Classic Machines Scrapers

Classic Machines: The Wabco D/111A scraper

Having covered the conventional model D scraper in the April 2008 edition of Contractor mention was made of the most significant offshoot of this machine, namely the elevating scraper variant which was initially called the model D/10E2. By Richard Campbell

Introduction of the Wabco D/111A served two purposes: As an entry into the land development sector, and to counter the threat that the John Deere 5010 posed to the small end scraper market – this was reflected the inroads that sales of this machine had had on LeTourneau-Westinghouse’s balance sheet. Other manufacturers were also looking seriously at the new type of scraper and planning models of their own, notably Euclid.

Discussions were begun with Hancock of Lubbock, Texas in 1960 for a suitable elevating scraper bowl. The model proposed was the Hancock type 10E2 which was of 10 cubic yards capacity and well within the hauling capabilities of the model D Tournapull.

Due to the utilitarian design of the model D, it was relatively easy to adapt the hitch to attach another kind of scraper to the rear of the machine. There were already attachments such as a rock hauler, crane, flat bed and logging arch available to suit customer requirements.

Where the model D/10E2 caused LeTourneau-Westinghouse problems was in the area of hydraulics, as all prior attachments were designed to be operated by electrically controlled winches. Electric motors could be used to power the elevator gearboxes but bowl adjustment and dumping were designed by Hancock to be hydraulic.

A solution was found by attaching a Vickers vane type hydraulic pump directly to the front of the engines crankshaft projecting under the radiator and routing the associated hydraulic lines along the right side of the machine to a small hydraulic tank which was located in the operators compartment. It was fortunate that this area of the model D was quite roomy.

The front frame was extended forward slightly and a new kind of front bumper added to protect the hydraulic pump. The necessary operating valves and levers were placed on top of the hydraulic tank.

This setup changed very little for the entire 25 year production span of the machine.

Powered by a 148 horsepower General Motors Detroit Diesel model 4-71 naturally aspirated four-cylinder inline diesel, the model D could be supplied with either a four-speed Fuller 5G720 manual step gear transmission or a four-speed Allison CLT3341 powershift transmission.

Most users preferred the Allison powershift and it is quite rare to find a model D elevating scraper with the manual transmission still installed.

By the time the final model of the 111A was introduced, engine output had risen to 160 horsepower and the transmission was the variable input Allison VCLT3361.

The designation of the machine was changed from D/10E2 to 111A around 1966. This coincided with an increase in bowl capacity from 10 cubic yards to 11 cubic yards.

Hancock’s original 10E2 featured a sliding floor with doze out election and a fixed cutting edge which was very useful for trimming up fills.

Twin electric motors powered the 16 flight elevator which gave it a tremendous amount of torque for loading. The motors were reversible to assist in unloading sticky material.

When Wabco changed the machines designation they made few alterations to the bowl other than extending the side sheets, thereby increasing capacity. The bowl lift cylinders were also beefed up somewhat from previous versions of the machine.

Most changes however were made to the tractor unit with better access steps, a wider windscreen, more horsepower and the standardization on the Allison VCLT transmission.

Steering was electrically controlled and it was essential to always maintain rated engine rpm for the optimum operation of the electrics. This was true not only from a safety aspect but also from a maintenance point of view as the electrical contactors would carbon up or pit at low voltages resulting in the loss of that particular circuit – particularly if that circuit controlled the steering motor!

Provided one looked after the electrical requirements of the machine it was a great scraper to operate.

One of the nicest (and most overlooked) features of the 10E2/111A was the no-spin differential. In bad underfoot conditions this allowed the wheel with the best traction to have the most power while limiting wheel slippage to the wheel with less traction.

Unlike the diff lock fitted to other elevating scrapers which effectively locks up the drive axle preventing wheel spin, the no spin element on the 10E2/111A allowed the machine to be ‘duck-walked’ through bad ground, a process which would do major damage the differential on a machine fitted with a conventional diff lock.

Although the standard listed tyre was the 18.00 x 25, most users preferred the wide base 23.5 x 25 for the better floatation it provided.

Due to its size and low tare weight the 10E2/111A was legally roadable in most places, adding to the machines versatility.

The Model D 10E2/111A with elevating scraper was a big seller for Wabco with several thousand being manufactured in two different countries over the machines production span. Wabco discontinued the 111A in 1977

The New Zealand Connection

Once contractors embraced the idea of the elevating scraper, sales of the D/10E2 and 111A began to take off with ultimately over 50 being delivered in the country.

The machine appears to have been more popular in the North Island rather than the ‘mainland’, and especially popular in the Wellington, Northland and Auckland regions.

Some operators included Ray Withers, Kay & Sons, Goodman Earthmovers, R.J.Marsh, Somners (Waipu) Ltd, Clouston & Lake and Northland Roadbuilders to name but a few.

Some of these machines can still be found putting in a day’s work.

Brief Specifications (late model 111A)

Engine:                     GM 4-71, four-cylinder inline, naturally aspirated, 160 horsepower

Transmission:          Allison VCLT3361 6-speed full powershift

Top Speed:              26mph

Brakes:                     S-cam expanding shoe

Steering:                   Positive electric motor kingpin steering, 90 degrees in each direction

Std.Tire:                   23.5×25 (in New Zealand)

Capacity:                 11 cubic yards

Operation:                Electric operation of elevator, hydraulic operation of bowl lift and ejector

Elevator Flights:       16

Turning Circle:         27’ 3”

Length:                     32’ 4”

Width:                      8’

Height:                     9’ 1”

Operating Weight:    14.8 tons (empty), 28 tons (loaded)

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