Old Mack Trucks

[JESSE1]

The length and axle loading laws changed to where there wasn't any advantage in running COE's. Conventionals generally ride smoother and like Bob said there's an advantage in having an engine and frame out front to absorb the energy of a collision.

 

[RobertN]

The pictures show some of the trucks with a two piece rim, ie a center portion, and the rim.

Why were those popular on some truck brands? Was there an advantage?

 

[Bob Rooks]

The length and axle loading laws changed to where there wasn't any advantage in running COE's. Conventionals generally ride smoother and like Bob said there's an advantage in having an engine and frame out front to absorb the energy of a collision.

It used to be that you could pull a 45' trailer in 50' states with a COE. That's probably changed. Dunno.
This is what the Aussie's can do (the "K" series is on private property only).
About the "K":
K represents the largest road trains operating in Australia, and therefore, the world. Called a "Powertrain" or a "Body and six", these machines operate at The Granites Gold Mine in the western Northern Territory, and are used in place of 200 t dump trucks, because of the distances involved on the haul run. A 600 hp 19 L Cummins engine powers the prime mover, whilst a 400 hp Cummins engine is installed in the rear trailer of the B-double, driving through an automatic transmission, giving a total of 1,000 hp. Weights of 460 t are achieved with ore loading in side-tipper bodies on a 62 mile round trip. As these trucks operate on private property, they are not subject to governed weight and length rulings, but instead are utilised in the most efficient way possible.

 

[joemd11]

COE trucks have terrible aerodynamics resulting in poorer fuel economy??? Sounds good anyway

 

[Bob Rooks]

The pictures show some of the trucks with a two piece rim, ie a center portion, and the rim.

Why were those popular on some truck brands? Was there an advantage?

The cast spoke wheels are/were standard equipment. Back when I was selling class 8 trucks "ten hole Budds" were optional (regardless of brand), as were aluminum, etc. Most rigs on the west coast favored the Budd wheels, midwest and east coast favored the cast spoke (cheaper? flatter country?) The Budds were much lighter and durable, and didn't carry the nickname "widowmaker".

 

[Bob Rooks]

COE trucks have terrible aerodynamics resulting in poorer fuel economy??? Sounds good anyway

:laughing: :laughing: Nope, sorry. The frontal area calculations are the same for both if I remember. What makes the difference is the spoilers on the cabs and trailers.

 

[JESSE1]

The pictures show some of the trucks with a two piece rim, ie a center portion, and the rim.

Why were those popular on some truck brands? Was there an advantage?

Those are called a Dayton wheel. Here's a comparison between the Dayton and Budd wheels. My '56 White WC22PLT on the left has Dayton wheels, the White 4400TD on the right has Budd wheels.

 

[California]

K represents the largest road trains operating in Australia, and therefore, the world. Called a "Powertrain" or a "Body and six"... used in place of 200 t dump trucks... A 600 hp 19 L Cummins engine powers the prime mover, whilst a 400 hp Cummins engine is installed in the rear trailer of the B-double

Is the second engine located in the trailer with four axles?

I hope their haul roads are wide! I've read that the Australian road trains whip around quite a bit. I can't imagine what it's like when two of the K-monsters meet and pass one another. How long are they?

I think a helper-engine arrangement was tried in Oregon a few years ago. Do you know anything about it?

Also - are the Australian offroad haulers the same giant trucks like were used for British Columbia log hauling on private roads? I saw those in BC long ago, and once saw one like those at a Chevron-Venezuela oilfield. No matter how long I stared at it I couldn't get my head around how big the thing really was. It looked at least half again wider than a road-legal truck.

 

[joemd11]

:laughing: :laughing: Nope, sorry. The frontal area calculations are the same for both if I remember. What makes the difference is the spoilers on the cabs and trailers.

Doh!

 

[RoyJackson]

COE trucks have terrible aerodynamics resulting in poorer fuel economy??? Sounds good anyway

I don't know about the fuel economy aspect, but passing a COE while driving a smaller motorcycle can be a real thrill when that blast of air hits you...

Since I'm the one who first asked the question about COE's "disappearance"...I knew some truckers hated them because of the "being the first one on the scene" aspect. I'd also heard there were more hassles with maintenance. I'm not a trucker, so no first hand knowledge...