More environmental bs. Axle load limits too low: Volvo boss calls for electric truck task force Heavy Vehicle Industry Australia (HVIA) chief executive Todd Hacking said current truck axle load limits are too low for electric vehicles. bigrigs.com.au So along with closing baseload power plants and paying for a part time generation capacity we'll have to pay for fixing roads that these trucks will stuff.
Just add more axles! We can all run electric super dumps at 80k gross with 15 tons of material on . . .
I see no mention of specific axle limits. What are they, and are they different all over the country?
What about the bridges?
Axle weights are standard across the country, very basically 6 ton on the steer, 9 ton on every dual tyred axle. Other things come into play like super singles and spaced axles etc.
80,000 lbs GVW-12 on the steer, 34 on the drive group, 34 on the trailer group. How much are they planning for extending the weight? I just went to Seattle this week, I-90 is in need of major repair. Re-bar can be seen where large patches of road surface eroded, and that came from truck traffic.
I don't know what they're asking for yet. The discussions are just starting with the Heavy Vehicle Regulator. The other unknown is whether the extra axle weight limits will be for battery powered trucks only or all trucks. I think it'll be ETs only because politics will be involved.
What most people don't realize is that the impact to the roadway isn't linear with increasing weight, it is exponential. Cars are basically irrelevant for loading concerns.
Natural Gas Vehicle (NGV) and Plug-In Electric Vehicle (PEV) Weight Exemption NGVs and PEVs may exceed the federal maximum gross vehicle weight limit for comparable conventional fuel vehicles by up to 2,000 pounds (lbs.). The NGV or PEV must not exceed a maximum gross vehicle weight of 82,000 lbs. (Reference Public Law 116-6 and 23 U.S. Code 127(s)) This is the U. S. They already are allowed a extra 2,000 to cover battery and/ or extra tank weight for natural gas. I'm sure the idea is to level the playing field, but in my mind if the field is level, it wouldn't tilt one way.
If they need the legal weight limits increased in order to have a practical product then the product isn't very practical and needs additional development. No special regs or exemptions.
Remember, the government will tell you what's bad, and what's good, no matter what is actually true.
In this state the total GVW has risen many times starting years ago from when freeways were first built in the 60's & 70's. GVW was back then 66,000 moved to 68,000 then 72,000 finally stopping at 80,000 for 5 axle. Then with extended weight permit 88,000 for 6 axle, then 101,000 for 7 axle then 105,500 for eight axle {drop} then the drop axle wasn't required some years later and returned to 7 axle. The road beds did fairly well up to a point but as the amount of container truck traffic increased the freeways took a beating. I don't believe the extended weight is all to blame rather the constant high amount.
Thank you. Those are metric tons right? 13,200 steer and 39,600 on a tandem group. That is plenty IMO. The roads take a pounding at that weight. My friend E. K. Dorwin complained bitterly when they allowed the super singles, and he was right. They beat a different groove in the road compared to duals. In the summer they are like a truck full of pizza cutters on the hot pavement.
My friend goes up I-5 once a midday week usually Tuesday from exit49 to 88 and his wife counts trucks going south. Usually around 300, last week over 500. So that's a lot of truck traffic in 45 minutes. Bad Bob
They actually increased the steer limits to 6500kg-14330lb back a couple years ago. Apparently to allow for the extra weight of the emissions equipment on the engine. The roads are all falling apart over here now, let alone giving them more of a belting by putting more weight on them.
Yeah that's some really stupid thinking. We'll just change some paperwork and viola. That Volvo guy needs to flip his script and make his trucks fit the roads that are there!
That is a fine example of the corporate way. SK, next time you drive over Snoqualmie take a look at the surface of the lanes along the lake to Cabin Creek it's only 6 years old roughly, can already feel it in the steering. How many million to complete that? Problem is there are thousands of trucks running LTL. Which adds to the problem of too many tires on the road, too much fuel burned, too many tires and too much wear and tear on the highway.
It's not the Volvo guy. The government/activists/whoever says; You can't build diesel trucks anymore. So he goes and builds an electric one. The buyers all say; We won't buy that, we can't haul anything with it. Now Mr Volvo goes back to the government/activists/whoever and says; A truck that meets all your rules is useless and nobody will buy it, you are going to have to figure out which rules matter. Now which rules do you suppose are the ones that will be kept? The ones that the government/activists/whoever they are are all lit up about at the moment. No worries about the roads anyway, we will just print off a whole big pile of mow y and rebuild them all so we can run the semis at 110k and save the air. Or whatever it is that we are saving.
Just how many ton's does this battery add? Obviously the Volvo guy didn't check what he was up against before he built it.
I didn't know that Pony, I've been out of the game a little while.
I only became aware of it when I bought the new truck Tones so I don't think it was really advertised. I can only speak for my little area, but in my opinion one of the major dramas we have had with our roads has been the exceptional rain we've had over the last 3 years. I don't think the roads were built to handle it because we get much more drought than flood. It's getting off topic, but I also think we as a country, with our large distances and small population will face unique challenges that the rest of the world won't with vehicle electrification. I don't think any geographically large country (or maybe any country period) is going to find it easy, I just think we are really going to struggle.
I wonder what they are going to do when crude oil production is cost prohibited and they won't have any more asphalt to fix roads anymore.
Mate, there are places here now where some dirt roads are better than the bitumen roads.
More State of Washington: There have been several traffic engineers recently explaining that when you go over 80,000 you see the freeway road deflection not able to return to it's original state of "rest." I 90 at least up to about MP 12, (Overlake) is a substantial subgrade of between 4' and 10' of specified pit run gravel topped by 12" of crush (again specified) 18" of asphalt and another 18" of concrete. If that will not hold up to over 80,000 pounds then weights need to be reduced. As the engineers describe the issue, a surface need to "return to a state of rest" before it is deflected again. If it does not return to it's state of rest, it will break up. At that elevation, frost and such do not play a normal role in damage. Weight is the only determining factor. A side note, Kummer bridge over the Green River has been sinking over the years. With a recent inspection, it has been found to be sinking quicker than expected. We can anticipate a new bridge "soon." The bridge was designed in the 1930s with what was thought to be appropriate foresight. Nobody imagined hundreds of gravel trucks at 105,500 every day pounding over that bridge.
That area from the east channel bridge I-90 to Issaquah is where you see the most damage, patches of road surface with rebar showing. Between the stretch container chassis and the amount of dump truck traffic {I counted 17 dumps in just that area on my way east} that section will be in a constant state of repair. Good addition to the thread Jumbo, thanks for the info.
Friend notice that you could be coming up on a tridem trailer( when they first arrived in BC) about 10 miles back by the pavement depression. ( Hwy 1 and Hwy 97. all asphalt). Cam
What I don't understand is the ground pressure is the same loaded, unloaded, or overloaded so why is deflection different.
Road building back in the day required compaction tests using a Beckerman Beam and a dial indicator. For you younger blokes it was a beam placed between the dual wheels of a loaded truck at one end and the dial indicator at the other. The idea was the truck slowly moved away and the deflection was measured on the indicator. The required measurement was written in the job specs. Anything less was good so I don't get what todays engineers are saying. Roads fail for the bottom up not from the top down, heck even the Romans understood this.
^^^This. Poor sub base = poor surface. And of course standing water is your enemy as well.
I'll try to explain it as it was explained to me. Whenever a weight passes over a surface there is deflection to a degree. Pick a number, say it deflects one thousand of an inch under 80,000. When over 80,000 passes over, it deflects 2 thousand of an inch. In each axle deflection, with less than 80,000 the surface can come back to the "rest" position or, original position. When a deflection is two thousands the surface can only return before the next axle 1 thousand leaving another 1 thousand still deflected. That remaining one thousands is what starts to break up. I just did a pretty crummy explanation, If you have a bit of imagination, you can understand what I was trying to explain.
You definitely need a good base, no amount of pavement can make up for it. The town I used to work in had multiple superloads pass through daily. I remember when they put up overpasses to help with traffic and they were tearing out the unneeded left turn lanes the asphalt was at least 2 foot thick and the road surface had 2" ruts from the traffic.
I think the point here is axle weights, and how that figures into the equation. Probably why the interstate system only allows 42k on a 8' tridem, but 43.5k on a 10' spread tridem. Or, you can put 20k per axle on a 10' spread tandem. The comment "over 80k" is misleading, you need to look at axle weights as part of the equation as well. I believe the hangup with these discussions is, right now, the percentage that overweight trucks are overweight is acceptable tolerances for the DOT at 80k gross. You start allowing 90k or 100k mainstream, that percentage is going to be considerably higher, and so will the damage to the roads. Same reason it was such a struggle to go up from 73,280 (or whatever exactly it was) back in the day.
Yeah I still don't get it as the pressure pushing down is still the same, I could see on a bridge and the whole structure has to take the weight.
I can only speak for my area but I've noticed the legal weight per axle drops as you add more axles to the group. Typically 9,100 kg on a single, non-steer axle, 17,000 kg on tandem and 21-23,000 kg on tridems. Axle spacing, super singles vs duals and road bans also cause some varience to those numbers.
?
The pressure pushing down is the same regardless of load, footprint does change but not pressure.
You need to explain your logic. For instance, if I have 28" pads on a D6, and a D8 sitting next to it also has 28" pads, if the undercarriage were the same length, the ground pressure would be considerably lower on the D6.
I think I see what you're saying, correct me if I'm wrong. The pressure remains the same because the footprint (more wheels on the ground) has increased to match the increased load?
Typical OTR heavy transport 75' long bumper to bumper with drop axle and 60" spread three axle trailer with 24" pin setting can carry 58,000 net frozen. 98,000 GVW. Depending on how equipped. Typical OTR transport 70' long bumper to bumper and 52" spread two axle trailer with 36" pin setting depending on how equipped can carry 44,000 net frozen. 80,000 GVW. Both using 53' trailers.
You guys are still debating legal loads, following DOT guidelines. Increasing payload by adding axles and reducing axle weights in groups larger than 2. The problem at hand is increasing axle weights beyond what is allowed currently. That is what's going to cause damage. Even if they only allow electric trucks to exceed the limits, those trucks are technically going to be overweight for what the road was designed for.
I don't follow this ground pressure logic. I don't know what the contact area is for an 18 wheeler, but let me just guess so we have a number; 8x8 contact patch per tire: 64 sq in. Multiply that by 18: 1152 sq in. So we have an empty rig that weighs 35,000lb, that is about 30lb per sq in. Load this truck to 80,000lb, now we are at 69lbs per sq in. I suppose the contact patch may increase some when you load the tires, but it isn't going to increase by 60%. When the dump truck sinks into the mud, you dump the load and drive out. The ruts going out are way shallower than the ones going in.
When the highways were built those were designed with lighter trucks at that time. This state like many others kept increasing GVW's by adding extra axles-The problem is the higher concentrated weight in roughly same length. In this state when GVW increased the wear and tear climbed right with it---quoting a retired wa st dot road forman of 35 years. But since then the total of truck traffic has more than tripled in some areas. You can discuss all the psi on deflection, fact is it's more legalized weight in roughly the same area, just more tires beating the hell out of it X amount more truck traffic than it was designed for at that time. For every action there is a direct and opposite reaction. As far as the E Truck---need to figure out a lighter battery system. Rebuilding a highway grid to accommodate a E Truck is nut's.
Economic stupidity over a environmental falsely, kinda like flattening a 1000 acres of trees to build a solar farm.
Entire idea of Interstate system was built around the basics of the WWII Era Autobahn, HOWEVER, the need to STRETCH the Concrete and expenses instead of a FULL 12" equivalent of Concrete with Two layers of reinforcing RODS, the option of 9 to 10" on one layer rerod or Screen Mesh and connector bars at expansion joints was consider More COST Effective. Then Asphaltic Concrete used as a Top Layer as the original Concrete eroded or cracked. Concrete was ALSO re-enganeared, where a CLAY additive for Plasticity and adhesive value was used instead of Lime, that is in essence adding DIRT which if watch a hand mixed concrete by a old fella, he will pitch a fit if ANY dirt gets in the Concrete. Batch plant operators take Sample of Stone and Sand to MAKE CERTAIN No dirt is shipped in. Back in the Day as TS Noted, started out 66,000 bumped to 70,000, Can still remember myself, 73,280 and eventually the 80,000 lb loads today, on roads INTENTIONALLY Designed for 60,000.
A tri-axle dump can legally gross 85K (don't remember exact legal gross) and change here in AL on state, county and other secondary roads. We regularly get 25 ton loads of stone delivered.
Your math is way off, if the tire pressure is 100 psi, then regardless of weight of the truck it stays at 100 psi, even if your just rolling a mounted tire on the ground or the truck is loaded to 200k, it's still 100 psi. A truck with tires at 100 psi that weighs 35k will have a contact patch of 350 sq inches, a truck of 80k will be 800 sq inches. More tires on the ground means each tire will be touching the ground less. The ground pressure stays the same with different loads, but the ground contact changes. I don't have a full understanding.
Stop complaining about the **** roads. You voted for her and we have to pay for the olympics somehow. LOL
No I bloody didn't
I wonder if we talk about Australian politics, they'll hear about it all the over in the US?
This still isn't making sense, but maybe it is just above my pay grade . . . Static pressure inside the tires doesn't change, I follow that. This idea of the contact patch doubling with a load not so much, but I guess I have never read any science on it or actually gotten out with a ruler to measure stuff. I do know as a matter of lot of seat o' the pants science that a loaded truck sinks a lot deeper than an empty one on a muddy job . . .
Tire pressure may stay the same, but the Psi put on the ground increases with weight. The air in the tires is not helium and holding the truck up. Imagine instead of tires, that the whole truck was supported on 4x4 square tubing. As you add weight , that tubing is pushing harder and harder on the ground. tires are no different than if it was a steel tube. The air in the tire just makes it a "semi rigid" square tube. The 100 psi in the tire is just whats required to hold it in its "square" form, not what its putting for pressure on the ground.
The tire squats as you load it more increasing it's footprint, and I can prove it to you. Take a couple pieces of poster board and slide then under the tire to measure the contact patch, find the square in of the contact patch, then check your tire pressure as it will be the same. Let half the air out and do it again. You can also do this to see how much weight is on a tire without a scale.
It sinks more because of soft ground, in hard ground the tire squats more. Also if you look at slightly sunk ruts from unloaded then drive back loaded the ruts are wider when you sink more.
The average Semi on 18 tires per square inch of tread surface in contact, presents less psi that a common loaded one ton truck on 6 tires, HOWEVER, that 80,000 lbs of continuous weight as opposed to a truck weighing 18-20,000 lbs has significant pressure loading across a larger surface area and creates a pressure wave within that pavement. Where takes at minimum 4 of those one tons to make a equivalent pressure wave they cannot be as compact an area while driving normally at speed yet they imprint heavier footprint in application of PSI. Change that to autos with ever smaller footprint to distributed PSI. The major issue of all the PSI per machine is how much weight these present to a defect area of pavement, a depression, a soft spot, a frost or expansion heave, all have effects. One of those defects hit by 9 tires each carrying 12k payload will self destruct faster than a three tires load at 3k each. Change that up by advancing Max GVW and number of tires, weight per tire does not change but impacts duration and repeated presentation do. Same difference beating a pavement with a 20# hammer, or coming in with a pavement breaker on a mini ex, both can accomplish same thing, just one is faster.
Ground pressure and tire air pressure are two different things. And I'm quite aware that a tire spreads a little with weight. The idea that there is only 100 psi of pressure on the ground regardless of weight is the preposterous idea here,
Especially when Air Pressure is NOT weight, but distinguished as a Pressure applied to the containing vessel per square inch. Woman Plant Helper at the Nuke REFUSED to move O2 and Acetylene Cylinders as had 2000lbs inside them, "Needed special Lifting equipment for the weight of 2000lbs" equates to the above statement. And YES she was an idiot, and YES she kept her job as well got promoted.
A tank with psi and a tire with psi are not even apples to oranges. With a tank you are measuring the force expanding outward on the tank so it does not blowout, with a tire you are measuring your ground pressure and also pressure to keep the tire integrity intact I took this today as a rough practical demonstration after unloading. This truck doubles in weight when loaded, 30k to 60k. Look at the tread blocks moving inwards and the 1x2 was at my finger loaded and it's moved 1" inward unloaded. If you don't believe me, do it yourself. Check the psi, load the truck, check the psi. Use card to figure up the ground contact area and load the truck and remeasure. No matter of fancy words changes this and if you are not considering the fact that ground pressure doesn't change when the subject is weight tearing up roads I doubt you will ever grasp the answers. Psi stand for pounds per a square inch by the way, care to explain how the ground contact patch goes up with the psi staying the same?
I didn't think the pressure inside the tire has much to do with this conversation. I thought we were talking about the pressure the truck exerts downward on the road, not the pressure the compressed air inside the tire exerts in all directions within the tire. Unless you are driving a military or sport vehicle tire pressure doesn't change. Unless you drive over the corner of a portable chain link fence. Then the pressure inside the tire can change rapidly. Fact.
A Tire is nothing more than a donut shaped tank. Think on that. BTW, next set of portables get to cross, explain that to the DOT Man.
Someone with the time and a loaded truck with a drop axle could settle this ground pressure argument. Park it on a concrete surface, put some black paint on the tire, put some paper on the floor and drop the axle. Back the pressure off a bunch and repeat the process. I could do it but I don't want to have to explain to everyone that wanders by the shop what the heck I'm doing and why I've got a loaded lowboy blocking everything to do a science experiment. And I don't care quite enough to bother.
Are only proving a flat tire face to road takes more area.
As a tire is pressed to a surface, the rest of that Elastic Material is able to expand, 100psi under compression on one point will expand the circumference not in contact.
And the 100# in the tire does not carry weight, the tire does. The only thing the air does is keep the tire mostly round.
My 2 cents worth in this debate. Compare a road with a runway. Road are constructed to carry a curtain weight per wheel as are runways. Yet an aircraft weighing several 100 tons may only have 10 to 16 wheels. Do runways break up as fast as roads? No they don't yet the tons per hour travelling along them may in fact be very similar. So what's the difference? The difference is in the constitution. Cost is also a factor and building roads for a 10 year life span or less when road 40-50 years ago were build for a 25 year life has become the norm. Now when it come time to fix roads, even though everyone has paid their road tax the grubermint says they can't afford it and have spent the dough on a MOD EDIT parade or some such thing. Most people are familiar with the road network in the Roman Empire and how great it was. Another fact in that deal is that while the elite were bathing in goats milk etc the roads went to **** and when the uprising happened it was the road conditions that slowed the Roman Legions so they couldn't quell it. Seems history is repeating itself again.
We are experimenting with electric asphalt mixes now. Instead of liquid asphalt, we use electrons to bond the material together. Sometimes static is a problem and the material sticks in the mixing box, but a few bounce sheets, and it comes right out. The bounce sheets also keep the truck boxes clean, so no more spraying with fuel... I mean the old soap
So the new pavers are going to have a couple wind turbines mounted to the top . . .
Not exactly. Most pavers while muscular from shoveling hot mix, are grossly overweight from beer and chicken. The plan is peddle powered spreader. They tried hamster power for the roller, but they didn't like the vibration, so back to the drawing board.
solar panels in the stripes, come on man!
That's why the wind turbines. Those beer powered peddlers are being found to fart under load too much, which is damaging the ozone layer and causing the global temperature to skyrocket. The wind turbines will fix everything.
Here, a 6 axle truck and trailer, is legal for 110,000lbs. Roads are terrible. Spring weight restrictions are on, and most secondary roads are 80%. I have been hauling gravel to a job site this week. Our plant is on an 80% road, as is the job site, but I have a magical piece of paper in the truck that allows me to haul a full unrestricted load, because it is a government job. If I go over the 110,000 gross, the fine goes back to the 80% restriction. Again, roads are terrible.
The P word people rant and roar about climate, and oil, and clean air, but they really don't care, they just want more money. Do I want clean air, and good health, sure, but the fact is that oil, and oil products are part of our lives for the near future. Maybe in a hundred years or so, but not today.
What is the material?
A tank with flexible walls. I don't go to scales and laws often have little to do with what's actually correct, just what tax they can get out of you. Guess nobody is going to measure their footprint of their truck and compare it to their tire pressure, well it is Sunday after all.
it's imaginary like all these electric vehicles the hippies say are going to revolutionize our world.
It's about ground pressure. If a 120 pound woman walks across a cushion floor in slippers, she won't make a mark. All her weight is spread out over the size of her slippers. If the same woman wears high heels, her heels will leave a mark. When she puts the weight to her heel, more pressure to a point. A truck with 2 axles puts more pressure on just 6 tires. The more axles, the more the weight is shared between the axles. The more wheels, the closer it gets to the slipper because even though it is the same weight, the weight is spread out on a lot of points, and it won't mark the road. One Amish man can't lift a house, but if a hundred others join him, and help cary the weight https://www.google.com/search?q=ami...#fpstate=ive&vld=cid:60913f9c,vid:hl5bqHQ4YrY
Foot print varies CF as weight is Applied, makes NO difference how much air is in that tire. Take your pickup for a drive after check air pressures cold, what are they hot? Air(N and O2 with a few odd others) expands and contracts as heat applied or allowed to cool. a 20,000lb KW as Mine(Scaled) with a 9000lb trailer will have rough same foot print as bobtail, add a 41,000 load and foot print expands sure, HOWEVER is due to Weight on the Axles. go from 9 on steer to 12,000 drives to right at 34 and trailer axles to right at 34, where Empty the Tractor drives at 13, trailer axles at around 7. Footprint changes Some, Weight increases for load applied, Air could give a Shiny Dime as to concern of added weight, will not add more than a few pounds PSI per each tire. Point as above, when a Large weight is spread across a larger area, it also produces a Pressure wave as it travels a path, watch a LGP Crawler tracking along in dirt, there is a defined compression and release as it moves, that very function happens even minutely on paved roads. As to Bitumin or Asphalt, at the early stage of Petroleum refining, it was a Waste Product, some was used as Fuel (Bunker) thinking was like a gooey coal, the rest discarded as was so much of it. Remains Gooey with heat, Terrible on roads in summer heat as traffic is as much a roller as is the drums that finished that surface. Cold it Shrinks, cracks form, water and in many places salts contaminate the layers, further weakening the Oil Based Mix. Is a Short Term Booger Patch no matter what the Enganears state.
I highly suggest you measure the foot print and compare it to your tire pressure.
There is a reason DOT requires wider tires on steer axles as weight increases.
Just Why? For What Purpose or Reasoning? Makes no difference as weight per square inch on the face of tire increases with machine weight increases. Just more less than sense thinking.
Are you afraid of learning something new?
Not New, and Not Learning.
Well anyway, how 'bout them Green Bay Packers . . . ?
Sorry I'm not much for sportsball
More watching XFL as wife is now, St Louis Battlehawks
I'm pulling a two axle belly dump today and was looking at the trailer tires while loading myself and realized some quick unscientific tape measure work would be possible. I'm hauling off highway so no scales other than under my fifth wheel so I have a pretty good idea of my weights. Empty, there's about 10k on the trailer axles and I estimate about 36k loaded. Tire tread is about 8.5" wide. Sitting on hard packed rock that's not perfectly flat but pretty close. Lots of variables but I think good enough for these purposes. Measuring the 4 outside duals empty, the contact patch is 5-6" long, loaded 10-11". My math tells me empty, there's about 27 psi on the ground. Loaded, about 50. So when the weight almost quadrupled, the contact area only doubled.
You have to use poster board or sheets of metal to slide under the tires to measure correctly
This is getting complicated ...
It's not, I'll try to find some time this week and show ya.
The idea that the PSI in ground pressure of an empty truck's wheels and a fully loaded one is the same is simply asinine. Final answer. If that were the case, there would be no need for weight limits except driving across a bridge. Wait, what??? That's not where you are going to go with this, is it??
Time to identify road solutions for 21st century trucks Australia’s heavy road freight transport industry will not be able to contribute to the necessary reductions in greenhouse gas emissions under the current axle load limits framework. Worse still, it is on a path to becoming the highest emitting industry in Australia if nothing is done. So what... bigrigs.com.au Hope this will work, first time I've tried to post a link.
Been using Chip and Seal in the US since the 19teens. My own Great Grandfather owned Havelka Road Oil Co. He then Gifted that to his oldest daughter and her husband that had the name changed to the Strobeck Road Oil Co. Soft, degrades rapidly, only good for secondary Low Traffic roadways and alleys here.
Chip seal, we got that on our road about 12 yrs ago. Saved money that year, patch and repair ever since and will need to be removed and redone soon. Only 19 houses on our road but every one except 2 have a suite or extra dwelling on the property (or 2). 5 cars per Property on average…….
I have one of those ifta stickers If,ta dot don't see it were good!