The History of Retaining Walls

Retaining walls date back to ancient Egypt, where they were used to harness the great power of the Nile river. Tired of flooding and soil erosion, Egyptians built Gabion style retaining walls from reeds to divert the flow of water from the Nile into reservoirs as well as fields for farming purposes.

While modern times have seen innovations in the materials used to build retaining walls, retaining wall applications have largely remained the same: preventing soil erosion, creating space and diverting water.

The History of Crosstie Retaining Walls

Crosstie retaining walls are made from the large wooden railroad ties found under railroad tracks throughout the United States. Most commonly, railroad ties, also known as wooden sleepers, are treated with many toxic chemicals used to make the heartwood more durable and as a lifespan preservative. Depending upon the intended railroad track’s purpose, each crosstie ranges in size from 8 to 9 ft in length and 8 by 8 inches width.

Originally used to build and support railway tracks, crossties were not intended for use as a retaining wall building material. However in the 1980’s a surplus of crossties gave the railroad an ample supply of a retaining wall material, at a cost they could control.

In the late 1980’s builders noticed the railroad company’s unique use of crossties for retaining walls, and realized that crossties would make a cheap and durable material for soil erosion prevention while grading and building new office parks and subdivisions.

How Tall Should a Crosstie Retaining Wall Be

Crossties which began as two or three feet tall retaining walls kept growing taller until they reached 6 feet in height, although some claim having purchased homes in the state of Georgia with crosstie retaining walls over 10 feet in height.

What is the Size of a Railroad Crosstie

8 ft 6 in ties are the most common, while 8 ft and 9 ft ties are used for light-duty and heavy-duty track, respectively.

The Environmental Protection Agency (EPA) has made it illegal to use treated railroad ties in home landscapes because they contain creosote, a known carcinogen. Creosote is a toxic chemical that can harm humans and plants.

Other chemicals used in the treatment of crossties used in retaining walls and known to be harmful to humans include the following (some of which are known to leech into the ground water): ACZA (Ammonium Cuprum Zinc Arsenate) and Pentachlorophenol. These industrial chemicals cause irreparable harm and health risks to humans, pets and nearby plants.

The lifespan of a railroad tie retaining wall is 25 to 30 years, depending on the quality of the wood and how well the wall is built.