the cars is perhaps 3 times the height of a loaded double stack car. The rock on the river side of the tunnel looks to be 2 to 3 times the width of the tunnel opening. Why would the builders have gone through all the work of building and maintaining a tunnel ,that looks like it could have easily been daylighteed?
Page 73 of the January issue of Trains Magazine shows a Westbound BNSF Railway stack train fololwing the Flathead River through tunnel #4 in West Glacier, Montana. The tunnel appears to be as long as, say, 6 or 7 railcars. The amount of rock above the cars is perhaps 3 times the height of a loaded double stack car. The rock on the river side of the tunnel looks to be 2 to 3 times the width of the tunnel opening. Why would the builders have gone through all the work of building and maintaining a tunnel ,that looks like it could have easily been daylighteed?
In addition to the technological limits of the time you also have to consider the state of the railroad busines back then. Since obviously things like Double Stack Intermodal trains, Autoracks, and Superliner passenger cars didn't exist yet and nobody fathomed of their existence they figured that as long as it provides clearance for the equipment around at the time no sense going to all the extra work.
Paul_D_North_Jr When I have an opportunity, I'll post a photo or two of mine from last April or so of the Gwynedd Cut, formerly the Gwynedd Tunnel, of the Reading RR - now SEPTA, about a mile southwest of the Borough of North Wales, PA - at Lat. / Long. N 40.19674, W 75.26733 per the "ACME Mapper 2.0 " application. It was a shallow tunnel - well less than 100 ft. cover - when first bored through loose sedimentary rock in the mid-1800's as part of the construction of the North Pennsylvania Railroad/ branch, but was 'daylighted' circa 1930 as part of the electrification of the Reading's suburban lines to provide sufficient overhead clearance for the catenary wires and high-voltage transmission poles above. Recently SEPTA was installing chain-link fencing and shot-creting/ 'guniting' portions of the sides of the resulting cut to reduce the incidence and extent of the rockfalls, esp. during freeze-thaw cycles, and that's when I took my photos one evening. It's a good illustration of the points made by several other posts above about rock competency, groundwater effects, and by cx500 about how a cut should and must be wider than the tunnel it replaces. (As a philosophical aside, that may be another instance of the ironic "the perfect is the enemy of the good", which here translates to in a wordier form to an apparent improvement being stymied by the contra-principle of "the perfect solution conforming to all current standards is the enemy of a better solution than the existing crummy situation".)
It was a shallow tunnel - well less than 100 ft. cover - when first bored through loose sedimentary rock in the mid-1800's as part of the construction of the North Pennsylvania Railroad/ branch, but was 'daylighted' circa 1930 as part of the electrification of the Reading's suburban lines to provide sufficient overhead clearance for the catenary wires and high-voltage transmission poles above. Recently SEPTA was installing chain-link fencing and shot-creting/ 'guniting' portions of the sides of the resulting cut to reduce the incidence and extent of the rockfalls, esp. during freeze-thaw cycles, and that's when I took my photos one evening. It's a good illustration of the points made by several other posts above about rock competency, groundwater effects, and by cx500 about how a cut should and must be wider than the tunnel it replaces. (As a philosophical aside, that may be another instance of the ironic "the perfect is the enemy of the good", which here translates to in a wordier form to an apparent improvement being stymied by the contra-principle of "the perfect solution conforming to all current standards is the enemy of a better solution than the existing crummy situation".)
Selected photos below. Commentary later when I have more time. Enjoy ! - PDN.
I wonder if anyone has some photos of that incident {I-40}, disastrous rock slide burying the interstate route. I have traveled thru there several times and was always glad when it was behind me.
Quentin
For those who do not think the rotten rock over burden can be disastorous just look at the Nc I-40 incident.
1. NC DOT built the west bound lanes of I-40 near the Tennessee line with a tunnel for the west bound lanes only.
2. To save money NC DOT shortened the east side of the tunnel about 500 ft from original plan so the approaches ended up under "bad" rock allowing the approaches to suffer constant rock falls that were easily controlled as NC DOT predicted.
3. BUT finally the "bad" rock let loose and burried both east and west bound under over 10M + tons of rock. It took NC DOT 8 months to remove the rock (had to be trucked some distance), shore up the approaches, rebuild the road bed (east bound torn up worse than west bound don't know why), install slide detectors and repave the road.
4. I'll admit that 8 months seems unreasonable even for a state agency. But even a RR would have had problems with that area as SOU RR has had. Its almost all shale rock in that location.
Oh, there probably were holes drilled for blasting in those cuts, Larry - maybe still by hand, perhaps air-powered, which by then had been proven and perfected just a few years before a few dozen miles away to the southeast over at the Hoosac Tunnel project. But those holes were so expensive to drill that the bare minimum number were used - and the dynamite used was so powerful and uncontrolled by our standards that it obliterated all traces of the drill marks. Any hole that was drilled got stuffed with the maximum amount of dynamite that it could hold, and of course it was all detonated as a single collective charge. Think about it a little bit - what would you expect to remain of the hard-rock side of a drill hole that was placed right next to a dynamite charge powerful enough to fracture the rest of the rock for at least a couple yards in each direction ?
carnej1I always marvel at what was accomplished by the early railcar mounted,steam shovels, steam drills ect. considering that a contractor had to lay temporary track by hand labor just to get the machinery into position to work..think of the Panama Canal..
Indeed - pretty amazing.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
mudchicken Just try moving all that overburden with a horse & fresno plus a few wagons. In 1885, mechanical excavators and bulldozers had not been invented by Holt et. al. When BNSF removed the old CB&Q tunnel at Guernsey, WY in 1998, it was a tough call to justify the expense even then. (and a major accomplishment when they finished) The geology of what is being removed, especially if groundwater is involved, is a major part of the decision. Then comes the issues of what do you do with the overburden and do you have the room to lay the slopes back without creating new problems (ask NS about Coshocton, PA or about several tunnels in the Heartland Corridor)....none of this is cheap.
Just try moving all that overburden with a horse & fresno plus a few wagons. In 1885, mechanical excavators and bulldozers had not been invented by Holt et. al.
When BNSF removed the old CB&Q tunnel at Guernsey, WY in 1998, it was a tough call to justify the expense even then. (and a major accomplishment when they finished)
The geology of what is being removed, especially if groundwater is involved, is a major part of the decision. Then comes the issues of what do you do with the overburden and do you have the room to lay the slopes back without creating new problems (ask NS about Coshocton, PA or about several tunnels in the Heartland Corridor)....none of this is cheap.
In 1885 there certainly were mechanical excavators of the Steam Powered, rail mounted variety, and their largest application during that period was R.R construction..but you're right, there was nothing like the modern, diesel powered and hydraulically driven monsters the construction industry uses nowadays...
I always marvel at what was accomplished by the early railcar mounted,steam shovels, steam drills ect. considering that a contractor had to lay temporary track by hand labor just to get the machinery into position to work..think of the Panama Canal..
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Paul_D_North_Jr First, since I don't have that issue of the magazine handy - Is this the tunnel ? Both captions say it is Tunnel 4.0 (not my photos, of course): http://www.railpictures.net/viewphoto.php?id=242535 http://www.railpictures.net/viewphoto.php?id=73533 Also - http://www.railpictures.net/viewphoto.php?id=243395 (no tunnel ID in caption) [snips]
http://www.railpictures.net/viewphoto.php?id=242535
http://www.railpictures.net/viewphoto.php?id=73533
Also - http://www.railpictures.net/viewphoto.php?id=243395 (no tunnel ID in caption) [snips]
Yes, it's the same tunnel.
When I have an opportunity, I'll post a photo or two of mine from last April or so of the Gwynedd Cut, formerly the Gwynedd Tunnel, of the Reading RR - now SEPTA, about a mile southwest of the Borough of North Wales, PA - at Lat. / Long. N 40.19674, W 75.26733 per the "ACME Mapper 2.0 " application.
Daylighting a tunnel in many cases, is not practically possible. Locations with such a cover elevation that would not even be considered to such a change.
Daylighting a tunnel will usually require removal of a huge amount of overburden and rock. A single track tunnel is often only 16' wide, but when considering its removal the engineer is more or less obliged to go with a modern roadbed section, including drainage ditches and the like, needing a width of something like 30' at the bottom. A vertical rock face is a recipe for future trouble, so figure on a 0.25:1 slope. When you reach the original surface, say 40' above track level, the width of excavation will now be 50', and that's only if it is competent rock all the way.
Assuming you can afford all the drilling and blasting to remove the rock, the next challenge is where to put the waste material, perhaps a million cubic yards of it. It can't just be dumped into the local valley because it will dam the river so it has to be hauled away to some other site. The railroad may have a suitable site with a big fill and plans to build a second track, but probably track time is not available to load and haul it by train. It's going to take an awful lot of truckloads if part of the haul is on public roads.
Daylighting is sometimes the only option when a tunnel becomes dangerously unstable due to ground conditions. It can be the better option when double tracking, since boring a new tunnel for the second track may be just as expensive. (In general trying to widen an existing bore for a second track is not a good idea, although no doubt it has been done.)
Essentially, daylighting a tunnel is going to be a major expense, and there are usually more urgent priorities for the capital.
John
After examining the maps of the Heartland corridor questions comes to mind.
1. The extension from Columbus, Oh to Cincinatti makes sense since starting out containers will need sortiing to make a full train to CIN. However when the Canal is finished and there may be enough traffic to run a direct train(s) from Portsmouth - CIN will that route upgraded?
2. With that in mind would NS eventually upgrade CIN - Chicago to reduce the requirement for Chicago traffic to go by Crestline? Anyone know how many miles that would save?/ ,
I had the same dumb question, Paul. I too found nothing but "...a city in central California".
ChuckAllen, TX
Paul_D_North_Jr [snip] Note that apparently none were "daylighted". I believe that method was studied for a couple of the tunnels, but discarded due to the loose/ unstable ground above requiring way too much more excavation to achieve the desired result. If I can find a link or quote to support that, I'll post it here too.
The 2-page NS article from January-February 2009 at the link below says that 1 tunnel was bypassed, and another one had its roof completely removed, which I take to mean 'daylighting':
http://www.thefutureneedsus.com/images/uploads/bizNS1.pdf
Another article from The Virginian-Pilot by Robert McCabe dated May 2, 2010 mentioned the bypassing of 1 tunnel, but not the daylighting:
http://www.thefutureneedsus.com/latest-news/norfolk-southern-raises-the-roof-on-the-heartland-corridor/
In any event, "day-lighting" was not the preferred method to improve clearances in almost all of these tunnels.
[quote user="Paul_D_North_Jr"]
Paul_D_North_Jr: What was that proposed route about ? Where was it coming from and going to that a 2-mile tunnel would have been needed ?
Oh, OK - looks like maybe just a routine line relocation / straightening, from around Hector/ Pisgah (about 30 miles east-southeast of Barstow) through the Bristol Mountains as stated to the east-northeast for about 50 miles to around Goffs, which is about 20 miles west-northwest of Needles. But it was likely just an office-study/ map review/ desk-top/ 'sand-table' level study. Plus, it would have to go through the southern portion of the Mojave National Preserve, and perhaps the Providence Mountains State Recreation Area as well. And all in California these days ? Good luck with that . . .
This was in the 1960's and was a joint study with the Atomic Energy Commission (or what ever it was called then), the Federal and State Transportation Departments and the Santa Fe Railway. It was made to determine if atomic explosions could be used for peaceful purposes, The tunnel was to be eliminated with a huge excavation created by the explosion(s). There is much more info about this. What was shown above was just part of the Santa Fe participation in the writing and the names shown were at that time Santa Fe engineers.
The concept was to locate both I- 40 and the railroad in the same ROW. Many factors including politics, treaties and money,.intervened. In the 1960's we could at least talk about such concepts.
The recently-completed Norfolk Southern "Heartland Corridor" clearance-improvement project for double-stacked container trains involved 28 tunnels. Here's how they were handled, per the "fact Sheet" at this link:
http://www.thefutureneedsus.com/images/uploads/Heartland_Corridor_Fact_Sheet.pdf
"Methods used to increase tunnel clearances:
- Excavate roof and replace liner (15 tunnels)
- Carve notches into arch roof to allow corners of containers to pass (7 tunnels)
- Lower or realign track (6 tunnels)"
Note that apparently none were "daylighted". I believe that method was studied for a couple of the tunnels, but discarded due to the loose/ unstable ground above requiring way too much more excavation to achieve the desired result. If I can find a link or quote to support that, I'll post it here too.
Paul_D_North_Jr What was that proposed route about ? Where was it coming from and going to that a 2-mile tunnel would have been needed ?
Paul_D_North_Jr "Fresno Scraper", the usually 1 or 2-horse (or mule)-drawn and of course much smaller ancestor of what is today usually called an earthmover, 'motor scraper', or 'pan', etc. See "The Fresno Scraper - Invented 1883 - A National Historic Mechanical [ ! - PDN.] Engineering Landmark", at: at http://files.asme.org/ASMEORG/Communities/History/Landmarks/5550.pdf Google "Fresno Scraper", and/ or see this link to the Historical Construction Equipment Association's website for a short history of scrapers generally: http://archives.hcea.net/index.php?p=digitallibrary/digitalcontent&id=10 - Paul North.
"Fresno Scraper", the usually 1 or 2-horse (or mule)-drawn and of course much smaller ancestor of what is today usually called an earthmover, 'motor scraper', or 'pan', etc. See "The Fresno Scraper - Invented 1883 - A National Historic Mechanical [ ! - PDN.] Engineering Landmark", at:
Google "Fresno Scraper", and/ or see this link to the Historical Construction Equipment Association's website for a short history of scrapers generally:
http://archives.hcea.net/index.php?p=digitallibrary/digitalcontent&id=10
As to the question, "to daylight or not," I recall one tunnel on the Southern's ascent of the Blue Ridge, west of Old Fort, N. C., which was very short and seemed to be holding two mountains apart--would they fall together if the tunnel were daylighted?
Johnny
Heck, the rest of that abstract - which is from 1964, of course - is the more interesting part [EMPHASIS ADDED - PDN]:
"THE STUDY WAS CONCERNED WITH DETERMINING THE FEASIBILITY OF EXCAVATING A CUT THROUGH THE BRISTOL MOUNTAINS NEAR AMBOY, CALIFORNIA, USING NUCLEAR EXPLOSIVES. THE PROPOSED RAILROAD ROUTE REQUIRED THE CONSTRUCTION OF A TWO MILE TUNNEL. THE PROPOSED CUT WOULD MORE OR LESS FOLLOW THE TUNNEL ALIGNMENT AND BE ABOUT 11,000 FEET LONG, WITH A MAXIMUM DEPTH OF ABOUT 350 FEET. CUTS HAVING DEPTHS OF LESS THAN 100 FEET WOULD BE EXCAVATED BY CONVENTIONAL METHODS FOR TECHNOLOGICAL AND ECONOMIC REASONS. GEOLOGICAL KNOWLEDGE OF THE AREA INDICATES THAT THE MEDIUM CONSISTS OF SOFT VOLCANIC ROCK UNDERLAIN BY META-GRANITE BEDROCK. USING CRATERING PARAMETERS FOR HARD ROCK, A TOTAL OF 22 NUCLEAR EXPLOSIVES RANGING IN YIELD FROM 20 TO 200 KILOTONS WOULD BE REQUIRED TO MAKE THE EXCAVATION. EXTENSIVE ON-SITE STUDIES ARE NECESSARY RELATED PRIMARILY TO SAFETY CONSIDERATIONS, INCLUDING DRILL HOLES, SEISMIC SURVEYS, HYDROLOGY INVESTIGATIONS, POPULATION SURVEYS, AND WEATHER SURVEYS."
What was that proposed route about ? Where was it coming from and going to that a 2-mile tunnel would have been needed ?
22 "nuclear explosives" over 11,000 ft. is about 1 for every 500 ft. of length on average.
One might think that 'blast-casting' as practiced in the open-pit mines to loosen and move the overburden dirt and rock from above the desired mineral bed, over to the hole where it was just mined from, would be an ideal application for this - aside from the radioactivity problem, of course.
But I don't think it would work too well for railroad applications, because of the 'overbreak' problem, among others. That occurs when the explosive is too powerful, and loosens rock beyond the widths and and depths of the cut that' are really needed. Then that additional shattered rock has to removed as well, so that it doesn't fall into the cut later on. Nuclear blasting would be helpful only when the rock is extremely hard - otherwise 'conventional' methods could remove it pretty effectively instead as well. And conventional methods could produce near-vertical rock walls, so that the 'excess' rock excavation is kept to a minimum.
Likewise, nuclear blasting wouldn't be of much help if another result is that the roadbed's subgrade was loosened and fragmented so much that it became unstable and then settled and compacted later on.
With advances in drilling and blasting technology since then - keep in mind where the equipment used to rescue those Chilean miners last month came from - and let along the public relations and permitting issues with anything nuclear - I believe conventional methods would be more cost-effective.
And faster, too - if nuclear explosives were used, then we'd have to allow a few thousand years for the site to cool down and for the radioactivity to decay to tolerable levels . . .
Good 'catch' - thanks for sharing that link !
SOU rr day lighted a bunch of tunnels on the CNO&TP (rat hole) Cincinatti - Chatanooga due to severe clearance problems. some old tunnels would not even clear the new Big John hoppers SOU was proposiing. Of course SOU got the city of Cincinatti to fund much of the project in return for higher tarrifs.
"A PRELIMINARY FEASIBILITY STUDY WAS CONDUCTED BY THE CALIFORNIA STATE DIVISION OF HIGHWAYS AND THE SANTA FE RAILWAY COMPANY OF POTENTIAL USES OF NUCLEAR EXPLOSIVES IN CONSTRUCTION PROJECTS FOR HIGHWAYS AND RAILROADS."
http://pubsindex.trb.org/view.aspx?id=110048
With a big enough fire cracker, what could become a candidate for daylighting?
mudchicken Just try moving all that overburden with a horse & fresno plus a few wagons. In 1885, mechanical excavators and bulldozers had not been invented by Holt et. al.
Pardon the ignorant, but what is a "fresno"? I tried googling the term, but that yielded nothing except the city in California.
First, since I don't have that issue of the magazine handy - Is this the tunnel ? Both captions say it is Tunnel 4.0 (not my photos, of course):
Also - http://www.railpictures.net/viewphoto.php?id=243395 (no tunnel ID in caption)
Next: As several of the posts above have alluded to, the cost per cubic yard of rock excavation by hand-drilling and blasting methods 'back in the day' was probably pretty much the same regardless of whether the rock was in a closed bore such as a tunnel, or in an open cut. So given a choice between X cubic yards with a tunnel and 5X to 10X with an open cut, the tunnel would have been less yards hence less cost and less time. Note too that since this one is such a short tunnel, the 'haul' of the 'waste' or 'spoil' rock or debris - "muck" and "mucking"* are the usual technical terms for it, even if it all consists of broken rock fragments - from the working face to the portal to dump/ dispose of it would not have been long, hence would not have added much to the excavation costs.
[*Edited - Added those words, which I couldn't think of yesterday - PDN.]
From a geotechnical perspective, these photos illustrate several aspects - though perhaps somewhat inconsistent - that would favor a tunnel over an open cut. First, in those photos such as this one - http://www.railpictures.net/viewphoto.php?id=243395 - can be seen some large blocky rocks in the ridge over the tunnel, which then drops off into the river. Those are likely igneous (volcanic) rocks such as basalt, which can be very hard, hence expensive to remove per cubic yard, which would favor the tunnel with less cubic yards.
Second, between those rocks and above the track level seems to be a looser or sandy material, as well as on the near side of the portal above the 4 oxide red covered hoppers, and in the far distance about 10 car-lengths to the rear of the tunnel, as well as closer in the other 2 photos - about 10 car-lengths in front of the tunnel. The loose 'talus' slopes can be seen, which indicates that as soon as some is excavated, more will slide down to replace it, which is a 'losing game' that will go on for quite a while if you let it. That aspect favors drilling a tunnel which can be lined - note the portal on the near side - to restrain the sand/ loose rock from falling in, and again minimizes the quantity that has to be excavated, handled, and disposed of.
Finally - and related to this last point - esp. in photo http://www.railpictures.net/viewphoto.php?id=73533 - note the ridge above the tunel and extending up the flank of the hill to the upper right. If the 'toe' of that spur was removed by an open cut, then what would hold up the rest of that ridge ? Where do you suppose it might end up if it does decide to obey the law of gravity and move downhill - like directly onto the track ? Again, the tunnel was likely the best and safest way to preclude that from happening.
[quote user="bedell"]
Couldn't some tunnels in snow country be considered natural snow sheds? A deep cut where a tunnel had been daylighted would fill with snow pretty rapidly in a storm.
[/quote]
I agree with the above comment. {again using a highway comparison}, but I remember way back when the first part of the Pennsy Turnpike was built....There were comments of it's design using tunnels..."The all weather highway", the theory being, the highway eliminated crossing the higher elevations of the mountain ridges more susceptible to winter snow.
Using a by pass route {even with same max. grade}, got the route up and over the mountain rise, when building the by passes, and hence more snow....at least In Theory.
And then there are the places were the original builders created a cut, and Mother Nature forced them to turn it into a Tunnel because once the underlying rock was exposed to the air it began to crumble and fill up the cut. The B&O with its very early construction had two cases like that in what is now West Virginia. The French also had a similar problem with the Fréjus Tunnel under the Alps to Italy, the majority of the very long tunnel was stable enough, but for a distance at the west end (French end) the rock began crumble filling the approach cut. They had to put a curve in the otherwise straight tunnel so as to pass through different rock strata, creating a new portal connecting to the existing line at a different point and also making the tunnel longer.
And perhaps a "short" tunnel does not require very expensive maintenance.
I don't know the costs comparison between boring another tunnel {roughly, a mile in lenth}, or go around with a massive excavation of land to bypass such tunnel.
The {auto}, tunnel {Laurel Hill}, in Pennsylvania, on Pennsy Turnpike is one example of what was done when they needed to create another 2 lanes to equal the turnpike's 4 lanes....Original tunnel was just 2 lanes, and become a bottleneck to traffic. Grade was maintaned at 3% max. as was original route. But a terriffic amount of ground had to be excavated to create the bypass. It was possible to do there but not in some other tunnel locations.
Cost difference....Unknown to me.
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