WJ-7 Fastening System

WJ-7 fastener is a kind of separate shoulder-free fastener used in ballastless track of high-speed railway in China. It is composed of T-bolt, nut, flat washer, spring bar, insulating gauge block, iron cushion plate, underrail cushion plate, insulating buffer plate, heavy spring washer, flat washer block, anchoring bolt and embedded sleeve, etc. In order to adjust the rail height, It also includes a rail lower high backing plate and an iron lower high backing plate.

WJ-7 fastening system primarily consists of T-bolts, nuts, flat washers, clips, insulating blocks, iron base plates, insulating buffer pads, rail base plates, anchor bolts, heavy-duty spring washers, flat shims, and embedded sleeves positioned within concrete sleepers or track slabs. The WJ-7 fastening system is designed for 60kg/m rails and is suitable for ballastless track systems without shoulder structures. It meets operational requirements for passenger-dedicated lines with maximum speeds of 350km/h and passenger-dedicated lines with maximum speeds of 250km/h (also accommodating freight).

►Key Component Functions and Selection

The spring clip is a critical component in the WJ-7 high-speed rail fastening system, available in two types: W1 and X2. The W1 spring clip is the standard configuration for general sections, while the more suitable X2 spring clip is used in low-resistance sections to ensure stability and safety under various terrain conditions. The under-rail pads also play a vital role in the WJ-7 high-speed rail fastening system. They are similarly categorized into two main types: A and B. Each type of pad has specific application scenarios—general sections and low-resistance sections—corresponding to rubber pads and composite pads, respectively. Type A pads are restricted to maintenance work on existing high-speed rail lines and must be replaced only on sections where Type A pads were originally installed. The functionality and selection of these critical components ensure the system's stability.