A bike path near my house is on top of an old Rock Island rail bed. The parallel former Milwaukee Road line 100 feet away is graded much better. For example, in a half mile stretch the Rock Island ROW rises and then drops 12 feet. The Milwaukee Road ROW- now the BNSF line through town- is flat as a pancake. I’ve seen other ROW from both in the area. In general, was the Milwaukee Road usually built to higher standards than the Rock Island in the same area?
I find this a little bit troubling, as I’d always heard that the Rock Island line was a mighty good road.
Most rail companies in the 19th century were created as undercapitalized entities and built as much mileage as they could and moved as little earth as possible to build that mileage. As more capital became available, sometimes it was reinvested into the physical plant to minimize changes in line elevation and increase the radius of curves.
The original location of tracks was dictated by more than capital funds. The need of water for locomotives, the lack of tools to excavate deep rock cuts, the flood plains of certain rivers or streams, plus the politics of states or towns and large land holdings.
Rock cuts on the Mohawk and Malone (NYC Adirondack Division, now Adirondack Railroad) are usually just wide enough. Accounts of early operations indicate that occasionally fittings would be knocked off steam locomotives, and even today we worry occasionally about whether cars like the dome will clear.
A common practice was (and still is) to use the dirt from a cut to fill in a dip. As noted, sometimes the economics would not allow for “outside” fill to be brought in.
One extremely large fill on the MA&N probably still has a trestle under it. The chief reason for building the trestle was to reach a spot on the other side from which fill could be obtained.
Capital available dictated each and every aspect you mentioned. Everything needs the lubrication provided by money (or the lack thereof). If there was enough money to ‘do the job right’, it was; if there wasn’t the job got done in the lease expensive way possible. It has always taken money to lubricate politicians - some have gotten very rich standing in the way of progress until they were sufficiently lubricated.
In the earliest days, cuts were made by horses pulling a hand scoop. When the scoop was full, the horses would slide it to carry the load to the dump location, usually quite near to the cut location.
Around 1880-1890, the steam shovel was introduced and this made cut excavating much more efficient. Cuts could be made deeper than before. Deeper/longer cuts would generate more fill, and this called for a means of soil transportation to get the soil to more distant fill location. The new transportation that accompanied the steam shovel was the “Dinky” (0-4-0T) or similar small locomotive, often operating on narrow gage track with very light rails such as 25-40 pound.
The track was extended over the fill area by building a trestle. The soil was carried in side dump cars which were convenient to unload by just by dumping over the side of the trestle.
The trestle was just temporary, and thus of low quality, and was buried in place as the filling commenced. Sometimes line improvements called for filling trestles that had been in actual train use for some years. These too were often buried in place.
So, the dinky, side dump cars, steam shovel, and trestle were all part of a new steam powered excavating system that would cut, transport cut material, and fill acro
The Sioux Falls line of the RI was built by the Burlington, Cedar Rapids & Northern Ry. That railroad became part of the RI in 1903, although they had control of it about 10 or 15 years earlier.
I imagine BNSF has improved its former MILW lines. I’m assuming the BNSF line you’re mentioning is probably the Mitchell Sub. All CRI&P routes into South Dakota were branches hence the elevation change you’re seeing. Branches are built much more cheaply for the most part than mainlines.
BNSF has certainly improved the track in terms of rail, ties, ballast, and bridges, especially after buying the Core Lines outright from the state about 15 years ago. But I don’t think they altered the profile or alignment in any significant way.
A perhaps even more important reason was that it was easier to create the fill by dumping carloads of dirt from the trestle, than doing it lift by lift with material carted in. One strong incentive to cover a trestle with fill was to elminate the possiblity of the trestle burning down.
FWIW, the Central Pacific had a number of trestles that were filled in after the transcontinental line was finished.
Reportedly they took the top off a hill to get the material needed…
One story regarding the trestle was that the state bridge inspector noted that it didn’t look all that healthy, to which the reply was that it was going to get covered anyhow.
Okay, I’ll bite. Why is it that anytime I propose using old railroad ties for landscaping forms, I’m reminded that without proper drainage, they’ll rot. Yet here we have load bearing wooden trestles being buried intentionally? What am I missing? [sigh]
The fill trestle has no purpose once it has been filled, so it is okay if it rots. If the fill is in a previously unfilled area, the trestle is contructed with low quality because it is only needed for the filling work.
However, the rotting will cause fill subsidence over time, which will require subsequent work in the future to raise the track by adding a little more fill.
That was the reason for filling the trestle. If filled without a trestle, dump cars would have to be dumped one by one at the starting edge of the fill, and then horse/ scraper scooped up, skidded out into the fill area, and dumped one scoopful at a time.
For a new line, the trestle had to be built from scratch with considerable labor and materials, even though the materials and construction were of low quality because they had no purpose after the fill was made. Essentially the temporary trestle was like a template for placing the dirt fill without any need for spreading it and grading it in lifts. As the trestle was filled, the fill soil was often water jetted to c
That was my first thought. I guess my surprise is with the expectation that subsequent remedial action will be “little”. I mean if you are talking about a 25’ fill, you are gonna have trestle members rotting 25’ beneath the surface,
And, I’d think that the framing members would really interfere with compaction. Isn’t “compaction” the alpha and omega of site prep?
I would imagine that operating trains continually over the trestle that has been made into a fill would aid in the compaction process as the trestle structure will be subject to vibratory forces with every train the moves across it.
My understanding is that oxygen is required in the decay/rotting process. The deeper timbers get buried in the fill, the less oxygen is available to sustain the process.
That is very true. Trains will deeply compact the fill over time, especially due to their impact vibrations from rail joints. And timbers buried deep will have rot resistance due to a lack of oxygen. Either too little oxygen or too little moisture will impede rotting. That is why wooden fenceposts first rot through at ground level where the combination of oxygen and moisture is just right.
I have to comment though since one of the railroads mentioned has a pretty good reputation in my view. Milwaukee road drained a swamp in Menominee valley in Milwaukee and built a series of drainage / shipping canals as well as a railroad shop complex on it. They also did pretty well traversing more than one swamp West of Milwaukee on the way to the Twin Cities and in Brookfield with the branch to Waukesha. I would venture to guess they were fairly good about building on swamp land.