Questions About the Railway Tie Association
How long has RTA been serving the industry?
The Railway Tie Association predecessor organizations date back to the late 1880's. In 1919 RTA was formed and renamed and has been in continuous service to the railroad, timber, and wood preserving industries since then.
Can I or my organization join RTA?
All Membership applications are subject to review by the RTA's Executive Committee. To see if you may qualify, please view the Membership Categories & Dues. If you decide to apply for membership, fill out the application and submit it for review. You will be informed by return email if your application has been accepted.
I'm a member, how do I create a member profile so I can login?
For additional information, see the About the RTA page
Basic Statistics
How many wood crossties are there per mile in the United States on average?
In 2009, there were 3,249 based on 19.5 on-center spacing
How many total crossties does that represent?
Approx. 705,033,000 for the US.
Approximately how many miles of railroad track are in the United States?
In 2008, approximately 217,000
Size
What is the typical size of mainline railroad ties?
Standard Ties = 7” x 9” x 8.5’ or 9’ long (mostly 8.5’ --- some 7x8 and 6x8 also in use)
Where are details about dimensions of ties?
Please see http://www.rta.org/Portals/0/Documents/RTA%20Specifications%20&%20Visual%20Guide%20to%20Tie%20Defects/RTASpecificationsBooklet.pdf for an online version of RTA’s Specifications Booklet.
How far apart are ties laid?
Standard spacing is 19.5 inches on center
Types of Wood for Ties
What wood species are used for ties and where did that wood come from?
While there still are some softwood species (approximately 4-6% of the total) used for crossties and bridge ties, the vast majority of species utilized today are hardwoods - mostly from the eastern and mid-western hardwood forests. The mix of species depends on the application and locale of sourcing, but a good rule of thumb is 50-60% oaks and hickory, and 40-50% other mixed hardwoods. The below are the allowable species per standards. Species with an asterisk are more abundantly used than other species. Species without asterisks are allowed but generally not used or are used in limited quantity:
Ashes* Gums* Oaks** (55-65% Red & White Oak)
Beech* Hackberries Pines
Birches* Hemlocks Poplars
Catalpas Hickories* Redwoods
Cherries Larches Sassafras
Douglas fir Locusts* Spruces
Elms* Maples* Sycamores*
Firs (true) Mulberries Walnuts
The complete list of allowable species as well as detailed discussions of ties are available in the Tie Guide at http://www.rta.org/Default.aspx?tabid=86 and the RTA Specifications brochure at http://www.rta.org/Default.aspx?tabid=90.
End users of the crossties – treating plants and railroads - in your area should be consulted prior to sawing to determine current needs.
The Market
What percent of the railroad tie market in the United States uses wood ties?
Wood maintains a 93%+ share of the market for ties installed in North America. Wood not only has certain desirable performance properties that make it ideal for a wide variety of track applications, but also the initial and long-term life cycle economics of the wood tie are one of the most important reasons that wood is so overwhelmingly chosen. The paper entitled Comparative Crosstie Unit Value and Costs gives more details on the economics of wood as compared to alternative materials.
What are the other materials used for ties?
The other products used include concrete ties (about 6.5% market share) and some steel and composite ties (0.5% share or less).
How many crossties does the industry produce each year?
Currently, the industry has the capacity to produce well over 20 million crossties annually. The recent high water mark for production was just over 22 million ties produced in 2006. Today the production stands at just over 20 million ties. For the most recent articles on this subject, please see the latest January/February and September/October issues of Crossties in the publications section of Crossties Magazine. These articles will provide historical and survey data along with annual forecasts of tie usage and demand.
How do costs compare between wood and other types of ties?
Based on a 2006 Zeta-Tech study, in general, wood ties have a lower cost per mile per MGT than any of the alternate tie configurations, except for applications in wet climates where the tie life is significantly reduced or for severe curvature high density applications.
In general, for moderate density tangent track of the order of 25 MGT per year located in a moderate climate zone of the US, wood tie costs ($/mile/MGT) are of the order of 60 to 80% of concrete tie track; 70 to 75% of plastic (composite) ties, and 80 to 85% of steel tie track costs.
For moderate density moderate curvature track (25 MGT per year) located in a moderate climate zone of the US, wood tie costs ($/mile/MGT) are of the order of 65 to 85% of concrete tie track; 70 to 80% of plastic (composite) ties, and 80 to 90% of steel tie track costs.
For dry climates, the wood tie costs represent a corresponding smaller percentage of the costs of alternate tie types; for wet climates, they represent a correspondingly higher percentage of the costs of alternate tie types. (http://www.rta.org/Portals/0/Documents/Research%20Paper%20&%20Articles/RTA%20Sponsored%20Research/Comparitive%20Crosstie%20Unit%20Value%20&%20Costs.pdf)
Do you disclose the companies that you survey for the monthly purchases report? How is the survey constructed and who are the major crosstie producers?
The reporters are members of RTA and comprise 99.9% of all ties produced in North America. We do not disclose our members’ names to non-member companies. This is not a survey but rather data generated through our monthly member reporting process which is a compliance requirement to be a member. Please note that sometime this year this report will be subscription based and not available to the general public.
Treatment
What is the history of treating wood ties?
Treating wood ties in the US began in earnest in the early part of the 20th century. It took several decades for them all to be treated. In fact, our records show that in the 1940’s approximately 10% of wood ties were still untreated. You may see the history of Class 1 wood crosstie insertions since 1921 at http://www.rta.org/Portals/0/Documents/Research%20Paper%20&%20Articles/Historical%20Wood%20Preserving%20Documents/Class%201%20Insertions%201921%20to%20Present.pdf.
What types of wood preservatives are used to pressure treat wood crossties?
Virtually all hardwood crossties produced in North America today are pressure treated with creosote or creosote solutions. The US Environmental Protection Agency (EPA) has approved and registered creosote for this industrial application. Other standardized preservatives that can be used include Copper Naphthenate and Pentachlorophenol although Penta has not been used by railroads in decades. Some producers also use a dual treatment system where borate compounds are applied prior to a second treatment with creosote. The borates diffuse throughout the hard-to-treat heartwood of many species and provides additional protection for wood used in high decay areas.
Also, in January 2010, the AWPA approved the use of ACZA (Ammoniacal Copper Zinc Arsenate) as an accepted wood preservative for the protection of ties. For example, Douglas fir is a strong, plentiful species – well-suited for use as ties – but not readily treated with other preservatives. Tests of ACZA-treated ties have shown low corrosivity and excellent spike-holding characteristics. The preservative enables wood to resist termite damage and fungal decay and has been found to reduce flame spread in wood timbers.
How far does creosote penetrate?
Some species treat nearly 100% while in others only the sapwood treats easily. In refractory (hard to treat) species, many railroads are using borates in a dual treatment process to provide protection to the heartwood.
What are the other approved treatments for hardwood ties?
99.9% of all wood crossties produced in the US and Canada are treated with creosote or creosote and oil blends. In addition to creosote, only Penta and Copper Naphthenate are AWPA approved preservatives for ties. CCA (copper chrome arsenate) is not recommended for hardwoods.
Copper Naphthenate (CuN) is an approved oil-borne treatment and we expect its use to grow over the next few years in conjunction with borate pre-treatments. Generally, it is applied with lighter oil carriers than creosote that may not provide the same extent of weather-proofing properties as the heavier creosotes. Because it is applied with oils that have higher flash points than creosote, some typical processing steps used when treating with creosote alone, such as sterilizing the ties under high heat to condition the wood and eliminate decay fungi that may have begun to grow while the wood is air-drying prior to processing, cannot be done. It is expected that CuN would be most effective in hardwood ties when used in high decay hazard areas if a borate pre-treatment was also used. Studies to this effect have been conducted by Mississippi State University and are reported here http://www.rta.org/Portals/0/Documents/Crossties%20Magazine/Nov%20Dec%2009/CuNap.pdf .
Borate compounds are now used as a pre-treatment for roughly 1-1.5 million ties per year (out of the 20+ million or so produced).
Over the years of testing (50+ documented years now for creosote - see the 1958 cooperative study http://www.rta.org/Portals/0/Documents/Crossties%20Magazine/Jul%20Aug%2009/Creosote%20Article.pdf ), creosote has proven to be the most efficacious and cost effective wood preservative for hardwood ties. It has significant weatherproofing properties and is an excellent preservative for hardwood species. However, some wood species are refractory (hard-to-treat) and the heartwoods of those species are almost impenetrable by any wood preservative with the exception of borate compounds which diffuse through the wood over time. Thus, for these refractory species that will be placed in high decay areas, it has now become relatively common practice to use borates as a pre-treatment to protect the wood prior to processing with creosote and then afterwards for up to 20+ years in service. This pre-treatment protects the entire cross-section of the wood tie providing excellent service life even in high biological-hazard service conditions.
Since ties are placed in service in a wide variety of climatic conditions in North America, each of these preservative systems has its place in railroad applications. Other systems are now under test by RTA, but not one is in use other than the ones mentioned here.
How can I contact manufacturers of pressure treated wood crossties?
Access to the RTA membership directory is available only to members of the association. You may apply for membership and, if accepted, you will be able to access the directory online. If you are not eligible for membership, RTA staff will attempt to facilitate members contacting you. You can send an email to us at ties@rta.org and we will forward it to appropriate contacts. Please make your inquiries as specific as possible and include full contact information including your name, your company name, and phone, email and physical address information. These inquiries should be of a serious business nature and will only be forwarded if the intent of the inquiry will further the goals and business interests of our membership.
Are treatment facilities clustered in certain regions of the US?
Approximately 46 North American treating plants are geographically located near the hardwood resource and accessible to the major railroads by rail. This necessarily means that a vast majority are east of Dallas and south of the Great Lakes. There are a few commercially important plants north and west of this area.
Is there any information about worker exposure to creosote-treated ties?
In conjunction with the Creosote Council and the Railway Tie Association, AAR met with EPA on September 26, 2003 as part of the re-registration process for creosote. The key point is that railroad workers do not manually handle crossties. Virtually all crossties are handled and installed by mechanized equipment. Workers who do come into contact with creosote treated crossties are required to wear long sleeve shirts and gloves to protect them from exposure. You may get further information at www.creosotecouncil.org.
Recycling Used Wood Crossties
What is the annual replacement rate of crossties in the United States for the last ten years?
2.5-3.0%. This translates to an average life in track of between 33 and 50 years.
How big is the market for recycling and utilization of used ties. USA and Canada?
Approximately 20 million wood ties are replaced each year in these countries. A majority are already recycled as landscape ties or disposed of as fuel in co-generation facilities. The number that may be disposed of in approved landfills is not known accurately, but may be as many as 3- 4 million. A survey we conducted in 2008 is available to members of the association.
How are wood crossties disposed after their useful life in track?
Additional information on topics such as the safe disposal of used crossties and special regulations is also available under Environmental Literature.
Where can I buy scrap hardwood from a sawmill? It would be perfect for our wood stove.
Thank you for your interest in scrap hardwood. Unfortunately, we are unable to suggest any mills that might sell scrap since most sawmills that cut railroad ties either use the scrap as fuel to run their equipment, turn it into wood pellets for other uses, or offer the scrap pieces to people in their local area.
Is it safe to burn treated ties?
Burning creosote wood in EPA approved facilities has been done for many, many years and is a widely accepted practice. However, RTA does not have a publication speaking to the details of what kind of requirements there are for specific facilities to be approved since the permitting practice varies from state to state, at least in the US.
Could you put me into contact with organizations or companies that deal in environmentally friendly treated crosstie disposal?
We can send your contact information to the Recycle/Waste Management RTA members to get in touch with you if they so choose.
Miscellaneous Questions
I came across some old ties that are currently being used as fence posts. They all have S-shaped bands that have been hammered into the both ends of the tie. Do you know what these are called and what they are used for?
The S shaped bands are called S-Irons and were once applied to ties to minimize end splitting. Some are still in track today, but railroads now use gang-nail style end-plates to control end splitting.
What about white ash that is infested with the Emerald Ash Borer that has spread to OH, IN, IL PA and looks like it will go further?
Ash is an appropriate species for ties. However, it seems that the EAB may be with us for some time. The main thing is not to transport the raw log with bark still intact any farther than necessary. To transfer any Ash product (logs, crossties, lumber, chips or bark mulch) out of an infested county, you must have the proper paperwork and inspections from the USDA. It is probably best to have the raw logs processed into ties or lumber as close to the source as possible.
Where can I find more information and maybe a map of railroads in the US?
How can I learn more about wood crossties?
The best resource for learning about wood crossties is The TieGuide. This comprehensive document not only can be viewed online, but also is available for download and/or purchase. It contains information on tie specifications, wood preserving, species properties, and much, much more. A limited number of free copies are available each year for classroom instruction in secondary school and college and university programs. Contact the RTA staff at ties@rta.org for more information.