Is This The Solution to Changing Standards? - continued
However, cost can’t be the only concern when specifying components for electrical installations; performance is essential as it goes hand-in-hand with safety. Even before Network Rail introduced the new standards, the popularity of GRP enclosures was quickly gaining momentum. Metal had always been the traditional, go-to solution because of its inherently robust nature, but as competition within the industry increased, many newcomers to the market were noticing that the incumbent favourite had several disadvantages that they could improve upon.
While metal enclosures are undoubtedly strong, an essential quality in a trackside enclosure, they are prone to denting when subjected to forceful impact. Once the metal is dented its protective coating will be damaged, which will allow for corrosion to occur, quickly compromising the integrity of the connection within. Of course, if the connection becomes compromised, then the conductivity of the metal makes the enclosure itself a health and safety risk.
A good quality GRP enclosure, by contrast, will have a tensile strength that, while not equal to, is still comparable to its metal counterpart, yet it will not dent and is not at risk of corrosion should the paintwork on the surface get damaged. In addition, the material does not conduct electricity, meaning there is no risk of electrocution should anyone come into accidental contact with the enclosure.
When most engineers are asked to specify the toughest enclosure possible they naturally turn to metals like stainless steel. This is a force of habit brought on by traditional misconceptions, and usually answered without the real-world considerations of cost and practicality.
While metal enclosures may offer the highest strength, when it comes to all round toughness, it’s easy to make a case for GRP.
Competence in Gravel Extraction
Modern duty cycle crawler cranes from Liebherr are being used by Kiesabbau Wiedemann for various tasks in the sand and gravel extraction industry.
The south German company has strengthened its position with four further machines, namely three HS 8070 HD and one HS 895 HD. Two of the duty cycle crawler cranes in Kiesabbau Wiedemann’s fleet proved their efficiency during the last year as part of an infrastructure project in Hungary.
The task of the duty cycle crawler cranes was the extraction of gravel material for the development of the Hungarian motorways. Despite the relatively large volume of the extraction, Kiesabbau Wiedemann decided against a larger machine and opted for two HS 8070 HD instead, thus considering the difficult soil conditions.
Thanks to the performance of the two 70-tonne Liebherr duty cycle crawler cranes, the ground pressure could be kept as low as possible while lifting the dragline bucket.
Approximately 16,000 Tonnes of Gravel per Day
For about one year, the duty cycle crawler crane worked twenty-four hours, seven days a week in order to meet the requirements for gravel.
Each machine was equipped with a 23 m long boom as well as a dragline bucket with a filling capacity of 3 m³. Every day about 16,000 tonnes of sand and gravel were extracted from depths of down to 12 metres. That means a turnover of approximately 330 tonnes per hour and machine.
Thus, in the course of the year, it was possible to meet the customer’s expectations and achieve approximately 5.5 million tonnes of material as required.
Kiesabbau Wiedemann provided a well-experienced team of six operators for the task. They worked in shifts and achieved low cycle times of under one minute.