View attachment retarder.jpg
yep they really do call it that....hahahah makes me laugh. thats in an old 789B which is around 20 years old, done more than 1000 000 Km's and nearly as many hours, swallowed more than 40 000 000 litres of diesel in its time, and still going. 10km/h as you can see up a 10% grade with 180-200t on board(payload) gross weight im sure is over 350t.
View attachment 793.jpg
793c, bigger, a bit newer, hell of alot nicer to drive, but still in the scheme of things it is pretty worn out. they have a payload of around 230 but you can overload them to around 250 or so before it will lock out and you are stuck going to the dump in 2nd gear the whole way. they have a gross mass of over 400t
Caterpillar are the only "LARGE" truck maker that still sticks with mechanical drive. They are in a niche that some companies still require, they are small enough (good turning circle) to be able to be used under a normal excavator operation in pit, but are capable of longer runs than the electric drive trucks. I dont know why this is but that is what I have been told. If the turning circle isnt an issue (ie there being loaded by a front end loader) they usually use kress trucks for long runs as they love the long drives and they carry more per load. All of the big cat trucks are 6speed (7th is reverse if you read above information posted) all pull around the same speed up a 10% ramp at their rated payload at around 10-12km/h, on flat ground they all have a top speed of between 55-60km/h (depends whos driving :lol:
). there are 4 braking systems on all Cat haul trucks, Park (air operated non cooled friction brakes), Emergency (modulatable version of the park brake), Service (a foot operated torque converter in each wheel brake), Retarder(same as what the service brakes use but on the steering column). There is a torque converter in each wheel, which is used for braking and the big throw on the retarder makes it highly modulate-able lol.
The electric trucks are apparently cheaper to maintain, and use less fuel for the same power. They are harder to drive from an operator perspective, mainly because of a delay in everything but steering. The brake systems arent as controlable as a cat as there is only a foot operated brake, which is tricky to use when your sitting on a floating air seat and your going over rough ground. And in wet weather they are hard to keep straight, partially because of the delay in power/brake systems, but also because they do not allow riding the brake while powering on(to keep wheels moving slowly while braking....).
yes you did read that correct, wet weather and haul trucks dont mix, even though they have an enourmous foot print on the road, when it rains, its like a tokyo drift session just trying to drive them back to a park up area.
Cheers
:wink: