The Driver says I have a question that has no real answer, so that is why I will ask it.
Lots of rain in the northwest. Mudslide onto the rails and train derails. Question is, if I own a class 1 railroad, is there any technology available to let me know if a mudslide is very possible in a certain area? Surely you don’t want to send a crew with a very expensive train loaded with very expensive goods without some idea if they are going to make it through this rain soaked area?
On my carrier, when Flood Warnings are issued, the MofW personnel are immediately notified of the warnings are are required to get Track Inspectors out to inspect the affected territory. Train operations will continue at reduced speeds through the affected territory with crews warned to be on the lookout in known trouble areas. The railroad is not shut down unless the MofW personnel see conditions in their inspections that warrant it. Part of T&E personnel being qualified on their territory is also knowing the routine trouble areas.
Probably misunderstanding the question, but I was under the assumption that landslide (and hence mudslide) detection fences have been around for many decades (wiki entry). The article even mentions a few UP and BNSF locations where landslide/rockslide fences are used.
New technology using patterns of sensors, among other ideas, continues to be developed.
I seem to recall a Trains article in the past two or three years about slide fence sensors on BNSF in northern Arizona between Williams and maybe Seligman or farther west. DC or MC might have a better recollection than I do.
PRR had them in the 1940s. A series of horizontal wires that were electrified. If one broke it activated a stop signal. But mud may have just oozed through. Much more effective with rocks or landslides.
This is a very different thing from slide fences or other devices that only indicate after a slide has occurred.
Theoretically, the answer is ‘yes’; you might for example maintain a network of simple sensors for ground moisture at various depths combined with seismometers and devices to detect relative motion. It has become dramatically cheaper – at least in principle – to build, power, and monitor this sort of thing in the past few years. But it is not exactly rocket science to understand when slides are ‘likely’ in most of these slide-prone regions, and I suspect that the warnings of actual incipient sliding might not be much quicker than those produced ‘after the fact’ by much simpler detectors like slide fences … particularly if vibration from a train induces the start of the actual slide.
This is a question that I expect someone like MC or PDN can provide extensive thought and experience on… [edit: I was writing this while PDN provided just such an analysis]
The 1959-1960 Santa Fe Williams-Crookton line change created rock excavations over 110 feet deep and in one case over one mile long. The exposed geology had volcanic material next under the decayed surface material followed by sedimentary deposits from materials deposited in layers when this area was under water. And finally there was ancient rock similar to that found in the deepest part of the Grand Canyon.
There were seams between the various layers of sedimentary deposits which after the excavation were exposed to current precipitation. These seams were tilted due to millions of years of the continuing creation of geology in this area. After moisture penetrated to these seams slippage resulted and a large rockslide causing a train to derail. Slide detector fences were subsequently installed which were connected with the newly installed CTC signal system so that trains would have ample time to stop if a slide occurred. They are still in place today.
(1) The bigger issue is the slides usually start off the railroad’s own R/W… (witness BNSF’s headaches in Washington State)
(2) Inclinometers/Wheatstone bridges can help matters by telling when a hillslide is likely, but PDN and Balt have filled-in that side of the equation.
(3) The water is the trigger, whatever you can do to run off water before it lubricates the slips/slumps/slides is what railroads try to do, but generally the big headaches are off the property.
(4) Mother Nature has a vicious mean streak and she is anything but predictable.
The mudslide situation between Seattle and Everett is unique for a couple of reasons which I will explain. I also explained once on the mudslides north of Seattle thread on the passenger forum. I am not an expert, but have seen the line several times from dome cars and locomotive cabs so I can generally describe it. I am interested in Geology so know the basic geology of the area.
Geography. For the roughly 25 miles between Salmon Bay Drawbride in Seattle and Everett the former GN main line, now BNSF Seattle Subdivision, sits about 25 feet above sea level atop a stone wall constructed of very large hunks of granite hauled down from the Cascade mountains. Eastward Puget Sound is on the left, and a series of roughly 200 foot high hills are on the right. The western crests of these hills are highly coveted for their view of the Sound and the snow capped Olympic mountains. Each of these hundreds of homes has a million dollar view.
Geology. The hills are “drumlins” deposited by the late Continental Glaciers some 15,000 years or so ago. The are north-south trending elongated hills composed of unconsolidated mud, sand, and occassional rocks. Their west slopes are relatively steep, steeper than the angle of repose of the material that makes them up. They are too new, in a geologic sense to have eroded to their angle of repose. That is why they slide.
Climate. It rains more or less continually for about nine months per year, so these drumlins are usually saturated. Come November and December winter storms are more or less continuousthru March, and some of them bring several inches of rain. That tends to oversaturate the drumlins, making them less stable than usual.
Note that virtually all of this action takes place off of and above the railroad’s right of way, which is probably 100 feet wide, or about 20-25 feet beyond the right of way ditch.
The GN relocated about 1.5 miles of line north of Edmonds in the 1950’s striking out acro
PNWRMNM: Good explanation. In western North Carolina there is an entirely different problem. Much of the area is on shale and tectonic movement over the years has caused it to tilt. Roads are often built above this shale increasing the weight on the shale. When it rains and water gets in the seams gravity pressure from above causes slip slides. AAA reports that many roads from all this rain have given way in the western NC area.
Many years ago I-26 was being built across the gorge from Saluda grade. Grading was finished and paying was due to start shortly. Minor hurricane remanents dropped a lot of water and a very long segment of the road washed away. Immediate bankruptcy for contractor.
Afterward when replacement was put out to bid no bids. Finally US DOT had to agree for a cost plus contract for anyone to bid. All due to shale.
The I-40 shutdown west of Ashville at the Tennessee border a few years ago has been attributed to a shale problem.
I read through all the postings very carefully. I did learn quite a bit. No need to worry, however. Your jobs are all safe. And it looks like the railroads do have this pretty well covered, especially since safety is top priority.
I was just thinking that the surefire way to do what you’re asking about would be to have Radar O’Reiley as the train’s conductor. He’d also be able to tell you when to expect choppers.
Paved areas and the roofs of the trophy homes on the bluff over the Puget Sound will shed a lot of water quickly during rain, and lawns also shed water faster than natural ground surface. Any cuts into the bluff along the rail line might also aggravate the problem. Shoreline erosion probably oversteepened the bluffs in the first place. There may also be subaeral erosion going on below the surface of the Puget Sound.