Contractor

Michigan’s Open Bowl Scrapers

While Michigan scrapers had been around for quite a while, as a scraper brand it didn’t really make an impression in New Zealand until it teamed up with Hancock and began to offer elevating scrapers in the late 1960s.

Your author has only ever seen one open bowl Michigan scraper in New Zealand, a model 110, and it has long since gone to the scrapyard.

I have been asked by several of our readers for more information on these older machines so the following is a brief overview of the history of Michigan’s open bowl machines.

Michigan, a division of Clark, surprised everyone when it introduced its first motor scrapers in 1957.

In a market segment that included Euclid, Caterpillar, LeTourneau-Westinghouse, Allis-Chalmers, Curtiss-Wright and International-Harvester there didn’t really seem to be any more room for another brand.

Michigan was after a share of the burgeoning US highway building programme. But it left its run a little late as most of the really big jobs had been almost completed by the time Michigan got its machines to market.

There were initially three models – the 8 cubic yard model 110, 13.5 cubic yard model 210 and the 22 cubic yard model 310.

All were of exceptionally clean, modern and functional designs and used Cummins diesels as their powerplants.

Also, they utilized all-Clark powertrains including powershift transmissions, differentials and planetary final drives.

Design of the bowl drew heavily on Euclid influence but apart from that one concession, the machines were ‘all-original’.

In 1964 the three models were joined by another machine, the 33 cubic yard capacity model 410 that was powered by a 570 horsepower Cummins VT1710-C diesel. This very large machine either did not live up to expectations or was introduced at a really bad time as less than 20 were ever manufactured and by the end of 1968, the 410 was discontinued.

Next to go was the model 110, discontinued in 1969.

However the news wasn’t all bad for the model 110 as it reappeared again in 1970 paired with a Hancock elevating scraper (Hancock was also, by this time, a division of Clark).

The models 210 and 310 soldiered on up until 1975 when they too were discontinued as Clark-Michigan decided to concentrate entirely on elevating scrapers.

Quite a popular brand in Europe (the model 210 sold particularly well there) but sales in the USA, UK & Australia were moderate at best.

Those contractors with other Clark-manufactured products in their fleets found to their benefit that the Michigan scrapers shared a high degree of parts commonality with their Michigan loaders & wheel dozers, a concept well ahead of its time.

The Michigan 210 Described

As the model 210 was the most widely produced variant we will examine this type in detail.

A 262 horsepower Cummins NTO-5-CI turbocharged 6-cylinder diesel provided the power and this was remotely connected via drive shaft to a Clark 4-speed full powershift transmission.

At customer’s request, a 290 horsepower GM 8V-71 V8 diesel could be fitted in place of the Cummins.

The all-Clark transmission, differential & planetary axle powertrain was a proven and reliable unit and gave few problems.

A quite respectable 29 mph was attainable in 4th gear on a smooth haul road.

Standard tyre equipment was 26.5×29 all round with air operated shoe type brakes providing the stopping power.

Very well styled, the 210 tractor unit looked modern and fast.

Twin, double acting steering cylinders were mounted low down in the well behind the engine compartment and were attached to linkage at the base of the machine’s triangular hitch.

As alluded to earlier, the bowl employed many of the design features of contemporary Euclid scrapers.

Holding 15 cubic yards struck and 20 cubic yards heaped, the bowl featured a 4-piece reversible cutting edge and was raised and lowered by two single-acting hydraulic cylinders buried in the gooseneck.

These were attached to levers and links on the bowl’s spreader bar while the apron was raised and lowered by a similar lever acting on a 13-foot length of cable.

Where the design differed to that of Euclid was in the use of a bulldozer type ejector instead of a roll-out type.

Bowl, apron and ejector were all independently controlled.

The operator sat in a relatively sparse & narrow compartment placed just ahead of the left wheel and was provided with an air suspension seat.

Instrumentation was mounted on a panel bisected by the steering column with the transmission shifter and bowl operating controls mounted along the left side of the bonnet.

A small sliding door allowed engine heat into the operator’s compartment in cold weather.

Optional equipment did include an insulated cab with a heater, but at an extra cost.

Your author has seen very few photos of early Michigans fitted with this cab. As the operator’s compartment on these machines was quite narrow it must have felt like being in a cell!

The New Zealand Connection

Andrews & Beavan was the New Zealand franchise holder during the heyday of the Michigan 110, 210, 310 & 410 open bowl, or conventional motor scraper.

As mentioned earlier, only one of these ever came into the country, a model 110, which was toured around looking for a new home (which it eventually found) and working on several projects before being retired to Sims Metals’ melting pot in 1984.

It is not known why more of these earlier machines weren’t sold in the New Zealand marketplace, however the company did have quite a measure of success later when promoting Michigan elevating scrapers in the late 60s, selling well over 20.

For the Diecast Model Collector

Apart from a very dated Mercury Lil’Toys offering of a model 310 to a very odd scale, there are no models available at all of any Michigan motor scrapers.

Scratch building one of these beasts would not be a very easy task (too many compound curves), so it’s fingers crossed that someone will see the obvious gap and produce a model before too long.

Brief Specifications – 1966 Michigan 210

Engine:                      Cummins NTO-6-CI, 6-cylinder, turbocharged inline diesel

rated at 262 flywheel horsepower at 2100rpm

Transmission:         Clark 4-speed full powershift with integral torque converter

Top Speed:               29 mph

Brakes:                      Air operated expanding shoe type on all wheels

Std.Tires:                   26.5 x 29 22-ply E-3

Steering:                    Full hydraulic, 90° each way

Turning Circle:         34’ 1”

Capacity:                   15 cubic yards struck, 20 cubic yards heaped

Operation:                 All hydraulic

Length:                      38’ 1”

Width:                         11’ 3”

Height:                       11’ 2”

Operating Weight:   24.5 tons (empty) 46 tons (loaded)

 

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