Bulldozer Question

[sapper740]

Originally Posted by Paul Ramsden

I know its not really a CMP question but you blokes seem pretty knowledgable about these things.
In have been reading accounts of the British using D4 and D7 Bulldozers. What do these designations actually mean? I presume it is weight or something. Picture comparisons or dimensions would be useful.
The reason I ask is I read an account of the British parachuting D4s into the Borneo Jungle and as a model maker thought it might make an interesting diorama. However in 1/35 scale I can only find the resicst D7. Would it be feasable to parachute a D7 or are they way too big?
I also found a Clarke Airborne Bulldozer, how does this relate in terms of D rating?
Thanks
Paul

It definitely wasn't feasible to para drop a D7 or even a D4 in WWII, at least out of a transport. The reason why? No aircraft existed during that time with a rear ramp that could be opened in flight. The C82 had a rear ramp, but the clamshell fairing couldn't be opened in flight. It would have been suicide to push a D4 out the door of a C46 or C47 in flight as the shift in C. of G. would cause a crash long before the dozer could have been manhandled out. I'll include a pic showing the effort taken to load a D4 into a C47...now try that while the aircraft is flying! I guess a dozer could have been slung beneath the bomb bay of a large bomber...I don't think it would fit inside, at least not completely. It would create terrible drag and probably adversely effect the handling of the bomber. I never heard of such a thing and doubt it ever happened. Derek.


(P.S.) Hmmm, it's not allowing me to upload a picture of several grunts manhandling a D4 into a Skytrain. Oh well, these days I'm happy to simply be able to post a reply!

[Keith Webb]

Originally Posted by sapper740

(P.S.) Hmmm, it's not allowing me to upload a picture of several grunts manhandling a D4 into a Skytrain. Oh well, these days I'm happy to simply be able to post a reply!

Here goes...

[sapper740]

Originally Posted by Keith Webb

Here goes...

Thanks Kieth, much appreciated! Y'know, after taking a good look at the dozer being loaded into the C47 in this pic, it's too small to be a D4, I wonder if it's a CA-1?

[George McKenzie]

Hi First I will say that the older cats pre 1936 numbers stood for horse power .A 30 cat had 30 HP a 60 had 60HP .The 35 was the first deisel .The R series were R being a gas ,RD is a deisel The RD 2,4,6,8 and some U series were the Catipiller modles used in the ww2 .I put a D7 in a Hurculies aircraft in Yellowknife where it was hauled to the artic we had to remove all the dozer parts ,blade and C frame maily because it was too wide ,not too heavy .I might add that these cats did not have canopies on them and when working in the bush kild alot of operaters from the tree tops comming down on them .Some were sheeted in with iron and used in combat They were so reliable that they made a great impact on the out come of the war George

[Lang]

Keith,

I agree with Sapper that it is a little baby Clarke air portable tractor.

[Lang]

Some Clarkair photos

the action scene is at Nadzab in the Markham Valley in New Guinea. The equipment all arrived by air.

[sapper740]

Originally Posted by Lang

Some Clarkair photos

the action scene is at Nadzab in the Markham Valley in New Guinea. The equipment all arrived by air.

Lang, you seem to have the same interest in the ClarkAir as I do. I have about 40 pictures of the little dozer and it's attachments, if you're interested in any, let me know and I'll email them to you. I've just posted to "Transporting the Clark-Air CA-1 bulldozer" regarding the temporary stub axles I've seen on them before. If you're interested, check it oout. Derek.