I've been churning out softskin conversion pieces for GMC trucks lately, and it got me thinking about building a Ponton Bolster Truck based on the Tamiya CCKW with a set of my banjo axles from Shapeways. But I'm short on hard info about these trucks and hoped the community might have what I need. I've seen a number of restoration threads of real ones with tons of photos, but for things like the pivoting bolster beam and the bars protecting the cab I really need dimensions. There are no scale drawings on the web that I can find - anyone got drawings or details from a TM to share? And on the bolster trailer, anyone know if they had the same standard DUKW 11.00-18 wheels and MD tyres as the truck?

For those interested, my recent SW stuff includes banjo axles for both Tamiya and Italeri kits in 1:35, as well as G7113 tractor and G506 Chevy conversions for the Italeri water truck. Other parts include a set of replacement (correct-length) DUKW rear springs & prop shafts for the Italeri/Airfix kits.

Thanks in advance for any info offered!

I've run into similar problems before (turrets on aircraft for example) and have contacted folks at those restoration sites. Usually they are more than happy to provide a few photos in exchange for a donation to their restoration efforts.

As for your banjo axles - I'll be ordering a set of the 1/48 ones as soon as I find a few other "must have" items on Shapeways, so I can combine the order.

Hi Robert,

I'll try, but the best build is over a decade old so I'm not sure if the owner still has the truck, or is even active on the forum anymore.

The 1:48 sets complete with frame are a lot easier than the 1:35 ones! Should be a straight swap of the kit frame & running gear...

I guess so. It would make maintenance easier...



H.P.

Outstanding assignment you have chosen for yourself! Can't wait as this offering is LONG over due. I would be extremely happy to have just the tractor and trailer conversion offered and to pose the trailer, piggy-backed onto the tractor as Frenchy shows above. The boats themselves might be more cost prohibitive due to print size. I will be your first customer.

Note the horn relocated.

Here the vehicle is in all its' glory!









The concept of segmented, telescoping bolster trucks is nothing new as it hails from the logging industry even back to the horse drawn days.



Found this image online some years back. Do not know who might be producing these beautiful long boats.

One challenge will be those high floatation, "super single" tires - the Italeri DUKW tires are extremely too small and someone (sorry memory does not serve) used to offer a resin conversion set for the DUKW that included new tires, correct length springs and proper differentials.

I suspect any TM manual for the DUKW rear end will also serve here for the Bolster Truck.

Some few CCWK's were also built to use the super single tires for, I assume, North Africa, the thought being that these tires would deal better with the sand. So these few trucks would have to use the longer spring suspension from the DUKW as well.


These super singles above don't look that much larger than the regular truck tire so maybe there were two sizes of "super singles" and Italeri just reproduced the wrong tire for their DUKW??????


These super singles however are so big they had to take the fenders off the Ben Hur trailer to accommodate them.


These tires are significantly larger than a standard CCKW tire!

Random reference photo:

Hi,
This conversion is something I have often thought of doing.

One work around would be to use the axles from Italeri"s DUKW.
Mig did a set of wheels for this a while back and would then fit direcly on and spacing on the springs should be correct, at least as far as fitting then goes. Then use the wheels from the dukw kit ob the bolster trailer.

The DUKW could then either be used in a water diorama or using the Tamiya wheels to make a very early version.

Regards Jason

This is where casting comes in handy. Make one mold, cast your wheels, and still have an intact donor kit. If it's not one you wanted, resell it.

The set of resin wheels that I bought included front and back springs, axles and differentials so no need to buy the DUKW kit at all.

Not sure these would be the best option....

https://www.track-link.com/reviews/1026

H.P.

Hi Rober and all,

My idea was mainly for people considering this conversion themselves rather than if you already have the
Parts required.

As for the Mig wheels that's the first negative review I have seen. I have them and they look great.

Another wheel option that's a bit more esoteric is a French rebuild that used one piece wheels with Michelin XCL tyres.

A useful reference may be Wheels & Tracks. Magazine issue 70 (I think) had a useful article on the bolster truck and touched on its M series replacement. If I remember correctly ( I am about 200 miles from home so it's hard to check there are some useful drawings of the vehicle and you should be able to scale things out.

Regards Jason

The wheels aren't a big problem - I designed a DUKW set of MDs (Military Desert) based on Kurt Laughlin's data on the real thing, and they are now available as a set from Resicast. But they have the central inflation hubs moulded in that are not used on the bolster truck, so I'm looking at the DEF set (or will do when my set arrives) or I can always 3D print my own. The Italeri wheels from their DUKW are just plain wrong, and sadly so are the Mig wheels.

Kurt supplied me with 1943 info where the Army was testing the use of the MD wheels on banjo-axled CCKWs, but by D-Day they had abandoned the idea of widespread issue because the main need evaporated once we had secure ports to unload on hardstanding. There were NDCC (non-directional cross-country) wheels developed that were similar to the MDs but had deeper tread and longer life, but I think they appeared post-war on things like the Class 530 fire truck, and eventually the M34/M35 series trucks that replaced the CCKWs. The 11.00-18 MD wheels on the DUKW were some four inches taller than the 7.50-20s on a standard CCKW, so were two inches bigger on each side, and were fatter across. This meant they could indeed foul the fenders of the Ben Hur trailer! The bolster trailer seems to have enormous fenders to compensate.

That's because most aftermarket item reviews judge accuracy on how well they match the kit part they replace or out and out say "I can't speak to accuracy but they look great!"

I wrote up my philosophy here:https://www.track-link.com/articles/1119

"After-market accessories are not kits. We buy kits figuring that it will more or less be a good representation of the subject, with the acknowledgement that there will always be some compromises if the kit is to remain affordable. Accessories, on the other hand, are purchased solely to correct or improve the kit parts. Given that they can easily cost 25% to 100% of the base kit’s cost, I have the expectation that they ought to be better than the kit part, if not downright perfect. With this in mind, I tend to be significantly more critical of an aftermarket item than a kit, even a kit made for the specialty market.

"People are going around making thumbs up/thumbs down decisions based upon the general look or upon nothing at all. If that’s all there is to it, why should a company try to get it right?"

KL

I have the desert modification information around here and the kit included tires, supplemental water and/or oil coolers, and an air compressor. I don't recall it involving the suspension.




It was the wrong tire alright. It doesn't match any real tire or even have a realistic cross-section.

KL

A museum nearby had a bolster trailer and the owner asked me to find out what I could about it. That was very little, mainly because these were not Ordnance or even Quartermaster items but Engineer equipment. Unfortunately the museum owner died about a year later and the collection scattered.

KL

A few more images from my files:

If you use those large resin cast super single tires you WILL definitely have to have extended longer rear springs.

I say that because I had already assembled AND solidly installed the stock rear suspension in my Italeri DUKW before receiving the new resin tires. Rather than run the risk of ripping that all out I was able to build spring extensions and relocate the axles to accept the larger tires!

Did some digging in the stash. These are the CMK Masters conversion set wheels as compared to the stock Italeri DUKW tires:

(I figured I would save the smaller Italeri tires to one day convert some Deuce model yet to be conceived.)

I think this comparison works because I ran the red line off the top of the Jeep tire and it runs parallel to the line of the running board so it therefore correctly projects the perspective forward. (30+ years of graphic arts, exhibit and stage design.)

So if you know the outside diameter of the Jeep tire this will give you a further size comparison.

Hi,

In the 3rd picture of Michael's most recent post of pictures you can clearly see the later French wheel/tyre combo.

Regards jason