Why are railroads still using creosote ties?

After all these year, and advances in materials why are creosote ties still being used?

Is it the price, compared to concrete?
Is pressure treated not as good?
Ease of use?

Why?

Well, in Concrete ties vs Wood Ties, I do know that while Concrete ties cost more, so far they do NOT last twice as long under US Freight loads, but in some cases have started cracking long before wood ties wood start wearing out. Under lighter loading (European/Asian railroads) they seem to be holding up pretty well. I have also read that railroads, even when using mostly concrete ties, use wood ties at turnouts because wood is much easier to trim to the correct length.
Hmm, I wonder about Oz rails, which have pretty hefty loading, and which (I believe) use concrete ties.
Not sure why composite ties haven't taken off, from what I read they are not much more expensive than wood ties, last longer, and are just as easy to use/mill/trim. Tradition? Lack of long term usage & wear testing?

I might add to this that the rail itself doesn't fare well with concrete ties. This from my experience with Sperry on the BN, where they had a thousand miles of concrete in Montana to Washington State.

On wooden ties, rail life is basically infinite. We're still using 1920s-vintage rail on some sections of secondary; and occasionally mainline. With concrete, the ties have no give - so the metal of the rail itself crystallizes and fissures. Rail life is about five years, I was told.

The ties make for a better roadbed, hold gauge, but upkeep cost is infinitely higher.

I thought creosote was banned as a carcinogen, but I do see a lot of new ties on NJ Transit that sure look like they are creosoted. So, are wood ties still preserved with creosote, or with a safer but similar-looking substance?

I just recieved a technical bulletin yesterday that creosote lumber is now banned in NY State, however RR's and utility companies are exempt. In effect, eveeryone regularly using creosote.

Creosote is a coal tar derivitive and contains a compound called cresol, which is a carcinogen.* The toxicity of creosote is what made it such a good preservative. I believe that most ties today are preserved with a petroleum derivitive which is less toxic and less likely to migrate into the water table.

*The International Agency for Research on Cancer (IARC) has determined that coal tar creosote is probably carcinogenic to humans. The EPA has also determined that coal tar creosote is a probable human carcinogen. (http://www.atsdr.cdc.gov/tfacts85.html)

outher chemicals that were used in wood ties were;
Arsenic, Dioxion, and Fermaldehyde.

The Poukeepsie bridge wouldn't have burnt in May of 1974 if they used concrete ties on the bridge.

gawlikfj wrote:The Poukeepsie bridge wouldn't have burnt in May of 1974 if they used concrete ties on the bridge.

Could the bridge have supported that kind of loading?
Besides, I don't think Concrete ties were widely used in the US during the early 1970s, let alone the 1950s/1960s era or whenever New Haven last replaced the ties on that bridge.

I know Sir Ray , Wishful Thinking .
I don't think anybody used concrete ties in the 50's & 60's but I wish they did.