Buoyancy of Railroad Ties: Floating or Sinking?

Railroad ties are crucial components in the construction and maintenance of railways. These ties, typically made of wood, concrete, or steel, serve various functions such as stabilization and support of railroad tracks. However, a common question arises: will railroad ties float or sink when placed in water? This article explores the factors that determine the buoyancy of different types of railroad ties.

Wooden Railroad Ties

Wooden railroad ties, despite being capable of floating, are not guaranteed to do so due to the type of wood and its treatment. Commonly used woods for ties include oak, as well as other hardwoods. The specific gravity (SG) of these woods is a key factor in determining their buoyancy. For instance, Western White Pine has a specific gravity of 0.40 and would float, while White Oak with a specific gravity of 0.73 would sink.

Many wooden railroad ties are treated with chemicals such as creosote to prevent decay and insect infestation. These treatments can increase the density of the wood, making it more likely to sink. For example, if a wooden tie has a specific gravity as high as 63 lb/cu.ft, as mentioned in the information provided, it would sink.

Concrete Railroad Ties

Concrete railroad ties are known for their durability and weight. These ties are densely packed and therefore significantly heavier than water. As a result, they do not float. The reason for this is simple: the density of concrete exceeds that of water. In contrast to wooden ties, the wooden ties with a SG of 0.40 would float, but concrete ties would not.

Steel Railroad Ties

Steel railroad ties are even denser than concrete ties and are used primarily in scenarios where increased strength is necessary. Similar to concrete ties, steel ties are much denser than water and will sink. The density of steel is approximately 7.85 g/cm3, while water has a density of 1 g/cm3. Thus, steel railroad ties will always sink when placed in water.

The Bottom Line

In summary, most types of railroad ties will not float due to their materials and densities. Wooden ties, especially those treated with chemicals, are more likely to sink. Concrete and steel ties, due to their inherent densities, will always sink when placed in water.

Related Keywords

Buoyancy Railroad Ties Floating

References

Specific Gravity and Weight of Wood

Specific Gravity of Wood Species Wood SpeciesSpecific Gravity 1Weight per ft3 Western Hemlock North0.4631.1 Western White Pine0.4027.2 Western Woods0.3624.6 White Oak0.7347.7

Source: Specific Gravity and Weight of Wood