An important part of the manufacturing process is how to move things around the works. Modern railway vehicle contain long sections of lightweight materials which, for example, need to be moved from the rolling mill to the welding jig. A 24 metre long steel section needs careful handling if it is not to be ruined by accidental bending while being swung from one side of the shop to the other.
It is worth mentioning here that a railway vehicle factory can be a very large place. If you say that a site requires one square kilometre of land, you would be in the right ball park - well, a very big ball park. This means that you have to move things around during manufacture. Very often, large parts, like underframes and roofs are made on jigs in a large shop and moved through assembly jigs to a final assembly jig. Moving a stainless steel roof 24 metres (65 ft) long is difficult because the roof will flex. Secure cradles need to be designed to protect parts which have to be lifted or moved from one area to another. Cranes will be required in all the shops. In the two photos above, the car roof is being manoeuvred in a large frame to prevent distortion. Overhead bridge cranes are the traditional type used for the larger items like this and a big shop will need at least two.
Another problem area is fixing bolts protruding from items shipped into the factory from a subsupplier. These will be damaged if not properly protected and handled.
Bogies run from the very simple cast steel design (such as the traditional US three-piece freight bogie which is basically a pair of side frames and a bolster - see Vehicle Suspension Systems on this site) to very complicated fabricated designs with steel spring primary suspension, air bag secondary suspensions and both tread brakes and discs (such as French TGV bogies). Many decisions have to be taken in selecting the bogie appropriate for the role. Besides the suspension system and brakes, it is necessary to decide whether to use inside or outside bearings, solid or hollow axles, and to choose the wheel diameter and tread profile. (See the railway Bogie on this site for an explanation of the various parts that make up a bogie)
Bogie assembly now begins in earnest and the parts similar to those shown on the railway Bogie , but applicable to our bogie will be assembled. If the suspension has chevrons, these will be the first items to be connected, if the suspension is using coil springs then that will be one of the last steps as the wheelsets are added. Next comes the air pipes, followed by the brake rigging, then the wiring and finally the wheelsets, culminating with the completed bogie undergoing a load test, (see picture), which will ensure that the suspension is installed correctly and the bogie is functioning as designed.Our company will develop three-axis bogies...
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