Should of stayed with wood

[Ron Wenrich]

http://news.yahoo.com/s/ap/20080228/ap_on_re_us/amtrak_cracked_ties

Amtrak has to spend millions to replace ties.  Seems that their concrete ones aren't lasting the 50 years that they have projected.  More like 10-15.  That's a little less than a wooden one. 

[SwampDonkey]

Can't beat a good thing. 

[DanG]

I didn't know Amtrak had their own rails.  The ones that pass through this area ride the CSX rails, which are on wood.

The railroad that runs by my place is on concrete, though.  I've heard that it is the only one in Florida, but I don't really know.  It doesn't have a lot of traffic, usually 2 trains per day, and it is holding up well.

[beenthere]

I've heard of attempts for many years of trying to replace wood ties with concrete, and thier life span was always much shorter than wood ties.  The constant pounding the ties get seem to make the difference. So, the news doesn't surprise me. The expectation of 50 years does however....seems more in line with the expectation for wood, not concrete.

Experience with concrete ties, going back to the 40's in Europe, provided knowledge that concrete just wouldn't take it. Wood is good.

But again, the enviro's (I know, prolly the wrong handle to use) with the preservative fears wood resource protection and "don't cut trees" mentality easily convince the Gov't entities to prescribe concrete....or so I think...   We find many ways to shoot ourselves in the foot, or like some say..."cut a fat hog in the rear".

[SwampDonkey]

I'm no expert on concrete ties, but just judging how long it takes before the decking on our major bridges gets redone, I would say they might last 5 years up here in our climate. It sure can't be cheap replacing wood with those things.

Kind of reminds me of the guy who wants to replace his $80/month utility bill with a gadget that costs $25,000 and has a life expectancy of 15-20 years. Factor in 3% annual inflation for electricity.

$25,000 = 960 (1 + 0.03)^x - 1
                             0.03

1.78125 = (1 + 0.03)^x

x√1.78125 - (1 + 0.03)= 0
x = 19.5 years 

Now factor in maintenance costs. What did ya save, zip and in all likely-hood you went behind.

look at 6% inflation

$25,000 = 960 (1 + 0.06)^x - 1
                          0.06
2.5625 = (1 + 0.06)^x
x√2.5625 - (1 + 0.06)= 0
x = 16 years and 3 months

So if your rate increase averages 6 % in this case your still better off on the utility.

[isawlogs]

 I was going to question the vivrating factor of a train going on ciment ties ... But Swamp sortof blew my thoughts out the window with his annalisist 

[SwampDonkey]

 

[logwalker]

Thanks Swampdonky, you just gave me a headache. 

[Tom]

Florida has begun replacing concrete bridges in the woods with wooden structures again because ot the durability and maintenance as compared to concrete.  I thought the little sawmills would benefit from the decision, but it seems that the timbers are being trucked in from "somewhere else".

[limbrat]

KCS pulled all the concrete ties from a ten mile experemental section about ten years ago between here and Marksville, parallel to La.1. They said at the time that there wernt a good enough base under it, after the tie wallowed a hole in the stone base the load was being transfered unevenly along the tie and causing them to crack. I think it would be hard to come up with something as elastic, durable and cost effective as a piece of treated wood.

[StorminN]

But again, the enviro's (I know, prolly the wrong handle to use) with the preservative fears wood resource protection and "don't cut trees" mentality easily convince the Gov't entities to prescribe concrete....or so I think...

I'm thinking it probably comes down to the concrete industry being more organized and having better lobbyists, bribing the Amtrak people or government entities better than the wood industry people.

True "enviros" know that concrete has a HUGE amount of embodied energy (from mining the materials to cooking the cement, to transporting it all) and concrete's not a renewable resource, where wood can be.

-N.

[SwampDonkey]

Thanks Swampdonky, you just gave me a headache. 

Just using the formula for annuity to calculate an approximate ROOT. In this case that root is the number of years it takes to spend the $25,000 through electricity costs.

Ci =initial cost of electricity in the first year = $960
P = price of equipment = $25,000
x = years to reach P through electricity costs
i = annual inflation = 3%

P = Ci *(1 + i)^x -1
               i

x√(P * i + 1) - (1 +i) = 0
                Ci


note: x√y = y ^1/x  = 1/x*Ln(y)

Where is LOGDOG when ya need'm

[Larry]

Burlington Northern has a main line out of the North Dakota/Wyoming coal fields to the power generating plants in the south.  They changed out wood ties to concrete maybe 10 years ago...at least on the 4 or 500 miles I have seen.  Trains sometime run every 10 minutes 24/7...until one falls off the track which isn’t too unusual.  I haven’t seen them returning to wood...of course maybe the concrete ties are the reason they can’t keep there trains on the track.

[Ron Wenrich]

I'm thinking that Amtrak has some lines that are high speed, and are not used by heavy freight.  You would think that would be a winning combination, but I imagine a lot has to do with the quality of the base, and the freeze/thaw cycles we get in the Northeast.

[Fla._Deadheader]

  How about the fact they are welding all the rails, so, the tracks HAVE to move from
 heat and cold, which will shift the bed and possibly leave voids or humps in the bedding, so the concrete can't acclimate

[SwampDonkey]

To make it easier to solve, we isolate X with logarithms.

P = Ci *(1 + i)^x -1
               i

P * i +1 = (1 + i)^x
 Ci

Ln (P * i +1) = x Ln (1 + i)
       Ci

x = Ln (P * i +1)
       ____Ci____
      Ln (1 +i)

[farmerdoug]

SD,

What is the gadget your neighbor is thinking about installing?

[Gary_C]

Just using the formula for annuity to calculate an approximate ROOT. In this case that root is the number of years it takes to spend the $25,000 through electricity costs.

They do have tables for that. 

Still got the cabin fever SD?     

Aren't there any females around?     

[SwampDonkey]

SD,

What is the gadget your neighbor is thinking about installing?

Just an example, but I have heard of folks considering one of those $45,000 windmills, and that isn't a very big windmill. How long will that take to pay for itself?

Just using the formula for annuity to calculate an approximate ROOT. In this case that root is the number of years it takes to spend the $25,000 through electricity costs.

They do have tables for that. 

Yeah, but why not use your PC's calculator and use logarithms instead. You could use log tables to I suppose.

[isawlogs]

 Ya , that would work , but then again so would a girlfriend .... or somebodys girlfriend .