What is a road spike?
A railroad spike is a fastener used to connect rails and sleepers or pads and sleepers. It is usually divided into five types: ordinary railroad spikes, frost-damaged railroad spikes, threaded railroad spikes, spring railroad spikes, and spiral railroad spikes.Ordinary railroad spikes are also called hook-head railroad spikes or dog-head railroad spikes, which are mainly used to connect rails or pads and wooden sleepers. Ordinary railroad spikes are made of No. 3 hot-rolled steel specified in the Chinese national standard GB702-72.
The cross-section of the nail rod is a square with 16mm on each side, and the nail length is 165mm. The head of the railroad spike is mushroom-shaped, and the shape of the lower part of the nail head is adapted to the shape of the rail bottom. The surface of the nail rod should be smooth, the flash should not exceed 2mm, and the displacement of the nail rod relative to the center line of the nail head should not exceed 1mm in any direction. There should be no cracks at the connection between the jaw of the nail head and the nail rod. The tip of the railroad spike is chisel-shaped, and the chisel mouth is perpendicular to the wood grain when nailed in to avoid splitting the wooden sleeper. The tip edge is straight, and the tip is not allowed to have burrs or folds that affect use. There shall be no bubbles, overburning or cracks on the surface of the spikes that hinder their use.
The material and manufacturing process of the frost spikes are exactly the same as those of ordinary spikes. The spike rod is longer than that of ordinary spikes. Because it is mainly used to treat track frost damage, it is called frost spike. Depending on the degree of track frost damage and the thickness of the frost damage pad, the length of the frost spike is 185, 205, 230, 255, and 280 mm.
Threaded spikes are generally made of No. 3 steel. Because the surface of the spike rod has threads, it is called a threaded spike. Its pull-out resistance is 0.5 to 1.0 times greater than that of ordinary spikes, but its thrust resistance is 50% less. Because it is inconvenient to disassemble and assemble, and it is difficult to adjust the track gauge, it is generally used on turnouts.
Spring spikes are made of round or square spring steel, and there are many types. Because the part that buckles the rail has a certain elastic deformation, it can greatly reduce the vibration of the rail, so it is called a spring spike. When the wooden sleeper is deformed under load, it can still maintain sufficient buckling pressure. Its pull-out resistance and push-out resistance are greater than those of ordinary spikes, but it is rarely used in China. Figure 3 shows the most commonly used spring spike on the railways of the former Federal Republic of Germany.
Spiral spikes are a part used to connect rails and concrete sleepers. The lower part of the spike rod is threaded and the upper part is a bolt. The spike rod is fixed in the reserved hole of the concrete sleeper with sulfur anchoring (see sulfur anchoring), and the upper bolt is used to fix the buckling parts (such as buckle plates, spring bars, etc.).
