Generally speaking, multi axle trailer or SPMT (self-propelled modular trailer) can be used to transport such super large parts, but it may not be suitable under certain circumstances, such as clear height limit requirements during transportation. At this time, a special kind of transport vehicles should be transported. They are bridge beam transport vehicles.
The basic structure of the girder bridge system is to bridge the beam frame for load on the front and rear separated transport modules. The transport objects are "lifted" by the beam frame, and the load is transmitted to the front and rear multi axle transport modules through the base of the beam frame, so as to realize load sharing. Since there is no wheel limit below the bearing surface of the beam frame, the height of the overall transport can be controlled very low, or even directly lowered to the ground, which is very favorable for some occasions requiring transport height; The loading and unloading of goods by bridge beam transporter is very convenient and safe, and some types can be realized by their own functions without the assistance of lifting equipment; In addition, the steering structure of the split transport vehicle is also very flexible. Even if the total length of the vehicle body is very long, it is not laborious when turning at a large angle.
The development of girder bridge has been quite mature, and their forms have differentiated into many different types, but they can be divided into the following four types.
One is a concave bridge girder with a support frame at the bottom. The middle part of the bridge beam frame sinks close to the ground and is in a "concave" shape as a whole. The transportation is directly carried on the support frame at the bottom. Because the beam frame on the side of the load area is very low, girder bridge trailer will be easier to lift the transportation from the side.
The second is the side girder bridge directly loaded on the upper part of the main beam. The overall beam frame shape is also similar to the first, in a "concave" shape, but the bottom is empty. The protrusions on the side of the transport object are directly loaded on the upper part of the main beam, which can be easily loaded and unloaded by adjusting the height of the beam. This mode of transport requires a stable supportable area to be installed on the side of the transport object.
The third is the high girder bridge. The load area of the beam frame is higher than the first two. The hanging belt fixed on the main beam is used to carry the load from the bottom of the transport. During transportation, the transport is basically wrapped in the middle, and the protection safety of the side is better.
The fourth is the clamp type girder bridge. The beam frames at both ends are not connected as a whole but are directly fixed at both ends of the transport object, which can minimize the self weight of the transport vehicle and facilitate loading and unloading of goods. However, this method requires that the transport object must have sufficient strength and standardized butt joints are installed at both ends. This method is often used to transport super large transformers, etc.