Pup trailers

[Skeans1]

Does the PUP trailer I posted have a converter dolly? It appears to be a permanent front axle. Probably has no bearing on the question, just thinking out loud

It has one, there’s a locking pin to center the dolly for backing up.

 

[3 Horse Ranch]

Does the PUP trailer I posted have a converter dolly? It appears to be a permanent front axle. Probably has no bearing on the question, just thinking out loud

I looked at the photos and didn't see any landing gear so I would assume that trailer has a turntable. It bears a resemblance to the transfer trailer chassis I mentioned above but without the tandem rear axles they have,

 

[3 Horse Ranch]

I cannot tell for sure but you may be right. The fifth wheel on some dollies sit real high and would be obvious. Others, the trailer rides more level.

None of ours had a lock for backing, and there wasn't a locking pin on the flatbed trailer I pulled years ago for a lumber yard.
The last dump pup trailer I pulled had a turntable lock. It was the only 4 axle pup I ever pulled that had a turntable. It could be backed unlocked, but it wasn't easy.

 

[Renze]

A wagon type trailer, with a roller slew bearing above the front axle, is the standard outfit for container transport in Europe as it is insensitive to incorrect weight distribution, and can be transferred without landing gear back and front.

Especially with a high center of gravity and little tongue weight of mid axle trailers, the back end of the truck is pushed around. You dont have that with a slew.

 

[Hay Dude]

So you straighten your truck/trailer, get out of the cab, walk back to the trailer and throw a lever to lock the front dolly for backing, correct?

 

[Hay Dude]

A wagon type trailer, with a roller slew bearing above the front axle, is the standard outfit for container transport in Europe as it is insensitive to incorrect weight distribution, and can be transferred without landing gear back and front.

Especially with a high center of gravity and little tongue weight of mid axle trailers, the back end of the truck is pushed around. You dont have that with a slew.

Hah, I thought the container would fall to the ground when he pulled away! Thats pretty sophisticated. Driver made it look easy.

 

[tree grower]

In the northeast pup trailers are most commonly used with log trucks, but they are not 'four-wheel' trailers. They are tandem axles with tongue weight on the truck.

 

[Renze]

So you straighten your truck/trailer, get out of the cab, walk back to the trailer and throw a lever to lock the front dolly for backing, correct?

Off course not, its a waste of tires, and the chassis needs to be a lot stronger to withstand the twisting.

With the trucms trailer coupler reasonably far behind the tandem turn center, the trailer reacts much more direct to steering movements so its easier to back up than with a farm tractor with the drawbar 2 feet behind the rear axle.

 

[ovrszd]

Off course not, its a waste of tires, and the chassis needs to be a lot stronger to withstand the twisting.

That's the intent. Lock the turntable for easy backing. Our military has many varieties of these and they work well.

 

[Hay Dude]

Off course not, its a waste of tires, and the chassis needs to be a lot stronger to withstand the twisting.

With the trucms trailer coupler reasonably far behind the tandem turn center, the trailer reacts much more direct to steering movements so its easier to back up than with a farm tractor with the drawbar 2 feet behind the rear axle.

Not sure we are talking about the same thing.
The dolly steers during normal driving, but require locking for reversing, right?

I didnt know if there was an air lock from cab, or a manual pin/lever set up.

 

[ovrszd]

Not a great picture but here's a HEMTT pulling a trailer. You aren't backing that trailer without a turntable lock. I've saw them used extensively. Lock assembly can be activated when in a turn. As the trailer straightens the lock engages. Same for releasing. Activate the release mechanism and when the tension is relieved it will unlock.

 

[Hay Dude]

It has one, there’s a locking pin to center the dolly for backing up.

Gotcha. Thats what I was figuring.

 

[Renze]

So you straighten your truck/trailer, get out of the cab, walk back to the trailer and throw a lever to lock the front dolly for backing, correct?

No, you just get real drivers behind the wheel. I have never seen a front dolly lock for backing up, though i understand the challenges backing that long HEMMT and that short trailer. Its a *****, but doable if you take your time.

Here you see a driver checking his own lights:

And here an everyday routine backing manoever:

We do have different drivers licenses for rigid trucks, truck with semitrailer and truck with pup trailers. When you get eastern bloc drivers you wonder what they have payd to get their license because they obviously didnt earn it with their driving skills

I do find it amusing that you guys are so cocksure that these trailers have turntable lock for backing...

 

[ovrszd]

No, you just get real drivers behind the wheel. I have never seen a front dolly lock for backing up, though i understand the challenges backing that long HEMMT and that short trailer. Its a *****, but doable if you take your time.

Here you see a driver checking his own lights:

And here an everyday routine backing manoever:

We do have different drivers licenses for rigid trucks, truck with semitrailer and truck with pup trailers. When you get eastern bloc drivers you wonder what they have payd to get their license because they obviously didnt earn it with their driving skills

I do find it amusing that you guys are so cocksure that these trailers have turntable lock for backing...

The trailers in your videos have no need for locking turntables. If you look closely, especially in the first video, the wheelbase of the tractor is similar or maybe slightly shorter than the distance from the tractor rear axle to the turntable. The longest distance is from the turntable axle to the rear axle of the rear trailer. A small amount of movement of the tractor front axle creates a large movement of the turntable. If that driver needs a lockable turntable he needs sent home.

 

[Skeans1]

No, you just get real drivers behind the wheel. I have never seen a front dolly lock for backing up, though i understand the challenges backing that long HEMMT and that short trailer. Its a *****, but doable if you take your time.

Here you see a driver checking his own lights:

And here an everyday routine backing manoever:

We do have different drivers licenses for rigid trucks, truck with semitrailer and truck with pup trailers. When you get eastern bloc drivers you wonder what they have payd to get their license because they obviously didnt earn it with their driving skills

I do find it amusing that you guys are so cocksure that these trailers have turntable lock for backing...

Try a mule train short logger trailer out in the wood a with a mile or two back in with the trailer down that’s why some of the dollies are lockable.

 

[oliver1555]

Here you see a driver checking his own lights:

Hmmm...
I never thought of doing it that way. I tend to just hop out with my flashlight and hammer and do a quick walk around, checking lights, tires, etc., when I am stopped. Maybe I'm making it too easy?

 

[Gee Ray]

Here you see a driver checking his own lights:

You could not afford to do that every day. Can you imagine how much rubber that leaves on the pavement?



My brother went to a warehouse in Philly that was underground. With all the columns in the way he watched a man back his pup trailer up to the dock to be unloaded. He did this and made it look super easy.

He then pulled up and dropped the pup so that he could unload the front trailer. He tried to back up the single for some 30 minutes before he could get back to the dock.

 

[ovrszd]

You could not afford to do that every day. Can you imagine how much rubber that leaves on the pavement?



My brother went to a warehouse in Philly that was underground. With all the columns in the way he watched a man back his pup trailer up to the dock to be unloaded. He did this and made it look super easy.

He then pulled up and dropped the pup so that he could unload the front trailer. He tried to back up the single for some 30 minutes before he could get back to the dock.

I once backed a 40' trailer into a jack knifed position loading dock around the corner of a building. I could not drive out because the trailer would short cut and hit the building. I tried for 30 minutes. Finally called the dispatcher and told him my situation. He said, not worries, we've had that problem there before, sit tight, I'll send a wrecker. I felt like such a failure, after feeling like such a stud because I had backed in there. Be careful what you wish for.

 

[4570Man]

You could not afford to do that every day. Can you imagine how much rubber that leaves on the pavement?



.

That was a single axel truck with a tag and a single axel trailer with a tag axel and the tag axels were off the ground so there was almost no scrubbing in that maneuver.

 

[groundcover]

Hay Dude what was your injury? Hope it wasn't too serious. Were you able to keep up your snow plow route or wasn't that needed ?