So what's the basic design criteria for
the Graynomad Overland Vehicle (GOV) and why build one at all when I already
have a fantastic 6x6 overland vehicle?
A few years ago we spent three months
living in (or rather beside) our 45-series Landcruiser (story starts here).
For the first two months or so of that trip the weather was great and
we wondered why we needed a motorhome at all. Then the weather turned
to crap and we knew, there's no substitute for a hard-sided warm box when
you get hit by a storm or freezing temperatures.
Still the freedom you get from having
a small vehicle cannot be overestimated. You can just poke you nose down
any fire trail with little thought about getting back out. The same cannot
be said for a 14-tonne truck.
So as you may know on our return from
that trip we pulled Wothehellizat Mk1 apart and rebuilt it as Mk2 which
was a lot smaller. Mk2 is great and about as comfortable as a motorhome
can be while still having the ability to get off the beaten track. No
vehicle is a perfect size however and there's a lot to be said for having
a small camper as well.
Therefore a small Landcruiser-size vehicle
with a house that can be lived in is what we want. We'll be keeping Wot
Mk2 (probably), think of the Cruiser as a holiday home.
The house should be as small as possible while remaining practical.
This is one reason a Landcruiser has been chosen as the host chassis,
I think that's as small as you can go and still be comfortable for
two people to live inside for long periods.
If possible the body should not protrude from the cab's lateral
envelope (the what?), in other words it shouldn't be any wider than
the cab. This means about 1700mm (67").
Overall height currently calculated at 2350mm (7'10") but
that still depends on a lot of things.
The body should be a light as possible. I always over-engineer
things but this time I really hope to make a light-weight body.
To this end it will be a monocoque design using composite panels
(foam/fibre glass), the only steel will be in the sub frame and
a few reinforcing points for spare wheel hanging etc. The sub frame
should be light enough for me to lift, not that I have to lift it,
that just seems like a good a design goal.
The Cruiser has a payload capacity of approx 1200kgs (2650lbs),
the finished product including all fittings, water etc should be
well under this limit. I have a target mass of 1000kgs (2200lbs).
We do not plan to live "beside" the rig as is common
with smaller 4x4s. The house must be comfortable enough for us to
live inside regardless of the weather.
This isolates you from the crap on the ground and means you can
camp anywhere you can find a few square feet of flat land while
paying no attention to long grass, mud etc.
Being off the ground also keeps you away from many annoying insects,
most notably sand flies.
I do not like canvas, I know it's light but it is noisy and almost
impossible to insulate. So the primary tilt top has solid sides.
However the secondary tilt top (over the Luton peak) may have to
have fabric sides, this is TBD.
Of course these will be fabric. There is no obvious way to incorporate
roll-out awnings into the body such that they are not exposed to
trees etc, so I plan to add sail track on both sides and run tarps
The primary pop top (or is it a tilt top) will be raised and
lowered by 24" electric actuators. The secondary pop top will
be raised manually, it may or may not have gas struts.
A backup system has to be devised.
Solar and the vehicle's engine (via a DC/DC charger) will be
the only sources of power. There will be no generator.
Depending on the inverter chosen it may be possible to charge from
shore power as well but this is not a necessity as I can't see us
being plugged in more than a few days a year.
We will be using the new semi-flexable panels, these are about
25% of the weight of standard glass panels. They will not however
be glued to the roof despite this being a commonly-touted feature.
This is a double whammy that stops heat dissipation from the panels
(bad for them) and also looses you your tropical roof.
There will be provision for 1 or 2 remote panels that can be placed
out in the sun.
At this point I'm looking at 720 watts on the roof and possibly
another 480 watts remote.
The only fuel required will be diesel, there will be no petrol
or gas (propane) used. This is for a few reasons, space, convenience
and cost. As the vehicle already has allowance for 180ltrs (47usg)
of diesel it makes sense to use that to the best advantage. Any
other fuel requirements mean the need for jerry cans, gas bottles
etc, all of which take up room.
Propane can be difficult to get in the outback and even if it's
available it can cost a fortune. Also all propane work has to be
done by a tradesman and certified.
So I plan to add a third diesel tank, this of course takes up room
as well but it is multi-purpose in that while the diesel in that
tank is primarily for the cooker it can be siphoned into the vehicle
It would be nice to have allowance for about 200lts (53usg).
This should be achievable by building the tanks into the body. There
will be 2 tanks, one for potable water and one for other water.
It will be possible to transfer water from the "potable"
to the "other" tanks.
The potable tank will in fact be two tanks with a balancing pipe,
thus if one fails it can be isolated.
Two 24v DC water pumps, nominally one for drinking water and
another for fresh water. But valves to allow each to work on either
tank as a redundancy measure.
External pump-in-a-box for filling from rivers etc.
A range of about 2000km (1240 miles) is the goal. With the standard
two fuel tanks and the third tank I install this should be achievable.
Why such a long distance? Are there no service stations in Australia?
There are plenty of course, I suspect that a 400k (250 miles) range
will get you between services stations just about anywhere except
a couple of long desert crossings. But in the outback the fuel costs
are extortionate. Much better to fuel up in a large town and not
have to do so again until the next large town. That can easily be
1000k (620 miles) but if you do any off road work and/or make some
detours you will use a lot more fuel.
Hence the 2000k range.
Assuming you are in the right place at the right season in Australia
one would expect to encounter temperatures no higher than the low
40s centigrade and anywhere in 30s would be the norm. Heat is difficult
to get away from, best not to bother trying and live with it, but
there are things you can do in the design to help.
Ventilation — There are three important
features for a living quarters, ventilation, ventilation and ventilation.
You can can any two of these as long as one of them is ventilation.
This means big shutters that open 100% and plenty of them, not
the poky little windows common in European overland vehicles.
Tropical roof — A second skin to your roof
with an air gap, the larger the gap the better but on a motorhome
usually 25mm (1") is all you want to do to keep the height
down. This tropical roof is easily obtained with no extra hardware
by covering your vehicle with solar panels.
Fans — They use naff-all power and really
help when there's no breeze. In general AC fans are better than
DC and the larger the quieter. Small DC fans make a heck of a racket
which is annoying during the day and impossible to live with at
night when you are trying to sleep.
That said I have an idea to used an array of computer fans with
PWM speed control. More later.
Provision to apply a positive pressure to the house while driving
to keep the dust out.
This vehicle is designed only for use in Australia,
as such it should never see serious cold weather. While it is possible
to have snow even in summer in some places the temps will seldom
get below freezing, so all the stuff the guys in the northern hemisphere
have to address (lagged pipes, heated grey water tanks etc) is not
relevant to this design.
That said it can get pretty darn cold in the desert at night (I
have seen bowls of water freeze over) and we do plan to spend a
lot of time in the high country (with the above possibility of snow)
so the house has to be well insulated.
None as such, but I may have a clever idea to use the diesel
cooker. Watch this space.
The back wall will have a Dometic double-glazed window with built
in fly screen and blind. In bad/cold weather this will be our window
to the world.
All other openings are just that, openings with no glazing. Shutters
provide protection from sun and rain and I'll make magnetically-attached
screens to stop the bugs.
The house electrical system is primarily a 24-volt system. 12
volts will also be available as will 240. At this point a 1000-watt
inverter is planned, this will allow the use of small power tools
such as a 4" grinder and our 800-watt kettle.
24 volts is chosen over 12 mostly because that allows me to run
my DC MIG welder directly from the battery bank but also because
it halves the wire sizes required.
Lithium, specifically 8x 160Ah LiFe04 cells. People will argue
about the numbers but these batteries have roughly 2-3 times the
capacity of lead acid batteries for same Ah rating and they are
So using a figure of 2.5x 160Ah of Lithium batteries is the same
as 400Ah of lead acid batteries. The lithiums weigh 45kgs (100lbs)
and the lead acids would weigh 120kgs (265lbs).
Lithiums are a bit harder to work with in a couple of ways but
they have other features that makes them far superior to lead acid.
I don't want this to get too complicated, but then I am an electronics
engineer and a guy's gotta have some fun.
I have no interest in fancy sound/video systems or the like but
do like monitoring and control networks to keep track of the solar
etc. So I may design a serial network of intelligent nodes for this
purpose. (Actually it's already designed really).
Apart from that all the usual battery, water, temp monitors.
All LEDs of course. External work/security lights as well.
At this stage I plan a 3-point (triangle) mounting using the
same of resilient mounts I used on Wothehellizat, just a smaller
Aluminium Kubelok with 8mm Coreflute infill.
- 15ltr Engel fridge, this will be set as a freezer.
- 30ltr Weaco drawer fridge.
- Eberspacher X100 diesel cooker.
- Electric blankets.
If starting from scratch I would probably go eutectic for the fridges,
but I already own the above.
Porta potti, possibly a second cassette. Maybe a "composting"
toilet? That needs some research.
None inside, sparrow wash or Whale pump with bucket outside.
Four toolboxes below sub frame level (actually part of the sub
frame) and a single locker at the rear of the body for recovery
gear, camp chairs etc.
Foot locker near entrance for shoes (assuming I buy some).
Hopefully heaps of internal storage.
Provision for storage of 46 homebrew bottles and the drum.
Standard steel split rims with pizza-cutter tyres.
All appropriate belts and hoses. Spring and shocky bushes. Power
steering, engine and diff oils, enough to do an oil change in the
field. Two complete spare wheels/tyres and a couple of tubes.
Probably leave standard springs but add BOSS airbags on rear.
Jury still out on that.
A good selection of tools, tyre levers etc. Electric rattle
gun. Also 24V DC MIG welder.
All the usual I guess, including
- Electric winch.
- Tirfor (because I already have one).
- Snatch, extension, tree protector etc etc straps.
- Ground anchor (Army spikes, DIY rack).
- Front and rear e-lockers.
- Maxtrax (or aluminium sand ladders).
- High-lift jack.
- Powder fire extinguishers,
- Reusable water fire extinguisher.
- First aid kit.
- Iridium satellite phone.
- Spot or InReach tracker gadget.