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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. BY RICHARD CAMPBELL
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 and DT series, and Cummins NR and 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.
The front axle was manufactured by Rockwell while the rear axle, differential and 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 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 seven seconds.
Machines equipped with manual transmission had an air-boosted clutch to reduce driver fatigue. A large steering wheel was the centrepiece to a dash panel which contained a full set of instruments, 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. PayHauler timelineAs 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 65s have the distinction of being in production longer than either the PayHauler 95 or PayHauler 100.
A PayHauler 100B emerged in 1967 and the type was discontinued in 1971 in favour of the all new four-wheel-drive PayHaulers which were about to be introduced. Not too small for the bigger jobs and not too large for local civil works and quarries, the PayHauler 65, 95 and 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 and 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 connectionInternational Harvester Corp of New Zealand imported approx 24 model 65, 95 and 100 PayHaulers in total.
For the modellerOnce 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 and 350, considerably larger machines than this month’s subjects. Brief specifications
Contractor Vol.34 No.4 May 2010 All articles on this website are copyright to Contrafed Publishing Co. Ltd. |
International Harvester 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.
Ross steering gear was utilised along with a hydraulic steering booster to make the operator’s life a little easier.
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 1950s the cab interior had few creature comforts and was fairly austere but roomier than a lot of the competition. For the day, the driver’s seat was very good quality and adjustable to suit different sized operators.
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.
The first customer was H Allen Mills & Son of Rotorua, which put its 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.
International PayHauler 100 (the most numerous NZ version)