Tandem Dumptruck vs Tri or Quad Axle

[thirdcoaster]

I was talking to a contractor friend today about the guy bringing fill sand to my jobsite. The trucks coming to my site are 10-12 yd tandem dumps. My friend is from another part of the country, and he is used to seeing dumptrucks with lift axles. I'm in South Texas, and tandems seem to be the norm here. Me no habla espanol, so asking the drivers anything is like talking to.....oh, nevermind.

How much load capacity do lift axles add to a tandem dump? How much tare weight does a lift axle add? Would it be cost-effective to run fewer trips with a larger, more expensive, quad axle truck versus more trips with a cheaper tandem?

I'm just curious if we're "behind the times" here.

[Red Bank]

I am suppose to haul 14 tons on my tandem, I usually haul 15 to 15 1/2 tons, if I added a lift axle I think I could haul 18 tons, so every 5th trip would be a freebie if I had a triaxle. I am not sure how much weight a lift axle would weigh, I am basing my numbers on what a friend of mine can do with his Mack triaxle. My truck is heavy, unloaded it weighs 23200 lbs according to the scales at the quarry. If triaxles and quads have not made it to south Texas, you could be the first kid on the block If I had a triaxle I could run my truck more than I do. For asphalt around here you have to at least have a triaxle, quad would be better.

[Willis Bushogin]

I am suppose to haul 14 tons on my tandem, I usually haul 15 to 15 1/2 tons, if I added a lift axle I think I could haul 18 tons, so every 5th trip would be a freebie if I had a triaxle. I am not sure how much weight a lift axle would weigh, I am basing my numbers on what a friend of mine can do with his Mack triaxle. My truck is heavy, unloaded it weighs 23200 lbs according to the scales at the quarry. If triaxles and quads have not made it to south Texas, you could be the first kid on the block If I had a triaxle I could run my truck more than I do. For asphalt around here you have to at least have a triaxle, quad would be better.

Good reply Red Bank, I dont own a tandem anymore, just because of this (of course I am thinking about buying a tandem, for those hard to get to places. I have 3 quads now and working them on a state highway job. The job should last about 13 months, what a life saver. One of my trucks was a Triaxle and it had room for another drop axle and I installed one and made it a quad ($5 more per hr) of course on this job, all they use is quads.
We are hauling dirt and rock on this job, but the other job we were on was asphalt hauling and we got paid by the tonnage, so if you couldnt haul the tonnage, you didnt make much money
In my area, tandems $50hr, Triaxle $58, Quad $65
Tandem 15-16 tons
Triaxle 18-19 tons
quads 22-24 tons
These trucks are light weight trucks and can gross more tonnage, but we have to watch out for the bridge law, for axle weighs

[Komatsu 150]

It also depends on state regs. In Illinois an extra axle gains so little we never see them on a dump. Only ready mix trucks have an extra axle and that's way back from the tandems. To gain wheelbase is the only way to make use of the extra axle. Well once in a while a truck from Wisconsin gets lost and we'll see a tri or quad.

[bigbob]

In NH you can certify a tandum to 65K, tri axle to 73K. My tandum will haul 20 tons legally at 65K.

[busdrivernine]

I was talking to a contractor friend today about the guy bringing fill sand to my jobsite. The trucks coming to my site are 10-12 yd tandem dumps. My friend is from another part of the country, and he is used to seeing dumptrucks with lift axles. I'm in South Texas, and tandems seem to be the norm here. Me no habla espanol, so asking the drivers anything is like talking to.....oh, nevermind.

How much load capacity do lift axles add to a tandem dump? How much tare weight does a lift axle add? Would it be cost-effective to run fewer trips with a larger, more expensive, quad axle truck versus more trips with a cheaper tandem?

I'm just curious if we're "behind the times" here.

Yes and no on behind times what TX does is they love the inner bridge weight formula and that screws you on the legal weight best thing to do is get about a 230 in WB truck put a 15 ft dump body on it . And then pay the state of Tx for a OVERWEIGHT OVER AXLE PERMIT. it will allow you 5% over the 34,000lbs on a tandem which is about 37500 then what ever the frt steering tires are rated for. I run 16ply so I can legal about 14320on steering axle so I can actualy scale 51820 total weight . With the tri axle you will lose the distance between the center of the steer axle and the center of the first axle. thus cutting the legal weight due to the inner brige formula TX is different for sure only one that I know will pull you on the portable scales and record your axle weights then pull you off and grab the tape measure to see what the inner bridge will allow you to haul . I call it GREED ! By the way the over gross, over axle permit for 20 counties cost me $531.00 plus posting a $10,000 bond .

[nedly05]

We would be better off with a tri-axle probably, but we could never fit it in half of the spots that the tandem zips into. I am legal for 18 ton, so I usually try to have on 17.5. My permit certifies my truck for 64,000, which gives me 20T but it puts me over on my rear axles, so really I am only legal for about 59,000. When I scale out at the quarry, as long as the weight readout on the scales reads less than 60,000 I am comfortable.

[Kgmz]

They "inner bridge rule" cannot be used with a steer axle and the second axle, it can only be used with the second axle and back. This is stated in the federal regulations, and all states are required to abide by the fedral regulations. With the only exception of states that are grandfathered if they had laws where they allowed more weight before the federal bridge law was enacted. Also stated in federal regulations, and Texas is one of the many states that is not grandfathered.

I looked at the Texas regulations and they have the same bridge law as we have in the NW, with one exception. They do not allow more than 80,000 lbs period except with special permit, no matter how many axles. Must be why you guys do not have dump trucks with pup trailers like we have.

And for a single truck the rules are the same as ours, so lift axles would be benificial.

Example my 2006 Kenworth T800:
Has a total wheelbase of a little over 20 feet and a 20,000 lbs front axle with 425 tires. This truck came from Colorado where lift axles are not normally used and for good reason. They allow 20,000 lbs on a single axle as long as the tires are also rated for that, same as bridge law. And for a tandem they allow 36,000 lbs on the interstate, and 40,000 lbs non-interstate roads, bridge law only allows 34,000.

In the NW with only a tandem I could only have a gross weight of 51,000 lbs at my wheelbase. With one lift axle that goes up to 55,500, and with 2 lift axles as long as the inner bridge is more than 11'6" you can carry 60,500.

I went with 2 Watson Chalin super light weight lift axles, 8,000 lbs capacity each. Here is why.

With one standard lift axle I would have added anywhere from 1,300 to 1,500 lbs of weight depending on the axle. So figure 1,500 lbs, I would have only gained 3,000 lbs of extra carrying capacity. With the 2 light weight axles, I added just under 1,800 lbs for both axles and gained 7,700 lbs of extra capacity. And then I could pull a lighter 3 axle pup trailer instead of a 4 axle pup trailer that I would have to pull if I only had one lift axle on the truck. Here we are allowed the max weight of 105,500 for a 8 axle combo as long as the total wheelbase is more than 69 feet. Also another reason for only 8,000 capacity lift axles, is they really only need to carry 5,000 lbs each.

In Washington we don't need a special permit for these weights, but need a continuous "Extended weight permit" in Oregon, and a excess weight permit in Idaho.

Links to bridge law

Texas
http://www.dot.state.tx.us/business/...ble_weight.htm

Washington
http://www.wsdot.wa.gov/NR/rdonlyres...gal_Weight.pdf

Oregon
http://www.odot.state.or.us/forms/motcarr/od/8111.pdf

Idaho
http://itd.idaho.gov/dmv/poe/bridgecj.htm


Most dump trucks and pups in the NW are 8 axle combos at 105,500 lbs with either 5 axle trucks with 3 axle pups or 4 axle trucks with 4 axle pups. There are some older 7 axle combos at 101,500 or 102,500 with 4 axle trucks and 3 axle pups. And 3 axle trucks (steer and tandem) with 2 axle pups are relics from the past, usually only used by a small contractor that doesn't need to haul much and is not going to hire the truck out.


I just wish there were the same rules for trucks in all states. Like in California my truck is not really legal and I can not use the lift axles.

[Orchard Ex]

I just wish there were the same rules for trucks in all states. Like in California my truck is not really legal and I can not use the lift axles.

Be careful what you wish for. The most restrictive regs are more likely to be adopted, then your truck will be unpractical at home too.

[JDOFMEMI]

I have seen a lot of dumps in CA now using lift axles, but I have no idea what weight they are running. I know you still can't go over 80K, but on a straight truck, I think they loosened up the rules some, based only on me seeing what they call here "super 10's" which is really a tandem with a lift axle.

[Bob Horrell]

In California, vehicle code 35551a. (bridge law chart) shows what weight is allowed for different number of axles and length of vehicle (distance between front and rear axle - wheel base).
My wheelbase is 20 feet 7 inches so I am allowed to use 21 feet. A three axle vehicle is limited to 51,500lbs provided the front end is good for 17,500lbs or more. The max for rear tandems is 34,000. A four axle is good for 56,000lbs. A five axle would still be 56,000lbs. So the way it is set up in California, you get a benefit for the 4th axle, but anything beyond that adds nothing.
In my case, since I have a 12,000lb front end and would be limited to 46,000lbs, the fourth axle gives me 10,000lbs more capacity. At 55,000lbs or more, you have to pay the federal fuel tax and fill out the appropriate IRS forms etc. My truck is registered at 54,999lbs which keeps me just below this requirement and only restricts me by one half ton.
When looking for my truck, I kept the above info in mind and looked for a truck that would give me the best bang for my buck. I wanted a heavy frame, and not a double frame for the weight savings - the fourth axle spreads the weight out over the frame making a double frame unnessary for the weight I can haul. My empty weight is 23,000lbs, therefor my max load is 16 tons.
I have a friend who has a 4 axle dump truck that is 3 feet longer than mine. He is allowed 58,000lbs gross. His truck has a double frame and heavier box than mine (he has 17 foot box - mine is 15 foot) and his empty weight is 26,000lbs. He also carries 16 ton load, but he pays federal fuel tax etc.
The bottom line is that you really need to research the laws that apply in your state so you can get/set up a truck that maximizes your potential profits from it.

[Kgmz]

Didn't know that about California, that you could use a lift axle on a straight truck. The only California dump trucks I have seen have been at the auctions, and they were usually transfers. Why do they not allow over 80,000 on a dump and pup combo?

For the others that don't know here are some pics of transfer setups, the first is a California transfer limited to 80,000 lbs, the second is a NW transfers setup for 105,500 lbs, the third is a California transfer, the forth is a NW transfer.

The last pic is the new standard for new dump trucks and pups around here, the 5 axle truck and 3 axle pup. And for the reasons I mentioned before with using a lighter 3 axle pup. Also that last pic of the NW transfer is also the new standard with the 5 axle truck and 3 axle trailer.

[tootalltimmy]

How do you turn a truck with 5 axles?
We see trucks and trailers in B.C. that have drop axles but they are not allowed to use them here. They can drop them once they cross the border into Washington.

[spitzair]

Holy smokes that all sounds complicated! Like Timmy says we're not allowed to use drop axles here, somebody once explained to me that the DOT thinks you can cheat at the scales with them somehow... If I remember right they allow you 17,500KG on a set of Tandems... On the front axle of the truck I drove I was allowed 8100KG for a gross weight of Truck and pup of 43100KG, or 95000Lbs. A lot of guys run tri-drives here and also tridem pups, some even quad wagons, not sure what they're allowed to haul but quite a bit from what I understand... It's been a while though so these numbers could be way off by now... The reach on the pup in that last picture looks like you couldn't get it into half the places you could a pup from up here... I once had a lady driving up the curb to pass everybody try to squeeze in between my truck and trailer in Vancouver when the curb ran out, not sure how she figured that was a good idea... Luckily she figured it out in a hurry and didn't cause any damage...
On edit - here's a picture of the unit I used to drive...

[Kgmz]

So thats where all our old 3 axle trucks and 2 axle pups went to.

You can hardly give away a 2 axle pup around here, and if they sell its usually for about $2,500 or less.

If you look at the reach on that pup in the last pic, look at that air can in the middle. These have a extendable reach, so all we have to do is release it and then slide it back in.


Tootaltimmy,
Its not bad driving these, those lift axles do turn. And once you are onsite and off the road you lift them, and have to lift them to back up. If they are down when you are backing, they will try and turn sideways and drag on you.