How to install type Ⅳ fastening system?

Rail fastening system, also called railway fastening system, is the important part of track. Basically, it is composed of rail clip, railroad spike, tie plate, rail pad and etc. For safety and comfort, rail fastening system must have character of enough clamping fore, good insulation, low rigidity, less maintenance and so on. There are lot of applications, sizes and design with different types of railway fastening system. According to requirement of railway section, reasonably select suitable rail fastening system will be helpful to give full play to its own performance benefits. Typical fastening system include type Ⅳ fastening system, E-clip fastening system, skl fastening system, high speed WJ-8 rail fastening system and etc.

About type Ⅳ fastening system

The type Ⅳ fastening system is a basic kind of rail fastening system. It is made up of rail clips, rail shoulder, rail insulation and rail pad.

Rail clip

By the installation position, rail clips for type Ⅳ can be classified into three types: C4, JA and JB. C4 type rail clip is generally used in the normal section, JA and JB type rail clips are applied in the rail connection. C4 type rail clip has a diameter of 20mm, and JA, JB type rail clips’ diameter is 18mm. Commonly, JA type is coated with grey paint and matched with No.7, No.8, and No.9 rail insulator; JB type is coated with black paint and matched with No.10, No.11, No.12 and No.13 rail insulator.

Rail shoulder

Rail shoulder is pre-embedded into the railway sleepers to fix the rail clips. The precision of embedding must meet the following requirements:

Rail insulator

Rail insulator can be divided into two types: G4 (for normal section) and G4J (for rail connection). There are seven specifications for each type, such as No.7, No.8, No.9, No.10, No.11, No.12 and No.13. No.9 and No.11 is used for standard gauge. All rail insulators are black except No.7, No.8, and No.9.

Special tips: it is not allowed to install high base plate to avoid deformation and breakage of rail clips.

Rail pad

Rail pad is a polyurethane mat between rail and railway sleeper. rail pad is mainly used to reduce the shock and vibration.

Type Ⅳ fastening system installation

Preparatory work

• Before installation, get the No.9 and No.10 rail insulator ready. Properly prepare No.8, No.10 and No.12 rail insulator in case gauge adjustment. At the same time, prepare relative rail insulator for rail connections.
• Prepare C4 type rail clips, and JA and JB type rail clips for rail connection.
• Rail shoulder in the railway sleeper must have accurate position. There are some situation can’t put into operation, for example, rail shoulder position is askew and upwarping; gap between two rail shoulder on the same side is not correct.
• Clean muddiness on the inside of rail shoulder and railway sleeper. Clean mortar in the hole of rail shoulder.
• Clean muddiness in the rail base.  

Installation steps

1. Put rail pad between two rail shoulder, rabbet center line of each side of rail pad is aligned to center line of rail shoulder.

2. Lay steel rail on the rail pad.

3. Install No.9 and No.11 rail insulator. Edge of rail insulator should fasten rail shoulder. When the specified rail insulator can’t reach the requirement or install because of manufacturing deviation of steel rail, railway sleeper and rail insulator, just exchange another one, no punching to push rail insulator into right position.

Special tip: using GJ4 type rail insulator in the rail connections.  

4. Before installing rail clip, keep steel rail, rail pad, railway sleeper and rail insulator closely attached.

Using special tool when install rail clips.

Keep rail clip flat, don’t pull hard during installation.

Any difficulty in the rail clip installation, use install tool and knock the tail of clips with a hammer.

When the distance between inside of small circle arc and end of rail shoulder is 8-10mm, rail clip is in place.

Installation adjustment

• Check rail gauge. Take rail clips down with special tool if they are not suitable.

• By the adjustment amount of rail gauge, refer to following table to choose suitable sizes.

Type Ⅳ fastening system maintenance

• In the initial operational stage, pay attention to the usage of railway sleeper and railway fasteners. When appeared suspension, uneven or twist warp of railway sleeper, tamp in time.
• If appear break rail insulator, rail pad or rail clip in the working, change them timely.
• In the stress-relieving of continuously welded rail track, take rail clip down with special tool. After that, check the position of rail pad and rail insulator.