Big Rig turning radius - RV-Dreams Community Forum

Lucky Mike · RV-Dreams Family Member

Big Rig turning radius

cejones4210 · RV-Dreams Family Member

So we have another question. Next spring we hope to start building a house in the country, close to our children. Presently we have a 25' Airstream, but are hoping to purchase a 38' fifth wheel next year. Hubby will be acting as General contractor and is working with a builder on the plans. One question he needs your input is how big of a turning radius will he need when he puts in a circular drive? We plan to put in a RV pad next to the house with full hook-ups to park it or friends to use if they stop in. His question is how big should the inner diameter be to turn around?

Alie and Jims Carrilite · RV-Dreams Family Member

A 5th wheel will turn inside of the Airstream. How much room I have no idea..

Terry and Jo · RV-Dreams Family Member

Unfortunately, I'm not sure we can give you a definite number because a lot depends on the equipment and driver. For instance, on the equipment, a Ford F450 has a much tighter turning radius than even a Ford F350. If you are considering a circular drive for folks to use prior to backing into a spot, the width of the drive will also be something to consider. That is due to the fact that the trailer wheels won't track exactly on the same path as the truck.

Terry

Bill and Linda · RV-Dreams Family Member

cejones4210 wrote:
One question he needs your input is how big of a turning radius will he need when he puts in a circular drive? We plan to put in a RV pad next to the house with full hook-ups to park it or friends to use if they stop in. His question is how big should the inner diameter be to turn around?

Cathy and David:

As Mike said from a difference perspective, there is no way to know this for sure without the specific trailer and truck length in question. It will depend on the length of the truck (not necessarily the turning radius of the truck although that is a contributing factor) and most importantly the distance from the king pin to the center of the axles on the trailer. Actual trailer overall length has no impact on turning radius assuming the rear end of the trailer doesn’t touch anything, like a bush or building, in the “swing.”

The king pin to axle length determines how far “inside” the turn of the truck the trailer wheels will come. The smaller the distance king pin to trailer axle center the less the trailer will go “inside” the turn. Totally different than a tag trailer who’s wheels will “tend” to better follow the track of the rear wheels of the truck and not come as far inside the turn.

If it were me, I’d try to get a rig that’s “close” and just go measure it as Mike indicated.

BTW, don’t forget – unlike the Airstream - you can “square jack” a 5er. That is turn the truck at 90 degrees to the trailer and make turns not possible with an Airstream (which I have.) Don’t know if this would help in the “turn around” department if I correctly interpreted that question. but i wanted to comment as a thought for consideration. But, as Mike said, that depends on the skill of the driver and the understanding of the technique used.

Bill

TXRVr · RV-Dreams Family Member

I live in the country with a circle drive that is 80 feet in diameter with 18 ft width. Wished I had made it 100, but it's enough to maneuver my 38' MH that doesn't bend in the middle like a 5W.

cejones4210 · RV-Dreams Family Member

As always, appreciate the answers/recommendations. A ways to go before we really worry about the actual driveway, but Dave likes to plan REALLLY far ahead and have all the nitty gritty details worked out. It's the "engineer" in him, but obviously Not mechanical or civil engineering. :)

Got to get this house sold and get on the road for the winter. Hope we won't be here through February! Will have been listed with realtor for a month this Thursday. Well, if it doesn't sell until Feb or Mar, we will go to the Airstream on our lot instead of someway warm. :(

kb0zke · RV-Dreams Family Member

I tried going on the websites of several larger MH manufacturers, hoping that one of them would give a turning radius, but none did. TXRVr at least gave you some numbers to work with. Perhaps some others would share their numbers with you, too.

Terry and Jo · RV-Dreams Family Member

I will now add to the confusion, especially considering TXRVr's comment. Perhaps he can chime back in with regards to what I will say. When considering his dimensions, keep in mind that some motorhomes have an extremely good capability with regards to turning radius. I've seen some that literally makes it seem like the front end is swinging sideways. Now, that said, a truck and fifth wheel may have a similar turning capability because they do "bend in the middle."

Terry

TXRVr · RV-Dreams Family Member

A bit more info. My previous MH was a 40 ft Alfa with a turning radius of 53 degrees which is higher than most. I do not know what my current 38 ft Newmar is, but I also assume not as much. Being that it's two feet shorter, I figure they are comparable in turning radius. I operate in forward and reverse to maneuver the rig onto my pad. It is the 90 degree "handle" to the circle. A fellow RVer has maneuvered his 32 ft TT and F250 in the space, but wasn't as easy as my MH because you take the truck mirrors out of play when you back up in a circle. My circle also has trees and landscaping in the middle. You can't cut the corner, so to speak. It was a fairly easy DIY project in that I used a small dozer and put down 5/7 stone.

Again, there are some woulda-shoulda issues. If I had been smart enough to "test drive" the circle in my MH I would have known to make the driving surface a bit wider. Which, actually increases diameter and comfort level. I put in full hook ups before I dozed the pad. A do over would have been to make the pad at a 45 degree angle instead of 90 and then put in the utilities. It was a fairly easy DIY project in that I used a small dozer and put down 5/7 stone.

I had a chuckle at the engineer in him comment. I have that gene. Which is why it took 8 months to finish the house. Fortunately, we lived in the RV on the pad and walked to work only a few feet away. blankstare Good Luck.

-- Edited by TXRVr on Saturday 30th of November 2013 07:25:54 AM

cejones4210 · RV-Dreams Family Member

TXRVr, great additional information. Dave is finding your input very helpful. His approximate measurements are 88 feet in diameter with the drive itself being 18 feet with the turns being about 32 feet. It actually looks like an egg shaped circle in the middle of a "Y" with the "arms being wider. He has a drawing so if I can get a copy I will try to post it here later.

cejones4210 · RV-Dreams Family Member

Ok, Dave made a revision the turns are 24 feet not 32 feet. Still attempting to add a picture.