Railroad tie

**Types of Railroad Ties:**
– Stone block ties were used on early railways like the Liverpool and Manchester Railway.
– Stone blocks were later replaced by timber ties due to maintenance issues.
– Bi-block ties with tie rods have similarities to stone block ties.
– Historical wooden ties were made by hewing or sawing softwood and hardwood timbers.
– Softwood ties are treated with preservatives like creosote or copper azole.

**Materials Used for Railroad Ties:**
– Stone Block Ties:
– Stone block ties were used on early railways.
– Stone blocks were replaced by timber ties due to maintenance issues.
– Bi-block ties with tie rods are similar to stone block ties.
– Stone block ties allowed horses to tread the middle path safely.
– Stone block ties were not suitable for soft ground.
– Wooden Ties:
– Historical wooden ties were made from softwood and hardwood timbers.
– Softwood ties are treated with preservatives like creosote.
– Wooden ties are susceptible to rot, splitting, and insect infestation.
– Some timbers like sal or jarrah are durable enough to be used untreated.
– Wooden ties can catch fire and develop cracks with age.
– Concrete Ties:
– Concrete ties are cheaper and easier to obtain than timber ties.
– Concrete ties have a longer service life and require less maintenance.
– Concrete ties are quieter than wooden ties on straight stretches.
– Concrete ties are required on high-speed lines in the UK.
– Most European railways use concrete bearers in switches due to cost and durability.
– Steel Ties:
– Steel ties are trough-shaped and lighter than concrete ties.
– Steel ties can be installed on existing ballast beds.
– Steel ties are 100% recyclable and require less ballast than wood or concrete.
– Modern steel ties handle heavy loads and adverse track conditions.
– Steel ties are economical to install and widely used in various railroad sectors.
– Plastics:
– Composite railroad ties made from recycled plastic resins and rubber claim a service life of 30-80 years.
– Plastic ties are resistant to rot, insects, and can offer additional lateral stability.
– Environmental benefits include replacing toxic creosote-treated timber ties.
– Hybrid plastic ties are used in various rail applications and offer benefits on bridges.
– Network Rail began replacing wooden ties with recycled plastic in 2009.

**Design and Applications of Railroad Ties:**
– Non-conventional Tie Forms:
– Y-shaped ties reduce ballast volume due to load-spreading characteristics.
– Y steel ties have high noise levels but excellent resistance to track movement.
– Twin ties like the ZSX Twin tie are suitable for tracks with sharp curves and bridges.
– Wide ties increase lateral resistance and reduce ballast pressure.
– Bi-block ties offer increased lateral resistance and are used on high-speed TGV lines.
– Dimensions and Spacing:
– Mainline railroad crosstie spacing is around 19-19.5 inches for wood ties and 24 inches for concrete ties.
– In the UK, sleepers are typically 8ft 6in long, 10 inches wide, and spaced 2ft 7in apart.
– Historical UK sleeper spacing varied based on rail length and joint proximity.
– The spacing at rail joints allowed for thermal expansion gaps.
– Different methods exist for fastening rails to railroad ties.
– Fastening Rails to Railroad Ties:
– Historical methods include spikes and cast iron chairs fixed to ties.
– Modern methods like Pandrol clips use springs to fix the rail to the tie chair.

**Reuse and Disposal of Railroad Ties:**
– Other Uses:
– Wooden ties can be recycled into sculptures or repurposed for various artistic or functional projects.
– Stone blocks from old railways can find new life in construction projects like loading docks.
– Railroad Ties in Gardening and Landscaping:
– Popular for creating retaining walls and raised-bed gardens.
– Used for building steps.
– Often made from decommissioned rail ties.
– Lifespan limited due to rot.
– New oak or pine beams available in the UK for garden construction.
– Railroad Ties in Construction:
– Used near railroad tracks, particularly by railroad employees.
– Entrepreneurs sell new ties for construction purposes.
– Introduce soil pollution due to dangerous chemicals.
– Some properties avoid them due to pollution concerns.
– Used in the UK for garden construction with non-toxic beams.

**Regulations and Innovations Related to Railroad Ties:**
– Railroad Ties in Law and Regulations:
– Germany prohibits their use as building material since 1991.
– Regulated by specific by-laws to protect health and the environment.
– Restrictions on areas frequented by children and in food production.
– Health risks associated with wooden railroad ties.
– Concerns about pollution from wood preservatives.
– Railroad Ties in Industry and Innovation:
– Steel sleepers still made and have a historical significance.
– Various publications and studies on railway engineering.
– Testing of polymer rail ties for the mining industry.
– Transition to recycled plastic sleepers by Network Rail.
– Development of composite railroad ties for various applications.https://en.wikipedia.org/wiki/Railroad_tie