Perentie Land Rover
The Australian Army is currently replacing its ageing fleet of Land Rovers, some of which are now starting to find their way into private ownership. But there’s much more to these very special, Australian designed and built, Land Rovers than meets the eye.
Land Rover has been a major supplier of vehicles to the Australian Army since 1959, but those supplied from 1987 under Project Perentie, and the later Project Bushranger, are unique to this country and in many ways superior to what was on offer from the UK.
The first Land Rovers supplied to the Australian Army (which for the most part I will refer to simply as Army) were Series II in March 1959. Although assembled in Australia, at Pressed Metal Corporation (PMC) in Enfield, Sydney, they were pretty much the same as their English cousins – with some alterations to suit Australian requirements.
In fact, the vehicle used for the initial evaluation trials in 1958, the “Army app-raisal unit” was the very first RHD Export Land Rover Series II (chassis number 142800001) to be assembled at Solihull.
Some 1,841 Series II, 4,776 Series IIA and 2,303 Series III Land Rovers were supplied to the Army between 1959 and 1981. The vast majority were 109” long-wheelbase versions; Series II and IIA with four-cylinder petrol engines, Series III with six-cylinder.
Like the earlier vehicles, these were essentially the same as the civilian versions, with some Army modifications, and were assembled at PMC.
There was a range of specialist vehicles, including 184 ambulances, with special bodies; Fitted For Radio (FFR) mobile radio stations; Maintenance Vehicles (mobile workshops), fire tenders and “gun buggies”: which carried 106mm recoiless rifles.
58 fully-imported 101 Forward Control models were supplied by British Aerospace, as complete packages with the Rapier mobile anti-aircraft surface to air missiles (SAMs), between 1976 and 1978.
Apparently, the first Land Rover Australia knew about the 101 being in Australia was when the Army started to order parts for them.
It is not known how many Land Rovers were used by RAAF or Navy units, but the number would be very small.
Through the 1970s 4WD sales in Australia began to grow exponentially as the civilian leisure vehicle market became mainstream. Vehicles from Japanese manufacturers, especially Nissan and Toyota, began to dominate the market, particularly due to their powerful four-litre six-cylinder engines.
Land Rovers, by comparison, were seen as sturdy and reliable, but lacking in comfort and highway performance.
A diesel engine had been on offer from Land Rover (UK) since 1957 but even by the late 1970s, with diesel power gaining in popularity following the second fuel crisis of 1979, diesel Land Rovers were considered under-powered for Australian conditions.
One 1981 report on the 2.3lt diesel Land Rover, with 45.6 kW, described it as producing “modest performance but with good economy.” By this time, Nissan Patrol was available with a 60kW 3.3lt diesel and Toyota Land Cruiser with a 77kW 4.0lt.
Land Rover (UK) was already planning to combat the issue of insufficient power by fitting the 3.5lt V8 from the Range Rover to its Land Rover models. However, by this time the Australian Army was moving toward an all-diesel fleet and Land Rover Australia knew that to remain a supplier to the Army it would need to offer a more suitable diesel engine.
In his thesis, Australian Development of the Land Rover One Ten for the Civilian and Military Market, then Engineering Manager for Land Rover Australia, Ray Habgood, wrote; “An extensive survey of available diesel engines was undertaken, and the 3.9 litre four cylinder Isuzu 4BD1 diesel engine was selected as the most suitable for our application.”
Four main reasons for the selection of the Isuzu diesel were identified.
- It was of similar size and performance to the Rover 3.5lt V8 petrol engine, meaning there would be little modification required on the vehicle for the diesel engine.
- Being an engine derived for heavy truck usage, it had a proven track record of market acceptance, reliability and durability, and would be un-stressed in the application to such a relatively light vehicle as the Land Rover.
- With its direct fuel injection system it provided very good fuel consumption with consistently high torque throughout the rev range.
- Future high-performance variants, particularly through turbo charging, were expected in the near future – which proved to be true.
A further consideration was that Isuzu were happy to accommodate Land Rover’s requirements and supply engines in sufficient numbers. “Isuzu and their trading company, C. Itoh, proved most enthusiastic partners, assembling special 4BD1 engines for our Land Rover applications”, Habgood explained.
Isuzu developed a noise reduction package for Land Rover’s application, which featured a double-skinned rocker cover and front engine cover, rubber mounted sump and modified pistons – as well as a special sump and flywheel housing.
Aluminium trays and 6x6
Another uniquely Australian requirement for Land Rover was the fitting of an aluminium flat tray with drop down sides. Other markets specified a pick-up body with fixed sides and a drop-down tailgate.
The 1.8m x 2.5m aluminium tray was developed and supplied by Hockney Alcan in Sydney. All locally-assembled cab-chassis Land Rovers had their wheelbase extended by 246mm, to 3040mm to accept the tray bodies, and the rear springs were uprated to increase the gross vehicle mass (GVM) to 3,200kg.
Land Rover, and other manufacturers, were aware that the Australian Army was in the process of evaluating its needs for replacing its road fleet, thanks to the Army Staff Requirement for lightweight and light trucks being released by the Department of Defence in February 1981. Of particular interest to Land Rover were its current in-service fleet of lightweight (1 tonne payload) vehicles, as well as an anticipated need for a light cross country vehicle with 2 tonne payload.
However, one of the Army requirements, due to Commonwealth Government stipulation as well as the need for local supply and support, was that the vehicles had to be assembled in Australia, with as much local content as possible. It was also necessary that the vehicles be based on those currently available to the civilian market, rather than purpose-built military “prototypes”.
“A detailed market survey identified a small but definite requirement for a specialized cross country vehicle with a payload of around 3 tonnes, and a tray area of around 7 m-squared”, Habgood explained.
A number of options were examined, including: reviving the British military 101 forward control; using the Spanish-built Santana forward control; adopting one of the available third-party British 6x6 conversions; marketing a specialized 4x4 vehicle of non-Land Rover origin; locally developing a forward control version of the up-coming Land Rover 110; or local development of a 6x6 version of the 110.
“The results of this evaluation clearly favoured locally developing a 6x6 version of the Land Rover 110”, Habgood wrote.
This was largely decided on the understanding of the military requirements, such as they were at the time, which would be the largest potential market.
As part of the evaluation process, a Sandringham 6x6 was imported by Land Rover Australia. The Sandringham was a privately developed conversion by Hotspur Cars (UK) and, while recognized and approved by Land Rover does not appear in any company literature.
“It had been suggested that a six-wheel-drive version of a Land Rover might be one way to do it”, Habgood recalled in a recent interview with this writer. “I went over to UK and we brought in one from Sandringham, to just have a look at.”
The vehicle brought in was in fact the first Sandringham with coil-sprung suspension, but still with the Series III cab.
“We found that the coil-sprung suspension had a lot of body roll”, Habgood reported. “That could have been developed out. We had a look at whether we would use the coil springs or leaf springs and decided that the load-sharing leaf springs would be probably the best way to do it.”
“We had a 109-inch Land Rover, which we had converted to six-wheel-drive ourselves. We did some comparisons between the leaf-sprung Land Rover and the Sandringham and the leaf-sprung Land Rover gave the best results.”
The ingenious rear suspension set-up features conventional leaf springs, with a central, pivoting hanger, or cross-over beam, that shares the load of the rear of the vehicle between the two rear axles.
This is done by mounting the front of the rear spring to the front of the hanger, and the rear of the front spring to the rear of the hanger, so they cross over. The added advantage is that it brings the two axles closer together, and reduces the overall wheelbase, without adversely affecting the off-road capability of the vehicle.
“We decided there were going to be so many modifications to the chassis itself that we wouldn’t use any of the Land Rover chassis, so we built up a tubular steel chassis that we could hot-dip galvanize”, Habgood explained.
The chassis, built of RHS tube for ease of manufacture and cost, also featured a “well” down the centre, between the wheels, which would be pivotal to the success of the vehicle, as will be explained.
Drive for the two rear axles was achieved easily and very cost effectively. The heavy-duty LT95 gearbox with integral transfer box from the 101 forward control, and used in the Range Rover, featured an output for the 101’s power-drive trailer. That is, a trailer that had its wheels driven from the Land Rover, which in effect gave six-wheel-drive when the trailer was in use.
“It was, therefore, only logical to utilize separate prop shafts from the transfer box to drive the front, centre, and rear axles”, Habgood detailed. The vehicle could then be driven in permanent four-wheel-drive for on-road and high-speed use, and in six-wheel-drive for off-road or cross-country applications.
While the Sandringham utilised standard Rover rear axles, the Australian 6x6 used two Salisbury hypoid bevel rear axles, with increased track width (from 1486mm to 1660mm) and thicker axle tubes. The two axles used common long and short half-shafts, with the differential on the centre axle being offset to the right and the diff on the rear axle offset to the left.
The width of the chassis also accommodates the spare wheel, slung underneath on a winch-down cable, as it was required for the spare to not intrude into the load area. As this would normally be the position of the fuel tank, twin tanks were mounted under the seats.
The front of the chassis, and therefore the cab, remained the standard width and used a standard front axle.
The six-wheel-drive civilian Land Rover was released in the mid-1980s, before supply to the Army had commenced. At least one of these was suplied to Esso oil company as a fire tender. The fire tender is listed on Perentie brochures, but none were built for the Army.
At least 33 civilian 6x6 Land Rovers were built at Moorebank, but the exact figure is not known. Some sources suggest the number could be as many as 100. Some, but it is not known how many, were also air-conditioned. Ray Habgood wasn’t able to shed any light on the numbers, but recalled it was most likely there were at least two packs (24 vehicles) built prior to awarding of the Army contract.
Army’s detailed requirements for Project Perentie – named after Australia’s largest monitor lizard, or goanna, for its cross-country adaptability, strength and speed over rough terrain – were released at an industry briefing in June 1982.
Seven vehicles were tendered for each of the light and lightweight categories. From these, in the lightweight (1 tonne) class those chosen for trials were the Land Rover 110 4x4, Jeep M10 and Mercedes-Benz 300GD – usually referred to as the G-wagon. In the 2-tonne category, only the Land Rover 110 6x6 and the Mercedes-Benz Unimog U1300 were selected.
To ensure the Land Rover 6x6 would be competitive in terms of performance with its rival, it was fitted with the turbo version of the Isuzu engine.
Three of each vehicle were delivered to the Army in September 1983, with Land Rover retaining one of each as a reference vehicle. One of each vehicle was subjected to accelerated durability testing at the Army’s Trials and Proving Wing, at Monegeetta, near Lancefield north of Melbourne. The other two were subjected to a comprehensive series of User Studies, including Hot Dry trials at Woomera in SA, Hot Wet at Tully in Qld and cold weather trials at Khancoban in the Snowy Mountains.
They also spent a fair bit of time with various Army units around Australia. The trials lasted about a year, after which time tenders were called for the delivery of production volumes, commencing in May 1986, for a limited number of Initial Production Vehicles (IPVs) and full production to commence in May 1987.
Initially, 2,500 4x4 and 400 6x6 vehicles were to be delivered over a three to four year term. This was later increased to a total of around 3,700 by the end of September 1992, with more than a dozen variants.
While Ray Habgood was in charge of the engineering side of things, it was Land Rover Australia’s Managing Director (and Deputy MD for JRA) Jack Heaven who was the real driving force behind the company’s push to win the Project Perentie contract, as Habgood recalled.
“Prior to (Perentie) we had tendered some trucks to the Australian Army, but we weren’t successful with that because we hadn’t put enough emphasis onto it right from the start. We didn’t concentrate enough on it, and relied too much on UK producing the vehicle that we tendered. So, this time we were quite keen to put our best foot forward, which is why we transferred the assembly of Land Rovers to Moorebank.”
“We felt that it was our contract, because we had been supplying Land Rovers to the Australian Army for 30 years before that. Jack (Heaven) was quite keen that we retained it and he was I suppose instrumental in making sure we did.”
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The BMC Experience Issue 12. Jan-Mar 2015 Magazine
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