Concrete, wood or steel, ( or bean counters vs. operations)

Trains Magazine General Discussion
1

This kinda ties in to the 286k thread.

What are the benefits of the concrete ties, or steel ties, over the cresoted wood tie?
I can see the pandrol clips being easier to use over the tie plate and spike, but have noticed they seem to come loose in curves more often.
We had three new 100 car plus receiving tracks constructed in 1998, and the contractor, W.T Byler, used steel ties for all three.

In a totally un-scientific comparison, I have noticed that the contractor is out there every six months or so, re tamping the tracks, and replacing a lot of ties, they seem to snap down the middle often, and several times this year they have had to back fill and re tamp a lot of low spots.

Of the six receiving tracks we have, the three new ones have steel ties, the old three, which were moved over to make room, are on wood ties.

In fact, when the contractor moved the three old tracks, they just shifted them to the side with a swing loader, literaly picking up the track and tie assembly and setting it over as a whole on the new roadbed.

We have had zero maintainance problems with the old tracks, riding on 30 plus year old wood ties, yet the new tracks seem the require quite a bit of ongoing work.

All six tracks sit on the same, newly laid roadbed, so I assume it tamping issue is directly related to the steel ties.

So this begs the question, is the cost savings on the steel or concrete ties enough to justify the added maintainance?

How about other structures, bridges and trestles?

We have several wood trestles here that seem to require almost no maintainance, even in the swamp like conditions of Houston.

Yet all of our steel bridges seem to need inspection and repair more often.

What I am getting at is, like 286K cars, are we seeing the future of the infrastructure being overwhelmed by “newer”, or cheaper inital cost products?

I can tell you from personal exper

2

about the only benefit would be that the newer stuff is problably initially cheaper than the old stuff, although the money save plus is blown on maintence and repairs later on down the road, but hey, you can expect some manager to figure that out.

3

Ed - Mudchicken will go nuts over this one! But two quick questions - what are pandrol clips and are the concrete ties made with any kind of reinforcing material? Or are they just formed ties?

Mookie

4

I thought pandrol was one of those female aspirins…

5

No, I think it is yourdol…

6

Mookie – pandrol clips are a kind of king size paper clip sort of thing which is bolted to the tie and holds the rail by spring pressure against the base of the rail – allowing a little give between the tie and the rail. And I believe concrete ties have rebar in them – I’d think they’d have to, but I’ve been wrong before!

Concrete vs. wood? Which is cheaper in your neck of the woods – the labour to replace ties or capital? Wood ties won’t last as long as concrete, but the first cost is cheaper – the real question (as usual!) is the life cycle cost… steel ties? dunno…

7

Firstly: A pandrol clip is a thing that looks like a paper clip on steroids. They fit into a hole in a baseplate that’s parallel to the rail. They can be taken out and replaced many times without loosing integrity of the toe load (with a spike in a wooden tie, if the spike is removed, the hole the spike was in must be plugged with a bit of wood or the spike won’t hold anymore) There are many different types of Pandrol clip, and I reccommend you check out their website: http://www.pandrol.com/

Concrete, wood or steel tie, well, each has its pros and cons.

Wood:
pro; wood is cheap & readily available, it flexes under load and thus provides some resilience, lightweight
con; wood decomposes, it can split if water gets into it and freezes, creosote treatement is not very environmentally friendly

Concrete (reinforced):
pro; long lasting (in the UK we have some that have been in service for 30 to 40 years), fixings are integral with the tie, very strong
con; heavy (it takes 6 blokes to lift one), quite rigid so do not offer any resilience, expensive, difficult to transport

Steel:
pro; cheap, light, stackable, so easy to transport, somewhat flexible so provide good resilience, fixings are integral with the sleeper (oops, sorry, tie), they have spade ends, so they hold the track laterally much better than other types of tie.
con; rail must be insulated from tie so as to not interfere with track circuits, steel suffers from fatigue so they may break if not tamped properly, they are U shaped so it is difficult to tamp the ballast underneath them properly

These are the main pros and cons and I’msure other reasons will be offered.

8

Mr. Hampton did quite nicely.

Ed, I imagine that the subgrade where the old tie were was there for years and somewhat better consolidated. Having worked at Baytown (for UP), I suspect that Houston has no clue what good subgrade is (as in keep trhrowing rock and marl on it and it will eventually quit sinking!) See comments in 286K thread.

Wood ties have been incredibly hard to come by for the past year , especially oak. In a yard with no signal work, steel ties will work well. (Signalmen HATE concrete and steel ties because of all the grounding and short circuit signal headaches)…

Concrete ties generally have some sort of mesh reinforcement in them, but not always are they rebar reinforced… Century Precast makes ties here in Denver right net to the main UP yard in town…That ain’t normal everyday concrete either!

You can’t spike a concrete tie either with a cut spike.

There is more out there besides pandrol pretzel clips. Thank the Aussies for the D-E clips and Europe for funky screws and the pandrol hairpins that replace spikes in wood ties…

EDster- subgrade failure is not that surprising with new construction at places like yours…They should have laid 8-10 inches of asphalt under there, then sand or sub-base, then the ballast. Steel ties have so little x-section (Look like a bent highway guardrail) that they are tough to get setlled and if a ballast compacter was not used during surfacing with the tamper and ballast regulator , oh well!!

In derailments, if the clip area that accepts the pandrol or D-E clip is toast, you now have an expensive piece of rip-rap. Find a new tie…same goes for D-E clips…

Pandrols and D-E clips eliminate the need for rail anchors in most cases.

If maintenance costs are going up after new construction, there’s a beancounter, division engineer, design engineer and an industrial engineer somewhere sweating bullets.

If the subgrade is failing

9

The concrete and steel ties also offer a higher modulus (stiffness) so the rail doesn’t dip down under a load (like a train going over it) as much, giving an overall smoother ride and less rolling resistance.
Ed
I would say that there are problems with the sub-grade (below the ballast) if the tamping doesn’t slow down soon. It does take a couple of years for the ground to “settle” after it has been distrurbed. Normally the ballast would take care of any resulting differences in the rate of settling. If the ground is swampy as you say, the tamping of the stiffer track may never end.

10

Well, the UP decided to purchase one million (yup, one million) plastic ties after extensive tests… They are made of recycled tires, bags, bottles, plus a sticking brand new polymer (not recycled). But plastic ties still have a small share in global tie renewals ( http://www.rtands.com/A/feature1.html ). But just another alternative.

just look at http://www.natk.com/ttcomp.html

11

Will follow Cedrite ties into the scrapheap of failed ideas?

What about the AZOBE African hardwood ties that are so-oooo tough you can’t drive a spike in them without drilling a hole first and throwing away the drill bit after one hole?

12

Well, perhaps plastic ties will be as important as steel today (marginal). Just a not-so-good idea still flying around. But who knows…

13

There’s one stretch of concrete-tied track that I see regularly during the non-winter months. Alignment looks good, and the ties (what I can see of them…dirt and ballast covers much of the center portion) look OK, but a lot of the Pandrol clips are broken off. Guess they aren’t as resilient as they could be. The track is about seven or eight years old, I think.

I’ve also seen places around the yard where an occasional steel tie is used, possibly to maintain gauge. They seem to put a steel tie after about three or four wooden ones, possibly to get the best of both worlds (steel ties to hold the gauge, wood to hold the lining).

The plastic ties are perceived to be the answer to maintenance problems in wet areas, where steel, wood, and concrete have disadvantages (I’m not sure I understand the disadvantages of concrete, unless the moisture somehow decomposes it).

14

Brother Carl! My thinking exactly - great minds!

Was wondering that about concrete and moisture, too!

Moo

15

Ok guys,
The new receiving tracks sit on the old roadbed, no new road bed was laid, they just squeezed these tracks into the exsisting space.
So settling should be a issue on all of six tracks, they are sitting on the same sub-roadbed that has been there since the late 50s, when the receiving tracks were constructed.
The entire yard propper was constructed in 1924, on dredge material from when the Army Corp of Engineers first dredged the turning basin and the ship channel.
We sit about 10 feet above sea level.
Put it this way, the yard is so old and un changed, if you went to the main street next ot the west side of the yard, and scraped the 1" asphalt off of it, you find brick street stones.

We have a welder on duty all the time, and standing orders to report any broken steel ties.
He goes out and welds them all day long.

The concrete ties were an experiment, they were installed when the switching lead was rebuilt in 1997, and used in the big curve it has.
We got a open top gon, loaded with steel balls, on the ground in the curve, one truck just destroyed them.

MOW is replacing them with steel, when they crumble to the point they no longer hold the clips to the rail.
I think the idea was that the concrete and steel ties hold guage better.

Another thought just occured, (slow on the up take today) if mudchickens side of the industry is moving towards these new materials instead of the traditional wood ties and 135lb rail.
If, and this is just my own observation, the short lines and smaller regionals trackage is showing its age, and the owners already have plans to replace or repair the really bad parts, are they not going to adopt the newer methods and materials, and heavier rails?
If so, wouldnt this fix the problem with the 286K cars?
Or, are they following the standard, cheaper is better routine, and replacing only the portions that fall out from under the cars sans old SP practices?

16

Concrete (and steel) ties not only require a new ballast, but also different MoW procedures and equipment as than wood. Plastic ties are supposed to work the same as wood while lasting longer (we will see…).

Regarding steel ties, I found this in a 20-year-old book
“… Steel ties are free from decay and insect attack, but they are subject to rust and wear at the rail seat and in the lug or other fastenings. These become loose, rattle and require frequent bolt tightening and renewal. A major disadvantage is de difficulty in adapting steel ties to bonded territory…”
still valid, isn’t it?

17

The UP uses different ties in different locations. They have used concrete in high traffic areas and curves where the clips make rail changeout easier. They have used Azobe in a few locations for tests. They have used plastic ties in locations that the soil chemistry or mositure would deteriorate wood ties. They have used steel ties in tunnels where the lower profile allowed them to gain an additional 4-6 inches of vertical clearance. Just depends on the application. I doubt you’ll ever see 100% one type of tie again.

By the way Mookie, concrete ties a pretressed, there is a series of stretched high strength cables running through the concrete to put the tie in compression and strengthen it. The cables are stretched, the concrete hardens and then the cables are relaxed, the cable trapped in the concrete tries to shrink back to its normal length, but is locked in the concrete. That compresses the concrete, making it stronger. Its like picking up a shelf of books by squeezing the books on the ends.

Dave H.

18

A few years ago I had a FRA track inspector ride our train. He said that when you used concrete ties you had to have good roadbed underneath. If you had spots where the mud would pump up from the bottom, a concrete tie wouldn’t last as long as a wood tie. The tie would start to crumble from the bottom.
He also said that if you had “soft’” steel rail, that because the concrete ties don’t give like wood ties, that the rail would break more often.

19

All of it just goes to show that the ‘track’ isn’t just the rails, eh? You have to consider the whole thing – subgrade, ballast, ties, spikes/clips/whatever, and rails all together, because they all have to work together as one coherent system – otherwise, you’ve got trouble!