Unihome Construction vs Conventional chassis

Topic: Unihome Construction vs Conventional chassis (Read 3449 times) previous topic - next topic

Unihome Construction vs Conventional chassis

July 28, 2015, 10:06:19 pm

I was discussing this topic with some coworkers and wanted to know if the "unibody" construction was any safer than the conventional box and chassis type motorhome when involved in an accident? I have heard the stories about the foretravel being uprighted and driven to the shop. Really? Common sense would dictate they are stronger than a aluminum covered wood frame on a chassis but in a roll over ...... would it really matter? Anyone witness a Fortravel in a serious accident? What was the outcome?
Just thinking.........................

Re: Unihome Construction vs Conventional chassis

Reply #1 – July 28, 2015, 10:18:15 pm

Foretravel Bridge crush ?

Re: Unihome Construction vs Conventional chassis

Reply #2 – July 29, 2015, 09:52:05 am

Foretravel Rolled?

Re: Unihome Construction vs Conventional chassis

Reply #3 – July 29, 2015, 10:25:33 am

The pictures of the Grand Villa that are on that thread don't look like a Unihome to me, but I suppose the coach may be a U225 or U240? Given the small size of the images, it is hard to tell. But for sure, not a U280 or U300 judging by the compartment doors.
Don

Quote from: Michelle – July 29, 2015, 09:52:05 am

Foretravel Rolled?

Re: Unihome Construction vs Conventional chassis

Reply #4 – July 29, 2015, 10:31:05 am

Every rollover is different depending on the speed, distance, what it hits, etc. While our coaches are well built, they don't have the strength of a commercial bus or BlueBird/Wanderlodge but don't pay the big weight penalty the Birds do. On the other hand, a lot of SOBs would be in pieces in the same rollover as the linked photos show. FTs are excellent compromises between the lightweight junk traveling down our roads and the tank like construction the commercial coaches use.

Pierce

Re: Unihome Construction vs Conventional chassis

Reply #5 – July 29, 2015, 10:57:45 am

Don,

IIRC that was an O22C (Oshkosh) chassis. This was a step before the Unihome.

Pamela & Mike

Re: Unihome Construction vs Conventional chassis

Reply #6 – July 29, 2015, 11:49:02 am

Do motor homes actually "roll over"? Most of them are tip-over, it seems to me. But I am not altogether secure in this belief. But if our rigs merely tip over and slide on their sides I suspect that the Unihome construction model would be more likely to hold together than the wood-frame-on-a-chassis model.

I know that our 22-year-old Unihome makes almost no sounds (creaking and groaning and squeaking) going down the road and a glass of water left next to the bathroom sink (oops) is still in place at the end of a 400-odd mile trip. The DW's parents, with a plethora of motor homes over a 40-year (plus) span, had RVs that made a fair bit of noise traveling down the road. But my hearing was better back then, too.

I'm sure that someone has done some research on this but it depends on who funded it as to whether or not the results of the research ever got published.

Craig

Re: Unihome Construction vs Conventional chassis

Reply #7 – July 29, 2015, 01:09:09 pm

I cringe whenever I see or read about an RV labeled Ultralight. I imagine it wouldn't take much to destroy it. My preference is something with protection built in. The penalty we pay for a heavier, stronger built more durable vehicle will and has proved to be well worth the sacrifice (if any) in miles per gallon.

Re: Unihome Construction vs Conventional chassis

Reply #8 – July 29, 2015, 01:19:24 pm

I see... then actually, the condition of that particular roll over doesn't really relate to the monocoque versus conventional framed coach chassis, though it does obviously relate to overall build quality of a Foretravel, whatever the platform. It would certainly be interesting to see pictures of a rolled Unihome or Unicoach, but we won't be volunteering ours as a demonstration unit!

Don

Quote from: Pamela & Mike – July 29, 2015, 10:57:45 am

Don,
IIRC that was an O22C (Oshkosh) chassis. This was a step before the Unihome.
Pamela & Mike

Re: Unihome Construction vs Conventional chassis

Reply #9 – July 29, 2015, 01:20:24 pm

Quote from: nitehawk – July 29, 2015, 01:09:09 pm

I cringe whenever I see or read about an RV labeled Ultralight. I imagine it wouldn't take much to destroy it.

I was all in favor of "ultralight" until I entered a few RVs that were supposed to be ultra light. Ultra flimsy was my impression. Our 1970 Streamlight 21' travel trailer (my fly fishing/kayaking/mountain biking partner) is only 3500 pounds so it would be classed as "ultralight" now but is far more sturdy than anything equivalent in the RV shows.

But heavier doesn't always equal stronger, either.

Craig

Re: Unihome Construction vs Conventional chassis

Reply #10 – July 29, 2015, 02:41:35 pm

I have seen a number of rolled foretravels. They fair well but usually are to totaled. One rolled over on the Alaska motorcade last year in fact. They do not break apart like the raised rail chassis coaches do.

Re: Unihome Construction vs Conventional chassis

Reply #11 – July 29, 2015, 02:52:25 pm

As contrasted by the Tiffin back east recently that just went on its side, and that just... came apart.

Re: Unihome Construction vs Conventional chassis

Reply #12 – July 29, 2015, 08:20:58 pm

Quote from: twobus – July 29, 2015, 02:52:25 pm

As contrasted by the Tiffin back east recently that just went on its side, and that just... came apart.

Almost exploded apart. Just awesome!

Craig

Re: Unihome Construction vs Conventional chassis

Reply #13 – July 31, 2015, 09:02:46 pm

Does anyone have photos of a Unihome under construction? I would like to see the framework of one before the sides and top fiberglass was applied. How are the front and rear axle frames attached?

Re: Unihome Construction vs Conventional chassis

Reply #14 – July 31, 2015, 09:47:06 pm

Quote from: FourTravelers – July 31, 2015, 09:02:46 pm

Does anyone have photos of a Unihome under construction? I would like to see the framework of one before the sides and top fiberglass was applied. How are the front and rear axle frames attached?

The basic construction is totally different than what you are asking to see.

Each side and roof and floor and compartment divider and bottom floor was vacuum bonded as an seperate assembly then they were bolted together.

In cool and humid weather you can see the steel framing outlined on the sides.

Slide outs changed the elegant engineering that the unihome originally had. No frame rails.

The body shell was the frame like an airplane. Slanted steel in the side walls on your coach is visible

Adding multiple slide outs required a set of main rails as holes in the walls lost that strength area and required a more conventional frame below the floor. Heavier by far.

Although the unihome and unicoach both had a bigger than the nominal 1 1/2 steel tubing where the track way is below the floor for the hose and wiring runs.

As slides were added I assume those steel pieces were enlarged considerably

I used to have photos of a naked unihome coach. Foretravel made it up for the buddy rally in 1988 if memory serves me. Steel only.

Wonder if grimes has a photo somewhere as I remember him and McGrath taking photos?

Unless Foretravel asked for no photos? They might have...

Re: Unihome Construction vs Conventional chassis

Reply #15 – July 31, 2015, 11:14:27 pm

I'm really surprised, considering the thousand's of FOT factory tours that have been given, that (apparently) NO ONE has ever taken and posted some photos. I have searched the Forum and the Web, and come up empty-handed. Hard to believe in this day and age, that there aren't at least half a dozen factory tour videos posted on YouTube... What is the story?

Of course, I must share the blame... I went on the Tour at the last Ladies Driving School, and didn't even think to take my camera.

Re: Unihome Construction vs Conventional chassis

Reply #16 – August 01, 2015, 01:09:06 am

Right! We went on the tour some twenty years ago and I gawked without a camera. The time period was just about when our coach was in production in 1994. Star stuck--in love. Note to self: Take Pictures.

Re: Unihome Construction vs Conventional chassis

Reply #17 – August 01, 2015, 05:53:11 am

Quote from: Chuck & Jeannie – July 31, 2015, 11:14:27 pm

I'm really surprised, considering the thousand's of FOT factory tours that have been given, that (apparently) NO ONE has ever taken and posted some photos. I have searched the Forum and the Web, and come up empty-handed. Hard to believe in this day and age, that there aren't at least half a dozen factory tour videos posted on YouTube... What is the story?

Someone has

Foretravel Factory Tour 2005

Re: Unihome Construction vs Conventional chassis

Reply #18 – August 01, 2015, 07:54:33 am

Thanks, Barry. When I was doing my search I saw that link on your "Foretravel Help Links" page, but I swear when I looked at it, it was "black", like a dead link.

I still think it would be nice (and profitable) if Foretravel would produce a professional Factory Tour video, and post it on YouTube. Some of the other coach manufactures have done this, and they get a lot of hits. It's (almost) free publicity - what's not to like? Or are they afraid that their old-fashioned, built-by-hand assembly line will not compare well to more "modern" operations?

Re: Unihome Construction vs Conventional chassis

Reply #19 – August 01, 2015, 08:10:01 am

Thanks Barry..... I should have known that you would have some of these type photos!

I,m just surprised to see that there are no through rails that connect the front and rear "trucks" ....for lack of a better description.

Re: Unihome Construction vs Conventional chassis

Reply #20 – August 01, 2015, 10:19:14 am

In the semi-monooque construction, particularly on the earlier no slide coaches, the welded steel side walls with all of the diagonals serve that function in a way. But really all of that super structure contributes to the rigidity and strength in effect creating a giant hollow box beam (two including the basement). It is all interdependent, stiffer, and and stronger than the raised rail chassis. Also, much more labor intensive to build! But it creates a coach lighter in weight for the size and carrying capacity, with a better power to weight ratio. I like it!

Don

Quote from: FourTravelers – August 01, 2015, 08:10:01 am

Thanks Barry..... I should have known that you would have some of these type photos!

I,m just surprised to see that there are no through rails that connect the front and rear "trucks" ....for lack of a better description.

Re: Unihome Construction vs Conventional chassis

Reply #21 – August 01, 2015, 10:35:17 am

"Through rails" would just duplicate what the semi-monocoque already does and add a lot unneeded weight. Full stressed skin monocoque would have been the best way to go but more expensive in a limited production motorhome like our Foretravels. General Motors was one of the pioneers in monocoque bus construction. The engine/transmission package just bolts to the "body" as well as all the front suspension. A combination of aluminum, steel along with a stressed skin make a super rigid and strong vehicle. See monocoque images at: gm monocoque bus construction image - Google Search

Bulkhead failures have absolutely nothing to do with the concept, only the way it was implemented.

Pierce

Re: Unihome Construction vs Conventional chassis

Reply #22 – August 01, 2015, 10:58:24 am

Quote from: John S – July 29, 2015, 02:41:35 pm

I have seen a number of rolled foretravels. They fair well but usually are to totaled. One rolled over on the Alaska motorcade last year in fact. They do not break apart like the raised rail chassis coaches do.

I caught a glimpse of the FT that rolled during the Alaska Motorcade 2015 as it lay in the mountainside. We were on the Motorcade tour and passed the accident site shortly after the edge of the road gave way under the unfortunate coach. I also saw it at a salvage area after it was "recovered." The rollover was relatively gentle. The damage to that coach was done during the recovery, not during the accident. Recovery included pulling on the front axle hard enough to bend suspension components and destroy the entry area.

When I viewed the recovered Foretravel, the outside panes on two of the exterior double paned windows were broken. The passenger side windshield was missing because the driver had kicked it out in order the leave the coach. All other exterior glass was intact. All the cabinet door were closed, all lamps were in place, all mirrors and glass inside were in place. It appeared the the structure remained intact and the coach retained its proper shape.

Another similar "high end coach" suffered a similar fate and was parked next to the FT. Most of the cabinets were down and the interior was a mess. The structure appeared to be racked, but did not come apart.

I hope never to test my FT by crashing it. I do prefer to be in a coach that could be recovered by a wrecker rather than a dumpster.

Re: Unihome Construction vs Conventional chassis

Reply #23 – August 01, 2015, 05:43:51 pm

Quote from: Chuck & Jeannie – August 01, 2015, 07:54:33 am

Thanks, Barry. When I was doing my search I saw that link on your "Foretravel Help Links" page, but I swear when I looked at it, it was "black", like a dead link.

I have to fess up. I saw the link was dead also for some reason and activated it. I knew someday this topic would come up.

Re: Unihome Construction vs Conventional chassis

Reply #24 – August 03, 2015, 01:01:58 pm

I'm more curious/worried about front impacts on the unicoach flat front style. There is a front cap with very little structure between the driver and the road. Pushing on the windshields flexes the mount/fiberglass. The unihome slant nose style has more structure up front, but not like a car or truck.

Affiliate Notice