The Small PayHaulers – International’s model 65, 95 & 100 rear dumpers
Determined to break into the off highway truck market, International Harvester introduced the model PayHauler 65 (18 ton capacity) and Payhauler 95 (24 ton capacity) in 1957.
I.H. engineers had made a close study of comparable Mack and Euclid off highway rear dumps and come up with their own hybrids which, as it turned out, were very successful.
These machines were simple to operate, easy to repair and exceptionally ruggedly built
A number of optional engines were available to suit customer requirements and these included the International UD & DT series, and Cummins NR & NH models.
Initially only Fuller manual transmissions were offered but before too long Allison powershift transmissions were made available to outfit the machine to customer specifications. The Allison transmission soon became a standard item although the Fuller manual type remained in the outfitting options for many years.
Heart of the entire PayHauler range was the massive main frame constructed of two variable section ‘I’ beams with a distinctive kink near the rear axle and plenty of cross-bracing. These gave the machines a real backbone to take on the hardest jobs.
Huge leaf spring packs front and rear provided cushioning for the vehicle and operator.
Ross steering gear was utilised along with a hydraulic steering booster to make the operator’s life a little easier.
The front axle was manufactured by Rockwell while the rear axle, differential & planetaries were all made by International Harvester.
The PayHaulers were quite quick with an average road speed of 37 mph.
For stopping power the Payhaulers relied on air-operated expanding shoe type brakes and those machines equipped with the Allison powershift transmission option also had the benefit of an integral transmission retarder to help slow down and preserve the service brakes on long downhill grades.
A choice of dump bodies could was offered – a tapered profile quarry type with much reinforcing to take repeated shock loading imposed by rocks and a general earthworks body which featured a straight profile.
The majority of New Zealand PayHaulers were equipped with the quarry body.
A single multiple stage hydraulic cylinder was employed on the Model 65 while the Model 95 and subsequent Model 100 used two cylinders.
Average dump speed was an impressive 7 seconds.
Offset to the left side of the machine was the operator’s cab, a steel structure with plenty of glazing.
As with most machines which had their design origins back in the 1950’s the cab interior had few creature comforts and was fairly austere but roomier than a lot of the competition..
A large steering wheel was the centrepiece to a dash panel which contained a full set of instruments,
Machines equipped with the manual transmission had an air=boosted clutch to reduce driver fatigue.
For the day, the drivers seat was very good quality and adjustable to suit different sized operators.
In order to cut down glare and dust adhering to the glass, the two-piece windscreen had an inverse taper, a feature which set the machines apart from their contemporaries.
As with most machines, the smaller capacity PayHauler range underwent its fair share of upgrades and improvements over the years. The PayHauler 65 became the 65B in 1964 and its capacity increased from 18 to 20 tons. A PayHauler 65C was introduced in 1968 with the type finally being discontinued in 1973.
PayHauler 65’s have the distinction of being in production longer than either the PayHauler 95 or PayHauler 100.
Rated at 30 tons, the PayHauler 100 was introduced in 1963 and was intended as a replacement for the 24 ton PayHauler 95 but in actual fact both were manufactured for a couple of years before the PayHauler 95 was finally dropped from the line in 1965.
A PayHauler 100B emerged in 1967 and the type was discontinued in 1971 in favour of the all new 4-wheel drive PayHaulers which were about to be introduced.
Not too small for the bigger jobs and not too large for local civil works & quarries, the PayHauler 65, 95 & 100 filled an important niche until the advent of more sophisticated machines.
When they were introduced they were the fastest machines of their type, easily outpacing comparable Euclid & Mack off highway haulers.
Due to their battleship-like construction many can still be found doing the occasional job or filling in when the main production machines are down for maintenance.
The New Zealand Connection
International Harvester Corp of New Zealand imported approx 24 model 65, 95 & 100 PayHaulers in total.
First customer was H.Allen Mills & Son of Rotorua who put their fleet to work on the Matahina Hydro project and subsequent other large jobs in the central North Island and Bay of Plenty regions. Other users included Horowhenua Earthworks, Earthmovers Waikato and Baker Construction (now C&R Developments) who still have the odd unit as a stand-by. For their age, C&R’s PayHaulers are kept in excellent condition.
For the Diecast Model Collector
Once upon a time Ertl produced a generic model of one of the smaller PayHaulers to an odd scale.
Considering the age of this model the detail is not too bad but examples are hard to find and can be expensive. For those readers who would really like to add one to their model collection the best place to start looking is www.ebay.com in the diecast construction models section.
This model is not to be confused with the later Ertl PayHauler releases which were of the PayHauler 180 & 350, considerably larger machines than this month’s subject.
Brief Specifications International PayHauler 100 (the most numerous NZ version)
Engine: International DTI-917, six cylinder, turbocharged, I=intercooled diesel
rated at375 flywheel horsepower
Transmission: Allison CLBT5860 6-speed powershit with retarder
Brakes: Full air shoe type on both steering and drive axle
Steering: Ross gear type with hydraulic booster
Std,Tires: 18.00×25 20 ply (front), 18.00×25 28 ply (rear)
Top Speed: 36.5 mph
Turn Circle: 28’10”
Capacity: 26 cubic yards (30 tons)
Width: 11’11” (with quarry body)
Weight: 24 tons (empty), 54 tons (loaded)