Promax's polyethylene range began with an idea Tim Strachan had in 1992. Working as a self-employed engineer at the time, he researched the market, found real demand for plastic water storage tanks, and went looking for the challenge of manufacturing and distributing them nationally. Rotational moulding was the method he settled on. He designed and built water storage tanks for homes and farms first, and opened his first factory in Whangarei in 1995. Everything that follows in the transport tank range, from skid frames to spray systems, traces back to that engineering habit of looking at a problem and building the answer.
From a Whangarei factory to a national footprint
When his sons Hamish and Walter joined the operation in the late-2000s, Tim was free to plan the next expansion. By 2007 he had achieved his original vision: plants in both the North and South Islands, supplying customers nationwide. By 2010 the business had outgrown the Whangarei factory, so Promax built a purpose-built factory and head office in Kerikeri. Promax is now the manufacturer of New Zealand's largest range of water management solutions, and in 2016 it produced the largest single piece plastic tank in New Zealand, with a capacity of 50,000 litres. Tim has since stepped back to an advising role, and Promax is run by Hamish and Walter. You can read more about the company and its plants.
Why Promax moved into transport tanks
Promax recognised demand for tanks built to move liquids rather than just hold them. At first it supplied the tank alone and left the rest to the customer. That changed. Thanks to Tim's engineering background, Promax now works closely with customers to produce complete tanker solutions, and can help build the complete package including pumps, sprayers and hoses for a turn-key drive-away package. It is a different job to moulding a tank and dropping it on a truck. The tank, the frame, the plumbing and the controls all have to work as one piece of equipment, on a vehicle that moves.
Why polyethylene, not steel or fibreglass
Promax Transport Tanks are all made from polyethylene, a light, strong and durable alternative to steel or fibreglass, with the benefit of being a lot more flexible and lightweight. On a truck, weight is payload: every kilogram of tank is a kilogram of liquid you cannot carry. Polyethylene also does not rust, which matters on a vessel that spends its life wet, outdoors and vibrating. The poly tanks are UV-stabilised to withstand the rigours of New Zealand's climate. The range now has more than 40 sizes, ranging from 20 to 30,000 litres.
What the tanks will carry
Promax's poly tanks have a wide range of uses. They are suitable for many liquids including water, milk and leachate, and for heavier fluids such as molasses and fertilisers up to 1.8SG. Specific gravity is the constraint that catches people out. A tank carrying water is carrying a lighter load than the same tank full of molasses, and the rating has to match what is actually going in it rather than what the tank looks like it could hold. Where the liquid has to stay fit to drink or to sell, the food-grade manufacturing materials Promax uses are what make that cartage possible at all.
Mounting and securing the load
The tanks are classified as a load, and securing the load is very simple by using the integrated tank pin mounting kits available for flat deck or skid-mounting. Steel skid frames for Transport Tanks allow simple installation and ensure the tanks can be mounted on any truck. The hot-dip galvanised frames have forklift points for easy mounting and dismounting when the tank is empty, so a tank can come off without a crane or a workshop visit. An optional extension plate gives you somewhere to mount pumps and spray bars, which keeps the whole assembly as one unit rather than a tank plus a collection of separately fixed parts.
Dust suppression and water delivery
Promax's Dust Suppression Spray System is used to wet down construction sites, road works, quarries and mining sites, and the unit attaches to all Promax Free-Standing Liquid Transport Tanks. Promax has basic Dust Suppression models available, or can customise to individual requirements. The truck-mounted spray system is easy to operate, galvanised for durability and available with in-cab remote control. For the wider case, see why dust control matters more than ever. Water Delivery Units are particularly popular during summer, use the same food-grade manufacturing materials, and can be easily fitted and removed from flat deck trucks, making a vehicle very versatile without tying up capital in a complete new vehicle.
Ball Baffles and load stability
The Promax Ball Baffles are an option across most Transport Tanks, made of food-grade material, in two different sizes. The low-displacement balls simply drop into the tank to act as a liquid movement suppressant, stabilising the load, reducing surge, increasing vehicle stability, and improving braking distance and cornering to the point of reduced wear on the vehicle. One small 195mm ball is recommended per seven-litres of fluid, while the larger 355mm ball is recommended every 40 litres. "You divide 10,000 by 40 and you have 250 balls placed in the tank that form a honeycomb throughout the liquid, which is where you get all the movement," explains Hamish. "It's a proven anti-rollover design." A 10,000 litre tank is probably the most popular size, fits on a 6x4, and works out at around 10-11 tonnes payload.
The Modular Tank System
The Modular Tank System offers flexibility and economy for transporting bulk liquids. Exclusive use of polyethylene eliminates rust issues and reduces weight, allowing for increased payloads. Mounted with the secure pin-mounting system, the tank sections can be drained individually, allowing for cartage of different liquids on the same deck, or linked to allow for equalised filling. The tanks are fully baffled longitudinally and latitudinally for stability and reduced wear. Being modular, it is expandable for different sizes of trucks and trailers, so the fleet dictates the tank rather than the tank dictating the fleet.
Building a custom unit
The Transport Tank side of the business has really evolved, from stand-alone tanks to a full drive-in drive-out setup, and Promax can also consult regarding building a custom Transport Tank unit. That is the practical value of keeping the engineering in-house. What you are carrying, what truck it is going on, how it gets filled and how it gets emptied are questions answered together rather than in sequence by different suppliers. If the job does not fit a catalogue configuration, the starting point is a conversation about the work the vehicle actually has to do.
Article source: Truckbody & Trailer