Traditionally, it’s a bed of stone, called ballast, which acts as a buffer between the sleepers and the ground in order to
maintain the rails in the right position. However, although ballast is present on 95% of high speed lines and 50% of urban
lines today, it’s starting to face serious competition from concrete.
On 95% of high-speed lines and 50% of urban lines, a bed of stones, called ballast, keeps the rails in the right position during the passage of the train. However, ballast is now facing stiff competition from concrete. While ballast is a widely proven technology and offers rapid installation, concrete guarantees, in turn, adaptation to narrow spaces (tunnels etc.), minimal maintenance, easy cleaning, less risk of damage to vehicles (no stones thrown up) and of course it avoids the extraction of ballast, not always easy.
