A large brute of a motor scraper, the International-Harvester model 495 was the only three-axle, open bowl scraper ever offered by the Company and it played a big part in New Zealand’s early hydro-electric dam projects. By Richard Campbell
We took a short look at the model 495 back in the December 2004 issue of The Contractor, but at the time, my space was somewhat limited for a full-on history.
Along with it’s sister machine, the model 295, the model 495 was the first motor scraper actually designed from the ground up by International-Harvester itself, all previous I-H scrapers being modifications of Heil Company designs.
International had acquired Heil’s construction equipment division in 1953, a smart move on I-H’s part as it saved itself millions of dollars in R&D costs.
With the announcement of the Federal Interstate Highway project in the early 1950s, there was obviously going to be a large amount of earthmoving equipment required, particularly bulldozers and scrapers.
International-Harvester had the dozer side of things well covered but it had no motor scrapers or towed scrapers of its own, relying on its outside suppliers for such items.
International could see the huge potential sales for such equipment on the horizon and so began shopping around for an established scraper supplier who may be wishing to sell.
Fortunately for I-H, it didn’t have to look too far as Heil were more than happy to do the deal.
International bought Heil’s construction division for around US$1m which was a considerable sum in those days.
With the acquisition came two models of motor scraper which were already in production, the 2C-500/MS-13 and larger 2C-800/MS-18, both known as “Heiliners”.
International re-branded the machines the 2T-55 and 2T-75 and production continued as normal.
Due to the hard loading characteristics of the original Heil bowls, I-H redesigned them from the draft arms back, altering the bowl pivot points and making them easier to handle. This alteration took place in 1956.
The largest I-H scraper, the 2T-75, only held 18 cubic yards heaped and the construction industry’s demand was for larger capacity, faster scrapers which necessitated International to come up with some new product if they were to remain competitive. Thus the 495 (and 295) motor scrapers came into being.
International started with a clean sheet of paper when developing the model 495.
It was powered by the Company’s recently introduced model DT-817 six-cylinder diesel engine which also powered its new TD-25 bulldozer.
In the model 495, the turbocharged DT-817 was rated at 375 flywheel horsepower.
As International-Harvester didn’t manufacture any transmissions large enough to suit their new scraper, they chose GM’s Allison division to provide a suitable gearbox.
The Allison four-speed powershift model CT5840 was chosen as suitable, and for those purists who still wanted a manual transmission, a Fuller RT1150 nine-speed with twin plate 17” Rockford clutch was available as an option.
Most sensible folks chose the Allison !
With this powertrain combination, the 495 could easily attain 32 mph on the flat.
The front steering axle followed a similar design to International’s existing PayHauler off-highway trucks, the PH65 and PH95, being mounted on semi-elliptic springs and featuring a hydraulic steering booster.
Conventional cam activated air brakes were fitted.
International-Harvester, who had decades of experience manufacturing trucks, built all their own drive axles and differentials.
At the rear of the tractor units main case was the 2-drum cable control (PCU), manufactured for I-H by Superior Industries and driven by an extension shaft off the engine.
A model 280A was fitted to units with the Allison transmission and a model 280F to those machine with the Fuller gearbox.
The unit was positioned in an unusual place, on top of the chassis, directly behind the cab which gave the driveshaft that powered it from the engine, quite a short run.
All of the 495’s contemporaries mounted their PCU’s at the back of the tractor main case.
International-Harvester manufactured a 24 cubic yard struck, 31 cubic yard heaped bowl for the 495.
All cable controlled, the original bowl had an unusual apron which was lever actuated via the ejector circuit.
In service, this soon began to cause problems when, in certain materials such as heavy clays, the apron would not open to allow the load out, and bending the levers in the process. This same problem also beset the original model 295 scrapers who utilized the same bowl aft of the goosneck.
An urgent fix was required and this caused a hasty redesign of the apron system and bowl resulting in a more conventional cable tower and sheaves being mounted on the gooseneck to lift the apron part way up at which point the lever actuator did the rest.
Many existing 495’s were retro-fitted with this apron system.
At the same time, bowl heaped capacity was raised from 31 to 34 cubic yards by the addition of sideboarding, I-H executives hoping the extra capacity would make the machine even more attractive for bulk earthmoving.
A fully equipped model 495 weighed almost 38 tons empty & ready for work.
Options
As was the norm for machines dating from the 1950s, there were not a lot of added on options available.
The standard model 495 came with a sunshade canopy but a fully enclosed cab with a heater and windshield wiper were available.
A choice of tyres was also available, the 27.00×33 was standard equipment with the wide base 33.5×35 as an option.
Into (and out of) Service
Introduced in 1958, International-Harvester delivered nineteen machines in the first year of production compared to fifty seven model 295’s.
This caused a little concern amongst the hierarchy as the 495 was meant to be a dragon slayer and compete head on with the Caterpillar 630A, Euclid SS-24 and Curtiss-Wright CWD320.
Unfortunately for International, this was not the case and sales continued to be poor (and slow).
A bottom dump option was also added in the hopes of picking up some of the bulk mineral/coal transportation market but even in this configuration, sales were practically non-existent.
By 1964 International-Harvester had had enough and discontinued the manufacture of the 495 after a total run of only eighty five machines.
By comparison, the 2-axle model 295 had sold over a thousand units and had gone into a 295B series!
The New Zealand Connection
International-Harvester 495’s were imported by the Ministry of Works (via International-Harvester NZ) to work on New Zealand’s largest hydro-electric dam undertaking at the time, Benmore.
A total of fifteen machines were brought in, all from a 1960 production run.
All of them worked in the South Island.
These machines served the MOW very well through several large dam projects with the fleet finally being disposed of, through Govt.Stores Board public auction, in 1974.
By this stage, some of the machines whose bowls had worn out, had been modified by the MOW to carry penstock castings, life after death if you will!
There were no International-Harvester 495’s sold to private contractors although several ended up intact in private ownership following the disposal auctions and did further work for their new owners. Fittingly, a model 495 is preserved (unserviceable) as a memorial at Benmore.
For the Model Collector
The International-Harvester 495 is a machine crying out for a model to be made of it but so far, none exist in any scale.
Hopefully some manufacturer will realize the vacuum here and produce one (are you listening Black Rat ?!)