Wothahellizat Mk2 compared in size to Wothahellizat
Photos of Wothahellizat Mk2 →
Wothahellizat Mk2 construction diaries →
This is a brief description of the design criteria
we have for our motorhome. There were three basic requirements, these being,
- To be comfortable to
live in for long periods of time (years).
- Be able to boldly go
where few motorhomes have gone before. Which is to say that it must
be capable of getting off-road.
- To be self sufficient
and able to stay in wilderness areas for extended periods, days, weeks
or even months.
Let's expand on these
If you're going to permanently live in and run a business from a vehicle,
then it has to be fairly large to be comfortable. Wothahellizat Mk1
was 34' (10.5M) in length, this was extremely comfortable to live in
but limiting when we got into the bush.
2 is smaller, approx 8.1 metres (26') in length.
Many of Australia's best landscapes are in areas that are hard to get
to. There are two issues here,
- The roads are often
extremely rough with washouts, creeks, boulders etc.
- Even if not that rough
they are unsealed and usually badly corrugated.
Any motorhome that is
to survive these roads for long must be very tough. The normal off-the-shelf
motorhome is built more along the lines of a caravan and designed for
use on bitumen. Their frames are often made of timber and the cabinet
work is usually just stapled together. A vehicle made with these construction
techniques will self destruct under prolonged outback travel.
When it comes to getting off road the normal motorhome doesn't cut it
either. With long overhangs, high gearing and low clearance they will
bottom out on the simplest of obstacles. There are three things that
give a vehicle off-road capability,
- the higher the better.
- all wheels must be driven to spread the engine's torque and reduce
the possibility of wheel spin.
- when the going gets tough you must be able to reduce the vehicle's
speed to a crawl but also maintain engine revs. This requires extremely
You only get these features
in a vehicle designed for off-road use. Combine this with the stronger
construction of an off-road vehicle and I believe they are the best
choice for the job.
If you are going to spend time and effort getting to a remote spot it
doesn't make sense to stay for only a day or two. If it's a nice place
then you want to spend some time there, a few days or even a couple
Do this in several places
in a row and before you know it you've been a month or two in the bush
with no supplies of electricity, food, water etc. Therefore the vehicle
must be fully self sufficient for periods of at least a month. This
means carrying enough supplies of all kinds. Let's do a few sums.
- I like a long neck (750ml bottle) of home brew each evening. As
I make 30 bottles per batch I need provision for at least two batches,
one fermenting and one for drinking.
- For outback travel you should allow 5 litres per day per person
(we'll forget about the beer for the moment). Add 5 litres for washing
etc and we have 10 litres per day, x 30 gives us 300 litres for a
month. We've managed to fit nearly 600 litres in seven tanks. What
about showers? When the water is scarce we make do with a bird bath.
- Some people can live with a just light bulb. However I run a photographic
business, this means regular use of phones, computers, printers etc.
Gas fridges are not known for their reliability and have to be kept
fairly level so we have a compressor style fridge. In fact we have
three fridges although not all are in use all of the time.
Also, as mentioned several
times, I want to be comfortable so I want to run electric fans (in
the tropics we sometimes need fans for most of the day and into the
night) and not be miserly with the lighting.
Fortunately much of
Australia is blessed with sunshine, and plenty of it. Solar is a viable
option for lower usage rates but cannot handle high usage. A generator
is noisy and requires quite a lot of fuel. Batteries last a lot longer
if they are kept "topped up" at near full charge, a generator
is very efficient at dumping current into near empty batteries but
not so good at applying small top up charges. Solar is exactly the
What's the answer? In
general we are totally self-sefficient with our solar panels and have
been living off them since 2001, however we also have a 2kva generator
for those times when the sun isn't shining. For example we once spent
a month under cover working on the truck, during this time we ran
the generator constantly.
- If you break down in the outback you don't just call the AA, you
fix it yourself. This means a comprehensive set of tools including
This all adds up to a
lot of space/weight. Most motorhomes I've seen don't even have enough
storage for the 65 bottles of beer, let alone the food, water and myriad
of things I haven't mentioned. You need a large truck to be able to
carry this amount of supplies.
Our ACCO has a GVM (Gross
Vehicle Mass) of just over 14 tonnes which is more than enough to carry
all the above.
Right elevation, truck in driving
Left elevation, truck in camping
motorbike dropped down and deck folded out.
On the left we have the kitchen bench with a sink at the bottom
and three-burner cook top at the top. The mangle stores in the utilities
area and swings out over the sink.
On the right are various storage compartments,
pantry, fridges, beer etc. There is also a nook with a small shutter,
this gives a little more bench space and will be used for coffee
making. The shutter will provide some airflow to what is otherwise
a fairly dead air area.
All "windows" are really openings with shutters and no
glass. As with Wothahellizat 1 we are going for maximum ventilation
and this version will have even more.
Bathroom & entrance
The 800-odd millimetre square area that on most motorhomes is just
an entrance has several uses. Depending on what is slid out or opened
up it is a shower, toilet, vanity, or kitchen bench, and of course
All the gas and water systems are contained in this area, there
is no piping of any kind leading off into walls to get to other
parts of the truck. This makes things cheaper and simpler to build
and a lot easier to maintain. There will be a large shutter on the
outside that, when open, will allow easy access to everything.
Originally I wanted the electronics to be here
as well but that didn't work out so the batteries, inverter, gauges
etc will now be in a compartment behind the left side of the lounge
Deck & motorbike
When driving the motorbike stores in an area that is either the
front of the lounge room or the rear of the deck according to what's
open. The bike is in a compartment that lowers to the ground with
the roof of the compartment becoming the floor of the rear half
of the deck.
The rear wall of the body opens both up and down
to become the second halves of both the deck roof and floor. If
the rear wall is not opened then we have a larger lounge room.
When the panels are open the rear half of the
deck is protected from the elements because it is actually inside
the body, although it to has shutters that can be opened if more
ventilation is required.
The lounge room has a full height passage down the centre but the
chairs sit on plinths about 300mm (1 foot) high. Inside these plinths
are six 84ltr (19gal) water tanks giving a total 504 litres (112gals)
stored internally with another 84 litres in an outside tank.
The rear wall of the room are glass bi fold doors,
when open these provide 100% opening to the deck area, or if the
deck is closed, opening these doors creates a larger room.
The bedroom sits over the cab and encroaches slightly into the kitchen
area. It to has shutters all around for ventilation. There is only
about 650mm (25") of headroom but there is a huge hatch that
opens the roof to the sky.
Whereas the "Design Criteria" section describes
the basic rational behind the major design decisions,
this section covers the actual specifications of the
ACCO Mk 5 ex-Army vehicle. The chassis has been extended
by 1 metre.
6354 diesel. 6 cyl, 6 litres (354ci), turbo charged.
SMA 475, 5 speed synchromesh.
range transfer case. Six wheel drive. Permanent four
wheel drive on rear bogie and selectable drive to
rims with 1200/20 tyres, 1 spare wheel/tyre, 1 spare
air over hydraulic split system enhanced with Jacobs
truck, 24v & 12v house. Total re-wire of
truck harness performed.
2.35m (7'8"), height 3.4m (11'), length 8.1m
(raw, no tanks etc): 6 tonnes (13,200lbs)
Chassis (including tanks, spare wheels, storage
bins etc): 6.5 tonnes (14,300lbs)
Total: 12,500 kgs (27,500lbs)
14,020 kgs (30,844lbs)
(14") under diffs, 500mm (20") under most
- 47 degrees
Exit - 47 degrees
Ramp over - 140 degrees.
litres (130gals) diesel, 100 litres (22gals) petrol
(for motor bike & generator).
(1125 miles) on-road. Off-road, depends on terrain.
(9 tonnes) PTO driven winch, pulls to front or
rear. 2x ground anchors, assorted shovels, chains,
straps, snatch blocks etc.
litres (130 gals) drinking/fresh in seven tanks, 55
litres (12 gals) grey. Serious filtration on drinking
water, use water from anywhere.
x 9kg bottles.
||4 x 100w, 2 x 125w and 4 x
250w solar panels giving a total of 1650 watts nominal of panels generating
51 amps @ 24 volts. 3300 watt inverter is also a 100 amp 24v battery
eu20i, 2000-watt 4-stroke inverter style generator.
Used only for backing up the solar system.
||14 x 120Ah 12v deep cycle AGM batteries
makes a 40,320Wh battery bank or 1680Ah @ 24v.
burner Highland gas cook top, 240 litre 24v Fisher
& Paykel fridge (120 fridge, 120 freezer), 30
litre Endel drawer fridge, 15 litre Engel chest fridge/freezer.
Atwood gas hot water system. Spinflo gas oven/grill.
Dometic (aka Eiberspächer) diesel heater.
aluminium tread plate over all of body. No protrusions
or visible windows/doors.
body is made entirely from steel. It is mounted to
the chassis at four points (diamond pattern) using
special rubber mounts. This system allows the chassis
to flex without affecting the body and also provides
good vibration isolation.
Provision for 65 long neck beer bottles and three
and AM CBs, hand-held UHF, NextG mobile phone.
and refillable water fire extinguishers accessible
from outside. Powder extinguishers and fire blanket
heavy items below chassis and most storage as low
roof provides shade, also well insulated with
ThermaSheild paint and closed-cell foam.
small compressor for running air tools and pumping
tyres but also used as a backup for the engine's
windows in living room fully open for ventilation.
has full-length "windows" (just openings,
no glass) on three sides at bed level to provide
for one Honda SL230 motor bike in lounge room.
toilet opens out for use then returns to allow
passage through entrance.
deck folds down to provide outdoor living space.
can be pressurised while driving to help keep
dust from entering.
self contained in the bush with no facilities
for periods of at least one month but probably
up to three months.