Yeah. I’ve never seen so many axles on a trailer as I’ve seen in Michigan. How do they turn a corner?
Very carefully actually. On an 11 axle rig (8 on the trailer 3 on the tractor, on the trailer most times only a tight 4 axles are on springs and the rest are on air with the ability to lift prior to going around a corner. Sometimes, they are all on air and you can choose in the tractor cab which ones you want to lift. The one I ran had 4 tight on air the two in the back lifted and the one in the front (which was spaced out at 10'2" from the centerline of the first stationary axle lifted too). Trailer was a 48 foot aluminum with a curtainside on it. One time I forgot to lift my axles when making a turn and the trailer reminded me real quick as it stalled the engine, the 3406 Cat dies in the intersection. Was embarrasing and then I tied up the intersection because they don't lift instantly. Takes about 15 seconds for them to begin to lift.
Michigan also has a law about lift axles and that is, once you lift them and make a corner, they have to be back on the ground (and tires rolling) within 300 feet of the corner and Michigan cops watch that real close. You go past the 300 feet and get pulled over, they will take you back to 80K gross on the portables and when you are loaded with 100 plus on the deck, the fine is astronomical.
With a Michigan Special (Sled), there is a whole lot more than just shifting gears.
With the axles on air, you have to know how much down pressure is equal to how much weight too. Had a whole row of gauges in the cab that told me how much down pressure was on each axle and I had to calculate in my head what that pressure was equal to in weight carried.
You have to know exactly how much weight each axle is carrying when you cross the scales. There are very strict rules that apply to axle loadings in Michigan. Used to run in your state as well. I could run in Indiana on certain routes with heavy haul permits at the same weight as I was tagged for in Michigan. Used to go to Indiana Harbor and Gary and pick up master coils and haul them back to North Toledo and Detroit. Usually a couple 40's but sometimes 5 20's. Loaded out of Butler, Indiana at SDI a lot too, as well as our plant which sits right next to SDI. One of the guys I hunt with is the current plant manager there.
Takes big power under the hood too. No weenie motors allowed. We always ran big Cats with 13 or 18 speed Roadrangers. Takes some serious horsepower and toque to get 160 thousand plus rolling and a lot of braking power to stop it too. Most of the Cats were turned up to the maximum allowable factory power and some were cranked past that, way past that actually.
Really dicey times are during periods of wet weather and snow-icy roads. Had many times of sweaty hands on the steering wheel knowing what was behind me. Nice thing about them is, with all the axles down, loaded they tended to go straight no matter how slippery the road was.
Retirement is nice but I do miss it sometimes.
Hope that explains how they work.