Ever since as I child watching steam on the PRR I have wondered just how long will these massive structures serve their vital roll? It would seem like oxidation, deterioration has to eventually take it's toll.
Any record of individual failures or reports of safety / suitability conditions? It would seem that replacement would be an astronomical expense.
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Hopefully PRR has a maintenance staff and program to keep them in good working order
@AlanRail posted:Hopefully PRR has a maintenance staff and program to keep them in good working order
Considering that the PRR died in the ill-fated Penn Central merger in 1968... the PRR does not maintain it anymore.
Amtrak and Septa now have ownership of the former PRR catenary. (Amtrak on the keystone/NEC and SEPTA for all the commuter branches). They do inspect their assets regularly; I've even see them do inspections via helicopter.
@Tom Tee posted:Ever since as I child watching steam on the PRR I have wondered just how long will these massive structures serve their vital roll? It would seem like oxidation, deterioration has to eventually take it's toll.
Any record of individual failures or reports of safety / suitability conditions? It would seem that replacement would be an astronomical expense.
Tom, I too grew up around these massive structures, albeit under Amtrak/Septa ownership.
While I have never seen any record of failures or safety / suitability concerns for the H beam, the original 1914 catenary along the Philadelphia-Paoli portion of the Mainline (Keystone Corridor) is showing it's age. These are tubular poles with no transmission overbuild, so it is not directly answering your question.
In this proposal, the third slide shows deteriorating conditions. Some background behind this proposal: Amtrak wants to move their 138kV transmission off the former Trenton cutoff and onto the mainline; the wealth along the mainline has been able to block this project from happening as they don't want to see taller electric poles in their area... I don't blame them.
(I've heard that the PRR wanted to do this in the 1930s, but it was blocked then too, cannot confirm the source on this part of it though.)
Back to the main topic, I believe Amtrak spent some time in the 1980s to refurbish the poles on the NEC? (Even placing utility overbuild in some areas?)
Tom,
This isn't the PRR, it's the DTI, and it's not steel structure on concrete foundations, but it has supported cat in the past and is now quite old:
Taken Sept 2000, Kodacolor 200. Melvindale, MI. Still there today (2021).
These structures are now almost 100 years old, having been erected in 1925 or thereabouts.
How much longer will they last?
(BTW: I've embedded the GPS coordinates in each file -- for those of you who might want to visit them, up close and personal, although I'm not sure if they will make it through the upload process.)
Mike
@Mellow Hudson Mike posted:Tom,
This isn't the PRR, it's the DTI, and it's not steel structure on concrete foundations, but it has supported cat in the past and is now quite old:
Still there today (2021).res are now almost 100 years old, having been erected in 1925 or thereabouts.
How much longer will they last?
Good question...
There's obviously been some erosion of the concrete through the 100 years. I suppose that question will be more seriously dealt with when...someday...a chunk of the overhead span succumbs to age, corrosion, erosion, seasonal freeze/thaws of Michigan,...and vibrations from continued passing trains. If it does some serious damage to equipment or personnel, I'm sure it will move up on the to-do list.
Anyway, should I survive 100 years (not likely considering my gene pool!) I doubt I'll look that good!
KD (Up the road from these monoliths in Meeeshigan)
Catenary support structures on Metro-North Railroad between Woodlawn, New York and Stamford, Connecticut (about 21 miles - completed in 1907) and from Stamford to New Haven, Connecticut (39 miles - completed in 1914), erected by the New Haven Railroad, are still in use over most of the division. The support structures and their concrete footings required significant rehabilitation and have been replaced with new structures in some places. About 1.5 miles of experimental arched catenary support structures in Glenbrook, Connecticut (just east of Stamford), built during the original electrification to New Haven, were replaced with new construction around 2010. Between New Rochelle, New York and New Haven (54 miles), the division carries Amtrak trains and is part of the Northeast Corridor with four tracks in most places. Amtrak's Northend Electrification between New Haven and Boston was built during the 1990s and is modern.
This link to a State of Connecticut website will be of interest...
MELGAR
@Mellow Hudson Mike posted:Tom,
This isn't the PRR, it's the DTI, and it's not steel structure on concrete foundations, but it has supported cat in the past and is now quite old:
Taken Sept 2000, Kodacolor 200. Melvindale, MI. Still there today (2021).
These structures are now almost 100 years old, having been erected in 1925 or thereabouts.
How much longer will they last?
(BTW: I've embedded the GPS coordinates in each file -- for those of you who might want to visit them, up close and personal, although I'm not sure if they will make it through the upload process.)
Mike
Despite their age, they appear to still be in relatively good condition. It's my understanding they were deemed too expensive to remove, so unless they start collapsing on their own, they will remain a monument DT&I.
Look how long some Roman arches have been up...
Rusty
I visited my grandparent's home town, Fairfield, CT., in June 2018. I took these photos from the Fairfield station platform of the the old 4 track mainline and the 1914 NH catenary supports.
It is amazing that my grandparents would have seen these same catenary supports when they were new in 1914 and that they are now powering Acela trains 100 + years later. I wonder if these supports will be in use 100 years from now. Certainly the 4 track mainline between New Haven and New York will still be in use. Maybe all the trains will be magnet levitation by the end of this century. NH Joe
Below: Looking east toward Bridgeport and New Haven.
Below: Looking west toward New York. If you took away the high platforms and the concrete ties on one line, this scene is essentially the same that I saw as a kid over 70 years ago.
Sorry about the PRR misstatement.
BUT ONE-WORD........................Infrastructure.
It has been stated that, as an example, the New York City subway system structures were designed to last 600 years without significant repairs. Same opinion with Penn Station.
@New Haven Joe posted:I visited my grandparent's home town, Fairfield, CT., in June 2018. I took these photos from the Fairfield station platform of the the old 4 track mainline and the 1914 NH catenary supports.
Below: Looking west toward New York.
New Haven Joe,
In your attached picture, looking west from the south platform at Fairfield, CT, catenary structure 687A, nearest the camera, is of modern construction. The next tower (probably 687) is of the original steel construction from the 1914 New Haven Railroad electrification. Good pictures.
MELGAR
@Arthur P. Bloom posted:It has been stated that, as an example, the New York City subway system structures were designed to last 600 years without significant repairs. Same opinion with Penn Station.
The PRR was known for it's long term infrastructure investments such as electrification and the numerous Low Grade Lines.
Penn Station, and other projects, were meant to be statements to the PRR's strength and might during the early 20th century. Conquering Gotham puts it best, (paraphrasing here) that the grandeur-ous original Penn Station was a monument to the railroad itself.
Back to the catenary... they are essentially transmission poles which do have a lifespan as they are exposed to the elements. Some utilities still have wood poles that are as old as (if not older than) the H-beam/ K-bridge catenaries.
@Prr7688 posted:Amtrak and Septa now have ownership of the former PRR catenary. (Amtrak on the keystone/NEC and SEPTA for all the commuter branches). They do inspect their assets regularly; I've even see them do inspections via helicopter.
Lets not forget NJ Transit, who also own former PRR catenary on what is now their North Jersey Coast Line.
Tom, I grew up and still live along the PRR mainline in central NJ. The H section catenary towers are riveted sections, built in the 1930’s. Set in 30”x30”’ wide concrete footings. In the 70’s the towers were doubled in height to carry long distance transmission lines. They were all originally painted silver. Except for rust the towers are in remarkably good shape.
The tower bridges that carry signal heads are significantly more rusted.
Around 1978 a Conrail freight passing through Metuchen station burned an axle bearing and several cars derailed. Besides the one boxcar that landed half off the overpass onto Main Street, another slammed into a tower. Twisting it badly but it remained upright. Subsequently the tower was encased in concrete up over the damaged section.
@Arthur P. Bloom posted:It has been stated that, as an example, the New York City subway system structures were designed to last 600 years without significant repairs. Same opinion with Penn Station.
That was likely assuming that they are doing reasonable maintenance, like regularly painting the structure. Look what happened with the Williamsburg bridge, in theory a steel bridge like that can last pretty much forever, but there is a catch, it needs to be maintained. The metal needs to be blasted down,primed and repainted from time to time, explansion joints in the road surface need to be cleaned and lubricated,drainage has to be maintained. The Williamsburg also suffered from relatively cheap construction, the steel used if what I recall is correct wasn't exactly highest quality.
Concrete likely can have a long life, but if you are talking standard concrete you can't get away from maintenance. Given the corrosive effects of pollution (thankfully with the death of coal and tight standards acid rain is no longer a problem) and also concrete dealing with vibration and the elements, there is some maintenance. Cracks need to be fixed, the concrete itself may need sealing, to protect it from water or pollution. If water gets in that is when you see chunks falling off and the concrete failing.
And yes, Roman concrete has lasted for thousands of years, there are Roman aqueducts still in use I believe. A lot of that had to do with the way they built things, the concrete they used was lime based and it is particularly hard and impervious (not indestructible, of course) (Other roman concrete was made from volcanic ash, not sure how strong that is). The old roman bridges have masonry foundations in the river and it has survived all those years, they modified the lime cement to be a form of hydraulic cement you can use underwater.
So why do they use the concrete utilizing Portland cement and sand? It is a lot easier to work with and is a lot more cost effective. Lime based concrete is really difficult to work with, I watch these channels on You Tube with people restoring old Chateaus in France, and they will use lime concrete because it is what was used originally. It is difficult to work with and also takes a lot longer to cure, in modern construction with time=money, it would add a lot to the cost in time and of course money (Just my opinion, I am far from an expert, not even really a novice
.
Again most of it comes down to maintenance, if you do the kind of maintenance you should these things can last a really long time. On the other hand you can argue that things like cantenery or a lot of buildings and such should be replaced, but that is another argument
There's a whole lot to unpack with the post above:
1) Steel even if painted doesn't last "forever". Corten steel is designed to rust (no painting) and the rust coating protects the steel, but even Corten doesn't last forever.
2) Steel used in bridges is much much higher quality steel than the steel used in buildings; Even so it still need to be replaced over time; paint even epoxy-coated is not enough to entirely stop rust.
3) Concrete comes in many forms depending on the admixtures such as marine cement that is used under water. Thus, there is really no "standard" cement; cement is essentially crushed limestone; Concrete is what I think you meant. { there are no rotating cement trucks they are concrete trucks.) Limestone may appear in crushed concrete as a material found in the cement used to mix concrete. Some builders use crushed concrete as a material for new concrete, in which it takes the place of a crushed mixing stone like limestone. Crushed limestone appears in some of the same applications as crushed concrete.
Reinforcement is placed in concrete to allow the concrete to have tensile properties since concrete is great in compression but not so good in tension. Also, depending on the conditions that the concrete will be subject to the reinforcement is placed with a larger "cover" of concrete to protect the reinforcement. Rusted interior-placed reinforcement can expand 2-4 times its original size and THAT can crack the concrete.
4) Mortar, not Concrete, that was used by the ancient Romans was made by mixing lime and volcanic rock to form the mortar, again not really concrete. Today's concrete that is made from Portland cement wasn't invented until1824 by an English fellow, Joseph Aspdin, who invented Portland cement by burning finely ground chalk and clay until the carbon dioxide was removed. Aspdin named the cement after the high-quality building stones quarried in Portland, England. When properly mixed with sand, stones and water becomes concrete.
Thus, I learned from many years as an engineer with the Portland Cement Association.
I will never argue with an expert on this, as I said I am not an expert. You are correct the lime I was talking about was mortar, it is what they were using on the chateaus to redo where it had come out on the walls. And yes, you are correct it is concrete, not cement. And yep, rebar is in there because concrete doesn't like tension. Concrete also comes in a variety of mixes that have very different attributes, I know when they put up buildings that the concrete being used for the floors and foundations is supposed to be tested (I am talking NYC here) and certified that it is the type called for in the plans. There was a big scandal in NYC with a testing firm a lot of the construction companies were using, they falsified results, it involved high profile projects including the new Yankee stadium.
Corten is actually genericized version of the brand name Core-Ten. The correct terminology is "self weathering steel" and comes in the following types: ASTM A588, A242, A606-4, A847, A871-65 and A709-50W 
Building steel is typically ASTM A992.
@New Haven Joe posted:"...It is amazing that my grandparents would have seen these same catenary supports when they were new in 1914 and that they are now powering Acela trains 100 + years later. I wonder if these supports will be in use 100 years from now. Certainly the 4 track mainline between New Haven and New York will still be in use. Maybe all the trains will be magnet levitation by the end of this century. " NH Joe
One time many years ago I rode on the Paoli local into Philadelphia with a friend who seldom rode the train. After a prolonged and contemplative period of staring out the window taking in the aging infrastructure, abandoned factories, warehouses, and "ghost advertising," he turned to me and said, "You know, there is no kind of old like railroad old." Seemingly nonsensical, but I knew exactly what he meant and never forgot it.
@Magicland posted:Lets not forget NJ Transit, who also own former PRR catenary on what is now their North Jersey Coast Line.
And also the NJT Morristown LIne, the Gladstone Branch and the Montclair Boonton Line…ex EL lines
The Morristown line has the oldest steel structures, using solid I beams and well as composite structures made of steel. The Gladstone branch was predominantly wood cat poles that have been renewed recently with some steel structures mixed in. Both line’s structures date from the 1930s (DL&W) and are still in good condition.
The entire ex-EL catenary system was refurbished by NJT in the early 1980s, when poles and structures were repainted and decayed structures replaced. The catenary system was also reinforced to handle the larger, heavier insulators and adjacent power supply devices when the system was converted from 3000v DC to 25KV AC.
The Montclair Boonton line is half older DL&W catenary structures on the old Montclair Branch portion, while the new Boonton line (Montclair) connection is more modern and recently constructed, extending the catenary to Great Notch yard…
Tom
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