Newswire had a story today about BNSF putting some cars on the ground here last night. The local paper has the story here which has a couple of pictures of three empty auto racks on the ground.
Question comes to mind about empty high center-of-gravity cars and whether they are more susceptible to instability in track conditions like swelling/sinking subgrade than other types of empty freight cars.
Just a random thought and question.
MBARSDG was reported to be in excess of 90 cars. The empty autoracks which derailed were near the headend. The train was climbing a 2.2 percent grade with the train stretched out through several tight curves. First cause that comes to mind is stringlining.
Like road railer {triple crown}, has done here in Muncie several times…
Not being a track man stringlining and/or ground instability comes to mind. Is this not the area that Amtrak and the commuter district want to straighten for higher speeds and less enroute times? It might cause the grade to be slightly more but a better HP/ ton ratio would compensate for that.
If the grade in the area is in fact 2.2 percent and the cars were near the head end of a 90+ car train stringlining is the most likely cause. Some carriers have rules concerning the placement of long cars vs. the trailing tonnage that is permitted behind the long cars in territory with relatively heavy grades…2.2 percent is a heavy grade.
In most railroad areas, heavy grades are also associated with a high degree of curvature as the civil engineers method of climbing elevation between A & B when the direct distance provides unacceptable grades is to lengthen the distance between A & B through curvature in conformance with terrain features until a acceptable grade is achieved.
If you have a SPV atlas of the area look at it.The track is a series of “s” curves ( 2 or 3 ) of less than 3 miles from Miramar north to Sorrento Valley that are together with speed limits of no more 25 MPH ( maybe less - anyone ??). As I remember the steep climb limited the steam freights and Santa Fe only ran 3 round trip passenger trips. Therefore no straightening was ever contemplated. Now Amtrak and the San Diego commuter district want to straighten it. The commuter district owns the line. My recollection of the ROW is that it will require a lot of soil removal to accomplish that but the problem of brush fires then rains and mudslides will need mitigation. A tunnel under the mountain has been talked about but I believe that the area is in on earthquake fault line?
True enough. Back in the late 1960’s, Trains has a photo sequence - by J.J. Young, Jr., I believe - of auto-racks derailing on Horseshoe Curve from exactly that cause.
Also, from one of the aerial photos with the newspaper article, as I recall there was a much shorter car - like a cement-hauling covered hopper - on each end of that cut of 3 auto-racks. One of the auto-racks had simply flopped on its side, parallel to the track; the other two had jack-knifed and were across the track, with one apparently having pivoted on its middle and headed downhill.
‘String-lining’ is certainly the ‘usual suspect’ here, but before I’d conclude that I’d want to know more about whether the train was heading upgrade or downgrade, and in which direction in that photo, to rule out other possible causes and sequences.
Good observation and correlation, not often pointed out, nor quite so eloquently as in this paragraph. [tup]
[quote user=“BaltACD”]
as the civil engineers method of climbing elevation betw
There are a series of 10 degree curves from just east of were the line passes under I-805 to the summit under Miramar Road, including a couple that qualify as “s” curves. The longest of the curves is where the line turns south from Carroll Canyon Road (for your LGB fans - near where Nancy Ridge Road intersects Carroll Canyon Road). Looking at a DRG of the 7.5 minute Del Mar topo, the line could be re-done with a maximum curvature of4 to 5 degrees, with the most work involving the longest curve.
First serious talk of a tunnel took place before WW1, and it has been brought up many times since then. I even used it as a topic for one of my homework assignments for 12th grade English - which was -um- almost 40 year
I would concur with the stringlining suspicion, now looking at the meandering nature of the Sorrento grade. It has been way too many years since I have ridden Amtrak north to anywhere, so I didn’t remember the exact routing (well, heck, I was too busy in the club car, but that’s another story). The train would have been pulling uphill and nearing the crest of the grade which I assume is underneath Miramar road.
A few years ago, BNSF put three (I think) boxcars on the ground at about Miramar Road, again coming south. The cars were at the end of the train and actually derailed a fair distance north of where they finally dumped and threw the train into emergency, which resulted in a lot of chewed up track that took a couple of days to put right, if I remember correctly. Starting in 1913, Santa Fe managed to dump one freight and two passenger trains on the grade, two going down and one coming up. Not the friendliest stretch of track.
As for a tunnel solution, that has been considered for maybe 120 years or so, coming close to actually being done a couple of times with world wars stopping them in their tracks. As for doing it now, even with the many Amtrak and Coaster trains running daily, I don’t think anybody in this state could get the money required to do such a project…
The local observers at socalrailfan.com say it had four units on the front and two DPUs on the rear. So, in addition to the questionable placement of empty autoracks near the head end, this incident also brings into question whether the DPUs were shoving their fair share of the load. DPUs have been used routinely on Surf Line freights for nearly a decade. Miramar Hill is tough on long, heavy trains. North slope is 2.2 percent with Tehachapi-style curvature. South slope is 2 percent, less twisty, and has two main tracks. The summit is very abrupt. The rest of the Surf Line is a rollercoaster of 1-percent grades. And keep in mind this train came over Cajon Pass earlier in the day. When I first started watching trains along the Surf Line in the mid-1970s, Santa Fe ran unit potash or soda ash trains to San Diego which often used mid-train slave power, which included a B-unit to house the radio gear. By the early 1980s, I was no longer seeing the mid-train power. Instead, I would occasionally see these heavy unit trains get doubled over Miramar Hill.
I’ve seen auto racks on their side in hump yards, where the pull-down assignment was pushing a long cut into one of the departure tracks. Fairly sharp curve from the ladder into the body tracks, and pushing creates even more lateral force than pulling. They are long cars with not very much weight even if loaded and, I suspect, a high center of gravity.
Bearing in mind how tall auto racks are, try not to be under one if it tips over. The safety message is to not stand close to passing movements whether high speed or crawling.
John
Here’s some photos of a derailment in Union Pacific’s West Colton Yard in Colton, CA a few years ago. There, too, an 85-foot auto carrier was coupled to a shorter car.
It is unknown what the exact cause was on the San Diego area incident, but I find it a remarkable coincidence that a long and short car derailed.