"Aussie" road trains

[V6 Diesel]

Was looking thru the latest issue of a Construction Equipment magazine and Shell has a "info" article on Rotella T.

The test was running (2) Cummins 600 engines pulling road trains for 186,000 miles in the outback with temps over 100F. Cooling towers are used for differential oil. Tractor/trailer length reached 174 feet, and weighed as much as 396,000 lbs. Test engines averaged 2 miles per gallon compared to 6 to 7 mpg for a typical rig here in the states. The fuel burned would be the same as a typical rig here running 600,000 miles.

Article stated at teardown valve deck, gear cover and oil pan had minimal sludge buildup. Cylinder liner crosshatch was preserved. Minimal deposits on piston crown, ring grooves and ring belt practically free of carbon deposits.

Engines maintained per factory recommendations and oil analysis never showed elevated contaminate levels. (uoa's not included)

 

[Mystic]

I have seen those road trains on television. They are incredible. They really do look like a short train travelling on the highway.

 

[SteveS]

These road trains run only in the north and west of Australia. They do present some problems though, if you're passed by one going the opposite direction you're almost blown off the road in even a large car.

And the dust, I'd imagine that the biggest problem with getting a long engine life would be air filtration, keeping the microscopic bits of the "big red" out of the engine.

I had some experience with a fleet of logging trucks here in New Zealand, they were a truck with a log trailer with a dolly trailer and a second log trailer and then a third dolly trailer and a thrid log trailer. A dolly trailer is a small two axle trailer which just carries the turntable for the log trailer following. These had 50 wheels and an all up weight of 180 tonnes (396,000 lbs). These were off-road trucks which carried the logs from the felling site down to the railhead. We used to do UOA on them at the 10,000 km service (6000 miles) and if the silicon was not elevated then the engine oil would be left in until 20,000 km (16,000 miles).

To get these moving out of a dirt 'skid pan' in the forest where they loaded the logs, the drivers would often lift the front wheels about 250 mm (10 inches) in the air. Never heard of them twisting a driveshaft, but they did have some problems with blistering the case hardening off the gear surfaces in the diff.

 

[Silk]

Wow,another Kiwi - g'day! I haven't had anything to do with the logging trucks,but I worked with a fleet using ''doubles'' which was a semi pulling a dolly with another semi on that,the semis being interchangable and the dollies having seperate rego of their own.

Anyway,the foreman I served my time under worked for a company that supplied trucks for Kaiangaroa forrest work,he said they geared them for speed as they were on private roads.Putting an engine together in the field,laying the bigend caps out ready - they would be covered in pumice dust,so he'd wipe them only to find them covered in dust 5 mins later.After a few attempts he just said bugger it and slapped it together.I wonder what pumice would show up as in a UOA,and if so,did it show in yours?

 

[Gary in Sandy Eggo]

I read about the Austrailian road trains several years ago in a give-away magazine at a truck stop along the I-5 in California. This article was dealing with moving livestock great distances, at high ambient temperatures.

The don't stop. To do so would kill the livestock. They also have the right away. The road is narrow, so if you encounter one while in a car, you're obliged to give way. If you get in the way, they'll plow right though you and never stop. If they encounter a broken down car that's somehow blocking the road, they'll plow right through it.

Regards, Gary in Sandy Eggo

 

[1040 WreckerMan]

I have never had the opportunity to drive a real road train but I have come as close as you're likely to get in the States. One of my jobs involves towing broken stuff. On occasion I've pulled around 200K up 15-30% grades and have been right around 180' in total length. Normally we don't tow that much weight as most trucks here are only good to 105,500 gross at the most. However dump trucks/heavy haulers and equipment can be quite a bit heavier. Nothing will pucker the seat quite like trying to start off on a 20% grade with 155k/lbs and having to lean out the window to see and steer with the brakes (unless you are trying to stop that load in the rain with only the brakes on the tow truck

)

The transmissions typically run about 250-280 with a load and the diffs run about 225-250 with a load. It is surprising how quickly the diffs cool off once the load is reduced after climbing a hill and rolling back on the flats. Although typically we are only dealing with 85-95dF ambient at the most, which helps temps come back to Earth reasonably fast.

 

[sprintman]

Nothing like road trains anywhere else. American truck engineers say it's he best testing environment anywhere. With the loads and high ambient temperatures things have to be right. Volvo now mandates Redline in diffs and g'boxes. get in a road trains way on a dirt road and you may die. Keep well clear.