# Do Concrete Ties really weight 850lbs?



## Crescent ATN & TCL (May 10, 2008)

An article in the NY Times was disscussing tie-replacement on the NEC and said that the ties weight 850lbs. Is this correct? I wouldn't think they would be quite that heavy.



> But Amtrak and New Jersey Transit passengers are about to get a lesson in how critical those 850-pound rectangular blocks are to running a railroad. That is because Amtrak has embarked on a project, expected to take at least six months, to replace 85,000 of them along the Northeast Corridor, one of the busiest stretches of rail line in the country.


Full Article


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## PRR 60 (May 10, 2008)

Yes.

Reinforced concrete weighs 150 pounds per cubic foot. A block of concrete one foot square by 8 feet long would weigh 1200 pounds. A concrete tie is an irregular shape, so 850 sounds sounds correct.


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## Rail Freak (May 10, 2008)

Crescent ATN & TCL said:


> An article in the NY Times was disscussing tie-replacement on the NEC and said that the ties weight 850lbs. Is this correct? I wouldn't think they would be quite that heavy.
> 
> 
> > But Amtrak and New Jersey Transit passengers are about to get a lesson in how critical those 850-pound rectangular blocks are to running a railroad. That is because Amtrak has embarked on a project, expected to take at least six months, to replace 85,000 of them along the Northeast Corridor, one of the busiest stretches of rail line in the country.
> ...


that's 472.2 per day???? :huh:


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## the_traveler (May 10, 2008)

Rail Freak said:


> Crescent ATN & TCL said:
> 
> 
> > An article in the NY Times was disscussing tie-replacement on the NEC and said that the ties weight 850lbs. Is this correct? I wouldn't think they would be quite that heavy.
> ...


Have you ever tried to lift them? 

Seriously, with all the Amtrak and commuter traffic on the NEC, along with the occasional freight, I'd say that's a lot!


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## WhoozOn1st (May 10, 2008)

PRR 60 said:


> Yes.
> Reinforced concrete weighs 150 pounds per cubic foot. A block of concrete one foot square by 8 feet long would weigh 1200 pounds. A concrete tie is an irregular shape, so 850 sounds sounds correct.


Is the 150 lbs. a constant, an average, a mean? No variables based on composition of aggregate? And does the weight include the track clip tiedowns molded in? Please pardon my ignorance.


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## had8ley (May 10, 2008)

I believe Mr. Harris would be the authority on this but the concrete ties the KCS/L&A used at one time had re-bar re-enforcement rods through them.


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## VT Hokie (May 10, 2008)

I remember reading 400 lb for a concrete tie vs 250 lb for a wood tie. But maybe that was incorrect.

Edit: maybe it was 400 lb for a wood tie...my memory's probably failing me!


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## jis (May 10, 2008)

had8ley said:


> I believe Mr. Harris would be the authority on this but the concrete ties the KCS/L&A used at one time had re-bar re-enforcement rods through them.


The ones being used on the NEC also have re-bar re-enforcement in them. You can clearly see them in the ties that have crumbled as a result of defect in manufacturing.


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## PRR 60 (May 10, 2008)

WhoozOn1st999 said:


> PRR 60 said:
> 
> 
> > Yes.
> ...


The 150 pound per cubic foot density is the standard value used to compute the weight of reinforced concrete. Concrete ties are reinforced. Plain concrete has a standard weight of 140 pounds per cubic foot.

Lightweight coarse aggregates can be used to reduce the weight of concrete. The so-called lightweight concrete can weigh as little as 90 pounds per cubic foot. Lightweight concrete is used in applications such as floor slabs to reduce the weight of a building and lower the structural requirements of support columns. The weight reduction comes at the cost of strength. Since ties are placed by machine, the weight is not a issue. Strength and durability are the requirements for ties, so normal concrete would be used.

The cast-in elements for rail attachment are only a minor contributor to the weight of the tie.


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## Green Maned Lion (May 11, 2008)

Rail Freak said:


> Crescent ATN & TCL said:
> 
> 
> > An article in the NY Times was disscussing tie-replacement on the NEC and said that the ties weight 850lbs. Is this correct? I wouldn't think they would be quite that heavy.
> ...


If they work around the clock, that means they are placing an average of 20 an hour, which involves quite a bit of work, by the way. If they don't work around the clock, only work 16 hours, 2 eight hour shifts, they are placing 30 an hour. That sounds pretty reasonable.


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## George Harris (May 12, 2008)

PRR60 has about everything I would say about the weight. The Northeast Corridor Ties are somewhat heavier than the average.

Go here www.lbfoster.com/uploadedFiles/Asset_Images/TiesProd2.pdf and you will see several concrete tie dimensions and weigths by one of their manufacturers. This is, according to news articles, NOT the company that manufactured the Northeast Corridor ties that are failing. According to one person that should know, the NEC ties are heavier than any other concrete tie used anywhere. the heaviest on the sheet I referenced is the one manufactured for Union Pacific. It weighs 705 pounds each, and is 8'-6" long It is 9 inches thick at the ends, 6.75 inches thick in the center, 7.5 inches wide at the top and 11 inches wide at the bottom.

For comparison, a standard wood tie for main line use is 7 inches thick, 9 inches wide and 8'-6" long and would weigh somewhere around 200 to 225 pounds, depending on the wood density and how much creosote it absorbed. This does not count tie plates and spikes.

George


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