Replacement of Brake Blocks on a Diesel Multiple Unit

In today's times, when fuel prices are increasingly high, more and more people consequently choose public transport for their journeys and travel. Railway vehicles, such as diesel multiple units, are considerably outdated compared to newer ones and more expensive to maintain. At the end of the diploma thesis, based on the testing, they made comparisons between brake blocks; they calculated and demonstrated time and financial savings. The successful use and positive feedback on the use of composite brake blocks on freight wagons contributed to the decision to experimentally install test composite brake blocks on DMU 813/814, test them and create comparative tables.

Problem

In today's times, when fuel prices are increasingly high, more and more people consequently choose public transport for their journeys and travel.

Solution and Method

Railway vehicles, such as diesel multiple units, are considerably outdated compared to newer ones and more expensive to maintain. On the latter, we want to enable passengers to have as comfortable and safe a journey as possible through modifications and innovations. At the same time, we want to at least partially reduce the high maintenance costs and noise through changes and upgrades, such as replacing cast iron brake blocks with composite ones. In the diploma thesis, they first described the diesel multiple unit in detail and presented the necessary information for easier familiarisation with the vehicle.

They described the series versions 813/814-000 and 813/814-100 and the composition of the vehicle itself. They briefly described the most important assemblies and devices of the vehicle and their operation. They presented DMU maintenance and showed an example of maintenance, particularly of the bogies and the braking system with brake rigging.

After presenting the vehicle, they tackled the comparison of cast iron brake blocks with composite ones, where they managed to obtain all the necessary information for cast iron ones, whilst not for composite ones. Unfortunately, they were unable to obtain the chemical composition of the latter, so they provided an approximate estimate ** of the composition of the brake blocks**. They presented the testing of composite brake blocks and informative monitoring of cast iron brake blocks on two different vehicles of the same series, which lasted two months.

The testing was successfully completed, despite certain problems caused by excessively large holes in the ear of the composite brake blocks, which are intended for inserting the cotter pin or brake pin.

Results

At the end of the diploma thesis, based on the testing, they made comparisons between brake blocks; they calculated and demonstrated time and financial savings. The successful use and positive feedback on the use of composite brake blocks on freight wagons contributed to the decision to experimentally install test composite brake blocks on DMU 813/814, test them and create comparative tables. For freight wagons, according to the European Union Directive on reducing environmental noise pollution, the use of composite brake blocks is mandatory, which means that in the future we can expect mandatory use of composite brake blocks on all railway vehicles.

Therefore, despite being aware that composite brake blocks are more expensive than cast iron ones, with the experimental replacement of brake blocks they sought a solution that would, due to less frequent replacement of brake blocks at inspection checks and extraordinary repairs, at least partially reduce the costs of overall maintenance. At the same time, the vehicle would also be in use for longer and spend less time on repairs, where it does not serve its purpose. With the help of available data in the company, namely on the value of cast iron brake blocks and the cost of replacement, and informative data obtained from the manufacturer of composite brake blocks, they demonstrated through calculations and graphs that the ** replacement of cast iron brake blocks with composite ones** ** is undoubtedly worthwhile**.

During the testing period, they saved 255.28 EUR, as the cost of replacing cast iron brake blocks amounted to 1,513.20 EUR, whilst the cost of replacing composite brake blocks amounted to 1,257.92 EUR. They would save on the frequency of changing brake blocks, which was also demonstrated by testing, which showed that the estimated wear of composite brake blocks is much lower than that of cast iron ones, which consequently also affects lower replacement costs. According to the results obtained, the cost of replacing brake blocks on diesel multiple unit 813/814 would decrease by 1,531.68 EUR on an annual basis.

Considering that 39 vehicles are in use, the savings on an annual basis for all vehicles would amount to 59,735.52 EUR. With approximately the same value of the coefficient of friction and hardness of both cast iron and composite brake blocks, based on the theoretical foundations of composite materials, we can conclude that in the latter, the load is distributed among the constituent components, which consequently increases wear resistance. During the creation of the diploma thesis, they became familiar with DMU 813/814, its operation and types of maintenance. They became familiar with cast iron brake blocks, their chemical composition and properties.

They learned about the advantages of composite brake blocks, such as reducing the cost of replacing brake blocks, reducing noise and preventing the possibility of fires in nature. It is interesting that the replacement of cast iron brake blocks with composite ones, due to the high price of the latter, seems pointless at first glance. However, at the end of the diploma thesis, we can confirm that the ** replacement of cast iron brake blocks is economically justified**. [deof_form download_text="DN-kamenšek-aleš.pdf" download_url="http://academia.eu/news/wp-content/uploads/2017/01/DN-kamenšek-aleš.pdf"]