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Dessauer Verkehrs GmbH saves high effort and costs with ice scraper carbon strip
Efficient de-icing of overhead lines - without glycerine | customer testimonial
Reading time: 4 Minute(s)
Date: February 9, 2024
Mobility

Despite ice and snow - free travel for Dessau's tramways

For transport companies, winter not only brings frosty temperatures, but also a problem that causes costs and effort: icy overhead lines. A challenge that Dessauer Verkehrs GmbH also had to contend with.

Holger Steuer, Head of Maintenance, explains how the company got to grips with the problem in a straightforward manner. The result: reliable tramway operation despite ice and snow.

 

→ Here you can download the reference report "De-icing overhead lines".

Despite ice and snow - free travel for Dessau's tramways

De-icing overhead lines with glycerine - a common and annoying practice in Dessau

"When frost was expected in the past, we used glycerine as a defroster to keep the overhead lines free of ice. Our catenary maintenance vehicle, which was equipped with a pantograph including a lubrication device, was deployed for this purpose. The dispatcher in the control center had to decide whether to use the vehicle based on the weather conditions."

Unpopular extra tours with the maintenance vehicle

"If so, this meant that a streetcar driver had to drive the entire route network again with the catenary maintenance vehicle after the last trip to lubricate the overhead lines with glycerine. The two-hour extra trips naturally met with little enthusiasm from his colleagues ..."

Up to 40 "lubrication runs" with glycerine per season

"Lubrication driving was not only a nuisance, it was also very time-consuming and costly. No wonder, because the catenary maintenance vehicle was used every day in freezing temperatures, i.e. 30 to 40 times per winter season."

Happy about less effort and costs in the winter season: Holger Steuer, Head of Maintenance at Dessauer Verkehrs GmbH

Will there be frost during the night or not? Glycerine often used purely preventative.

"It wasn't easy for the control center to assess whether the catenary maintenance vehicle needed to be deployed or not. We agreed that glycerine would be lubricated at temperatures of 1 degree Celsius and lower to be on the safe side. Because once the overhead line is frozen, it's too late ... In hindsight, we have to say that 80 percent of the trips were unnecessary."

Schunk's field service recommends the ice scraper carbon strip

"As a customer of Schunk Transit Systems, we benefit from regular contact with their field service. Our contact person had already introduced us to the ice scraper carbon strip some time ago. The scraper is fitted with a copper rail that removes ice from the contact wire. However, we were concerned that this rail could damage the overhead line. That's why I initially only used the Schunk solution on the catenary maintenance vehicle."

Good relationship: Schunk customer service on site in Dessau.

Uncomplicated conversion of the roof-mounted pantographs

"After we had successfully tested the Schunk solution on the catenary maintenance vehicle, the time had come in the winter of 2022/23: We equipped 3 of our 10 streetcars with the special collector strips - 2 pieces per vehicle. The conversion was very straightforward and took less than half an hour per contact strip. To ensure that the equipped vehicles were the first to drive ahead in the morning to clear the overhead line of ice, extra parking spaces were reserved for these tramways."

Ice scraper grinding strip replaces expensive glycerine

"Today, we can say: we are delighted with the ice scraper carbon strip! Last winter, we were able to almost completely dispense with expensive glycerine spraying. The de-icing of the contact wire worked reliably and brought us enormous savings. To be precise: 2 weeks of machine use per month, a total of 120 working hours and 80 % glycerine.

Only in one case did the overhead line have to be burned free due to very difficult weather conditions. In very high humidity and very low temperatures, such extreme frost had formed that it could not be removed with either the ice scraper carbon strip or glycerine."

"With the ice scraper carbon strip from Schunk, we were able to save 2 weeks of machine use and a total of 120 working hours per month last winter."

Holger Steuer, Dessauer Verkehrsgesellschaft mbH

 Ice scraper strip heated and unheated detail
The ice scraper carbon strip can be developed to customer specifications and can be fitted with a brass or copper scraper strip, for example.

Ice scraper contact strip prevents weather-related train failures

"By using the ice scraper contact strips, we were able to avoid train failures caused by the weather. In the past, failures had occurred in severe frost, as very low temperatures can mean that the glycerine is not always applied evenly. This can still lead to icing in places. We didn't have this problem with the Schunk solution."

Copper rail on the contact strip without negative influence on the contact wire

"Contrary to our fears, we have not had any negative experiences with wear on the contact wire. The grinding pattern on the contact strips was completely normal. In terms of service life, we assume that the contact strips will last for 3 to 4 winters.

For the current season, we have again equipped vehicles with the ice scraper carbon strip so that the control center can access the vehicles at any time if necessary."

 

The scraping pattern of the ice scraper carbon strips in Dessau after 2 winter seasons.