Tunnel Grinder?

[bubbajustin]

This is mainly for Hi-Cube boxes, and double stacks right? MC, scary stuff. Good thing no one got hurt.

[Paul_D_North_Jr]

The Delaware, Lackawanna & Western's Factoryville Tunnel - just a mile or two south of the famous Tunkhannock Viaduct in Nicholson, PA - was drilled circa 1911, still in the steam age, as a double-track tunnel on a pretty low-grade line relocation.  It is about 3,000 ft. long and has 1 or 2 "vent holes" at about equal spacing.  They could equally well have been contractor's convenience shafts as RWM suggests - the topography there would have lent itself to that.  henry6 is more familiar with it and may be able to clarify.

- Paul North.

EDIT - Not far away - like 12 miles to the southwest - is the fairly long double-track Vosburg Tunnel on the former Lehigh Valley Railroad's mainline, a water-level grade along the North Branch of the Susquehanna River.  I've never been through it in a position to observe whether or not it has vent holes - again, henry6 would likely know - but I doubt it.

Much farther to the southwest are the 3 former PRR tunnels for the Allegheny Summit at Gallitzin, PA, about 10 miles southwest of Altoona, on the same very heavily-trafficked main line as the Horse Shoe Curve, all drilled during the steam locomotive era.  The 2 longest and essentially parallel tunnels - Allegheny and Gallitzin, each about 3,000 ft. long, and each on ascending 1.0 per cent grades for the predominantly westbound traffic through them - both had ventilating systems during the steam era [since removed].  I recall a Trains article [April 1957 issue] said that the ventilating systems could handle a train every 7 minutes [or something like that].  Accounts seem to vary as to whether or not there was also a vent hole - but that too may have been a contractor convenience, and I seem to recall that there was at least 1 roof collapse that led to an inadvertent 'daylighting' or a hole, so that may have been more by accident than design.  The 3rd tunnel - the New Portage Tunnel - is about 1,600 ft. long and was double-tracked during most of its life.  However, since most of the traffic through it was eastbound and hence downgrade, I believe it has no vent holes and never had a ventilating system. 

There were and are numerous other tunnels throughout Pennsylvania of varying lengths, such as the double-track Black Rock and Flat Rock Tunnels for the Reading Railroad along the Schuylkill River to the north of Philadelphia, the single-track CNJ Nesquehoning Tunnel in the coal regions, etc.  As far as I know none of them had a vent hole, nor did they have a ventilating system, but none were over the 3,000 ft. range as best as I can recall.

One of the 'grand-daddy's' of tunnels is the Hoosac Tunnel, of course.  It had a large central shaft, but that was created solely to provide 2 additional 'headings' from which to drill the tunnel.  Later, when a vent system was installed - because that shaft wasn't doing the job - a large fan was installed in it to act as a forced-draft chimney.  That didn't work too well, either because early in the 20th Century the Boston and Maine RR installed catenary and went to electric operation through the tunnel - the steamers were just towed through.  The electric operation ended during the 1940s, I believe, as diesels took over and the exhaust problem was diminished, along with traffic levels.

Which reminds me - one feature that Hoosac still has on its western / North Adams end is doors, which remain closed until a train gets close.  The 3 ft. narrow gauge East Broad Top Railroad in south-central Pennsylvania [not too far from Altoona] had 2 or 3 shorter tunnels, which also had doors - but no vent sdhafts or ventilating systems, either, as best as I can recall.  One explanation that I've read for those doors at the ends of tunnels is that they 'bottled up' the air in the end of the tunnel.  So, when the approaching train acts like a piston and pushes the air that's already in the tunnel ahead of the train, that air - instead of just going out the approaching end - is instead forced to flow around the sides and top of the locomotive, and thereby pushes the smoke farther back along the train, and towards the entering end - that's the theory anyway.  I've also read that the purpose of the doors is to keep the winter winds from freezing the inevitable groundwater drips in tunnels onto the rails and creating slipepry conditions, which is also plausible.

Hope this is helpful.  If I can get the data on the lengths and grades of the tunnels that I've mentioned above, or think of any other examples that may shed light on this, I'll post it here as well. If anyone has that data or corrections or clarifications to what I've already posted above, please feel free to add that in here, too.

- PDN.

[Railway Man]

NP Red

The post photos were taken at the Cascade loops near the Frazier Mudslide site. I only saw three tunnels but they all had this type of work done on them. One was only shaved on one side though. Yes, as noted above, this tunnel had a 15 ft section about 150 from the portal that did not have a liner on it. I don't think it was a old vent hole because the tunnel was only 400 ft long. How long would a tunnel need to be to have had vent holes?

Thanks for the information!

Vent holes have never been a standard practice in North American railroading.   They are ineffective at clearing smoke.  A forced-air ventilation system is employed in certain tunnels that due to length, adverse gradient, and frequency of trains do not self-clear sufficiently rapidly.  With steam locomotives, there were some North American tunnels as short as 2,500' on adverse grades with heavy traffic where ventilation systems were deemed necessary and installed.  For diesel locomotives, there are very few North American tunnels less than 25,000' that have required ventilation systems.

The "vent holes" you observed in the Cascades are actually a construction convenience for the contractor to dispose of muck from the tunneling operation.  The competent rock conditions and steep canyon wall of this location enabled this convenience.  Usually either the topography, the rock conditions, or both, make this infeasible.

RWM

[NP Red]

The post photos were taken at the Cascade loops near the Frazier Mudslide site. I only saw three tunnels but they all had this type of work done on them. One was only shaved on one side though. Yes, as noted above, this tunnel had a 15 ft section about 150 from the portal that did not have a liner on it. I don't think it was a old vent hole because the tunnel was only 400 ft long. How long would a tunnel need to be to have had vent holes?

Thanks for the information!

[Paul_D_North_Jr]

mudchicken, thanks for those additional details.  They paint a very complete picture of what one of these projects can be like - together with the usual railroad 'happenings'.  As U.S. Supreme Court Justice Oliver Wendell Holmes, Jr. once wrote, ''Upon this point a page of history is worth a volume of logic''*.  These operations are of like kind.  Thanks again.

- Paul North. 

* New York Trust Co. v. Eisner, 256 U.S. 345, 349 (1921), per http://en.wikiquote.org/wiki/Oliver_Wendell_Holmes,_Jr. [which isn't a 'bad read', either].

[mudchicken]

One moment the roadheader was grinding noisilly along, the next there was a large WHAM! followed by silence and super thick dust. (the tunnel portals were belching dust) When the dust cleared enough, the road header was buried and the operator was covered up to his waist in rubble. We were extremely lucky that nobody got hurt.

The roadheader induced a second collapse to clear out additional loose material....a month later the operating department "corked" the tunnel by sending a 19' 4" stack train through the incomplete notch that still had only 18'5" in some of the notch corners. (I'm sure the Superintendent didn't accuse his operating & mechanical cronies at Richmond of doing THAT on-purpose)

[Paul_D_North_Jr]

Yeah, MC, I figured you'd relate to that, sure enough - and your example above is just about perfect for the point I'm making.  ''Murphy's Law'' applies, in spades.

So was it gradual - running out like from a dump truck, only it didn't stop for a long time - or a sudden ''WHUMMPP'', where the typical 'Oh, ****' expression applied to both the situation then, and the condition of some of the personnel's underwear . . . .    That's when you find out exactly what Johnny Cash and others are singing about in their songs about coal mine collapse tragedies, etc.

- Paul North.

[mudchicken]

When I caved-in the tunnel "on purpose", the voids behind the tunnel liner had been thoroughly grouted to refusal, we pumped grout in there for weeks.....It still caved-in when we broke through the liner with the road-header.  Fortunately most of it fell into our air-dump and muck cars - but there was still plenty of redwood tunnel liner, spalled rock, fractured rock and chunks of grout we had to dig out. We discovered about a 6-foot void behind where the liner was.

"and not even then" applies.

[Paul_D_North_Jr]

NP Red

Note 2 thIngs about this photo -

1.  In the dark gloom and shadows way in the background - I'd estimate at about 100 ft. back in - the top portion of the cross-section changes from its basic semi-circular here in the foreground to a more angled 'clearance diagram' type of polygon, with the upper corners 'clipped' and angled in on each side, etc.  I suppose there was sufficient clearance there too, as it doesn't look like any work was done - but it doesn't appear as if there's the same extent of clearance as in the foreground.

2.  Depending on how thick the semi-circular roof liner of this tunnel is, I'd be concerned about cutting those grooves - or any grooves - in it.  If it is several feet thick - unusual and expensive, but not unheard of - then OK, probably no harm done.  But if the liner is less than say, 12 inches thick, then those grooves run the risk of creating 'hinge points' in the roof and for the tunnel to buckle there.  Or, a kind of a 'score line', where the middle roof section could possibly break free and fall down. 

Whether any of this is an actual concern depends on the geology of the overlying rock and its integrity and competency, groundwater flows and lubrication, fault lines, and other geotechnical matters, as well as the structural engineering design and actual construction of the liner with regard to reinforcing steel, designed hinge points and loads, etc.  This is likely not the 'best case scenario' - if it was, then a liner wouldn't be needed in the first place - so there must be a concern.  If that is just generally loose rock and water, then even a hacked liner can porobably contain and confine it.  But if there is a 'worst case scenario' of something like a near-vertical seam of rock that is extensively faulted and fractured so that it doesn't have much support or restraint from the adjoining beds or layers, and it has since shifted and settled so that most of its weight is bearing on and is now being carried by the tunnel liner - then ''Be afraid, be very afraid, and exceedingly careful and cautious with and around it''. 

Within the last month I read a report about a worker - a truck driver who was just standing there waiting for another load, I believe - who was killed by a roof collapse in 1995 during the ConRail enlarging of clearances for double-stacked containers in the Allegheny Tunnel at Gallitzin, PA [about 6 miles upgrade from the Horse Shoe Curve].  I seem to recall that there was a finding that too much of the tunnel roof had been left unsupported - unlined, or unshored, etc.  There is also a report of a collapse during that project resulting in a hole to/ from 'daylight' above, as also happened during the original construction of one of those tunnels - a school above had to be demolished and rebuilt as a result, too.  Moral - Don't trust the ground above a tunnel liner unless and until it's been thoroughly investigated, and not even then.

- Paul North. 

[mudchicken]

Proper term is "road header", most are german or austrian built......I spent most of  1989 and 1990 raising the roof in two tunnels  above the springline and dropping the floor of another in California (ATSF Franklin Canyon tunnel project at Martinez/Glen Fraser/Christie CA.......IT is not done with a Loram shoulder cleaner and what is shown in the photos is incrediibly mild)

I have dozens of photos from those days, but no sane way to post them....Imagine an electrically powered cat-tracked dozer on a flatcar with an articulated crane on the front with two spinning balls with teeth (or two spinning drums with teeth) at the outside edge of the crane boom.

At Martinez, CA the locals kept calling the fire department on us at Tunnel 2 because they thought the tunnell was on fire - It was gray rock dust.

DMU - (1) If you drop the floor, where are you going to run trains? You cannot operate under traffic. (2) If you do drop the floor, better hope the geologist was right. Ours wasn't - the tunnel floor flooded 2 feet deep in water that was not supposed to be there.  (Tunnel 1 at Martinez CA under CA Highway 4)

-ps...you haven't lived until the Superintendent accuses you of caving-in a tunnel on purpose!

[espeefoamer]

In the bottom photo,the tunnel portal looks like the Bat Cave.

[Geared Steam]

Paul, neat stuff, thanks for the links.

[Paul_D_North_Jr]

That big yellow on-track machine in the top photo above is a shoulder ballast cleaner, not a tunnel ceiling grinder, although I concede that the size and spacing of those big bucket wheels make it appear as if it would be ideal for that.  It's shown in the 'traveling' mode or position - the bucket wheels will move sideways to extend out another couple of feet when in and then down into the ballast when in 'working' mode or position.  Also, the leading bucket edges are way too wide and flat to be used sucessfully to chip away rock and concrete, though they'd be fine for loose stone or even 'cemented' ballast - compare with the 'spikes' on the excavator-mounted grinder similar to the one for the Hoosac Tunnel [as shown in the photo from the preceding post above].  Finally, in the other photo of this machine that's on the website linked above, an excavator can be seen in one of several trailing gondolas that have a couple feet of clean ballast stone in them.  That's to provide and place 'make-up' ballast to restore the shoulder ballast profile to make up for the dirty stuff that's removed - especially important in CWR territory to maintain a full ballast section to keep the rail from buckling in hot weather conditions, etc.

- Paul North. 

EDIT - Here are some links to photos of it in action, from a trip report in August 2002 at - http://faculty.simpson.edu/dick.tinder/www/082402Creston/082402Creston.html  From this sequence, you'll see that the cleaner is moving towards the photographer - note the motion between the 1st 3 photos, and how the new 'ditch' appears between the tracks where it has already passed, esp. in the 2nd photo, and in the 3rd photo, how the left wheel is creating a 'windrow' where it is disturbing the shoulder ballast -

http://faculty.simpson.edu/dick.tinder/www/082402Creston/loram1.jpeg 

http://faculty.simpson.edu/dick.tinder/www/082402Creston/loram2.jpeg 

http://faculty.simpson.edu/dick.tinder/www/082402Creston/loram3.jpeg 

http://faculty.simpson.edu/dick.tinder/www/082402Creston/train6.jpeg - note how the right cbucket wheel has been pulled back in to provide more clearance for the approaching train.

And a manufacturer's - Loram's - website for it -

http://www.loram.com/Services/Default.aspx?id=244

- PDN.

[Geared Steam]

Ran across the website today after reading this thread, the Cascade tunnel and the machine mention in the above post?

The website is here.

 

 

[carnej1]

carnej1

I saw some video of Guilford's project to raise clearances in the Hoosac tunnel and the primary "implement of destruction" the contractor employed was a rotary cutter head (similiar to a continuous miner) mounted on the boom of a Hi-Rail Gradall telescoping hydraulic excavator..............

Link to a pic of one of the machines used on the Hoosac job...this one is mounted on a large conventional backhoe excavator rather than the hi-railer Gradall in the video I saw:

http://www.hoosactunnel.net/images/yGrinder.JPG

[carnej1]

I saw some video of Guilford's project to raise clearances in the Hoosac tunnel and the primary "implement of destruction" the contractor employed was a rotary cutter head (similiar to a continuous miner) mounted on the boom of a Hi-Rail Gradall telescoping hydraulic excavator..............

[Railway Man]

It's an adapted "continuous miner" machine.

In an unlined tunnel in most cases it is cheaper by far to crown-cut than lower the floor.  Often in a lined or partially lined tunnel, crown cutting is cheaper too.  Dropping the floor in a lined tunnel undermines the lining, and in any tunnel dropping the floor runs usually runs into serious drainage problems and sometimes vertical alignment problems.

It's usually easier to crown-cut under traffic than lower the floor, because the crown-cutting can be done piece-meal whereas lowering the floor usually requires taking the tunnel out of service for several days (several days if alll goes very well, that is).

RWM

[DMUinCT]

Weird!!     Most cases they dig out the tunnel floor rather than compromise the roof.

[NP Red]

What type of machine is used to do this kind of grinding on the roof of a tunnel. Is this a common way to get another 8 inches of height? Does it do both sides at once?