Triple or double axle dump trailer

[H-Ranch]

I have a 20' dump trailer with 4' sides and 96" width. Unless my math is wrong that can carry about 24 cords of fire wood.

If you stacked wood level with the sides you would have 5 cords. Depending on species call it 5000 lb per cord and you're already over what pickup trucks are rated at with a conventional trailer. 24 cords would be 120,000 lb.

 

[Jhenderson]

Your reasoning is as bad as your math.
As discussed before, 10 K axles are available in single wheel configuration. 10K brakes are larger than 7 K and provide More braking power, 3 - 7K axles are no cheaper than 2-10K , and no oil bath cap ever “ Fell off” . They get knocked off by careless drivers. If they fell off every class 8 truck on the road would be sitting when the front hubs self destructed.

 

[softdown]

If you stacked wood level with the sides you would have 5 cords. Depending on species call it 5000 lb per cord and you're already over what pickup trucks are rated at with a conventional trailer. 24 cords would be 120,000

OK - I was told a cord was 3' x 3' x 3 - roughly a pick up short bed load. It is 8' x 4' x 4'. More than twice what a long bed can comfortably carry - with 18" sides.
In the Colorado mountains we deal with aspen and pine. The dry weight changes significantly in this arid air.

 

[pdqdl]

3x3x3 is a cubic yard, the usual measure for dirt and gravel. A cubic yard of topsoil is generally a bit less than 3k lbs. Gravel, sand, & concrete are somewhere close to 3k per cubic yard, depending very much on the source of the material. Some concrete comes in at more than 2 tons/cubic yard.

These are important considerations if you are toting these materials rather than firewood.

 

[softdown]

A cubic yard of cement mix, in the yellow bags, weighs about 3500 pounds as memory serves.

 

[pdqdl]

I think you are probably about right on that.

I buy concrete blocks that have 24 cu ft. in them. The guys at the plant that makes them say that they can weigh up to 4k, depending upon the nature of the mix. I think most of the blocks come in at 3k. Some concrete is heavier than other batches, but I'm not sure how.

 

[softdown]

Stronger concrete contains larger media. Small rocks instead of gravel. I would guess the ultimate weight is determined by the media composition. But a variance from 3K to 4K sounds high.

 

[pdqdl]

That was always my thought too. I always thought how much and what type of cement and how much water was always a factor, too.

 

[rarefish383]

Some good trailers have been named. Take a look at Pequea trailers. I started with a single, 6'X8' dump. I had friends that got Brimar and EZdumpers. Both were rust buckets in 5-6 years. I sold mine for almost what I paid for it 15 years later. Absolutely zero rust through. Bought a duel 6'X10' and it's just as tough. I know you are looking for a bigger trailer, I'd just recommend taking a look at Pequea's line up.

 

[les-or-more]

Your reasoning is as bad as your math.
As discussed before, 10 K axles are available in single wheel configuration. 10K brakes are larger than 7 K and provide More braking power, 3 - 7K axles are no cheaper than 2-10K , and no oil bath cap ever “ Fell off” . They get knocked off by careless drivers. If they fell off every class 8 truck on the road would be sitting when the front hubs self destructed.

Yes 10k axles are available on singles.
Yes their brakes are bigger.
Yes the single tires are more expensive than duals.
7K axles are a quite a bit cheaper, the tires are cheaper, the axle kits are spread out more on triaxles allowing for a lighter frame, a lighter frame allows for more payload out of the same GVW. That is the goal, payload, people focus way too much on having heavy frames, instead of a balance between frame size, design and axle configuration.

 

[Jhenderson]

No, 2single tires for a 10K axle aren’t more expensive than 4 for duals. The frame and 3 axles on a top of the line 21,000lb trailer isn’t appreciably lighter than the frame and 2, 10K axles . While 3, 7K axles are cheaper up front, the maintenance on 3 lighter duty axles will far outweigh the extra cost of a quality 10K setup over the life of the trailer. You can pay now, or pay later. Been there, done that, multiple times.

 

[CaseyForrest]

As an owner of a dual axle Diamond C Gooseneck with an engineered frame, I can attest to the quality of the trailer over PJ, Sure Trac, Load Trail et al. Is it a worth a $10,000 premium over a triple axle Sure trac?? Only you can decide that.

You wont be giving up any maneuverability, you're just spreading the load out over 3 axles instead of 2. The trailer will pivot on the center axle and the front and rear axle will scrub, so you're not REALLY creating more tire wear, other than it will be more pronounced on the triple axle over the double axle. Id think its a wash, but I have never owned a triple axle. I would personally still be inclined towards 2 axles instead of 3.

Diamond C customer support seems to be top notch as well. When I got my trailer home and went to grease the equalizer pins on the suspension, one of them wouldn't take grease. They sent me 2 new ones immediately.

I would also recommend the Shocker... once you dial in the air pressure for given loads, it pulls so much smoother.

 

[les-or-more]

As an owner of a dual axle Diamond C Gooseneck with an engineered frame, I can attest to the quality of the trailer over PJ, Sure Trac, Load Trail et al. Is it a worth a $10,000 premium over a triple axle Sure trac?? Only you can decide that.

You wont be giving up any maneuverability, you're just spreading the load out over 3 axles instead of 2. The trailer will pivot on the center axle and the front and rear axle will scrub, so you're not REALLY creating more tire wear, other than it will be more pronounced on the triple axle over the double axle. Id think its a wash, but I have never owned a triple axle. I would personally still be inclined towards 2 axles instead of 3.

Diamond C customer support seems to be top notch as well. When I got my trailer home and went to grease the equalizer pins on the suspension, one of them wouldn't take grease. They sent me 2 new ones immediately.

I would also recommend the Shocker... once you dial in the air pressure for given loads, it pulls so much smoother.

The tire wear is worse with 3 axles, but the tires are cheaper. A 10k axle the tire and wheel combo is going to be upwards of $500 a piece if they will each carry 5k. The triple only requires 16" E rated tires which are cheap over all. I built trailers for a couple of years, we shipped several hundred a year. I am certain the cost to build a tri axle is quite a bit less than a tandem.
I built my trailer in 2000 it is 24 feet long and routinely carries equipment that weighs it GVW, so overloaded. It only has an 8 inch channel frame, rust will put it out of service from road salt. I spent a crap load when I built it buying epoxy paint and primer. It desperately needs to be sandblasted and repainted but has held up exceptionally well under our winter road conditions. I built it with tie downs and front and rear ramps to haul snowmobiles as well.

 

[Jhenderson]

Fayette trailers ( where I do business) has a 235/75/17.5 Provider on a steel wheel for $375. These are the same tires I’ve gotten 11 years and over 100,000 miles on. They’re rated at 6000lbs and are regroovable. A singe 16 inch on a dual rim is $275. I don’t see the savings.

 

[les-or-more]

Fayette trailers ( where I do business) has a 235/75/17.5 Provider on a steel wheel for $375. These are the same tires I’ve gotten 11 years and over 100,000 miles on. They’re rated at 6000lbs and are regroovable. A singe 16 inch on a dual rim is $275. I don’t see the savings.

375 X4 =1500
411X3 =1233
https://www.ebay.com/itm/10k-Tandem...303931768305?var=&vxp=mtr&hash=item8c6bf237ac$5800
https://www.ebay.com/itm/7k-Triple-...294081076533?var=&vxp=mtr&hash=item8a03b06d8a
$3740

$2000 difference in price from same place for the two kits. Then you deduct the lighter frame, steel costs could easily be another grand off the total cost.
Then look at the extra carrying capacity of the tri-axle because the axles will carry another thousand and the trailer is lighter so will carry more yet.

 

[Jhenderson]

Axle kits? I didn’t realize the OP was building, I thought he was buying. The specs on the 10K kit make your point on tires. The ones provided won’t cover the axle wt. What else in those kits is sub par?
I don’t understand your reference to 411 x 3 vs 375 x 4.
You originally were talking tire and wheel cost. How many times are you going to replace cheap tires in 100,000 miles? Particularly in tri axle applications. Decent tire/ wheel combos over 3500lbs are about $250 each. Decent , not the best. Cheap isn’t always the least expensive. A light frame? Add in the 3rd axle , springs, hangers, etc. If I’m looking to dump a lot of wt, or pull my trailer in and out of rough landings on construction sites , I prefer plenty of frame. Compare the frames on a a 10 wheeler to a single axle dump truck.
You’re also overlooking the additional wt and cost of a heavy hoist you need to dump that extra wt you can carry. That’s built into a quality trailers price tag.
I guess it comes down to $$$ vs quality/ cost of ownership per mile. We’ve become a penny wise , pound foolish society. 30 years of pulling dump trailers with pickups has given me an education. Maintenance can eat your profit margins quickly .

 

[les-or-more]

You originally were talking tire and wheel cost. How many times are you going to replace cheap tires in 100,000 miles? Especially in triple axle trailers. Cheap isn’t always the least expensive. A light frame? Add in the 3rd axle , springs, hangers, etc. If I’m looking to dump a lot of wt, I prefer plenty of frame. You’re also overlooking the additional wt and cost of a heavy hoist that comes in the sticker of that higher quality trailer I referred to. Axle kits? I didn’t know the OP was building his own trailer.

I have been responding to your assertions.

3 - 7K axles are no cheaper than 2-10K ,

The tires are cheaper the axles are cheaper the hanger kits are cheaper and by a significant amount. Who is building the trailer is irrelevant, it is cheaper to build a tri axle 10 ton trailer than a tandem axle trailer. I have done my best to give you an apples to apples comparison, my own personal preference is for a tandem axle configuration, that however doesn't negate the facts. A trailer with 3 7k axles can legally carry more weight.
Most trailers around here are in the scrapyard because of corrosion not for being broken. We could argue for eternity over every little detail. I have attempted to point out that like many things this is subjective, what you consider to be high quality may not be to someone else. Trailers are built to haul payload, the lighter the trailer the more payload you can carry. We all know the lighter the frame the shorter the lifespan, the key is finding the balance we find acceptable.

 

[Jhenderson]

While I disagree on some points you make I understand what you’ve said.
Please tell me what you meant by 411x3 vs 375 x4 ?
6 Tires and wheels that carry 3500 lbs cost the same as 4 17.5 tires that carry 6000 lbs. and you’ll change the 6 more often.
I don’t deny the axles are cheaper.
I’d like to see tare wt’s on both considering the extra axles and a bigger hoist to dump all that extra wt. That’s assuming the manufacturer doesn’t upgrade the frame size to accommodate the increased gross.
It’s all irrelevant considering the OP is long gone from this discussion.

 

[les-or-more]

I understand what you’ve said. Please tell me what you meant by 411x3 vs 375 x4 ?

$411 is the current price for a pair of 16" tires and wheels times three for a tri-axle equals $1233.
$375 per tire and wheel times 4 equals $1500.

I guess it comes down to $$$ vs quality/ cost of ownership per mile. We’ve become a penny wise , pound foolish society. 30 years of pulling dump trailers with pickups has given me an education. Maintenance can eat your profit margins quickly .

Where is the balance point? I agree with you.
Here is another angle in August of 2020, I put new backing plates, bearings, drums, tires and wheels on my trailer. I got called away before the shoes were adjusted. A buddy called me the next day in a bind needed to move his skid steer. I told him to go ahead but be careful the brakes were not adjusted. He set the gain to max forgot to set it back, one brake was close to proper adjustment the other three were not. When he brought the trailer back the one that was close had flat spotted the tire to the belts in several places, an expensive lesson. A ruined tire in under 25 miles, and no he is not an idiot, it was a perfect storm of stupidity though that could have happened to a really expensive tire. The worn out tires I took off were goodyears that cost me $80 or $90 more per tire than the new ones. I was reluctant to put the cheap tires on but it was all I could get at the time with the covid nonsense.

 

[Jhenderson]

Where are you buying 3500 lb tire and wheel combos for that $? As for your buddy? Education is expensive. I’ve got my Doctorate. Good talking with you.