BACKGROUND OF THE INVENTION AND PRIOR ART

The present invention relates to a method of protecting a high load, transported by means of an electrified track- guided transport system, against electrical flashover caused by the vicinity to electric contact lines. The present invention also relates to a device for carrying out the method and to use of said device.

In electrified track-guided transports, such as railway transports, the height of the load is limited by the distance between the upper edge of the rail and a safe headway, > 150 mm, to a live contact line with supporting live cantilevers. By safe headway is meant the distance from the top part of the load to said live contact line. The size of the load, in height, is limited by said safe headway, which is negative since this may necessitate manufacturing the pro- duct in several parts and then, after transport, assembling these parts at the final destination. Alternatively, it may be necessary to manufacture the product with dimensions that deteriorate its performance to a level below that which is actually desired.

To be able to transport as high loads as possible, the transport may be allowed to be performed with a diesel locomotive, while at the same time the contact line is caused to become dead. However, this method is time-consuming and very costly since in many cases the load has to be transported over considerable distances. In many cases, however, it is not possible to make the contact line dead along many and long railway lines since this is not feasible within the framework of scheduled timetables for other traffic. In addition, different lines may be owned by different operators, which additionally complicates the task of rendering the entire transport route dead. SUMMARY OF THE INVENTION

The object of the present invention is to bring about a solution that does not exhibit any of the above-mentioned drawbacks. In particular, a solution is aimed at which allows increasing the size of the load in the vertical direction .

This object is achieved according to the invention with the initially mentioned device, which is characterized in that the device comprises a mat of an electrically insulating material. With such an electrically insulating material, the distance between load and electric contact lines may be reduced without the risk of electrical flashovers increasing. An additional advantage is that the load may be made higher than earlier. This is particularly advantageous if the basic structure of the load can be influenced by the fact that the height may be increased. Another advantage is that, during transports, it is not necessary to render any electric con- tact lines dead, which entails a faster and simpler transport of the load while at the same time the other traffic is not affected.

According to a preferred embodiment of the invention, the above-mentioned mat consists of a flexible material. One advantage of using a flexible electrically insulating material is that, because the material is bendable, it is possible to use it over a broad spectrum of varying sizes of the load.

According to another embodiment of the invention, the electrically insulating material has an insulation level, Um, which at least amounts to 170/70 kV. The requirements for such an insulation level apply to equipment that is to be used in the contact line and the electrically insulating material shall at least fulfil the same requirements for insulation level. When these requirements are fulfilled, the distance from the load to the live parts in the contact line may be reduced by up to 150 mm. According to a further embodiment of the invention, the device comprises at least one spacer which is arranged between the electrically insulating material and the load. In this way, the electrically insulating material will have a highest point, which facilitates water run-off and hence reduces the risk of electrical flashovers caused by the vicinity to the live contact line.

The invention also relates to methods, in electrified track- guided transports of high loads, of protecting said load from electrical flashovers caused by the vicinity to electric contact lines, where a mat of an electrically insulating material is arranged adjacent to the load and between the upper side of said load and said contact lines. A further aim is for the electrically insulating material to be arranged so that it covers the whole upper side of the load and also so as to cover part of the side panels of the load adjoining the upper side of the load. Hence, the risk of electrical flashovers between the load and electrical contact lines is reduced.

According to an additional embodiment of the invention, the electrically insulating material is arranged with a highest point on the upper side of the load. This ensures that any water collected on the electrically insulating material runs off and does not risk causing electrical flashovers between the electrically insulating material and the contact line.

In addition, the invention relates to use of a device accor- ding to the above which, in connection with electrified track-guided transports of a transformer or a reactor, is configured to protect the transformer/reactor from electrical flashovers between the transformer/reactor and an electric contact line.

BRIEF DESCRIPTION OF THE DRAWING

Figure 1 shows a load arranged on a railway wagon, the load being covered with a device according to the invention. Figure 2 shows a side view of a load arranged on a railway wagon, the load being covered with a device according to the invention .

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be illustrated in various embodiments, wherein the device according to the invention has been applied to a load.

Figure 1 shows a side view of a railway wagon 3, standing on a rail 1, on which a high load 5, such as a transformer or a reactor, is loaded. The figure also shows a live contact line 7 with associated electricity pylons 9 and supporting cantilevers 11. The distance 13 in air between the top part 15 of the load 5 and the contact line 7 is determined by the height of the load 5 counting from the bottom of the railway wagon 3. To enable transport of the railway wagon 3, including its load, the wagon 3 is coupled to one or more hauling locomotives (not shown) . By a high load 5 is meant in this context a load 5 whose top part 15, viewed from the bottom of the railway wagon 3, is located ≤ 150 mm from the live contact line 7.

To make it possible for the top part 15 of the load 5 to be < 150 mm from the live contact line 7, without the risk of electrical flashovers caused by the vicinity between the load 5 and the line 7, a mat 17 of an electrically insulating material is arranged over the top part 15 of the entire load 5, and also down over part of the sides of the load 5. The mat 17 is advantageously made of a flexibly bendable electrically insulating material, but also a stiff electrically insulating material may be used.

Figure 2 shows a side view, viewed in the longitudinal direction (X) of the rail 21, of Figure 1. Between the upper part 25 of the load 23 and the mat 27 of electrically insulating material arranged above the load 23, a spacer 29 is arranged for the purpose of creating an uppermost point 31 on the mat 27 when the mat is arranged so as to cover the load 23. The uppermost point 31 of the mat 27 lies closer to the live electric contact line 33 compared with the point 35 which is the point where the mat 27 is in contact with the edge between the side edges 37 of the load 23 and the uppermost part 25 of the load. This creates a slope on the mat 27 which facilitates run-off of water. The uppermost point 31 on the mat 27 should be located straight below the live contact line 33, since this, when any water has run off, redu- ces the risk of electrical flashovers caused by the vicinity to the live electric contact line 33.

The invention is not limited to the embodiments shown but may be varied and modified within the scope of the appended claims.