TerraLiner:12 m Globally Mobile Beach House/Class-A Crossover w 6x6 Hybrid Drivetrain

egn

Adventurer
To have a huge all wheel drive camper and consider Euro campsite use seems a bit contradictory though??? :)

I thought the same. :coffeedrink:

But, if you don't want to spend a similar amount of money for a regular camper, then you sometimes have to use a regular campsite, when visiting some places. We never had a problem with our truck and found a place. Of course, we always got a lot of attention, when we drove through narrow alleys sometimes breaking tree branches and marking the road with the rubber of the XZLs. :smiley_drive:

To reduce the impact of the XZLs on the patch I always drive straight onto it. But the pattern will be visible when 3 t per wheel hit the grass. :sombrero:

If it is possible we always try to find a place away from any city and village.

IMAGE_8BBFF1E5-3671-4945-A9AF-542E6B112D44.JPG

It is true that in Russia the height is limited. We had the problem of a railway tunnel height of about 3.6 m, but there was also a way over about 20 railway tracks just after the station. We had to call the railway station to open the barrier and they had to stop the complete traffic. :wings:
On the way back we decided to go a different road through an industrial zone. There it was only about 1" above our cabin at one place. It is not easy sometimes, but this is one interesting part when traveling with a large vehicle.

In exchange not being able to visit all this tight location, we get stuck at places that are not reachable by other vehicles. :victory:
 
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biotect

Designer
Hi grizzlyj, egn,

Thanks for the replies.

Initially I was imagining this as a "go anywhere" sort of motorhome, with "anywhere" including both the Third-World and the First-World -:smiley_drive:. A bit paradoxical, creating a motorhome that is mechanically robust enough to handle bad roads in the Third World, and some off-road desert driving, but because it is so robust, it's not suitable for use in western Europe...... :confused:

However, your points are very well taken, especially the point about the tires. I know continental Europe, and I know just how fussy continentals can get about aesthetics, and the grass.

Furthermore, just like the United States, in Europe over the last 3 or 4 decades almost every aspect of life, and every square meter of available space, has been legislated to death. For instance, cash-strapped communities have realized that they can "enclose" what was formerly free, un-legislated parking space, and turn it into a source of revenue. Where I lived in Switzerland for a few years the mayor's office in a small town did just this, without consulting the locals. As it turns out, doing so was not only non-consultative, it was illegal. And this was Switzerland: a country that has direct democracy, and (mostly) law-abiding citizens. There was a big backlash, and the people forced the mayor's office to not only back down, but to also erase the blue lines on the road painted thus far, blue lines delimiting those magically created, new, fee-paying "parking spaces".

grizzlyj, I appreciate what you wrote about RV parking being subject to even more restrictions in England (I now live in London), and it is true that the continent is still looser. Perhaps especially countries like France and Spain, because their populations densities are so much lower. But unfortunately, the continent is catching up fast..... :violent-smiley-031:


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1. What to Expect?


grizzly, those entrance arches to many European RV campsites: how high do you figure they are, usually? Also 3.5 m, like Russian bridges?

You mentioned before in your first post (to which I still need to respond…..), that the standard Euro-camping pitch is 5.99 m. In your personal experience, do longer pitches exist at many Euro campsites, and if so, what is their usual maximum length? I've tried looking this stuff up on the web, as well as in books about RV-ing on the continent. But most descriptions tend to be dated, or they are just as impressionistic as anything that experienced RV-ers on a forum such as this will say. However, on a forum such as this, at least the impression will be more up-to-date.

Same question to you, egn: when you use your 9.3 m camper as a motorhome in western Europe, do you always have to "sleep on the grass"? Is it very difficult to find standard parking at western-European RV campsites, because of your camper's 9.3 m length?


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2. Ideal length?


Also, egn: would you consider your 9.3 m camper an ideal length? If you could change the length, would you prefer something smaller or larger?

Rob Gray, for instance, who created the “Wothahelizat Mark 1”, and drove it all over Australia for many years, has famously decided to go smaller with his second, “Wothahelizat Mark 2” version. Mark 1 was 2.5 m wide, 4 m high and 10.5 m long, while Mark 2 is now 2.35 m wide, 3.4 m high, and just 8.1 m long – see http://robgray.com/graynomad/wothahellizat/wot1/index.php , http://robgray.com/graynomad/wothahellizat/wot1/plans/index.php , http://robgray.com/graynomad/wothahellizat/wot1/specs/index.php , http://robgray.com/graynomad/wothahellizat/wot2/index.php , http://robgray.com/graynomad/wothahellizat/wot2/plans/index.php , and http://robgray.com/graynomad/wothahellizat/wot2/specs/index.php :

wot1vs2.jpg

Note that I had mistakenly imagined that a very large, 3-axle motorhome would be registered in Europe as a bus, and not as a truck -:oops:. But if it's registered as a truck, it makes sense that the 12 m limit applies -- again, see http://www.internationaltransportforum.org/IntOrg/road/pdf/dimensions.pdf .

I then wonder how Newell coaches that are 13.7 m long are registered in the United States, as buses or trucks?


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3. Turning Radius and Rear-Axle Steering



I had also simply assumed that a truly functional, large, “go anywhere” motorhome would not only have “all wheel drive”, but also “all wheel steering” or “tag axle steering”, as per Newell coaches, courtesy of ZF industries.

Although most Newell motorohomes are 45 feet long, they have a 37 foot turning radius (just 11.28 m!!), because their rear axle also steers:

2.jpg

For information about Newell rear-axle steering (RAS), see http://www.rvmagonline.com/features...tter-inside-newell-s-2013-2020p/photo_05.html , http://www.rvmagonline.com/features...etter-inside-newell-s-2013-2020p/viewall.html , http://www.luxurycoachlifestyle.com...ble-tag-axle-functions-newell-coach-work.html , http://www.luxurycoachlifestyle.com...scussion/2842-tag-axle-newells-pros-cons.html , http://www.fmcmagazine.com/back-issues/2013/october/7483-newell-2020p , http://www.fmcmagazine.com/back-issues/2006/february/6269-newells-redesigned-p2000i , http://www.motorhome.com/rv-reviews/motorhome-reviews/newell-coach-f3-0/ , and http://www.photoandtravel.com/rvtravelfeb06.html .

And for information about ZF industries RAS, see http://www.zf.com/corporate/en/homepage/homepage.html , http://www.zf.com/eu/content/en/great_britain/corporate_uk/homepage_uk/homepage.html , http://www.zf.com/eu/content/en/gre...rvices_uk/product_range_uk/product_range.html , http://www.zf.com/eu/content/en/gre...n_the_uk/products_bus_uk/products_bus_uk.html , http://www.zf.com/na/content/en/uni...lder_us/bus_axles_folder_us/bus_axels_us.html , http://www.zf.com/zfXmlServlet?resu...ivisionShortcut=&languageISOCode=en#toggleBox , http://www.zf.com/zfXmlServlet?resu...ivisionShortcut=&languageISOCode=en#toggleBox , http://www.zf-lenksysteme.com/en/products/cv-steering-systems/rear-axle-steering-system.html , http://www.zf-lenksysteme.com/en/pr...s/e-controlled-rear-axle-steering-system.html , http://www.zf-lenksysteme.com/uploads/media/Hinterachs-Lenkanlage_RAS_E.pdf , http://www.zf-lenksysteme.com/uploads/media/Hinterachs-Lenkanlage_RAS_EC_E.pdf , http://www.zf.com/media/media/en/do..._flyer/Bus_Antriebstechnik_Achssysteme_ZF.pdf , http://www.zf.com/media/media/docum...logy_flyer/ZF_AxleSystems_Coaches_US_EN11.pdf , http://www.zf.com/media/media/en/do...echnology_flyer/TB-Mobilitaet_erfahren_DE.pdf , and http://www.zf.com/media/media/en/do..._1/2011_uitp/txuitp2011_13_Servocom_en_zf.pdf.

Here are images of two of ZF industries' rear-axle steering mechanisms:

3.jpg 4.jpg

I used to think that the tag-axles of Prevost coaches, used by luxury bespoke fabricators such as Marathon, Liberty, Featherlite, and Millenium, could also steer.

But neither Prevost's main website, nor Prevost's specific motorhome website, mentions tag-axle steering, and there is no mention of tag-axle steering in any of the major product literature – see http://www.prevostcar.com , https://www.prevostcar.com/content/conversion-coaches , https://www.prevostcar.com/content/driver , http://motorhome.prevostcar.com , http://motorhome.prevostcar.com/section/product , http://motorhome.prevostcar.com/product/drivability , https://www.prevostcar.com/sites/default/files/2011_prevost_brochure.pdf , https://www.prevostcar.com/sites/default/files/x3-45vip_specs_2013.pdf , https://www.prevostcar.com/sites/default/files/le-mirage-xlii-entertainer_specs_2013.pdf .

On the other hand, apparently Newmar now offers tag-axle steering as well – see http://www.rvbusiness.com/2013/04/newmar-displays-product-optimism-at-confab-2/ .

Furthermore MCI, a maker of buses and luxury touring coaches, has long offered tag-axle steering – see http://www.mcicoach.com/index.htm , http://www.mcicoach.com/service-support/serinfo/serinfo02B.htm , http://www.mcicoach.com/service-support/serinfo/serinfo11A.htm , http://www.mcicoach.com/fyifrommci/story/0213.htm , http://www.mcicoach.com/luxury-coaches/passengerDseries.htm , http://www.mcicoach.com/literatureAssets/specDSeries/ , and http://www.mcicoach.com/literatureAssets/specDSeries/files/assets/common/downloads/publication.pdf . But, to my knowledge, there have not been many motorhome conversions of MCI buses with the same – see http://www.luxurycoachlifestyle.com/forum/major-mechanicals/396-steerable-tag-axle.html .

In sum, in the American Class-A motorhome market, at present I can only confirm that Newell and Newmar offer tag-axle steering. Newell offers it as standard equipment, and Newmar offers it in its top-of-the-line model. But there may be other manufacturers.


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4. Rear-Axle Steering for Commercial Trucks



In the world of commercial trucks, Mercedes, MAN, and Volvo all now offer tag-axle steering as an option.

Volvo, for instance, offers this as a fairly “standard” sort of option – see http://www.volvotrucks.com/TRUCKS/U...KEY-FEATURES/Pages/steerable-multi-axles.aspx :

1.jpg



Mercedes offers active, hydraulic tag-axle steering as a factory-fitted option for Actros construction trucks:

actros_engine-gearing-axles_trailing-axle_456x245.jpg

See http://www.mercedes-benz.com.cy/con...ngines_gearshift_axles/components.fb0010.html .

And of course, a Mercedes Actros chassis can be custom-specified via the CTT service (Custom-Tailored Trucks) – see http://www.mercedes-benz.com.cy/con...river/bodybuilder/custom_tailored_trucks.html , http://www.mercedes-benz.com.cy/con...me/driver/bodybuilder/bodybuilder_portal.html , and https://bb-portal.mercedes-benz.com/portal/?L=en&ls=1 .

Finally, MAN offers steerable rear axles via its “modification competence center” – see http://www.truck.man.eu/man/media/c...s_website_truck_master_1/Spezialfahrzeuge.pdf and http://www.tr.man-mn.com/man/media/migrated/doc/mn_group_2/Spezialfahrzeuge__de_en_.pdf .


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5. All-Wheel Steering Off-Road?



Now the obvious question will be,

“Rear-wheel steering is fine if the rear axle is not powered. But surely it is mechanically
impossible, or at least very difficult, to combine all-wheel drive with all-wheel steering???”

The answer is that this is not impossible, and it has already been done, and countless times, in vehicles designed to handle harsh off-road conditions.

Off-road, all-wheel-drive, all-wheel-steering vehicles do exist, and they constitute an important and distinct vehicle type.

They are called "all-terrain cranes".

ZF industries seems to fabricate most of all-axle steering systems used by all-terrain cranes, of the sort made by Liebherr, Grove, Linkbelt, Tadano, and Terex – see http://www.zf.com/corporate/en/products/product_range/special_driveline_technology/index.html , http://www.zf.com/corporate/en/prod...special_vehicles/special_vehicles_cranes.html , http://www.zf.com/na/content/en/uni...ansmissions/mobile_crane_transmissions_1.html , http://www.zf.com/media/media/en/do...gy_flyer/Technik_die_bewegt_Kranfahrzeuge.pdf , and http://www.zf.com/media/media/docum...vehicles_flyer/Innovations_of_Great_Value.pdf .

As a concrete example, see for instance a 3-axle model made by Liebherr, at http://www.liebherr.com/AT/en-GB/products_at.wfw/id-20789-0/measure-nonMetric , and especially page 7 of the pdf at http://www.liebherr.com/AT/en-GB/products_at.wfw/id-20789-0/measure-nonMetric/tab-13289_1477 . Below are images from the same PDF; the most important image for our purposes is the fourth:

1.jpg 2.jpg 3.jpg 4.jpg

It is not clear to me whether ZX industries is the only specialized supplier in this all-terrain crane market, because in its product literature, Linkbelt seems to cite RH Shepard as a steering-systems supplier – see http://www.rhsheppard.com/systems.htm .

Below are some more links, just in case you want to explore a bit, with a cup of coffee in hand.....:coffee:

1. Liebherr, at http://www.liebherr.com/en-GB/default_lh.wfw , http://www.liebherr.com/AT/en-GB/default_at.wfw/measure-metric , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-179-0/measure-metric , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-8058-0/measure-metric , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-20789-0/measure-metric , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-20789-0/measure-metric/tab-13289_1477 , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-3661-0/measure-metric , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-3661-0/measure-metric/tab-2275_1477 , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-2537-0/measure-metric , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-8059-0/measure-metric , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-8059-0/measure-metric/tab-5635_1477 , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-8134-0/measure-metric , and http://www.liebherr.com/AT/en-GB/products_at.wfw/id-8134-0/measure-metric/tab-5636_1477 ;

2. Grove, at http://www.manitowoccranes.com/en/cranes/grove/grove-products , http://www.manitowoccranes.com/en/cranes/grove/grove-products/all-terrain , http://www.manitowoccranes.com/en/cranes/grove/grove-products/all-terrain/GMK3050-1 , http://www.manitowoccranes.com/en/cranes/grove/grove-products/all-terrain/GMK3055 , http://www.manitowoccranes.com/en/cranes/grove/grove-products/all-terrain/GMK3060 , http://www.manitowoccranes.com/en/cranes/grove/grove-products/all-terrain/GMK4100B , http://www.manitowoccranes.com/en/cranes/grove/grove-products/all-terrain/GMK4115 , and http://www.manitowoccranes.com/en/cranes/grove/grove-products/all-terrain/GMK4115L ;

3. Linkbelt, at http://www.linkbelt.com/index.htm , http://www.linkbelt.com/lit/home_cranes1.htm , http://www.linkbelt.com/lit/products/rtc/rtc80110/home_rtc80110.htm , http://www.linkbelt.com/lit/products/rtc/rtc80130/home_rtc80130.htm , http://www.linkbelt.com/lit/pdf/rtc/80130/rt80130b.pdf , http://www.linkbelt.com/lit/products/rtc/rtc80150/home_rtc80150.htm , and http://www.linkbelt.com/lit/pdf/rtc/80150/rt80150b.pdf ;

4. Tadano, at http://www.tadano.com , http://www.tadano.com/products/index.html , http://www.tadano.com/products/productstype/allter/index.html , http://www.tadano.com/products/productstype/pdf/mobile_crane_line_up.pdf , http://www.tadano.com/products/productstype/allter/pdf/ATF50G-3.pdf , http://www.tadano.com/products/productstype/allter/pdf/ATF70G-4.pdf , http://www.tadano.com/products/productstype/allter/pdf/ATF90G-4.pdf , http://www.tadano.com/products/productstype/truckcranes/index.html , http://www.tadano.com/products/productstype/truckcranes/pdf/GT-550E-2.pdf , and http://www.tadano.com/products/productstype/truckcranes/pdf/GT600EX.pdf ;

5. And last but not least, Terex at http://www.terex.com/en/ , http://www.terex.com/en/products-services/equipment/index.htm , http://www.terex.com/cranes/en/index.htm , http://www.terex.com/cranes/en/products/index.htm , http://www.terex.com/cranes/en/products/newequipment/index.htm , http://www.terex.com/cranes/en/products/newequipment/allterraincranes/index.htm , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_057324.pdf , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_057328.pdf , http://www.terex.com/cranes/en/products/newequipment/allterraincranes/Challenger3160/index.htm , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_057518.pdf , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_047889.pdf , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_047890.pdf , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_059286.pdf , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_047888.pdf , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_047891.pdf , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_026208.pdf , http://www.terex.com/cranes/en/products/newequipment/allterraincranes/AC100-4L/index.htm , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_011807.pdf , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_028368.pdf , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_047726.pdf , http://www.terex.com/cranes/en/products/newequipment/truckmountedcranes/index.htm , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm03_006954.pdf , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_047900.pdf , http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_047901.pdf , http://www.terex.com/cranes/en/products/newequipment/militarycranes/index.htm , and http://www.terex.com/cranes/en/idc0...b/@cra/documents/web_content/ucm02_048122.pdf .


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6. Moving Towards an SOR.....



In closing, agreed, it might be best to imagine this vehicle as something more specific, as a vehicle intended exclusively for off-road/expedition/Third-World travel.

Egn, above you posted a much-admired classification of off-road vehicles:

So, here may be a first important question that has to be answered here:

1. Should it be an Overlander, that is moved comfortable and fast mainly on paved roads, but robust enough to be moved slower on unpaved roads and occasional use in light to medium off-road situations?

2. Should it be an Overlander, do be able to be moved comfortable and fast mainly on rough paved/unpaved roads with occasional movement in medium to heavy off-road environment?

3. Should it be an Overlander, to be able to be used in medium to very heavy off-road environment, with the cost of less comfort regarding travel on paved/unpaved roads?

Others may feel differently, but my own inclination is to opt for the second choice. Like you, I am personally not that interested in rock-crawling, hence my comparative lack of interest in the Unimog.

Now I may be wrong about this, but I suspect that most of those who buy UniCat or ActionMobil expedition motorhomes are much like myself, equally unnterested in rock-crawling. So for most of them, the Unimog is probably overkill. Instead, they are looking for a motorhome that will allow them to negotiate bad-roads in the Third World, and do some desert driving.

Sure, the market for weekend rock-crawling is much bigger when vehicles are smaller. But it seems silly to rock-crawl in a vehicle as large and expensive as a UniCat or ActionMobil. So the second option in your list seems to best describe the largest “block” of potential customers, in this particular market-segment. This also seems to be the market-segment that Earthroamer targets -- see http://earthroamer.com , http://earthroamer.com/xv-lt/driving/ , http://earthroamer.com/xv-lt/driving/on-road/ , and http://earthroamer.com/xv-lt/driving/off-road/ .

Now the SX-45's rigid, torsion-free frame + progressive coil spring format has particular interest for this market-segment, because it promises the possibility of a “fully integrated” design. Whereas those who incline towards the third choice, will probably not be interested in the technology and format in any case, because they will want the incredible flex that a Zetros or Unimog chassis brings to extreme off-road environments. grizzlyj, I suspect that you are in this camp?

However, those who opt for choice 3 have to ask themselves (as must expedition motorhome manufacturers), whether 3-choosers are the majority, or the minority. My strong suspicion is that they are in the minority; that most potential customers for large, UniCat or ActionMobil type vehicles will opt for choice 2.

All best wishes,



Biotect
 
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egn

Adventurer
First, I wouldn't concentrate to much on the limitation of the campsites for such type of expedition vehicles. Such a vehicle should be capabable enough to be able to stay away form any facilities at official campsite for some time. This I think was also the point grizzlyj wanted to make. Using campsites with their limitations should be the exception not the rule. Then my experience is, that you can always find a solution.

Typical campsites in Germany and other EU countries are in the range of only 80 to 120 sqm. Normally you have no side that is longer than 10 m. Everthing larger are special places and not very often available. As the roads to the sites are narrow you often can park only on sites that are at a corner, because you cannot move to sites in between without driving over other sites. The reason for this size is that the sites were designed for trailers an no RVs. Trailers are easily moved by hand or with a mover to any position on the site.

We are still happy with our size. I wanted to be shorter than 10 m because of the ferry tarif, and it made no sense to have more overhang at the rear. 6 m living space inside is a good compromise for us with this type of vehicle. Of course, more is better, but without more length outside. In this regard, an integrated solution would be great. As I wrote, we had an integrated camper in the past with a total length of 8.2 m. The cab was integrated in the living room and it was really nice to use the space above the seats for a pulldown bed. This all gave a great feeling. We had to get used to the shorter room in the new camper.

In Germany you have to register a RV camper as camper. This is a special vehicle category also defined in the EU legislation. It is a vehicle between a car and a truck. In Germany there is also special tax category for this, and you also get special assurance tarifs and the use of the ferrys is cheaper than the truck tarif, even you have the same weight. With heavy campers you are also exempt from special road worthy checks and you don't have to pay toll on German Autobahn.

I don't know wether it makes sense to have all-wheel steering with offroad vehicles. All the moving parts are in danger to be damaged in rough terrain, and the more complexity you have the more can break. The KAT and propably the SX45, doesn't even have a differential between the two rear axles of the 6x6 and 8x8. This can been seen at tight turns on roads, where you always leave some rubber behind.

THe two front axles of a 8x8 are in danger to be damaged at high speed. A friend has converted an 8x8 to 6x6 by cutting the last axle for driving offroad rallyes. He did this for better weight distribution because the normal 6x6 is to heavy at the front when no load is transported. And for rallye use you pack no extra load on the truck, you even make it lighter. He discovered that his second front axle is at serious risk getting damaged, when he drives very fast over bumps. Ok, this is no large problem when you drive slow, but sometimes when driving offroad it is not easy to see bumps and holes very good, to slow down early enough.

So I think it is best to keep suspension and steering as simple and robust as possible.
 
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biotect

Designer
Egn -- the image you posted at the top of this page is terrific, and thanks for the link to the article in "Wired".

As mog indicated above, Bran Ferren of Applied Minds, who designed this bug-out vehicle, also designed the Maxi-Mog, in collaboration with Thomas Ritter of UniCat -- see http://www.maximog.com , http://www.maximog.com/faq.html , http://appliedminds.com , http://en.wikipedia.org/wiki/Applied_Minds , http://battellemedia.com/archives/2004/06/a_morning_with_danny_hillis.php , and http://en.wikipedia.org/wiki/Bran_Ferren .

All best wishes,



Biotect
 
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egn

Adventurer
All-terrain cranes are no real off-road vehicles. They are so heavy and have so small tires that the load on the surface is extremely high. Often the road to the intended place of use has to be prepared specially to cover the weight. They don't have to be constructed as robust as a real off-road vehicle, because the move only at pedestrian speed in the construction side.

Who will be the typical customer of such an expensive vehicle?

It will not be the hot rod in the twenties, but someone at higher age, acting more carefully, having the value of the vehice in mind, not to forget the health of his family traveling with him. He will think twice about going into risky heavy terrain, and drive a longer easier way if available. If he wants to have real off-road fun he will use a second vehicle.

BTW, the above largest off-road RV will not be very capable off-road, because it will be just to heavy and to long for only 3 axles. The Maximog is a much better concept. But in my opinion the are both totally over designed. They show that the owner fears everything outside the vehicle and protect him like a space ship from the perils of the environment. That are typical vehicles that you will see only at road shows, but never on travel in the real world.

This is also the danger with your proposed concept. It may be bought just by the same people that already have luxury cars, a luxury yacht, a luxury coach and will be completed by a luxury off-road RV. If it is only a pure concept design, that doesn't really matter. There are numerous concept designs of all kind of things that look great, but will never make it to the market, because there is no real world use case or market for them. But if you want a more realistic result than you should define the potential target market first and then define the SOR accordingly.

Should it be for younger people, may be family with smaller kids?
Should it be for mid-age people with older kids?
Should it be for an older aged couple?
...

Each of this target customers require a different design, or you develop a concept that can be changed over time to match the requirements in different phases of life.

Just some ideas ...

Emil
 
Last edited:

biotect

Designer
Hi egn,

Thanks for that feedback – it moves things along nicely. Just some more questions, and in the fourth section, an observation.


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

1. The Second Choice?


In the last section of my post above, I wrote that most potential customers shopping for a very large, UniCat or ActionMobil type motorhome, are probably not interested in rock-crawling, nor extreme, Ralleye-style off-road travel. And that, as such, a Unimog might be overkill. It seems that most potential customers would opt for the second choice, in your list of choices. Do you agree?

It seems to me that you, personally, have opted for the second choice with your MAN-KAT, because as you explained in the “pivoting frames and mounting campers” thread, you deliberately lowered the distance between the rear tires and the lower edge of the platform:

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 platform at about 1.70 m. I didn't keep the original distance between the rear tyres and the lower edge of the platform, but reduced it about 5 cm to save height. This is no problem because we our motorhome is not intended to be used in the extreme 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 off-road rallye vehicle. Other people installing 16.00R20 tyres on an old KAT will have the same problem with platform 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 hydraulic suspensions 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.
– see http://www.expeditionportal.com/for...35?highlight=pivoting+frames+mounting+campers.

I get the impression that you are a fairly typical sort of customer for this range of the market, and that's why having these leisurely discussions with you are proving so valuable!! :ylsmoke: It's still 5 or 6 months away from when my thesis project "officially" begins, but in the two weeks that I've been blogging on the ExPo forum in earnest, I feel that my thinking has advanced by many additional months.....

So if you are in fact typical for this market-segment, then the second choice is probably where my design efforts should be targeted, right?


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

2. Length Questions


You personally opted for 9.3 m, and you and your wife are happy with this length. But you also think that the vehicle should not be designed around the size-limitation of European RV-park camp-sites. So are there any other reasons why 9.0 m long would be preferable to 10.0 m, or 10.0 m preferable to 12.0 m, the upper legal length-limit?

If ferry toll costs were not an issue, does a 12.0 m length make sense? And if not, why not?


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

3. All-Wheel Steering


I agree with you that systems should be as simple and robust as possible, so that nothing critical is likely to break down far from civilization.

However, that's exactly why I was so stunned when I came across the literature about all-terrain cranes. These things are really robust, they are built like tanks, and they are built to work. They are commercial vehicles that have to be on-site and working properly 24/7, so that their operators can recoup their investments and turn a profit. Often they will work at considerable distance from any kind of paved road, so if they break down off-road, it will be a big hassle to recover them, and the down-time will cost their operators plenty.

The all-terrain crane “market”, in short, probably forces crane manufactures – and ZF industries – to produce very reliable products. Furthermore, because time is money, the newest cranes can also travel at comparatively high-speed (65 mph) on paved roads and highways. When you described these cranes as slow, I think you might still have in mind the off-road cranes of 20 years ago?

The only question is whether they can travel at high speeds off-road. The SX-45 and the Tatra 815 series not only can handle off-road terrain, they can handle it fast – see
http://www.tatratrucks.com , http://www.tatratrucks.com/trucks/customer-segment-catalog/defence/ , http://www.tatratrucks.com/trucks/c...ity-heavy-duty-universal-cargo-troop-carrier/ , http://www.tatratrucks.com/trucks/product-catalog/t-815-7/ , http://en.wikipedia.org/wiki/Tatra_815 , and see the dynamite video at http://www.tatratrucks.com/about-th.../vojenska-rada-tatra-t-815-7/?section=defence . Also see:

SHORT VERSION:


LONG VERSION:


I fully agree that the frame of an all-terrain crane is much too heavy. Such a frame is designed to bear the weight not just of the vehicle, but also of the huge crane on top, and whatever load it might be lifting.

But the frame of an offroad crane does not interest me. It's the ZF-industries all-wheel-drive/all-wheel-steering that interests me.

So my only question is whether ZF all-wheel-drive/all-wheel-steering, of the sort used by cranes, could also reliably handle lots of bad-road driving at reasonably high speeds? I don't expect it to handle extreme ralleye-style off-road driving, or rock-crawling. But if it can handle bad-road driving just as well as standard Tatra or SX-45 steering, then why not?

It's also worth noting that both the front and the second axles of the SX-45 8x8 can steer. Only the rear two axles do not steer. So if the second axle of the SX-45 has already been fitted with steering designed to work in concert with the first axle, then maybe it's not such a small step to add two more steerable axles at the back? This would make a huge difference to the turning radius, and overall maneuverability in tight spots.

So don't worry, I am not so unrealistic as to propose using an off-road crane chassis as the basis for a motorhome!! That's not the reason why I brought up off-road cranes. I only brought them up because they have all-wheel-steering, and they have all-wheel-steering designed to work hard, and handle harsh conditions.


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

4. Why a Fully Integrated Camper?



In a post on the first page of this thread, grizzlyj questioned whether an integrated design was even desirable. I've been marshaling a long list of reasons in response, and will post my full argument in about a week. But egn, I very much appreciate your own explanation:

We are still happy with the size [of our expedition motorhome]. I wanted it to be shorter than 10 m because of the ferry tarif, and it made no sense to have more overhang at the rear. 6 m living space inside is a good compromise for us with this type of vehicle. Of course, more is better, but without more length outside. In this regard, an integrated solution would be great. As I wrote, we had an integrated camper in the past with a total length of 8.2 m. The cab was integrated in the living room and it was really nice to use the space above the seats for a pulldown bed. This all gave a great feeling. We had to get used to the shorter room in the new camper.

Now grizzlyj's comment on Page 3 of this thread got me thinking:

To have a huge all wheel drive camper and consider Euro campsite use seems a bit contradictory though??? :)

I started wondering, why contradictory?

Sure, expedition motorhomes have big wheels, they are large, and they might not "fit" into the spaces available at European RV-parks. But one of the most important reasons why expedition-style vehicles stand out in RV parks, is because they look so different. As many have suggested, big UniCAT and ActionMobil vehicles look like garbage trucks. And the main reason why they look like big garbage trucks, is because they have a non-integrated design.

So one major design goal, perhaps, should be to create an exterior for a fully integrated expedition motorhome that will not stand out so much. An exterior that will seem perfectly happy and visually “at home” in an RV park, European or American. An exterior that will only signal off-road capability by the size of its tires, and ground clearance, but little else.

Sure, the lack of suitably large "pitches" or hook-up sites in most European RV parks will still be an issue. But the potential market for such a vehicle is not just European. One can also imagine American buyers who, given a choice between:

(A) a Class-A motorhome that is not off-road capable,

versus

(B) an expedition-style motorhome that is almost as large as a Class-A, and that only looks a bit different because of the size of the tires,

....might choose the latter.

And they might be willing to pay a 10 or 20 % premium for the latter, because it has the added ability to travel outside the United States, for instance, in Latin America.


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

5. Fully Integrated Earthroamer



It would be interesting to know how much Earthroamer customers use their vehicles inside the United States, in comparison to how much they use them overseas. Earthroamers are mechanically designed to handle Latin-American "bad-road" travel. But one thing that makes Earthroamers so attractive, is that they look like visually standard, albeit rather big, truck-campers. And what's more, Earthroamers are very beautiful truck-campers:

xvlts_big.jpg MASTER-Profile-both-550-in-front-of-650-3000px.jpg FINAL-complete-650-master-with-kelci-b.jpg

Again, see http://earthroamer.com , http://earthroamer.com/xv-lt/driving/ , http://earthroamer.com/xv-lt/driving/on-road/ , and http://earthroamer.com/xv-lt/driving/off-road/ .

One can then imagine these vehicles fitting in perfectly well in any American RV park. Nobody would ever describe Earthroamers as "garbage trucks". And no doubt their American owners probably do use them as "double-duty" RV's: as motorhomes for both American and foreign travel. In America, at least, there is probably nothing "contradictory" about using these huge, all-wheel-drive campers on standard RV campsites.

Egn, you wrote a bit about cost, and don't worry, I will be keenly aware of overall cost. In terms of market-demographics, I think the target should be exactly the same age-cohort and income-bracket addressed by ActionMobil, UniCat, Earthroamer, and up-market American Class-A manufacturers. But even this market demographic usually cannot afford to buy two big, expensive motorhomes, one for the First World, and a second motorhome for the Third World. So if it were possible to design a fully integrated motorhome that functions well in both contexts, and that costs roughly the same as an ActionMobil, it might prove a popular product…..:)

In a nutshell, the design challenge -- as I see it -- is to create a "fully integrated Earthroamer". The design challenge is to create a "go anywhere" motorhome that, like the Earthroamer, will be visually at home everywhere. But a vehicle that, unlike the Earthroamer, might have a UniCat-style pop-up; and that, like the Hymer, will have swivel seating and a fully integrated interior; and that, like the SX-45, will have a rigid, torsion-free box-frame, with progressive coil suspension, to make that interior possible.

All best wishes,



Biotect


 
Last edited:

biotect

Designer
Rear wheel steering is certainly possible and has been done on an expedition truck: http://www.unicat.com/en/pics/VXL16HD-2.php

Many thanks for that.

The following is from the UniCat specification page for the same vehicle, the VXL 16-HD "special". See http://www.unicat.net/en/special.php :


Chassis

Volvo FH 12 4x4
Wheel base 4800 mm (15' 9")
Engine erformance 338 kW/460 hp Euro 3
Max. torque 2200 Nm (1622 lb.-ft.)
Volvo 6-speed automatic transmission
All wheel drive with center differential lock
Differential locks for front and rear axle
Independent wheel suspension, wheel travel 325 mm (13")
Hydropneumatic suspension
Rear axle steering
Disc brakes front and rear
Hydraulic leveling system
Tires 16.00 R 20 Michelin XZL, tubeless
Tire pressure regulating system to regulate pressure while driving
4 chamber fuel tanks, capacity 1015 liters (268 US gallons)
Dual fuel prefilter with water seperator
Car alarm system
Air suspended seats
Satellite navigation system (GPS)
Additional gauges for engine and transmission monitoring
Back eye camera
Integrated airconditioner
Roof rack with branch guard
Crane for loading of spare wheel
Searchlights left and right
Truck horns
Xenon high beam lights


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

Just curious: would you know why these customers specifically requested rear-axle steering? The vehicle does not seem particularly long or difficult to maneuver.

And, any thoughts about why not more UniCat customers request the same, especially those who buy the larger vehicles?

All best wishes,



Biotect
 
Last edited:

Victorian

Approved Vendor : Total Composites
I have no idea... Unicat started this truck just when I left the company. I know only what the website tells us.
 

egn

Adventurer
Look at the image:

VXL16HD.5-560.jpg


It shows the weak points of such a concept. All this thin elements are all at risk when you move through rough terrain. Hitting one rock and you may have a serious problem. If the wood branch had moved a bit higher it would stick between the steer control and either block or break it. This also causes low clearance. It seems to be not more than about 6".

The components of the hdro pneumatic suspension is also at risk if the truck sinks into mud and has be pulled out.

The questions is why someone is paying a lot of money for something like this for a 4x4. The only reason I can think of is that his parking spot at home is to tight to reach without rear steering.

That would certainly be nothing for me.

Compare this to the clean suspension of the KAT:

KAT_rear.jpg

KAt_rear_detail.JPG

There is nothing sensitive located below the frame.
 
Last edited:

biotect

Designer
Hi Egn,

Some great images of the clean suspension on a KAT!! And you are no doubt right. I am not an engineer, nor a mechanic, so I am really in no position to judge.

However, I would like to play “devil's advocate” for just a bit longer.....

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

If I understand your argument correctly, the same problems that you identified with your first image above, should also apply to the steering mechanisms on the first two axles of an 8x8 MAN SX-45? And, for that matter, they should also apply to the steering mechanism of your KAT? In other words, at the beginning of your post, you seem to be arguing that these will be problems for any steering mechanism. And you seem to reason that, as such, it is best to limit the steering mechanism to just one axle. Because at least one axle has to steer.

However, your second and third images appear to make a different argument. They seem to suggest that the front steering mechanisms of the MAN SX-45 and KAT are much better designed, and they avoid these problems by not locating any sensitive elements below the frame.

So if this is true -- if the same problems do not apply to the front steering of a KAT or an SX-45, because MAN has created a completely "clean suspension" with "nothing below the frame" -- then surely MAN could do the same with rear-axle steering? If MAN has figured out a way to make the front two axles of the 8x8 SX-45 and KAT steer, without creating the problems that you illustrated beautifully with that first image, then surely MAN could install rear-axle steering that also avoids these same problems?

As I wrote above:

I fully agree that the frame of an all-terrain crane is much too heavy. Such a frame is designed to bear the weight not just of the vehicle, but also of the huge crane on top, and whatever load it might be lifting.

But the frame of an offroad crane does not interest me. It's the ZF-industries all-wheel-drive/all-wheel-steering that interests me.

So my only question is whether ZF all-wheel-drive/all-wheel-steering, of the sort used by cranes, could also reliably handle lots of bad-road driving at reasonably high speeds? I don't expect it to handle extreme ralleye-style off-road driving, or rock-crawling. But if it can handle bad-road driving just as well as standard Tatra or SX-45 steering, then why not?

It's also worth noting that both the front and the second axles of the SX-45 8x8 can steer. Only the rear two axles do not steer. So if the second axle of the SX-45 has already been fitted with steering designed to work in concert with the first axle, then maybe it's not such a small step to add two more steerable axles at the back? This would make a huge difference to the turning radius, and overall maneuverability in tight spots.

So don't worry, I am not so unrealistic as to propose using an off-road crane chassis as the basis for a motorhome!! That's not the reason why I brought up off-road cranes. I only brought them up because they have all-wheel-steering, and they have all-wheel-steering designed to work hard, and handle harsh conditions.

In short, your second and third images above suggest that MAN has figured out a way to create completely "clean" steering for two axles up front. So why not also for two axles in back?

If this were to add significant complexity to the system, and if it were to make the undercarriage much less robust, then sure, it would not be desirable. But there seems no reason to think, a priori, that it should. If MAN can create a reliable, trouble-free steering mechanism that is "clean", with "nothing below the frame", for the first and second axles of the 8x8 SX-45, then there is no reason to think that MAN could not do the same for the third and fourth axles.

I know my reasoning here is very simplistic. And because I am not a mechanic nor an engineer, I am no doubt missing something important. So my apologies in advance if this reasoning seems thick-headed or stupid.


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

Is Rear-Axle Steering Desirable, from the point of view of potential customers?



In a previous post you also seemed to suggest that rear-axle steering is unnecessary, because you personally can get along quite well without it. You personally can handle your 9.3 m KAT without rear-axle steering. But if you read the posts about Newell tax-axle steering, you will see that many Newell owners positively love the added maneuverability that it provides. Once they experience tag-axle steering, most owners of Newell coaches never want to go back to a fixed tag-axle -- again, see http://www.rvmagonline.com/features...tter-inside-newell-s-2013-2020p/photo_05.html , http://www.rvmagonline.com/features...etter-inside-newell-s-2013-2020p/viewall.html , http://www.luxurycoachlifestyle.com...ble-tag-axle-functions-newell-coach-work.html , and http://www.luxurycoachlifestyle.com...scussion/2842-tag-axle-newells-pros-cons.html .

Now what I will try to design here is a vehicle that suits a broad spectrum of potential owners. So even if some do not need tag-axle steering for a 10 m, 11 m, or even 12 m motorhome, I can still imagine that many would welcome it. But again, only if it does not add significant complexity to the system. Only if MAN can add third and fourth axle steering that is every bit as robust and trouble-free as the steering for the first two axles.

Of course, there is the added benefit that tag-axle steering makes a 10, 11, or 12 m motorhome realistically possible, from a maneuverability point of view. One of the major criticisms of very large motorhomes is that they are difficult to maneuver, if only because their turning radiuses are so large. Newell owners will claim, however, that because of tag-axle steering, handling a 13.7 m long Newell feels like handling a much smaller 8 m or 9 m vehicle. So from a marketing point of view, that's certainly something to consider, isn't it?

Think of the issue this way. Could Newell sell as many 13.7 m coaches as it does, if it did not offer tag-axle steering as standard? Tag-axle steering is precisely what makes the exceptional length of a Newell coach possible, and realistically maneuverable, from a customer point of view. This excursion into rear-axle steering may seem too mechanically "detailed" at this stage of the game, and a bit irrelevant. But actually it is completely relevant, because rear-axle steering will have an impact on one's assessment of overall realistic vehicle length. With rear-axle steering, an expedition motorhome could be 11 or 12 m long, but it would still maneuver like an 8 or 9 m vehicle. So this seems worth serious consideration.

All best wishes,


Biotect
 
Last edited:

biotect

Designer
For the technical details regarding how 6x6 or 8x8 all-wheel steering might work, the PDF's provided by Liebherr on its website are particularly useful – see http://www.liebherr.com/AT/en-GB/products_at.wfw/id-20789-0/measure-metric , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-20789-0/measure-metric/tab-13289_1477 , http://www.liebherr.com/AT/en-GB/products_at.wfw/id-3661-0/measure-metric , and http://www.liebherr.com/AT/en-GB/products_at.wfw/id-3661-0/measure-metric/tab-2275_1477 . Other crane manufacturers offer similar products, but as near as I can tell, their product literature does not go into the details of all-wheel steering to nearly the same extent as Liebherr's pdfs.

Again, just want to emphasize that it's the steering mechanism that I am interested in, and nothing else about these cranes -- certainly not their heavy chassis!

Here are some images from those PDF's.

First, how 6x6 all-wheel steering might work:

1.jpg 2.jpg 3.jpg 4.jpg

Second, how 8x8 all-wheel steering might work:

5.jpg 6.jpg 7.jpg 8.jpg

If you have some time to look over these images, and indicate how steering on the rear axles might run into problems different from steering on the front axles (or axle), that would be terrific.

All best wishes,


Biotect
 
Last edited:

grizzlyj

Tea pot tester
Hiya

Where did you find cranes that do 65mph? Limited to 56mph or much less in Europe I would think especially heavier ones in STGO categories? And everything possible is done on a building site to try to ensure they do not experience anything like offroad. The rep will nearly always visit to check before his precious crane arrives, and if more hardcore needs putting down beforehand at your cost then that's what you do. From what I've seen these have as much off road capability as a normal RV :) The biggest I've seen was this year, 1100 ton lift, 9 axles most of which steered, weighed about 90 tons, £24,000 a day :Wow1: The first two days it did nothing while a firmer access and platform was formed, the next two it broke down, then a day to erect, worked for about another four, de-rig another day. All chargeable.

Anyhow.

I almost bought a VW Transporter camper a few times in the past few years. The first time was about 6 years ago and a Bilbo's T4, one of the extra cost options was lower springs. The very low profile poptop only added about an inch to its travel height, but everyone wanted the lower springs because at just a tiny bit under 2m it could get almost everywhere a car could. The LWB was a tiny bit bigger than a normal parking space so that was much less common. All these people compromising on ground clearance and interior space (LWB camper conversions work much better IMHO, yet only about 400mm longer) so they can get everywhere on tarmac.

Every step up whether height, length, width, weight, axle loading or even black tank vs cassette removes another layer of places you could've gone.

Surely you know how many German, French etc etc councils use Unimogs year round, I don't think they have much call for rock crawling ;) Essentially any Mog is most likely too small for where your thoughts are going, but the portal axle design, and the fact that the gearing within that allows lighter weight axle and driveshaft components, means using a Mog can help your camper stay light. The portals will also give more under diff clearance than anything else on comparable tyres so you're less likely to sink in the first place with less weight, and won't ground out when others already have. You don't want to be digging a truck out! I believe portals make CTIS easier and cheaper too. All that without considering chassis flex.

Round and square cab mogs can have rear wheel steer as a factory option, using (from what I've seen) backwards mounted front axles with hydraulic rams to steer at below 30kph approx. The Volvo above may have been converted to rear wheel steer by Unicat not Volvo? Certainly that doesn't look like a truck that would have 16.00R20s as an option from the manufacturer.

Wouldn't big a-typical American RVs be based on mass produced and relatively cheap chassis'? So I know basic Mog and Zetros chassis are easily £100,000 in a basic form, how much is a MAN KAT or Tatra?

A Mog chassis that can be 14tons gross weighs about 5 tons cab only. A 4x4 Zetros that can be 18 tons gross weighs about 8 tons cab only. What does a bare chassis 4x4, 6x6, 8x8 MAN/Tatra weigh? It would be easy enough to build a nice Mog camper for two and stay well below 10 tons loaded.

Personally I would like a hard sided poptop 4x4 camper for 4 people, on 14.00R20 tyres or there abouts, if it could cruise at 70 then lovely but 56 will do, 2.9m high, 6.9m long and as light as possible. Mercedes or MAN based for parts, Euro 3, 300+hp, 10mpg(UK), diff locks, flex, isolating camper mount, hydraulic winch, efficiently charged big battery bank and lots of solar.

People say its the journey not the destination. IMHO the journey would be too greatly compromised by the size vehicle you seem intent on aiming for, there are too many places it would prevent me from getting to. And I have no interest in campsites. What does 12m long get me that 7m can't do 95% as well? People also say if you want to have the luxury of home when travelling then stay at home. The point of going places is to see them, not be stuck on the city limits because you opted for separate bedrooms and don't fit :)

You could also bear in mind the current economic climate? Of course there are people who still want to spend £500000+ on a huge AWD camper (if its true Unicat only clear maybe a dozen a year in total then just 8x8s may be one or two with existing competition), but if you could build what I described above for somewhere near £100000 you would sell loads. I don't think that currently exists unless you build it yourself. Unicat prices seem to be approximately similar to larger house prices, so quite a few people could afford one if they sold up for a year or two. The number of Euro campers who spend £100000 on something for a few weekends a year and is left on their drive the rest of the time is quite surprising to me. I want a big Bremach, a small Zetros, a bigger U20 Mog, axles more common for parts than portals. Bimobil use a 4x4 Iveco chassis but that chassis looks overcampered (I just invented that ;)). The 7.5 ton licence limits produce chassis that as a 2-4 person camper will most likely end up at about 8 tons reading from peoples experience. The truck market thinks everyone want as much as axle limits will take above that, so 4x4 and 18 tons seems the standard but is bigger than 2-4 people need. IMHO that again is where a Mog comes in because there are chassis at 12-14 tons and can be on big tyres from Merc. MAN 4x4s are not well represented in the UK dealers let alone Tatras (so I know more about Merc stuff), so if there is a 4x4 10-14 ton chassis that can come on 395s or 14.00s from the maker other than Mogs I'd like to know :)

Small and efficient is the future, even in the huge off road luxury camper market ;)
 

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