Torch cutting of rail for final gap preparation is:

The process of torch cutting rail for final gap preparation is considered prohibited in thermite welding practices due to the potential risks and safety concerns involved. Welding operations, especially in rail applications, require precision and the integrity of the rail material. Torch cutting can introduce thermal stresses and may lead to changes in the properties of the rail, such as hardening or causing heat-affected zones, which can compromise the structural integrity of the rail.

Additionally, the risk of introducing contaminants, which can affect the quality of the weld, makes torch cutting an unsuitable method for preparing rails in this context. Instead, approved mechanical methods, such as rail saws or grinding equipment, are typically used to prepare the ends of rails for welding. These methods ensure a cleaner and more precise cut, which is critical for achieving a high-quality weld and ensuring the safety and performance of the rail system. Hence, the prohibition of torch cutting in this phase of rail preparation reflects a commitment to maintaining structural integrity and overall safety in rail welding operations.