Cat 775G dampers in operation

stroj na zpracování kamene

Dampers Cat 775Gs are two-axle trucks weighing well over a hundred tons that are built-in Decatur, Illinois, USA, at a factory located about three hours’ drive southwest of Chicago. Before they made it to Měrunice, they had a train ride to the port, where they were reunited with her hull, and then they sailed across the ocean. The outer tyres and walkways were assembled here at the quarry.


What is the manoeuvrability of the machines?

We slid back down to the bottom of it and headed for the dump. We wait for the other damper to empty and I wave to the driver, who stops and opens the door. I follow him up the staircase and take the other seat in the cabin. “Hi, I’m Jarda, feel free to call me by the first name, we keep things informal here,” says the engineer, passing by his colleague. I’m tempted to ask how hard it is to manoeuvre such a giant, and Jarda, as if sensing this, let me turn the steering wheel. “Like nothing, huh?” He laughs and says that the power steering helps with movement, as does the fact that the front axle is not powered and is therefore relatively light.


What is the load capacity of the dampers?

The official payload of the Cat 775G is 64 tons, but in reality, it can carry more. As with all Cat fixed dampers, the 10-10-20 rule applies. This means that at 90% to 110% of its load capacity, it can carry 70 tons just fine. The ten per cent of the cost may even be between 110 and 120% but must never exceed 120%, i.e. 76 tons. The data would be recorded in the machine’s memory and could play a role in a possible claim. With a damper, the worker makes over thirty turns a day. The Cat 775G is a proven model, the prototype of which was tested for 33,000 motor hours before being put into series production.


Technical equipment

Compared to its predecessor, the Cat 775G offers five per cent more power and fully automatic transmission shift comfort comparable to an automatic car. The damper has a 12-cylinder diesel engine with an inverter. At the rear is a converter, a gimbal and a fully automatic gearbox with electronic control, supplemented by a module that monitors torque and gives shift instructions accordingly. The top speed is 67 km/h and due to sufficient engine power, it can be reached even with a fully-loaded car. A comfortable and safe ride is ensured by pneumatic-hydraulic shock absorbers filled with oil and nitrogen with automatic stiffness control that varies depending on the load.


What about customer service?

Tomáš Hrdina mentions one more advantage, which is the customer service he receives from Zeppelin CZ. “If I have a problem, I pick up the phone and call an operator who deals with it specifically. We are satisfied with Caterpillar equipment and this is not only due to the quality of the machines but also to the service that comes with it,” says Tomáš Hrdina. The lifespan of a fixed damper is approximately twenty years, so choosing the right machine is certainly not to be underestimated.


Source: Lomy a těžba

Published: 27.6.2021