Coming the other way, spotted in the rear view mirror. Looked to be New, clean tar tank trailer, super singles, and one of rear axles was pulled up off the pavement (as a tag axle would) Did I see correctly ?
Why not, assuming he was running empty?
Wouldn't be unusual in Europe. It's not uncommon here to see tri-axle semi-trailers equipped with not one but two tag axles. Usually one axle is set to come down to the road before the other as the trailer axle load increases, so even if the trailer was loaded (but not up to full GVW) it might be running with one tag axle in the air.
Lift axles are getting pretty common with any cargo that doesn't get back hauls. Last fall i saw a cattle truck that in dodge city that had 1 lift 1 drive on the truck and 2 lifts on the tri trailer. That was a little shocking.
You can get gooseneck and pintle trailers now with lift axles as well.
A lot of trailers are set up to be able to raise one axle when empty to save tire wear.
I figured as such but seeing how it was a standard 2 axle set up, odd to see one up. And only one on the road. We also don't get triple trailers thru here either.
Everything's about efficiency these days, even with super singles pulling one axle up not only reduces friction drag, it probably helps the aerodynamics a bit. Fruitliner just announced they've achieved 12 mpg for a highway tractor... considering we were happy with anything over 5 back when I was driving, that's amazing!
Some of the tandem axle dry cement tankers around here have a lift axle on the closest axle to the truck.
Heck I can remember more than a few cars and pick-ups that would be lucky to do that "back in the day"!
I had an uncle drove a 3/4 ton standard cab GMC with a 454 auto... 8 mpg empty, 8 mpg loaded to the tire limit, didn't matter.
My '13 6.7 get's 13 empty and 13 loaded. 11 if I'm pulling a trailer.
That's terrible. My dad's 97 two wheel drive dodge dually with the Cummins 5.7 and five speed still gets 20-21 highway with a quarter million miles on it. My 97 when I had it, same rig except 4X4 with oversize tires and a tiny bit of tuning ran 17-18 highway and 15 pulling a triple axle gooseneck loaded. Progress?
Triple axle trailers are common in Europe, simply for GVW reasons. A truck can weigh up to 44 tonnes (97,000 pounds) GVW on six axles, or 38 tonnes (84,000 pounds) on five. So a 3-axle tractor (usually one of the rears is a tag) plus a triple axle trailer are very common. Also using the tags has the advantage that when you're running empty the braking is far better because you have more load on the wheels that are actually in contact with the road.
Only in HP and torque. Then again I do have a lead foot..
Nige, triple as in (3) separate trailers behind one tractor. They are over the border in Ohio (20 miles away) but not allowed in Pennsylvania. Used to be no doubles here, I knew a couple of drivers employed to just the drive the 40 miles thru Pa on I-90 from Ohio to New York (both allowed doubles) ferrying doubles that had been split down to singles.
" A ton of freight, 450 miles, on one gallon of fuel"....gee now where did I hear that...?
Sorry, I should have explained it more clearly. A 3-axle trailer behind a 3-axle tractor unit. You can see from the photo the centre axle on the tractor is a tag plus also the front and rear axles of the trailer.
No your description was fine, seen many, I was the vague one.
What I don't get is the little "7k" axles they are putting on some end dumps here. I don't recall if that weight is right or not for sure. But there is a dirt pit here that has Aluminum end dumps with 3 axles on them, but the 3rd is a little single tire drop axle. I think the driver said it was only worth 7k, but I could be wrong. Sent from my SAMSUNG-SM-G900A using Tapatalk
Good to see you again DB. If they are short trailers it's probably for bridge law stuff. If not, not the difference between tandem/tri in most states is 6-8k so that all the third axle needs to carry.
I dont under stand why more trucks dont have tag axles instead of 2 drive axles? Alot of trucks could get by with a tag if the driver was trained how to use it. I think i know now.
There used to be a lot of fleet tractors with tags, and some rather ingenious models where the tag nested in behind the drive axle rigidly when towing say a 40 footer, and the tag came away from the tractor for use as the dolly when pulling doubles. There were two fifth wheels. Slick. I think the reason you don't see more of it here is the variety of road surfaces and inclement weather where you need all four pulling, tire wear, and given the big power engines in favor, you need a really big single axle to handle the torque. Used to drive single screw day cab cabovers running 350-375 Cummins, the pumpkin in those axles was huge. Think about putting 650hp to the ground on one axle with duals, how long would the tires hold up?
I saw a IH truck that was set up for this. I didnt know why you would need a pintil hitch down in front of the fifth wheel. I am always looking at trucks going down the road and i had never saw one before that one and that was last year.
At a dirt pit we were loading out of this week the guy had two old cabovers - A GMC and a Chevy. I think it was the GMC that had one drive axle and what looked like a factory rear drop axle with air bags. All I can say is the men that drove those trucks were real truck drivers..:cool2