OzDigger
Colonel
- Joined
- Jan 7, 2006
- Messages
- 8,215
As a historical note, the Eucalyptus were first imported by the Southern Pacific Railroad because they grow very rapidly and were to be used for replacement ties. Even today you can see lines of them along former and current rail right-of-ways. However, the wood proved to soft for railroad ties.
Eucalyptus timber ranks amongst the hardest and most durable timbers in the world. But much depends upon what species of Eucalypt is used, and the age the tree is cut. To early, and it's mainly sapwood that soon splits, twists or warps after it loses moisture.
Environmental concerns means there is a trend towards concrete sleepers (railway ties) downunder. However many Australian states still use timber. The average service life of a Eucalpt railway sleeper is 20 to 25 years with some seeing out 50 years: http://www.cqfa.com.au/documents/1181619278_sleepers_fact_sheet.pdf