pivoting frames and mounting campers

biotect

Designer
Hi Moe, LukeH, ntsqd,

Thanks for the responses; very informative.


**********************************

1. Moe:


This is a design "thesis project" that I will be working on, in earnest next fall, i.e. beginning in September. I've been anticipating a bit, trying to determine the engineering constraints. Please see my first post on page 33 of this thread, for a more thorough explanation.

The basic issue is this: from a purely design point of view, expedition motorhomes seem awfully space-wasteful. In the lingo of the wider RV industry, they are “non-integrated” designs in which a body is simply placed on a truck, whose cab remains separate. So the seating gets duplicated. This contrasts markedly with the most advanced European designs, for instance, Hymer motorhomes. In almost all Hymer RVs, the driver’s seat and passenger seat swivel 180 degrees, and do “double-duty” as dinette seating. Again, please see my post on page 33 for pictures.

I still have to research the design-history of this innovation, but I suspect that it began with the VW Westfalia "camper van", back in the 1960’s -- see http://en.wikipedia.org/wiki/Volkswagen_Westfalia_Campers . Almost all van-sized motorhomes employ double-duty swivel seats to save space, including “Sportsmobile”, which also makes vans that specifically target the expedition market – see http://www.sportsmobile.com/4_4x4sports.html , http://www.sportsmobile.com/4_maxim07.html , http://www.sportsmobile.com/sections/4x4/maxim/maxim07_spread.jpg :


1.jpg


Now the interesting thing is that top-of-the-line Hymers are big. Maybe not as big as Class A American motorhomes, but certainly as large as the biggest expedition motorhomes. So if double-duty swivel seating seems worthwhile in a big Hymer, you’d think it would be worthwhile in a UniCat or ActionMobil, too?

As near as I can tell, the main thing that prevents this, is the need to fix cab and body separately, because the latter has to be mounted on a 3-point pivoting frame. Class A American motorhomes and Hymers can be fully integrated designs, it seems, because they don’t need 3-point pivoting frames. And they do not need 3-point pivoting frames, because “regular” RV’s typically do not experience the same stresses as expedition motorhomes.

However, I then came across the SX-45 brochure, and began wondering why this technology had not yet “migrated” over to UniCat or ActionMobil. As stated in the post just above, ActionMobil has already built at least one 8 x 8 expedition motorhome on a MAN KAT military chassis. So perhaps ActionMobil has good enough relations with MAN military, to be able to request a SX-45 chassis? Would it really cost that much more? The engineering has already been done, and perhaps all that MAN needs to do, is combine the SX-45 chassis with the same engine and drive train used by the 8 x 8 TGS – which, by the way, is the chassis used by Unicat in the large build referenced in the previous post; and so too, the chassis used by Armadillo in one of its large builds.

I will be booking appointments with various companies in Germany and Austria, including ActionMobil and UniCat, to do some more direct, “on the shop-floor” research in June. I have two passports, German and Canadian, and speak German reasonably well, so it should be interesting. At present, I am still trying to establish who I should contact at Rheinmettal MAN, the company that has taken over production of the SX-45.

In the meantime, I figured it would be good to post the MAN brochure on the Expedition Portal, and see what the forum’s response would be. Many thanks, Moe, for your enthusiastic reception!


**********************************

2. Ntsqd:


You mentioned that the system you described has been used by the American military “since at least WWII and possibly earlier”. I f you have any links to websites that detail visually what you described above, would you be willing to pass them along?


**********************************

All best wishes,



Biotect


PS – Again, the practical query: How might one upload photographs in such a way that potentially anyone could see them, and not just members who are logged-on? Some of the uploaded images in these threads have a kind of "privacy filter" that prevents outsiders seeing them, while others do not. Mine at present seem to be filtered, but I would like to take the filtering off.
 
Last edited:

biotect

Designer
Hi Moe,

Many thanks for the analysis, and I agree, it may be just a cost issue. But mine is not really a “research” project, in the sense of being just verbal analysis. Rather, it's a design project. I am currently attending design school, so my project will be a concept vehicle, complete with models and illustrations.

Sure, it will be the MFA-exercise of a student. But you might be surprised how much long-term effect some of these exercises can have…. Often transportation designers do their “best” work – in the sense of most innovative – when completing their MFA's. Because once we begin working in the industry, there’s a tendency for thinking to ossify. There is a big market for “independent industrial design studios”, for instance, because companies often find that their own in-house designers simply lack the breadth and distance necessary to create truly innovative products.


*****************************************

1. Studio Synn and Christopher C. Deam

For instance, when Knaus Tabbert decided to shake up the trailer industry a bit, and create a “conceptual” caravan-of-the-near-future – a “technology carrier” that would test innovative design, materials, and products in concert – it did not go in-house. Rather, for their “Caraviso” concept-trailer, Knaus Tabbert turned to the independent design-studio “Studio Syn” – see http://www.examiner.com/article/knaus-tabbert-caravisio-the-shape-of-caravans-to-come , http://www.studio-syn.de/en/studio/category/ueberblick , http://www.studio-syn.de/en/projects/category/alle_projekte , http://www.studio-syn.de/en/projects/article/caravisio1 , http://www.studio-syn.de/en/projects/article/caravisio , http://www.knaus.de/knaus/neuheiten-2014/caravisio-2014.html , http://www.knaus.de/en/knaus/novelties-2014/caravisio-2014.html , https://www.facebook.com/caravisio , and http://www.carscoops.com/2013/09/caravisio-caravan-will-cruise-you-into.html .

Likewise, when Airstream began realizing that it’s customer base was significantly aging, and that it had to update its interiors or die, it turned to Christopher C. Deam, an outside, independent designer – see http://www.nytimes.com/2012/02/23/g...s-airstreams-interior-up-to-date-qa.html?_r=0 , http://www.curbly.com/users/diy-maven/posts/1198-trailer-chic-the-vision-of-christopher-deam , http://www.cdeam.com/projects/discipline/airstream , http://www.cdeam.com/project/international , http://www.cdeam.com/project/international-signature-series, http://www.cdeam.com/project/sterling , http://www.designaddict.com/design_index/index.cfm/Christopher_C._Deam , http://www.airstream.com/travel-trailers/intl-sterling/ , etc.

Most American motorhome manufacturers, it seems, are forced to offer cabinetry that's best described as "colonial kitsch", with color choices ranging from plaid green to brown plaid, because that's what the American market seems to demand. Just contrast the interior of a typical American Winnebago, for instance, with the interior of a German Hymer. Even some of the Airstreams sold in the United States still offer colonial kitsch cabinetry – see http://www.airstream.com/travel-trailers/classic/photos-decor/ .

But this “market-led” mentality has limits, because often customers don’t know that they would love something different, until they actually see something different. Until Airstream hired Deam, its interiors were just like other RV’s. Deam describes the situation in a NY Times article:

"What I found was, you had this great streamlined aerodynamic modern exterior, and then you opened the door and it was like grandma’s kitchen. There was a disconnect between the exterior and the interior. You approached the trailer and there was the magic promise of the future, and you walk in and it was like a log cabin on wheels. What we decided was, we had to do some kind of archaeology, stripping it down and getting rid of all the gewgaws and clunky interior, and taking it back to something really essential. I simplified it and emphasized the horizontal lines and put in a lot of fluid, curved laminates." - http://www.nytimes.com/2012/02/23/g...s-airstreams-interior-up-to-date-qa.html?_r=0 .

Because of Deam, Airstream’s product line now feels more “European”, which Airstream signals by designating the trailers “International” in the American market – see for instance http://www.airstream.com/travel-trailers/intl-serenity/photos-decor/ , http://www.airstream.com/travel-trailers/intl-sterling/photos-decor/ , http://www.airstream.com/travel-trailers/land-yacht/photos-decor/ , and http://www.airstream.com/travel-trailers/land-yacht/photos-decor/ . Airstream trailers spec’d for the European market also seem to have been designed by Deam – see http://www.airstream-germany.com/index.html and http://www.airstream-germany.de/download/Airstream2013de.pdf . The irony here, of course, is that these trailers were in fact dreamt up by a superb American designer, and in that sense, there's nothing "international" about them at all!

As you might appreciate there’s also an economic payoff, because Airstream has now achieved even more “product differentiation” within the saturated American RV market. Airstreams were already a rather unique product because of their exteriors. Now (most of them) are also unique because of their interiors, too.


*****************************************

2. The 1990’s “haute-IKEA” aesthetic of German Expedition RV’s

The world of really big, off-road-capable RV’s is, for the most part, German – pace Earthroamer, GXV, Tiger, etc. As such, the interiors of UniCats and ActionMobils have not resembled grandma’s colonial-kitsch-kitchen for quite some time. But even still, in comparison to the wider German RV industry, UniCat and ActionMobil interiors do seem a bit behind the times.

The interiors of most UniCats and Actionmobils seem to amount to little more than “haute-IKEA” , in the sense that a rather boring, 90-degree, rectilinear, T-square aesthetic predominates, of the sort that characterized IKEA products back in the 1990’s and early 2000’s. Again, see http://www.actionmobil.com/en/4-axle/interior-design , http://www.actionmobil.com/en/3-axle/globecruiser , http://www.actionmobil.com/en/3-axle/atacama , http://www.unicat.net/en/info/MXXL24AH.php , http://www.unicat.net/pdf/UNICAT-MXXL24AH-MAN8x8-en-es.pdf , http://www.unicat.net/en/info/EX70HDQ-MANTGA6x6.php , http://www.unicat.net/en/pics/EX70HDQ-MANTGA6x6-2.php , http://www.unicat.net/en/info/EX70HDM-MBActros6x6.php , http://www.unicat.net/en/pics/EX70HDM-MBActros6x6-2.php , http://www.unicat.net/en/info/EX63HDSC-MANTGA6x6.php , http://www.unicat.net/en/pics/EX63HDSC-MANTGA6x6-2.php , http://www.unicat.net/en/info/EX70HD2M-MANTGA6x6.php , http://www.unicat.net/en/pics/EX70HD2M-MANTGA6x6-2.php , http://www.unicat.net/en/info/EX63HDM-MANTGA6x6.php , http://www.unicat.net/en/pics/EX63HDM-MANTGA6x6-2.php , http://www.unicat.net/en/info/EX63HD-MANM4x4CC.php , http://www.unicat.net/en/pics/EX63HD-MANM4x4CC-2.php , http://www.unicat.net/en/info/EX58HD-MANTGA4x4.php , http://www.unicat.net/en/info/EX58HD-MANTGA4x4.php , http://www.unicat.net/en/info/EX45HD-UnimogU5000.php , and http://www.unicat.net/en/pics/EX45HD-UnimogU5000-2.php .

Sure, I love the "New York loft" sense of space provided by the Unicat pop-ups, and this format has since been copied by other fabricators, for instance, the American operation GXV – see http://globalxvehicles.com , http://globalxvehicles.com/vehicles/ , http://globalxvehicles.com/global-expedition-vehicle-pangea-4x4-rv/ , http://globalxvehicles.com/gxv-pangea-gallery/ , and http://www.examiner.com/slideshow/gxv-launch-pangea-expedition-vehicle-with-vertical-slide#slide=1 . But if anything, the GXV “Pangea” interior is even more wretchedly utilitarian and lacking in design sense, than anything produced by UniCat.

The pity here is that the interiors of non-expedition, “regular” German mobile homes are usually very well-designed, and are certainly better than Winnebagos or Fleetwoods. The German designers who work for Ketterer, Hymer, Westfalia, EuraMobil, Knaus Tabbert, etc. all seem to handle curvilinear asymmetry with aplomb – see for instance http://www.ketterer-trucks.de/en/models/category/c/travel-motorhomes/model/continental-12000-2.html , http://www.hymer.com/en/ , http://www.hymer.com/en/models/integrated/hymer-starline/experience/ , http://www.hymer.com/assets/files/m...e/epaper-STARLine_englisch/epaper/ausgabe.pdf , http://www.westfalia-mobil.net/en/ , http://www.westfalia-mobil.net/en/modelle/amundsen/amundsen-allgemein.php , http://www.euramobil.de/integraline_ls_galerie.html?&L=1&L=1 , http://www.euramobil.de/integra_galerie.html?&L=1&L=1 , http://www.gizmag.com/caravisio-camper-concept/28978/ , http://www.gizmag.com/caravisio-camper-concept/28978/ , and http://www.knaus.de/en/knaus/novelties-2014/caravisio-2014.html . But none of this German curvilinear design expertise seems to spill over into expedition motorhomes, even though UniCat and ActionMobil are just down the road, and both are German-speaking companies.

For what it’s worth, high-end American luxury coach manufacturers like Newell, Liberty, Marathon, Featherlite, and Millenium also try to deliver a more contemporary, curvilinear product – see for instance http://www.newellcoach.com/the-coaches/photo-gallery/ and http://www.newellcoach.com/newell-coaches/coach-1508/ . But Newell seems to handle curvilinear asymmetry less successfully than Hymer or Euromobil, and it costs 4 or 5 times as much!

So cost is not the only constraint, it would seem. Either you have the designers and craftsmen who can pull off a Hymer interior, or you don’t. I suspect that ActionMobil and UniCat could have more interesting, up-to-date, curvilinear interiors, if customers began demanding as much. But until customers do, their interiors will continue to look like what they are, namely, interiors designed mostly by engineers.


*****************************************

3. Courageous Color, ARC, and Art Deco

My other quibble with the RV industry in general, is that it plays things rather “safe” when handling color. If one compares the interiors of all of the above brands – European and American, regular RV and expedition RV – to the new Airstream interiors, one huge, glaring difference becomes obvious: the color choices of most motorhome manufacturers tend to be muted, a restricted palette of whites, greys, browns, and blacks. Whereas Airstream, since it hired Christopher C. Deam, has developed the courage to handle strong, vibrant interior color, and a dramatic mixture of materials.

However, even the interiors of Airstream trailers will seem somewhat tame, when compared to the interiors created by the bespoke conversion specialist “American Retro Caravan” (or “ARC”) – see http://www.arcairstreams.co.uk , http://www.arcairstreams.co.uk/refits/retro , http://www.arcairstreams.co.uk/blog/category/retro-airstreams/ , http://www.arcairstreams.co.uk/blog/2013/02/the-airstream-safari-with-the-egg-shaped-hole/ , http://www.arcairstreams.co.uk/blog/2013/02/a-closer-look-at-that-luxury-padded-bedroom/ , http://www.arcairstreams.co.uk/refits/luxury , http://www.arcairstreams.co.uk/blog/category/luxury-airstreams/ , http://www.arcairstreams.co.uk/refits/corporate , http://www.arcairstreams.co.uk/blog/category/corporate-airstreams/ , http://www.arcairstreams.co.uk/refits/catering-and-bars , http://www.arcairstreams.co.uk/blog/category/catering-airstreams/ , and http://www.arcairstreams.co.uk/blog/category/cafe-airstream/ .

What really impresses me about ARC is their bold color choices (complementaries like green and red, yellow and purple); their mastery of curvilinear, aluminum-detailed cabinetry; the asymmetrical layouts; and the retro details throughout – port-hole windows, jet-engine spot-lamps, and circular-grilled air vents, for instance.

My strong design preference has always been for Art Deco and Streamline, although nowadays these tend to be rebranded as neo-Deco, diesel-punk, deco-punk, glam, retro, etc. I'm an avid follower of "Lord K's Garage" diesel-punk blog, for instance – see http://www.dieselpunks.org and http://www.dieselpunks.org/profiles/blog/list?user=0n7d9yl571cmt . I partly grew up in South Florida, and fell in love with South Beach "Tropical Deco" as a kid. Many of ARC’s more colorful trailers – the Apollo 70 in particular – have interiors that are best described as “Miami Deco” – see see http://www.amazon.com/Tropical-Deco-Architecture-Design-Miami/dp/0847803457 , http://www.pinterest.com/search/boards/?q=miami deco , http://www.pinterest.com/search/boards/?q=tropical deco , http://www.apollo70.co.uk , http://www.beautifullife.info/interior-design/apollo-70-airstream-bar/ , http://brosome.com/the-apollo-70-airstream-bar-is-the-perfect-place-to-have-a-drink/ and http://hiconsumption.com/2014/03/apollo-70-airstream-bar/ .

For me, Art Deco is the modernist design-aesthetic that should have dominated the 20th century. But for whatever reason, lots of people found the puritanical-minimalist, black-white-grey, Bauhaus rectilinearism of Mies-and-co ever so convincing, perhaps because it was so cheap on the details and colored paint? Remember, I am German, so perhaps I am “allowed” to take a swing at Mies and the Bauhaus…. The 1990’s/early 2000’s rectilinearism of IKEA is then the direct descendant of the Bauhaus aesthetic, as are the UniCat and ActionMobil interiors.

However things have changed dramatically in architecture and design since the late 1990’s, when “organic-tech” first became fashionable. And as already demonstrated above, German RV manufacturers like Wesfalia, Hymer, Euramobil, etc. have been offering more curvilinear interiors for quite a while. One could even say that an Art Deco/Streamline aesthetic never really disappeared, persisting in certain design niches, transportation design in particular. If only because rectilinear, squared-edged vehicles are not that functional, i.e they're not aerodynamic.

So let’s just say that, even though UniCat and ActionMobil are not building grandma’s colonial kitchen, they are now at least 2 decades behind the times, vis-à-vis wider design trends. Their engineering is no doubt top-notch, and Victorian quite rightly defended UniCat's engineering and careful craftsmanship in an earlier post. But just take a look at the links above, check out Wesfalia, Hymer, Euramobil, et al, and everything that I have written here will seem kind of obvious.


*****************************************

4. Back to Engineering

Now don’t worry, I realize that the bulk of this post was very off-topic, because this is an engineering thread about 3-point pivoting sub-frames. But just thought I should state all the above, so there’s no mystery as to where I am “coming from”. I am a designer, who wants to “prod” the expedition-RV industry a bit, with a concept vehicle that breaks a few unwritten rules.

For instance, my suspicion is that companies like ActionMobil and UniCat are still mounting camper bodies on 3-point pivoting sub-frames mainly due to inertia, and not cost. And they are still doing 1990’s-style “haute-IKEA”, because customers have not demanded more. It sort of takes an outsider like me to come along and say, “Hey, why couldn’t you do x, y, or z instead?”

By far the best way to do that, in the world of design, is by presenting alternative imagery.

I’ll keep you posted, but in another thread….

All best wishes,



Biotect
 

biotect

Designer
Hi Moe,

Many thanks for the analysis, and I agree, it may be just a cost issue. But mine is not really a research project, in the sense of being just verbal and quantitative analysis. Rather, it's a design project. I am currently attending design school, so my project will be a concept vehicle, complete with models and illustrations.

Sure, in the end it's just the MFA-exercise of a student. But you might be surprised how much long-term effect some of these design exercises can have…. Often transportation designers do their best work – in the sense of most innovative – when completing their MFA's. Because once we begin working in the industry, there’s a tendency for creativity to ossify. There is a big market for independent industrial design studios, for instance, because companies often find that their own in-house designers simply lack the breadth and distance necessary to create truly innovative products.


*****************************************


1. Studio Syn and Christopher C. Deam



For instance, when Knaus Tabbert decided to shake up the trailer industry a bit, and create a conceptual "caravan-of-the-near-future" – a technology carrier that would test innovative design, materials, and products in concert – Knaus Tabbert did not go in-house. Rather, for their “Caraviso” concept-trailer, Knaus Tabbert turned to an independent design-studio called “Studio Syn” – see http://www.examiner.com/article/knaus-tabbert-caravisio-the-shape-of-caravans-to-come , http://www.studio-syn.de/en/studio/category/ueberblick , http://www.studio-syn.de/en/projects/category/alle_projekte , ttp://www.studio-syn.de/en/projects/article/caravisio1 , http://www.studio-syn.de/en/projects/article/caravisio , http://www.knaus.de/knaus/neuheiten-2014/caravisio-2014.html , http://www.knaus.de/en/knaus/novelties-2014/caravisio-2014.html , https://www.facebook.com/caravisio, http://www.gizmag.com/caravisio-camper-concept/28978/ , and http://www.carscoops.com/2013/09/caravisio-caravan-will-cruise-you-into.html :

Caravisio_01.jpg

Caravisio_Fotos_Prototype (27).jpg

Likewise, when Airstream began realizing that it’s customer base was significantly aging, and that it had to update its interiors or die, it turned to Christopher C. Deam, a wonderfully creative, outside, independent designer – see http://www.nytimes.com/2012/02/23/g...s-airstreams-interior-up-to-date-qa.html?_r=0 , http://www.curbly.com/users/diy-maven/posts/1198-trailer-chic-the-vision-of-christopher-deam , http://www.cdeam.com/projects/discipline/airstream , http://www.cdeam.com/project/international , http://www.cdeam.com/project/international-signature-series, http://www.cdeam.com/project/sterling , http://www.designaddict.com/design_index/index.cfm/Christopher_C._Deam , and http://www.airstream.com/travel-trailers/intl-sterling/ :

Deam1.jpg

airstream.jpg

Now to be sure, most American motorhome manufacturers seem forced to offer interiors that are best described as "colonial kitsch", with color choices ranging from plaid green to brown plaid, because that's what the American market demands. Just contrast the interior of the typical mid-market American motorhome with the interior of a German Hymer. Even a few Airstreams sold in the United States still offer colonial kitsch cabinetry – see http://www.airstream.com/travel-trailers/classic/photos-decor/ :

8526f5187983e9f2f45b1404355f5326.jpg

But this market-led mentality has limits, because often customers do not even know that they might like something different, until they actually see something different. And until Airstream hired Christopher C. Deam, Airstream interiors were not that different. Deam describes the situation in a NY Times article:

"What I found was, you had this great streamlined aerodynamic modern exterior, and then you opened the door and it was like grandma’s kitchen. There was a disconnect between the exterior and the interior. You approached the trailer and there was the magic promise of the future, and you walk in and it was like a log cabin on wheels. What we decided was, we had to do some kind of archaeology, stripping it down and getting rid of all the gewgaws and clunky interior, and taking it back to something really essential. I simplified it and emphasized the horizontal lines and put in a lot of fluid, curved laminates." - http://www.nytimes.com/2012/02/23/g...s-airstreams-interior-up-to-date-qa.html?_r=0 .

Because of Deam, Airstream’s product line now feels more “European”, which Airstream signals by designating the trailers “International” in the American market – see http://www.airstream.com/travel-trailers/intl-signature/photos-decor/ , http://www.airstream.com/travel-trailers/intl-serenity/photos-decor/ , and http://www.airstream.com/travel-trailers/intl-sterling/photos-decor/ :

ec274f48191131dbb0cdef4581109787.jpg

Also see http://www.airstream.com/travel-trailers/eddie-bauer/photos-decor/ , http://www.airstream.com/travel-trailers/land-yacht/photos-decor/ , http://www.airstream.com/travel-trailers/sport/photos-decor/ , and http://www.airstream.com/travel-trailers/flying-cloud/photos-decor/ . Many of the Airstream trailers spec’d for the European market also seem to have been designed by Deam – see http://www.airstream-germany.com/index.html and http://www.airstream-germany.de/download/Airstream2013de.pdf . The irony here, of course, is that these wonderful trailers were dreamt up by a superb American designer, and in that sense, there is really nothing "international" about them at all!

As you might appreciate, there is a potentially big economic payoff here, because Airstream has now achieved even more product differentiation vis-a-vis the saturated American market for caravans. Airstreams were already a rather unique product to begin with, because of their exteriors. Now (most of them) are also unique because of their interiors, too.


*****************************************

2. The 1990’s “haute-IKEA” aesthetic of German Expedition RV’s



The world of really big, off-road-capable RV’s is, for the most part, German – pace Earthroamer, GXV, Tiger, etc. As such, the interiors of UniCats and ActionMobils have not resembled grandma’s colonial-kitsch-kitchen for quite some time. But even still, in comparison to the wider German RV industry, UniCat and ActionMobil interiors do seem a bit dated.

One might charitably describe the interiors of many UniCats and ActionMobils as “haute-IKEA” , in the sense that a 90-degree, rectilinear, T-square aesthetic predominates, of the sort that characterized IKEA furniture back in the 1990’s and early 2000’s. Again, see http://www.actionmobil.com/en/4-axle/interior-design , http://www.actionmobil.com/en/3-axle/globecruiser , http://www.actionmobil.com/en/3-axle/atacama , http://www.unicat.net/en/info/MXXL24AH.php , http://www.unicat.net/pdf/UNICAT-MXXL24AH-MAN8x8-en-es.pdf , http://www.unicat.net/en/info/EX70HDQ-MANTGA6x6.php , http://www.unicat.net/en/pics/EX70HDQ-MANTGA6x6-2.php , http://www.unicat.net/en/info/EX70HDM-MBActros6x6.php , http://www.unicat.net/en/pics/EX70HDM-MBActros6x6-2.php , http://www.unicat.net/en/info/EX63HDSC-MANTGA6x6.php , http://www.unicat.net/en/pics/EX63HDSC-MANTGA6x6-2.php , http://www.unicat.net/en/info/EX70HD2M-MANTGA6x6.php , http://www.unicat.net/en/pics/EX70HD2M-MANTGA6x6-2.php , http://www.unicat.net/en/info/EX63HDM-MANTGA6x6.php , http://www.unicat.net/en/pics/EX63HDM-MANTGA6x6-2.php , http://www.unicat.net/en/info/EX63HD-MANM4x4CC.php , http://www.unicat.net/en/pics/EX63HD-MANM4x4CC-2.php , http://www.unicat.net/en/info/EX58HD-MANTGA4x4.php , http://www.unicat.net/en/info/EX58HD-MANTGA4x4.php , http://www.unicat.net/en/info/EX45HD-UnimogU5000.php , and http://www.unicat.net/en/pics/EX45HD-UnimogU5000-2.php .

Sure, I love the "New York loft" sense of space provided by the UniCat pop-ups, and this format has since been followed by other fabricators, for instance, GXV – see http://globalxvehicles.com , http://globalxvehicles.com/vehicles/ , http://globalxvehicles.com/global-expedition-vehicle-pangea-4x4-rv/ , http://globalxvehicles.com/gxv-pangea-gallery/ , and http://www.examiner.com/slideshow/gxv-launch-pangea-expedition-vehicle-with-vertical-slide#slide=1 . But, if anything, the GXV “Pangea” interior strikes me as even more doggedly utilitarian and lacking in contemporary design sophistication, than anything produced by UniCat.

[Brief aside: If memory serves, it seems that it was ActionMobil who first pioneered box-style pop-ups in expedition motorhomes. But please correct me if I am wrong about this.]

The pity here is that the interiors of Germany's non-expedition, “regular” motorhomes are usually very well-designed, and are decidedly more contemporary than most American mid-market models. The German designers who work for Ketterer, Hymer, Westfalia, EuraMobil, Knaus Tabbert, etc. all seem to handle curvilinear asymmetry with aplomb – see for instance http://www.ketterer-trucks.de/en/models/category/c/travel-motorhomes/model/continental-12000-2.html , http://www.hymer.com/en/ , http://www.hymer.com/en/models/integrated/hymer-starline/experience/ , http://www.hymer.com/assets/files/m...e/epaper-STARLine_englisch/epaper/ausgabe.pdf , http://www.westfalia-mobil.net/en/ , http://www.westfalia-mobil.net/en/modelle/amundsen/amundsen-allgemein.php , http://www.euramobil.de/integraline_ls_galerie.html?&L=1&L=1 , and http://www.euramobil.de/integra_galerie.html?&L=1&L=1 :

HY13_BMD680_I_Sitzgruppe_Laviana_1.jpg

HY13_BMD680_I_Küche_Laviana_7.jpg

2.jpg

But none of this German curvilinear design expertise seems to spill over into expedition motorhomes, even though UniCat and ActionMobil are just down the road, and both are German-speaking companies.

For what it’s worth, high-end American luxury coach manufacturers like Newell, Liberty, Marathon, Featherlite, and Millenium also try to deliver more contemporary, curvilinear interiors – see for instance http://www.newellcoach.com/the-coaches/photo-gallery/ and http://www.newellcoach.com/newell-coaches/coach-1508/ . But on my own view, Newell seems to handle curvilinear asymmetry less successfully than Hymer or Euromobil, and costs 3 or 4 times as much.

So cost is not the only constraint. Either you have the designers and craftsmen who can pull off a Hymer interior, or you don’t. I suspect that ActionMobil and UniCat could have more contemporary, curvilinear interiors too, if customers began demanding as much. But until customers do, their interiors will probably continue to seem driven mostly by engineering considerations.


*****************************************

3. Courageous Color, ARC, and Art Deco


My other quibble with the RV industry in general, is that it plays things rather “safe” when handling color. If one compares the interiors of almost all of the above brands – European and American, regular RV and expedition RV – to the new Airstream interiors, one huge, glaring difference becomes obvious: the color choices of most motorhome manufacturers tend to be muted, a restricted palette of whites, greys, browns, and blacks. Whereas Airstream, since it hired Deam, has developed the courage to handle strong, vibrant interior color, and a dramatic mixture of materials.

However, even the interiors of the newest Airstream trailers still seem a bit tame when compared to the interiors created by the bespoke conversion specialist, “American Retro Caravan”, or “ARC” – see http://www.arcairstreams.co.uk , http://www.arcairstreams.co.uk/refits/retro , http://www.arcairstreams.co.uk/blog/category/retro-airstreams/ , http://www.arcairstreams.co.uk/blog/2013/02/the-airstream-safari-with-the-egg-shaped-hole/ , http://www.arcairstreams.co.uk/blog/2013/02/a-closer-look-at-that-luxury-padded-bedroom/ , http://www.arcairstreams.co.uk/refits/luxury , http://www.arcairstreams.co.uk/blog/category/luxury-airstreams/ , http://www.arcairstreams.co.uk/refits/corporate , http://www.arcairstreams.co.uk/blog/category/corporate-airstreams/ , http://www.arcairstreams.co.uk/refits/catering-and-bars , http://www.arcairstreams.co.uk/blog/category/catering-airstreams/ , and http://www.arcairstreams.co.uk/blog/category/cafe-airstream/ :

luxury1-109-800-600-80.jpg

What really impresses me about ARC is their courageous color choices (split-complementaries like red + blue-green, blue + yellow-orange); their mastery of curvilinear, aluminum-detailed cabinetry; their asymmetrical layouts; and the retro details throughout – port-hole windows, jet-engine spot-lamps, and circular-grilled air vents, for instance -- see http://www.ehow.com/facts_5649966_split-complementary-color-scheme_.html , http://www.incolororder.com/2011/11/art-of-choosing-split-complementary.html , and http://www.tigercolor.com/color-lab/color-theory/color-harmonies.htm . Sure, most people will not want over-the-top, vibrant color in a motorhome that they have to live in, day-in, day-out. And the more colorful ARC designs tend to be catering, café, and bar trailers. But check out some of the moderate ARC designs, where they still use color in strategic, calibrated ways to give interiors a sense of spaciousness and joy -- see http://www.arcairstreams.co.uk/refits/retro .

My strong design preference has always been for Art Deco and Streamline, although nowadays these tend to be rebranded as neo-Deco, diesel-punk, deco-punk, glam, retro, etc. I am an avid follower of "Lord K's Garage" diesel-punk blog, for instance – see http://www.dieselpunks.org and http://www.dieselpunks.org/profiles/blog/list?user=0n7d9yl571cmt . I partly grew up in South Florida, and fell in love with South Beach "Tropical Deco" as a kid. Many of ARC’s more colorful trailers – the Apollo 70 in particular – have interiors best described as “Miami Deco” – see http://www.amazon.com/Tropical-Deco-Architecture-Design-Miami/dp/0847803457 , http://www.pinterest.com/search/boards/?q=miami deco , http://www.pinterest.com/search/boards/?q=tropical deco , http://www.apollo70.co.uk , http://www.beautifullife.info/interior-design/apollo-70-airstream-bar/ , http://brosome.com/the-apollo-70-airstream-bar-is-the-perfect-place-to-have-a-drink/ and http://hiconsumption.com/2014/03/apollo-70-airstream-bar/ .

For me, Art Deco is the modernist design-aesthetic that should have dominated the 20th century. But for whatever reason, lots of people found the puritanical-minimalist, black-white-grey, Bauhaus rectilinearism of Mies-and-co ever so convincing, perhaps because it was so cheap on the details and color paint? Remember, I am German, so perhaps I am “allowed” to take a swing at Mies and the Bauhaus….:) The 1990’s/early 2000’s rectilinearism of IKEA is then the direct descendant of this Bauhaus aesthetic, as are most UniCat and ActionMobil interiors.

However things have changed dramatically in architecture and design since the 1990’s, and over the last 10 years “organic-tech” and "blobitecture" have displaced modernist rectilinearism. In effect, these are curvilinear, organic outgrowths of "hi-tech" architecture, made possible by CAD -- see http://www.kuriositas.com/2011/01/blobitecture-rise-of-organic.html , http://en.wikipedia.org/wiki/Nicholas_Grimshaw , http://en.wikipedia.org/wiki/Santiago_Calatrava , and http://fr.wikipedia.org/wiki/Architecture_high-tech .

And as demonstrated above, German RV manufacturers like Wesfalia, Hymer, Euramobil, etc. have been offering more curvilinear interiors for quite some time. One could even say that the Art Deco/Streamline aesthetic never really disappeared, persisting in certain design niches, transportation design in particular. If only because rectilinear, squared-edged vehicles are not very functional, i.e they're not aerodynamic.

So let’s just say that, even though UniCat and ActionMobil are not building grandma’s colonial kitchen, they are now roughly 2 decades behind the times, vis-à-vis wider design trends. Their engineering is no doubt top-notch, and Victorian quite rightly defended UniCat's careful engineering and craftsmanship in an earlier post. But just take a look at the links above, check out Wesfalia, Hymer, Euramobil, et al, compare for yourself, and everything that I have written here may seem somewhat self-evident.


*****************************************

4. Back to Engineering



Now don’t worry, I realize that the bulk of this post was very off-topic, because this is an engineering thread, about 3-point pivoting sub-frames. But just thought I should state all the above, so there’s no mystery as to where I am coming from. I am a designer, who wants to poke the expedition-RV industry a bit, with a concept vehicle that breaks a few unwritten rules.

It's easy enough to create wild designs that have no basis in engineering reality, and the world of transportation design is littered with concept vehicles that never got built, because they can't be built -- at least not cost-effectively. It's much harder to think through the incremental changes that are much less dramatic, but that, over time, can cumulatively revolutionize a given vehicle-type.

For instance, my suspicion is that companies like ActionMobil and UniCat are still mounting camper bodies on 3-point pivoting sub-frames mainly due to inertia, and not just cost. I may be wrong about this, and this needs investigation. But it's at least a possibility. A fully integrated off-road mobile home would be highly desirable, and perhaps not that much additional engineering is necessary to pull it off. This might be an "incremental" change, from an engineering point of view, but one that would change the game dramatically from a design point of view, with significant consequences for overall interior plans, layouts, the efficient use of limited space, etc. Similarly, I suspect that ActioMobil and UniCat are still doing 1990’s-style “haute-IKEA”, perhaps because customers have not demanded more. It sort of takes an outsider like me to come along and say, “Hey, why couldn’t you do x, y, or z instead?”

By far the best way to do that, in the world of design, is by presenting alternative imagery.

I’ll keep you posted, but in another thread….:)


All best wishes, and many thanks for your feedback,





Biotect
 
Last edited:

egn

Adventurer
As KAT 1 owner I can say that the frame isn't totally stiff. This is also the reason why the load platform of the military base is fixed by springs and not bolted or fixed by screws.

But it is stiff enough so that springs are good enough even in the worst off-road situations. But even then I put my cabin on a 4-point pivoting fixture with the distribution of the force over are large segment of the frame, in order to keep the expensive cabin away from any structural stress. This has worked perfectly during the last 7 years. Some people have fixed their pivoting fixture only at a few points and got damage at the L frame sitting on top if the closed master box frame. This shows that there are considerable forces at work.

The normal ladder frames used by MAN LE/TGS/TGA and others are very flexible in contrast. This has to be in combination with leaf springs to get acceptable offroad capabilities. This soft frames work fine in the typical use scenario of a few 1000 mls in construction environment during lifetime. But if you drive 10.000s of mls on bad roads with constant torsion caused by uneven road and swinging load on top, the risk that something breaks at the ladder frame is high. There have been several reports about frame damage of LE models after driving many miles on the bad roads in South America. Of course, it also depends on the load and speed you drive. Very often such camper trucks are constantly near their upper weight limit.

The Tatra central frame tube of T813, T815, ... is even stiffer than the frames of MAN KAT and SX military trucks. But it is also much heavier.

The reason why the MAN stiff frame trucks are not used more widely is that they are military technology with low production count. No one would spend more than US$ 300.000 new for the base truck when the regular ones cost only 1/3. The military trucks are only affortable used when about 20-30 years old. Currently the KAT I 4x4 can be bought from Vebeg for much less than US$ 10.000, because they are more than 30 years old.

In the user manual of my KAT I 6x6 you can read the following description:
The truck 7t mil gl is a transport vehicle that is able to follow tanks (chain or wheel).

This is shown at every point of the construction. I have driven bad gravel roads in Russia with 50+ mph where other road vehicles drove only 10-20 mph. The spring suspension gives a very comfortable ride. In Schweden I once forgot to put the cap of the engine oil refill on top of the flat oil coolers of the engine. After driving about 5 miles on gravel road to a recreation area, I remembered that I have forgot something and found it still at the same place.

Regarding design, you can ask 10 people and get 20 different opinions. In my opinion if someone has serious interest in going on a large trip away from civilisation a simple functional design wins hand down. Using to much curvature will loose valuable space inside the box. It makes just no sense to have a lot curvature at the outside when the size limits are rectangular. The so called modern designed interior and exteriour is more destined to show how rich and wealthy you are. Driving with such a luxury expedition vehicle through 3rd world countries is not the best way to get in touch with friendly local people, it is more a way to get in contact with bad people. Understatement is a better way here. And most people buying such vehicles from the established market leaders understand this. The people that look for top design in such vehicle will finally fail to go on any long voyage and the vehicles are for sale very soon.
 
Last edited:

biotect

Designer
Dear egn,

Vielen dank! You explained a huge amount with your post.

So even when used in heavy mining work, even as loader-tippers, MAN TGS frames are still flexible?

From your description, it does seem that a very rigid chassis with progressive coil suspension is the best way to go, as opposed to a more flexible chassis with leaf suspension. This is basically the difference between the SX and HX series, it would seem. And of course it's the difference between the SX and commercial TGS trucks.

So, given a choice between a 10 or 20-year old used KAT 1 chassis, versus a new TGS chassis, the used military chassis is the better choice, right? Because it will be stiffer, and will have progressive coil suspension?

************************************

You said that your KAT 1 frame is not totally stiff, and MAN's product literature seems to suggest that the HX series is also not totally stiff either. MAN military only promises 100 % torsional stiffness for the SX-45.

But do you think the SX-45 would be stiff enough to completely eliminate the need for a 4-point pivoting sub-frame? Or do you think a pivoting sub-frame is still needed, even for the SX-45?

Furthermore, does the SX-45 also need a load platform fixed to the chassis base with springs, and not bolted or fixed by screws? As per your KAT 1? Clearly, such a spring-loaded platform is needed for the KAT 1 and the HX. But do you think it is also needed for the SX-45?

************************************

It seems hard to find more detailed information about the SX-45 on the web. I've tried to find the proper contact person at Rheinmetall MAN, but so far, no luck. So if you know of any really good, informative websites (auch in Deutsch!), websites that detail SX-45 payload mounting, would you be willing to pass along the links?

Finally, do you think a camper body could be directly mounted on a Tatra T813 or T815 frame? Or, even then, would you still strongly recommend a spring-loaded base platform, and/or a 4-point pivoting sub-frame on top of that?

Once again, many, many thanks,


Biotect
 
Last edited:

egn

Adventurer
I know no difference regarding TGS frames depending on use.

The KAT I is the first truck of the military truck series of that lead to the SX series.
- KAT I 4x4, 6x6, 8x8
- KAT II 8x8 build for the US Army
- KAT I A1 with Deutz 513 engine
- KAT I A1.1 with MAN engine and hydraulic suspension
- KAT I Multi
- SX-Series
There were also some Prototypes X-number in between, which were the base of many airport fire trucks build by Rosenbauer and Ziegler. To reduce development and production cost over time MAN put more and more parts from the civil production lines.

The HX is based mainly on civil components, except for the modular cab. Before the HX there was also a cheaper "light" KAT called KAT III LX with leaf springs build for some other countries.

For fast offroad driving in my opinion the stiff frame coil suspension combination will always be better then the bending frame leaf spring combination. But it also has disadvantages in some situations where the range of the suspension is not large enough. The load platform of a KAT is much higher than with other vehicles as there has to be enough room for the subended wheels. . This high center of gravity does allow only a limited side angle until it will tip over. This has been "fixed" in some way by introducing the hydraulic controlled suspension HEPLEX starting with A1.1 model.

As far as I know the SX has the same frame as the KAT and therefore isn't 100 % stiff, just as the KAT. But you don't need a pivoting suspension for a load, just some springs to fix any load.

I would even allow some flex with the Tatra, if the vehicle is going really offroad. When a frame is about 10 m long there will be always some flex that has to be compensated, apart from pure extension or contraction caused by temperature changes.

The KAT Story can be read in this Book.

I had once access to MANTED the MAN modell and construction database, but I cannot remember if it contained information about the SX series. But you may post your questions in the german KAT forum. There are a lot of knowlegable people around there that may know all the details you need.
 

biotect

Designer
Egn,

Many thanks. You've answered a lot of the questions that I had, and I've ordered Ocker's book from Amazon.de. I am just at the beginning of my research process, but your feedback has helped immensely. Just found the threads in which you discuss your own build and provide pictures, at http://www.expeditionportal.com/forum/threads/11614-MAN-6x6-camper and http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/20933867.cfm . A terrific rig, and the blue exterior is great!


*************************************

Casting about a bit using the Google pdf-search, I came across a document that includes a detailed diagram of a container loading system for a MAN KAT A1.1. See http://gulf.pexi.com/pdfs/Pexi_Surplus_MAN_Container_Chassis.pdf , and here's the diagram:


1.jpg


*************************************

Also came across an “Army UK” page, for a surplus MAN KAT A1 8x8 Cargo Truck with HIAB crane, that seems to equivocate as to whether the box-frame is stiff or not -- see http://man.army-uk.com/equip.php?ID=346 .

It first claims that the box-frame does not pass along any torsion, even when driving at full speed in difficult terrain. Then in the middle it states that the frame is based on the TGA, and is “low torsion". And finally, a few paragraphs later, it claims that the KAT A1 frame is similar to the SX series, in so far as it is “100 % torsionally stiff”:

“No strategic vehicle is more reliable and long-lived.

The A1 series is probably the most mobile and reliable truck on earth.
It is primarily deployed as a carrier for sensitive weapons systems, since its
boxed frame structure does not pass on any torsion, even when driving at full
speed in difficult terrain. It is the only truck with a loading interface on which a
Patriot system can be mounted entirely without compromising mobility.
Vehicles in the A1 series are military trucks with strategic importance. Their rigid
axles and boxed frame construction give them an unsurpassed record of mobility
and reliability in any terrain.

It was scheduled for 30 years of use, making it the military vehicle with just about
the lowest lifecycle costs of any in existence……

A strong basis – the ladder frame.

The body-friendly, low torsion ladder frame of the MAN CAT A1 8x8 is based on
the tried and tested series frame of the civilian TGA range and is
designed for service with a large off road proportion – reliability
built-in. It is made of high-strength, fi ne grain steel and has riveted
and bolted cross members and a steel bumper. Due to the low
torsion frame, comfortable and gentle transport is guaranteed.
The lateral acceleration acting on the platform or body is low.

Comfortable and robust – the leaf suspension.

Like the frame the suspension has stood the test in many thousands
of MAN vehicles. The leaf suspension further developed for
the A1 & SX with long, wear-free, rubber mounted springs, large shock
absorbers and stabilisers absorb most ground irregularities.

100 % torsional stiffness – the box-type frame.

The extremely torsion resistant box frame with hollow longitudinal
members and welded tubular cross members put the A1 & SX in a
class of its own. With this design the suspension absorbs even
extreme terrain irregularities. The desired consequence: the body
remains unaffected even during fast off-road driving.”



So you would probably say that we should trust only the second claim in the middle, that the frame is "low torsion", and not "100 % torsion free", right?


*************************************

Here are some additional pictures from the same website, for a MAN KAT A1 8x8 15t container carrier (also see http://man.army-uk.com/equip.php?ID=346 ):


870_manwithtl-1.jpg

947_manwithtl-2.jpg

505_manwithtl-3.jpg

212_manwithtl-4.jpg

825_IMG_9054.jpg

744_IMG_9060.jpg

740_man_SX-3.jpg


On a vehicle of this type, how high off the ground do you think a full-width, 2.54 m wide payload would be? Where exactly would the container begin on the sides? At 1.5 m above grade? At 1.6 m? I know that this will depend partially on tire size and pressure, i.e. whether they're Michelin 14.00 R 20 (approx. 1.26 m in diameter), or Michelin 16.00 R20 (approx. 1.34 m in diameter). And so too, load weight.

The standard MAN KAT schematic gives H3 values for the two tire sizes, 1.249 m and 1.28 m respectively. But as the pictures of this vehicle make clear, a full-width payload has to mount well above that, and in particular, above the wheel arches:


761_MancatGab_eng.jpg

85_IMG_9058.jpg


Put another way, for design purposes, where should one realistically think of the payload (i.e. the camper) as beginning? At 1.5 m above grade? At 1.6 m?


*************************************

You wrote:


I had once access to MANTED the MAN modell and construction database, but I cannot remember if it contained information about the SX series. But you may post your questions in the german KAT forum. There are a lot of knowlegable people around there that may know all the details you need.


I have already done extensive downloading from the MANTED database for civilian trucks, at https://www.manted.de/manted/epl/einstieg.epl?sprache=us , http://www.manted.de/manted/aufbaurichtlinien/gb_all.html , and https://www.manted.de/manted/epl/einstieg.epl . But would you know the link for the military version? Is it accessible to the public?

Ever since Rheinmetall AG took over MAN military, public information about MAN military trucks seems less readily accessible.

Again, many thanks,


Biotect
 
Last edited:

egn

Adventurer
I think the broschure mixes statement for HX and SX. The SX is based on the KAT frame and is nearly torsion free and th HX is based on the civil TGA frame.

The height at which a cabin on a KAT/SX will be located depends heavily on the weight. My cabin was originally about 2.48 m high and the total height at 18 t with 14.00R20 tyres was 3.90 m. An unloaded KAT has its plattform at about 1.70 m. I didn't keep the original distance between the rear tyres and the lower edge of the plattform, but reduced it about 5 cm to save height. This is no problem because we our motorhome is not indended to be used in the extrem situations, where this extra space is needed. It is designed as overlander and we wouldn't risk it by pushing it to very extreme terrian where crawling is necessary. The risk causing damage would be much to large. It is our home and not an offroad rallye vehicle. Other people installing 16.00R20 tyres on an old KAT will have the same problem with plattform distance.

As I added solar power in the meantime, the total height is now about 3.95 cm, when it is fully loaded with 1300 l fuel and about 650 l water and other supplies for a total weight of about 18 t. Even if I wanted I couldn't install 16.00R20 tyres.

There is still room between tyres and cabin when the suspension limiter is hit on both sides. But the tyres will hit the cabin when we would crawl through extreme terrain, where one side of the axle is going up and the other side is going down into extreme position. The cabin is protected against collision by a 4 mm thick aluminium plate at the lower side. With hydraulik suspenions of an SX the height can be kept constant independent from load. A friend, who is also one of the best KAT mechanics available, has installed a hydraulic suspension to his 4x4 and can control everything regarding suspension.

Regarding your project you will run into a serious problem with the SX - the placement of the engine. The engine of the KAT/SX is located behind the crew cab and not below like the TGA. The reason for this that the military versions have to be able to be transported on railway and concurrently the fording depth has to be kept to at least 1.20m. So the engine has been placed behind the crew cabin. Another reason for this placement was that originally the KAT was designed to be able to swim. But after first successful tests with the first 3 prototypes this concept has been dropped because of cost.

So to get everthing on even level you would have to move the living level to about 2 m height. The cockpit would alse have to be moved up considerably to get the advantage of an integreted layout. As you have seen in rv.net I had an integrated camper before the KAT. We liked this integrated arrangement very much and also had the idea to put a bus hull onto it. But because of all the effort we dropped this Idea very soon. Because of the watercooled engine of the SX it will be not as hard, but still a major rework will be necessary.

I see only two solutions to get this done. Both replace the standard engine and driveline:
1. Move the engine with conventional driveline to the back like with a bus
2. Use a diesel/electric/hybrid driveline

The first has been already done by a KAT II owner. He replaced the standard engine by a tank engine and put it to the end of the frame. He build everthing by himself and had documented it in the lkw-allrad from, which not available any more. But he is still active in the kat-forum.

The second solution has much more appeal to me, because I am electrical guy and have a lot of interest in electrical vehicles. If I would have about $300.000 to spend freely, I would convert my KAT to a serial hybrid vehicle with two smaller generator units, battery storage and 3 powerful electric motors for an electrical range of 100-200 mls. The outside would be covered fully with solar cells to get at least a small part of the energy from sun directly. But this is just a dream. :sombrero:

This all is now getting more and more off-topic and should be discussed in detail in a new thread.
 
Last edited:

egn

Adventurer
Today I looked through my large collection of truck images, especially the KAT ones, and found the build of an integrated camper. When you get the KAT book on page 118 you will see an image of it. It was build by Unicat based on the Austrian version of the KAT. It doesn't look very appealing. The silhouette of the cab is just extended to the back. I have two more images in my collection, but as I don't own the rights I cannot post them here.

In the book there is also stated that all of the KATs converted by Action Mobil and Unicat at that time where prototypes and not the original military vehicles. This may be the reason why we don't see that many KAT campers from both manufacturers. Another reason may be that the technology is now more than 20 years old and the customers want modern trucks, even the modern engines will cause a lot more problems regrarding fuel and maintenance in 3rd world countries. It may be also that the export restrictions on modern military vehicles prevent the use for recreation purpose.
 
Last edited:

Victorian

Approved Vendor : Total Composites
I guess you are talking about this Unicat MAN Kat?
 

Attachments

  • unicat_0005.jpg
    unicat_0005.jpg
    322.6 KB · Views: 62
  • unicat_0006.jpg
    unicat_0006.jpg
    259.5 KB · Views: 75
  • unicat_0007.jpg
    unicat_0007.jpg
    308.1 KB · Views: 64

biotect

Designer
Dear egn, moe, et al,

Again, I can't thank you enough for all the feedback.

As you suggested, I've started a new thread, titled "Fully Integrated MAN or TATRA 6x6 or 8x8 Expedition RV, w Rigid Torsion-Free Frame", at http://www.expeditionportal.com/for...-8x8-Expedition-RV-w-Rigid-Torsion-Free-Frame . The title is not poetic, and does have an “engineering” ring to it. But that's just as well, because the engineering constraints here are critical. Only if such a vehicle were cost-effectively possible from an engineering point of view (as moe suggests), does it have any kind of broad future in the market.

I am also still not certain that a rigid frame is absolutely necessary as a base-chassis for an integrated camper body, given Iain_U1250's pictures of a Unimog from the 1990's, with a fully integrated unibody, which he posted earlier in this thread – see http://www.expeditionportal.com/for...mounting-campers/page33?highlight=pivot+frame . So I hope that the new thread continues to discuss such fundamental engineering issues, because they are clearly important.

Note that I had to cut the "i" and the "o" in "Suspension", because the title blocks have a character limit. I figured that "Suspension" was the best word to abbreviate, because the other words should be full-length and easily identifiable, for search purposes. So too, I had to compromise by using the phrase "Rigid Frame" instead of "Torsion-free Frame", because of the character limit.

If any of you can think of a better title for the thread, I am all ears.

Moe, I appreciate your feedback as regards the desirability of posting an "SOR - Statement of Requirements". As the engineering discussion evolves, I will definitely develop one. But initially at least, I want to leave things more open, because in the beginning I would like the thing to be driven by considerations of what is realistically possible, from an engineering point of view. However, I did label the new thread "6x6 or 8x8", to indicate the rough ball-park. And clearly, a 6x6 will be far more practical than an 8x8.

On the other hand I wonder, for instance, whether the "rigid frame + progressive coil suspension" concept works as well over rough terrain when the vehicle is 4x4 or 6x6, as opposed to 8x8? Watching the video that egn just posted, the 8x8 seems to have a great deal of grip or "traction", simply because it has 8 wheels, wheels that a 4x4 or 6x6 by definition won't have. But maybe I am mistaken in this speculation?

Egn, I've been following up your leads regarding “Tatra”, and will also post in the new thread with thoughts and questions about engine-location and type.

And so too I will repost this message, slightly modified, in the new thread. So if you want to respond to it, probably best to do so there, and not here.

All best wishes,


Biotect
 
Last edited:

Forum statistics

Threads
185,822
Messages
2,878,587
Members
225,378
Latest member
norcalmaier
Top