The standard positive line contact rail is mounted on insulated brackets spaced between 3 to 5 meters apart, with an allowable tolerance of ±10 mm for bracket positioning. In special areas such as stations, transitions, bends, ramps, or expansion joints, the distance between insulating brackets must be at least 3 meters to maintain stability and safety. This ensures proper alignment and prevents excessive stress on the system.

Steel-aluminum composite contact rails use common connectors for fixed connections between adjacent rails, allowing for reliable current conduction. The precision of the connecting holes and fishplates ensures minimal movement between components, maintaining a stable electrical connection. The joints must be perfectly aligned to ensure that the exposed stainless steel surfaces are flush and free from any distortion or twisting. The installation accuracy is strictly maintained at 0.5 mm to guarantee smooth operation.

The expansion joint is designed to accommodate thermal expansion and contraction caused by temperature changes, current-induced heating, sunlight exposure, and rail movement. It is essential that the expansion joint aligns properly with the contact surface of the adjacent rails to allow seamless passage of train wheels via the pantograph. The expansion joint itself measures 1975mm in length. In straight sections, it should be placed as close to the center of two brackets as possible, with at least 400mm of space between each end of the joint and the nearest bracket. However, in curved sections, placing an expansion joint can create significant tension on both the insulating brackets and the sliding blocks, leading to accelerated wear and potential failure.

Therefore, expansion joints are typically avoided at bends. In rare cases where a bend with a radius smaller than 300m requires an expansion joint, the joint must be carefully positioned. Although it still functions, the tension transfer mechanism is adjusted so that the load is redirected to the insulating supports. This consideration is crucial due to the spacing between anchor points and must be addressed during installation.

In addition to connecting two separate steel-aluminum composite rails, intermediate connectors are used to introduce external power into the contact rail system. Each connector can handle 8 to 12 wires of 240mm² cross-section, ensuring a secure and efficient power supply. The wires must be installed with sufficient clearance to prevent additional forces from being applied to the rail, which could restrict its longitudinal movement.

At the ends of the safety trolley line, there are two types of elbows: one for mainline applications and another for yard lines. The mainline elbow is 5.2 meters long, with a height difference of 126mm between its two ends. The yard elbow is shorter at 3.4 meters, with a height difference of 129mm. An ordinary joint connects the elbow to the contact track, ensuring that the pantograph can smoothly engage and disengage from the rail at rated train speeds, maintaining consistent and safe power delivery.

Tangless Thread Insert

Tangless Helicoil Inserts do not require a tang to complete the installation process and therefore, do not require breaking of a tang after installation resulting in spent coil sections for disposal. Instead, a Tangless coil Thread insert includes an insert-driving notch to aid in the installation process.

Tangless Thread Insert,Tangless Coil Threaded Insert,Thread Inserts Without Tang,Tangled Wire Thread Insert

Shenyang Helisert Technology Co., Ltd , https://www.helisert.com