OKA

They have some restoration advantages compared to many similar aged vehicles.
Many components were "borrowed" from other common vehicles.
Sheet metal is all flat, glass is all flat, most mechanical bits are still readily available and if not, it is viable to use something else or make one.
For instance, with the one that I am building up as a light weight motorhome at the moment, I have replaced a lot of the sheet metal with 1.5mm gel coated fibreglass sheet that is glued-on, and cab door windows are 6mm scratch resistant polycarbonate.
And there are 2 specialised OKA parts suppliers, one in Melbourne and one in Perth (who also has much of the original tooling).
Cheers,
Peter
OKA196 motorhome

Peter,

Not to put a dampener on your build, but are you sure that polycarbonate replacement windows are legal in in Australia? From my understanding of the ADR’s, (ADR 8/01) Polycarbonate replacement windscreen and side windows are only legal on race cars, specific Off Road vehicles, and some earthmoving and heavy machinery. It is not legal on passenger cars and trucks used on public roads and highways.

Macca.

Thanks Macca.
Windscreen not permitted.
No complaints from my engineer regarding the side windows. :)
My engineer once said to me "If you always did everything according to the rules, you would not need me."
Fingers crossed.
Cheers,
Peter
OKA196 motorhome

From what I read some caravan and bus side windows are polycarbonate and compliant. Light weight, strong, less prone to shattering from impacts or vibrations and can be double glazed offering better installation etc.

I have been using polycarbonate in the rear windows of the OKA for about 15 years after braking acrylic ones on a regular basis.
Never broken a polycarbonate one, although standard polycarbonate does scratch more than acrylic. The scratch resistant polycarbonate version is far superior, but a lot more expensive.
Cheers,
Peter
OKA196 motorhome

.
My engineer once said to me "If you always did everything according to the rules, you would not need me."

That's what solicitors say too.

Engineers have done a couple of things for the OKA that were technically "against the rules".
The two DIY rear seats in the camper section are sideways facing with a table between them. They have lap seat belts and are approved for travel use.
We have an approved child seat mounting fitted on top of the engine cover between the driver and passenger seats in the cab. If you read the "rules" this would not seem to be possible.
My son actually had both of these things approved by an engineer in Queensland when he borrowed the OKA and I had them re-approved by my engineer in Adelaide later.
Cheers,
Peter
OKA196 motorhome

Hi Pete,

That is not my reading of the ADR’s regarding passenger side windows with respect to road vehicles as opposed to race vehicles and heavy machinery. However, as long as you have your eyes wide open with this, and your engineer signs off, and your State Transport Authority agrees with your engineer’s interpretation of the relevant ADR.

Batts,

Passengers are not permitted to travel in caravans when “on the move”, so this ADR does not apply to them. As for busses not having safety glass side windows, I am not sure if the OKA, comes under the classification of a bus. It may well do, and if it is registered as a bus, this would be how Pete’s engineer can get this approved. This then begs the question as to what licence category Pete has. If the OKA is registered as a bus, then technically it requires a rigid bus licence to drive it.


Regards, Macca.

There were lots of OKAs registered as (tour) busses if they had sufficient passenger seats, but that comes with a significant registration cost impost and lots of other rules that have to be complied with, like annual inspections.
There is a maximum age that a "bus" can be before it can not be a "bus" any more.
Most OKAs that move to private ownership quickly get re-specified as campervans/motorhomes which come with a different set of rules but they are cheaper to maintain on an annual basis. Many of those retain the original (safety glass) windows and some of the original seats.

My current OKA was a "bus" when purchased but quickly became a "motorhome" and it had a GVM of 5.5T which required a "Light Ridged" license. The GVM was subsequently increased to 6.6T (a "Light Ridged" license is good for a GVM of up to 8T). The new build will have a GVM of 4.495T which only requires a car license. There is no intention, at this stage, to install approved seats in the rear, but I could.

It is all a bit of a mine field and having an engineer "on tap" is essential to avoid major stuff-ups.
I am currently working through one that I had not come across before.
The diesel tanks (3) are all DIY designed rotomoulded polyethylene. I made the moulds and had them locally moulded.
The largest is 200L but has no baffles. I was concerned about that, but it seems to be fine with the engineer. The fillers have screw-on caps with 'O' rings so they need seperate air bleeds. The fuel is subject to 1G vertically down from gravity plus 1G horizontal from braking forces. The resulting force vector is at 45 degrees upwards and forward. The length, angle and height of the vent must ensure that no fuel can overflow through the vent and onto the road.
It seems that all of my 3 vents will pass OK and I could have easily modified them if they had not, but this was all new to me.

These are not just OKA issues, of course, they apply to any DIY build.
Cheers,
Peter
OKA196 motorhome

Sometimes "don't ask the question unless you know the answer " applies.
Dave.