The surviving locomotive in December 2019:
Greetings from Alberta
-an Articulate Malcontent
Thank You.
Some information on the Proctor test for compaction:
https://www.globalgilson.com/blog/proctor-compaction-test-a-basic-guide
Not only does soil compaction require force, but it also depends on soil type and moisture content. Too much moisture creates a film around every particle which prevents them from achieving an interlocked effect in the compaction. When this overly wet soil is compressed for compaction, it is like dough. You push down here and it rises up there.
Too little moisture fails to produce the thin film of water that lubricates the particles to help them slide together. Looking at the soil being loaded in the video suggests that it is too dry for optimum compaction.
Water could be added to the soil by wetting down each load dumped. Also, breaking up and saturating soil with high pressure water hoses is another form of soil consolidation called “jetting.” This at least breaks down soil chunks to eliminate any large voids in the fill, but it leaves the soil too saturated for proper compaction.
Proper soil compaction with compacting equipment must be done in layers called “lifts.” These are horizontal layers of fill laid down in a controlled loose thickness such as 8 inches. I am guessing that such perfected compaction was never done on railroad fills in either the original work in the Pioneering era or in the massive fills made shortly after during the line relocation/improvement as shown in the video. However, I have seen photos showing the “jetting” process being used.
Heavy clay soils pose the most problems for compaction. The clay particles are fine, and this creates conations of the soil holding too much water for proper compaction. On roadbed projects, this may require using methods to dry the soil as it is placed in fills.
Some filling work has fill placed directly into open water. This results in a finished fill that is woefully insufficiently compacted for a long time as underwater settling takes place. I read old history about the CMStP&P adding a second mainline to their route along Lake Hazeltine in Carver County, MN. In 1915. They widened the roadbed by filling into the lake. I assume this was done by dumping soil from dump cars while working off of the existing, established fill of the first mainline track. Apparently, they did not run any trains on that new fill during its construction. They finished the fill, laid the track on it, and ran the first train over it. This was a regular passenger train eastbound in the morning. When the train hit that plastic fill, it broke through and sank. Their approach speed was not too high, but it was not slow enough to stop at the first sign of trouble. Then engine went down into the muck, broke steam pipes, and killed the engineer due to scalding.
I have a vague recollection about RR fills typically taking 5 or so years to fully settle under traffic. Along those lines, Trains had published a picture of an NP articulated locomotive that derailed while being used to speed the settlement of a recent fill.
On a related note, my cousin's husband had worked for the Montana Highway Department for a number of years and one pf his early jobs was taking soil samples for compaction testing. That left a niggling question in my head as to what was involved - eventually bought a book on geotechnical engineering to satisfy my curiosity.
The lower layers of the fill will be gradually compacted by the weight of all the fill above them. Obviously, that effect diminishes the closer the fill gets to the track. Once the track is being carried by the fill, it will be a few years to a few decades until the settlement decreases to no longer require more attention than the adjoining track.
Early in my career an assignment was to monitor the superelevation in an industrial park lead curve on a fill that was only about 10 feet high, and only about 5 - 6 years old. For as long as I had that position - a little less than 2 years - every couple months it would settle so much that the curve had 'negative elevation' = the outer rail of the curve was up to 1" below the inner rail, not a good condition and a possible defect, depending on whose criteria was being applied. So a crew would spend about a day adding ballast and then raising and tamping that section. The owner spent some money on a geotechnical investigation to see if that condition was being caused by a sinkhole (no, it wasn't), and may have tried lime or cement stabilization, but that didn't solve the problem either. My thought at the time was that the compaction specifications for the fill were either not very high or weren't followed, but I never saw those specifications or any tests to confirm or refute my suspicion. In general I think compaction specifications are not as stringent as they could or should be - which with modern equipment can be achieved within reason - but that is a topic for a different forum.
- PDN.
The weight of the fill will compact that below it. The top of the fill will be the area not compacted thusly.
rrnut282Some believe, incorrectly, dropping the soil or other material from a great height will compact sufficiently upon impact.
Count me in that number. I stand corrected.
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...
As long as the original timbers are still supporting the track, no extra track surface work is needed until the timber rots away. Most likely, most of the timber will stay as-is as there isn't as much oxygen to promote decomposition. Worst case, the top foot or two is all that decomposes.
Some believe, incorrectly, dropping the soil or other material from a great height will compact sufficiently upon impact.
Question. Since filling in a bridge does not allow for compacting the fill is there a requirement for later much more surfacing of the fill area to keep track useable ?
Erik_Mag The angle of repose of the fill looks a bit steep for an ordinary fill.
The angle of repose of the fill looks a bit steep for an ordinary fill.
Thank you for using the phrase "angle of repose". I took geology as my lab science in college (figured a farm boy couldn't go wrong with rocks and dirt), and finally (42 years after graduating) was able to use something I learned in my lab science class to understand what someone was trying to communicate.
NDG Steam Shovels, Again! Thank You Mr. M M Re the text on Steam Shovel Management. Mining and Railways and Big Equipments run together. Here is another Great Project which must hold the title for the amount of men and machines in one location. The Panama Canal. https://www.youtube.com/watch?v=VdGNOhtbgCw Showing the Flag. https://www.triviapeople.com/wp-content/uploads/2015/11/Roosevelt-PanamaCanal.jpg The centre casting of the table was hollow, by Teddy's left knee, and bushed with a bronze bearing to allow chain and table to revolve on centre as boom swung. Boom swung by a cable with it's own steam engine and drum. The man on the Boom racks the Dipper in and out against the bank using a two cylinder steam engine which exhausts at the top of the boom, he opens the bucket door latch w a lanyard. Note flexible steam pipe couplings above pulley. Steam Shovel Engineer and controls, Throttle top left. Many Trestles were constructed with the INTENTION of filling them in at a later time. In this way untreated timber, often cut locally in mountainous country, was used, saving the costs of treatment and shipping. The Trestles would then be filled before the timber life expired using the completed railway to transport material. As timber was available during construction in the mountains, CPR used coal burning locomotives fired on wood as readily available rather than shipping in coal great distances and demands for steam not as great as on through trains. The same applied to bridges that were planned to be finished in stone or concrete for their Abutments and Piers, Steelwork above. Quick Trestles in wood, first, then, once the line completed, move in heavy materials and steelwork by rail. Thank You.
Many Trestles were constructed with the INTENTION of filling them in at a later time.
In this way untreated timber, often cut locally in mountainous country, was used, saving the costs of treatment and shipping.
The Trestles would then be filled before the timber life expired using the completed railway to transport material.
As timber was available during construction in the mountains, CPR used coal burning locomotives fired on wood as readily available rather than shipping in coal great distances and demands for steam not as great as on through trains.
The same applied to bridges that were planned to be finished in stone or concrete for their Abutments and Piers, Steelwork above.
Quick Trestles in wood, first, then, once the line completed, move in heavy materials and steelwork by rail.
Another trestle from the area that was definitely intended to be temporary, note the permanent construction beside it. Even the cheapest of pioneer roads had to build long steel spans across large waterways, for floods with floating debris would clog and demolish the shorter gaps of trestles. Most large rivers had steamboats at that time as well, though this stretch of the North Thompson did not (too many rapids and rocks).
The above bridge(s) are here:
https://www.google.com/maps/place/51%C2%B040'22.6%22N+119%C2%B038'23.5%22W/@51.672937,-119.6420607,491m/data=!3m2!1e3!4b1!4m6!3m5!1s0x0:0x0!7e2!8m2!3d51.6729369!4d-119.6398721
And today:
https://railpictures.net/photo/479574/
Much more detailed info on this particular fill:
http://www.exporail.org/can_rail/Canadian%20Rail_no413_1989.pdf
And a photo of the trestle while under construction:
https://www.bclocalnews.com/news/north-thompson-valley-voices-from-the-past/
One of the locomotives that was owned by the contractor is now preserved at the B.C. Forest Discovery Centre. Due to his small fleet it most likely worked on the Lyon Creek job.
Building a trestle and then filling it in is probably more common than one thinks. the large fills on the western edge of Omaha on the UP's Lane Cut-off were built that way. There's a picture of one being filled in hanging in a UP building in Council Bluffs. I've seen it on the internet, too.
On the Boone and Scenic Valley's line there are 8 locations between their high bridge and their Des Moines Rivwr bridge that had trestles that were filled in over time. The FDDM&S interurban filled them in using cinders from their on-line generating plant. Some years back, they were doing some maintenance work at the bottom of one of these fills and unearthed part of the wooden structure.
Jeff
Steam Shovels .. all you ever wanted to know !
https://archive.org/details/steamshovelminin00marsuoft/page/n4/mode/2up
Not far from me (5 minutes) is a fill of an old iron bridge (actually the 2nd bridge at that site) of the Catasauqua & Fogelsville Railroad, but they used iron furnace slag instead of earth or rock.
From https://en.wikipedia.org/wiki/Catasauqua_and_Fogelsville_Railroad#Reading_control
Between 1916 and 1919, furnace slag was dumped under the Jordan Creek high bridge so that it could be replaced by a fill and culvert.[5]
Link to Bridgehunter.com page on it, showing a sketch of the first bridge:
https://bridgehunter.com/pa/lehigh/bh80168/
The construction of the 3rd bridge in 1917, showing some of the filling of the 2nd bridge in progress to the left (track in the foreground is the Allentown & Slatington Electric Railroad - note the 3 poles on the left for the trolley wire);
https://bridgehunter.com/pa/lehigh/bh80169/
Bridge and fill today - still in use by NS, about 1 small train (3 - 4 cars) each way a day - view from the other direction (looking west):
https://bridgehunter.com/pa/lehigh/ns---jordan-creek/
I've seen steam powered cranes and pile drivers on Manhattan construction sites in the early 1970s. In the early 1990s I saw a steam powered dredge in the Hudson river near Poughkeepsie. I would have loved to go on board but it was anchored in the middle of the river.
The Central Pacific filled in many of their trestles in a relatively short period after the line was built. Main reason for the trestle was that it was faster to put in a trestle than a fill. Having the trestle made it easier to construct the fill as the earth was simply dumped from cars on the trestle.
There's a fill on the Carson & Colorado grade just below the tunnel on Montgomery pass that looks like a filled in trestle. The angle of repose of the fill looks a bit steep for an ordinary fill.
As the story goes, a large fill on the line north out of Utica is the product of a trestle built there. According to the story, a state bridge inspector looked the structure over and noted that it probably wouldn't last very long.
The railroad was unconcerned, as the only reason the trestle was built was to get to a source of fill on the north end. Apparently the top of a hill was removed and dumped over the trestle.
The line is still in use, and I'd imagine that if the fill was ever removed, the remains of the trestle would still be evident.
N 43.26415 W 75.18281
On CN in B.C, the trestle was originally built as part of Canadian Northern's main line to Vancouver. Today it on the CN Clearwater Sub, which sees well over 20 freight trains each day.
https://www.youtube.com/watch?v=Jp8R0YJ8NpI
As noted in the uploader's comments, the exact location is not far north (timetable east) of Avola, BC. Exact location appears to be here:
https://www.google.com/maps/place/51%C2%B052'47.8%22N+119%C2%B019'14.4%22W/@51.8799444,-119.322559,489m/data=!3m2!1e3!4b1!4m6!3m5!1s0x0:0x0!7e2!8m2!3d51.8799328!4d-119.3206565
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