There used to be good money in the liquid bulk business. The required equipment is so specialized that it presented somewhat of a barrier to entry into the market. That’s still the case, but there are more players in the game now, and competition is keeping rates at near-1980s levels. Fleets, both private and for-hire, are now trying to make up for the low rates by optimizing their trailer spec’s to increase utilization and carrying capacity. 

“With fleets now having nearly exhausted ways of reducing cost, their only alternative is to carry more payload and hope the competition isn’t right behind them on upsizing,” says Robert Pahanich, vice president of maintenance and procurement at Transcourt, which specializes in leasing tanks. “This presents some real challenges for fleets that want flexibility, because sometimes the dedicated tank isn’t compatible with available backhauls.” 

That’s the nature of the tank business in a nutshell. There are many different types of tank trailer, and many are designed to haul specific products or types of products. Spec’ing dedicated tanks will often preclude the carrier from carrying other cargo.  

Take solvents, for example. They are a common commodity and widely distributed, and for the most part do not require specialized equipment. They can be carried in aluminum or stainless steel tanks. They are usually alcohol- or petrochemical-based, so they will require a trailer rated for flammable products, but they are usually not temperature-sensitive. In most cases, the trailer won’t require an insulated barrel.  

Many of those types of product are very light, weighing somewhere around five or six pounds per US gallon. (By comparison, an imperial gallon of water weighs 10 pounds, whereas a gallon of some heavy corrosive products, such as nitric acid, can weigh as much as 16 or 17 pounds per gallon.) 

Shippers want as much product as possible on the truck, so carriers are opting for ever-larger tanks. That means tackling related weights. Choosing aluminum over stainless steel can save as much as 6,000 pounds. Foregoing insulation can reduce weight by another 3,000 pounds. But this becomes a problem when carriers are looking to match the tank trailer to compatible backhauls. 

Nabil Attirgi, president of Montreal-based Bedard Tankers, says the construction material for the tank barrel very much depends of the commodity being transported.  

“There really is no such tank as a general-purpose tank,” he says. “Take a material like 316L stainless steel. It’s probably as close as we can get to general-purpose.” But its cargo temperatures are limited to around 150 Celsius (300 Fahrenheit). Transport Canada and the U.S. Department of Transportation have additional ratings and classifications that must be followed when hauling certain hazardous cargo, further complicating the spec’ing exercise. 

“Before we take on a job for a customer, we get them to check with their customers or shippers to ensure that the tank will be compatible for their cargo,” Attirgi says.  

You can now see where trying to optimize a tanker to carry solvents would create problems when sourcing backhauls. You can’t put hot product in an aluminum tank. You can’t put corrosives in an aluminum tank. You can load -solvent in a stainless tank, but if it’s insulated you might lose out on up to 10,000 pounds of payload your -competitor might be able to haul. Because of its weight, you’ll likely opt for a smaller barrel. So again, you limit your -carrying capacity. And even if you went for a largish stainless steel 316L tank, holding about 7,000 US gallons, drivers would be mighty unhappy about hauling 2,500 gallons (a full load weight-wise) 
of heavy acid in a barrel that large. The surging equipment would beat them to death.     

Lightweighting  

Whenever the conversation turns to lightweighting, bulk carriers are always held up as examples of the significance of every kilo of tare weight. Every liter of product is a billable commodity. The more you move,  the more you make. What might be absent from those conversations is the potential cost of shortcutting your lightweight spec’. Lightweight equipment is expensive, and sometimes there is a tradeoff between weight and durability. Tank trailers often stay in service 20 years or longer. That’s no place for a flimsy spec’. 

Despite fleets’ concerns over weight, Attirgi says he hasn’t built a trailer with a spring suspension in seven or eight years. “The air suspensions tend to be heavier, and there’s usually more maintenance involved, but the wear and tear on the frame and the barrel is a fraction of what it used to be,” he says. “There’s no give and no flexibility in a tank barrel, so all the roughness of the road comes right back to the barrel through the spring suspension. Springs are lighter, but they are harder on the equipment.” 

Likewise for disc brakes. Attirgi says disc brakes are on about 20% of his orders now, and that’s up considerably in recent years. He notes that while disc brakes are slightly heavier and more expensive, they reduce maintenance costs and you don’t need to spec’ an automatic greasing system.  

Fleets aren’t looking to cut 50 pounds here and 100 pounds there. They recognize that’s a mug’s game. But they are more than willing to look at big cuts, like switching from dual tires to wide singles.  

“It’s hard to skinny up a trailer,” Pahanich says. “You can spend a lot of money and not really get a substantial weight reduction. Fleets will spend money on components that will last longer, such as galvanized steel or aluminum instead of carbon steel for subframes, cross members and even landing gear. That will keep the trailer out of the shop longer and lighten it up a bit.” 

Given the long life expectancy of a tanker trailer, there’s often a mid-life rehab or replacement of the undercarriage. So fleets are looking to keep the trailer in service as long as possible, and that often conflicts with the weight-reducing strategies. 

If you’re new at tankers, or maybe a good customer has asked you about providing that service, you’ll need to ask a lot of questions about the product being hauled before shopping for a trailer. It all begins with product compatibility. Once you have the right material for the tank, then the spec’ing process begins. And if you’re considering food-grade or milk transport, that’s a whole other story. Attirgi says those tanks are in a category unto themselves.  

“They are built to a different code than a chemical tanker, and they are even required to be built in a separate clean bay with specially trained welders,” he says. “Food-grade is not something you take lightly.” 

With so many different types of tanks in service today, from basic bulk liquids to compressed gasses, hot products, oil tanks, and glass-lined acid tanks, just making the equipment choice is a process in itself. Your customer will know what they need, but you can make a lot of mistakes along the way if you’re not an expert at spec’ing tanks. Rely on the advice of professionals.  

EXTRA: The rise of liftable axles 

Tank carriers tend to travel a lot of empty miles. Whether they are fuel haulers returning from service station deliveries, businesses that use dedicated tanks for food-grade products, or asphalt haulers returning from road building jobs, the trip back to the terminal is almost always unladen.

Enter the opportunity for a new generation of lift axles.

Lifting unneeded axles improves fuel economy by eliminating some tire-induced rolling resistance. It also improves tire wear by putting more weight on the deployed axle. Running lightly loaded on fully inflated tires induces uneven wear. There are also said to be safety benefits to running with the minimum number of deployed axles. It’s thought to improve traction in wet and snowy conditions.

According to Robert Pahanich, vice president of maintenance and procurement at Transcourt, which leases tanks, these liftable axles are a hot item on customer wish lists in selected applications.

“You won’t see us approving three liftable axles on a quad-axle trailer, but tridems and tandems are fine,” he says. “Much of North America already allows these axles, or at least does not prohibit them. Ontario, being one of those notable exceptions, is now looking into the feasibility of allowing them – and they will sooner or later. They aren’t there yet, but having said that, we are already leasing a lot of equipment in Ontario with the so-called smart lift axles.”     

In today’s hyper cost-sensitive world, the spec’ could be worth the few extra pounds incurred by adding a lift kit.