Wood is one of the most important components in the history of transportation. Nearly every mode of transportation up until modern times has used wood in one way or another, from wooden wheels to wooden ships. Iron began to change all of that and nothing was more monumental in changing the course of history then the railroad. Despite that, wood was still a necessary ingredient in keeping the railroad moving.
In the mid-1800s as railroad building boomed two materials were necessary to build the track: iron for the track and wood to bury in the ground to keep the track in place. Stone was originally used for this task and was common in England in the early days of railroading and it even made an appearance here in the US but quickly fell out of favor. Wood was much easier to procure and to cut meaning track could be laid quicker and more efficiently. Oak was the primary wood for the task but some lines also used a treated Douglas fir, which was cheaper but not as strong. Wooden pegs, treated in a copper solution to strengthen it, were used to attach the track to the tie.
While cheap and much less labor intensive to produce and with a nearly inexhaustible supply there were drawbacks. The ties rotted easily from both exposure to the weather and insects and the ties were prone to damage as more and more trains rode over top of them. Being wooden they were also susceptible to fire, as the states of Georgia and South Carolina found out when William T. Sherman paid them a visit during the last years of the Civil War. These “Sherman neckties” were a common sight through the south when Union soldiers would take the ties, place the rails on top of them, light the ties on fire and when the iron was hot they would wrap the rails around a tree rendering them unusable.
Over time the ties has been replaced by more durable materials like concrete or steel but given the amount of track in this nation replacing all of it is a nearly impossible task. There are most certainly still railroad ties made of oak in a rail line near you. Oak railroad ties have served another purpose more recently. They have become popular in landscaping and gardening to create retaining walls or as steps and in the building of docks or boathouses. This use of recycled railroad ties is controversial due to the wood preservation which used coal tar, creosote, salts and heavy metals and can be dangerous when coming into contact with human tissue. It is seen as so dangerous that Germany has banned their reuse outright and the EPA does not recommend it due to the creosote.