Looking at Vintage Caravan framework

[cobber]

The other day I passed disparaging remarks about The framework (what there is of it ) on Trodlers Rowvan, for which I now apologize Richard
i13.photobucket.com/albums/a278/mrfxfj/RIMG0985.jpg (the image has been deleted )
I was comparing it with the frame on Ol’ 36.

I thought it might make an interesting subject to compare those of our vans that have had the frame exposed during restoration.
Books such as Keith Winser's "Plans for Australian Caravans" show the way he thought it should be done, but I thought it would be interesting to see how it was done
Another 1936 van is the one in the Birdwood museum, much
different to my Ol’ 36

Another great example is Retro1’s Castle caravan shown to us back in 2004

Cobber.
Your contribution go here:-

[Don Ricardo]

G'day Cobber,

Another really interesting thread you've started here. The pics you've posted prove once again that there are many ways to skin a cat, or in this case provide a framework to put the skin on a caravan.

A couple of years ago Mark T posted some photos of Doug and Vicky's Don 120 during restoration which showed the framework the Don company used:
vintagecaravans.proboards30.com/index.cgi?board=photo&action=display&thread=1135121702
The photos of interest are the 4th and 5th in the series. The 4th shows the framework for the rear of the van, while the 5th shows the left hand side (from the front) where the galley is located.

Having looked at the photos you've posted, I'm a bit surprised at how 'mimimalist' the side frame for the Don is. The company described its body and frame as follows:

"Built on the aircraft principle of 'stressed-skin' construction; framed with kiln dried mountain-ash, spruce, and steam bent bows; tongue and groove flooring. Exterior covering of resin-bonded plywood, cut from 25 ft. sheets with minimum jointing. Ceiling of 'Cane-ite' insulating board of 1/2 in. thickness (equal in insulation to 15 ins. of solid concrete)."

Somebody with some engineering know-how can interpret that for me, but I suppose it means that the framework doesn't have to be very heavy because the strength of the body comes from the combination of the frame and the ply.

I'm just glad they decided to use the Cane-ite rather than concrete!!

Don Ricardo

[cobber]

G’day Don,

That thread you posted is a good example of how a dedicated restorer goes about things eh? Where are Doug & Vicky now ?

Much of the rigidity in many vans is provided by the inside fittings I think, things like the cupboards.. wardrobes... beds, etc.
It has been mentioned somewhere on the forum before that if you are doing a full restoration it is wise to leave those items intact and replace the external ply first.

I have not had the need to remove the side panels off Ol’ 36 but from what I can see (inside the wardrobe) it has a substantial frame there also.
Those vertical ribs on the front of Ol’ 36 are not laminated... they are solid bits of wood, steam bent I suppose, do you know if that is the case on the Don’s... Don ?

Cobber.

[Franklin1]

When I took the back covering off Franklin Freedom, I thought it was a bit "light on" with framework... (photo is from a post last year)



When the restoration starts on this van proper in a couple of months, I was thinking of experimenting with steam bending more struts across the back to better support the outer skin, and provide additional anchorage framework for the bed. Would like to do a similar job to what you've got on Ol' 36, Cobber.

So far all I've done is tested the pressure cooker to make the steam...

Al.

[Don Ricardo]

Hi Cobber,

Being the seeker after truth that I am, I set out to answer your question about whether the vertical ribs of Dons are solid wood or laminate. The only exposed part of the framework in our 140 model is in the storage area at the rear of the van under the divan. The following photo shows one half of the area with the left hand side being the middle divider:



The vertical ribs are solid wood which has been bent to shape, as shown more clearly in the next photo:



The surface of the ribs are quite rough, and I wondered if it was the top layer of a piece of laminate. However, I scraped the paint off a small area and confirmed that they are a single piece of wood.

Given that the function of the rear area of the 14 ft Dons is/was different to the 12 ft vans (ie a divan in the 14ft and the table, benches and cupboards in the 12 ft 120's), I was trying to work out whether the basic framework of the models was the same by comparing my photos with Doug and Vicky's, but I'm not really any wiser. The exposed area under our divan is too small to get much idea, and I don't know how much of the frame is missing in Doug and Vicky's van.

Don Ricardo

[cobber]

Don,

Thanks for going to the trouble to confirm that the Don doesn't have laminated ribs. When I looked at that last photo I thought it looked as though it was laminated, then I read your explanation
Obviously the Don factory would have had the facilities to bent timber and this is one of the questions I wish I could solve regarding Ol' 36.... was she factory built and if so... where.

Al,

Not sure I would go to the trouble of trying to steam bent vertical ribs for Franklin Freedom, It ain't easy. I gave up trying to curve the wooden "J" mould on Ol' 36 and finished up taking W.A. Will's advice and "Kerfed" it, and come to think of it I can't see why that wouldn't work for you, if you wanted to go to that extent.

Cobber.