Twin D8

[widget]

Hi all
I found this on the web, might be of interest to some........ A bit of text with it also


Twin D8 built by peterson CAT in 1954

One of Peterson’s early signature designs was the twin D8, patented in 1954 as the “Tractor with Twin Power Plants”. The proto-type was built in San Leandro’s Special Equipment Shop (aka SEQ) in response to the need for more horsepower and a wider blade capacity. The “twins” found a variety of uses, serving as a stopgap for higher horsepower requirements until CAT came out with the D9 in 1955

[Rustypete]

Euclid built their twin aka TC-12, basically by taking 2 x C6 machines and deleting 2 frames to mount them side-by-side.
I remember going with my father to see the demonstration at Upper-Cwm-Twrch OCCS in 1960 or so.

This machine came into view with a wide full coal blade, most impressive.
The driver then slewed and showed the machine's Achilles Heel as the machine bogged and could not extricate itself. another demo machine came over [a C6] and hitched up, but could not get the 12 to move.
The foreman whistled up the site dog [a Cat D8/2U[certainly a cable-blade], which was hitched to the C6 and pulled the whole entourage out.
The Bowmaker boys weren't half chuckling about it.
The Achilles Heel apparently was that when turning the twins only have the power of one unit to drive them in the turn, whereas conventional machines have full-power.

[Deas Plant]

Hi, Rustypete.
Hate to hafta tellya this but a a couple of bits of your post are incorrect.

The twin-power TC12 was the FIRST crawler tractor that Euclid built, NOT the second. It was always a twin-engined crawler with ONE engine driving EACH track and had the FULL power of THAT engine available to that track at all times unless the steering clutch was disengaged.

There were four ways of steering the TC12 - by the steering clutches and brakes, by the throttles, by putting one track in a higher or lower speed that the other and by putting one track in forward and the other in reverse.

They were powered by two GM 6-71 diesels and started at 388 hp, growing to 440 hp at the end of production. Along the way, the name changed to Terex 82-80 and then, I think, to Terex TC12 just before production ceased.

The single engined Euclid C6 was introduced 2 or 3 years later with only one 6-71 engine.

You can find more 'information' about it here:

http://www.heavyequipmentforums.com/showthread.php?8878-Euclid-TC-12-Dozer

and here:

http://books.google.com.au/books?id=oyX4X1B_hLsC&pg=PA22&lpg=PA22&dq=Euclid+TC12+history&source=bl&ots=_NcOztVonw&sig=11vuuXKmklxMux2OODgNWEZ35K4&hl=en&sa=X&ei=fAy8UsOZFYfKkgX7oIGoBw&ved=0CGsQ6AEwCQ#v=onepage&q=Euclid%20TC12%20history&f=false

On the 'Siamesed' D8's, there were three of them built. One of the first two - the first, I think - went to a clearing contractor on the Hungry Horse Dam project in Montana in, I think, 1949, while the other went to a power station in Ohio for coal stockpile work. The Montana machine was fitted with a rake while the Ohio machine had a 'normal' dozer blade.

The third one, the unit shown in your photos, was the only high-clearance on and was built for King Ranch in Texas. It was fitted out with a 'funnel' dozer and rear mounted root plow built by the Holt Caterpillar dealership in Texas and was used for one-pass clearing of mesquite on the King Ranch. I understand that it was later replaced by a Cat D9G modified to high-clearance and fitted with a similar funnel dozer and root plow arrangement.

Hope this helps.

Just my 0.02.

[modelman093]

Here's my model of the D9g with Holt equipment.

[Deas Plant]

Hi, Modelman093.
That is one very neat job. Thanks for sharing.

I suspect that it might have required quite a bit of grunt for that job 'cos I've read that some of the mesquite they were dealing with grew to around 40 feet tall.

I did e-mail King Ranch asking for more information about their Siamesed D8's but the e-mailed back saying they would require a $70.00 search fee to go into their archives to look for it. At the time, I was gathering information for a display of Buster Peterson's 'toys' for an upcoming vintage machinery show in California and any information that they supplied would have been free publicity for them but they didn't see it thataway. They didn't get any $70.00 either.

On the plus side, a contact in the Netherlands sent me a batch of photos from God knows where that showed the unit split and on two railway carriages for shipping to Texas. The world can be a wonderful place.

Also included in the attachments is a copy of the patent application for these jiggers. See the PDF file.

Just my 0.02.

[widget]

Some great input there guys Its kept me busy for a while.

The patent attachment is fantastic and well worth a browse through, its explains everything really well.

The nearest ive got to demolishing mesquite is the pancakes when i was in Arizona

Richard

[westernc]

xxxx

[westernc]

sorry a bad test...

[westernc]

Hi Deas Plant

Allis Chalmers HD38 Garrison Dam Peter Kiewit and Morrison Knudsen in 1949 (sorry for the quality)

[westernc]

and Western Contracting HD 19 (1948-1960) picture from the HCEA