PHASE OUT: Lift axle operations are in a state of flux in Ontario as the province plans to remove non-steering lift axles.
TORONTO, Ont. – Non-steering lift axles are taking another step towards obscurity, as Ontario prepares to introduce the latest changes to its rules that govern weights and dimensions.
While about 75 per cent of Ontario’s tractor-trailers already meet the province’s Safe, Productive, Infrastructure-Friendly (SPIF) standards, many existing multi-axle configurations don’t meet the related requirements for stability and vehicle control, Ontario Ministry of Transportation project leader Ron Madill told members of the Canadian Transportation Equipment Association (CTEA) recently.
Ontario has been pushing for several years to phase out the non-steering lift axles that are blamed for about $300 million in annual damage to roads and bridges. SPIF designs, however, incorporate self-steering axles.
“The vehicles of most concern are generally the heavier (multi-axle) vehicles,” Madill said.
Semi-trailers with one to three axles were addressed in 2001, dump semi-trailers followed in 2002, and semi-trailers with four or more axles – as well as doubles – will be addressed in the latest changes to rules to be introduced in 2006.
Rules for straight trucks and their trailers will follow in about 2007. “We really don’t know where we’re going (with those),” Madill said.
Groups such as the CTEA submitted their final comments on the new rules in November.
Under the revised regulations (expected to be unveiled by June) there are plans for 11 different tractor-trailer configurations that would be legal on Ontario roads, although two six-axle models could be added to the list for use between Ontario and Michigan. (While the latter designs were initially shelved on the basis of computer simulations, real-world testing has allayed some of the related fears, Madill said. “We’re seriously looking at it.”)
Some of the rules for the different trailers are common, such as a maximum semi-trailer length of 16.2 metres, and an allowance for additional lift axles that aren’t actually used on Ontario highways.
The main focus of the latest round of changes is the introduction of five-axle trailer designs that incorporate a tridem and a pair of self-steering axles. Shorter wheelbase designs will require one self-steering axle on each side of the tridem, while models with longer wheelbases will require both of the self-steering axles in front of the tridem.
“It’s a delicate balance of maintaining sufficient payloads, trying to harmonize with the Michigan rules, trying to meet our bridge and pavement requirements, and trying to have vehicles that meet performance requirements,” Madill told Truck News.
Each axle will have a maximum weight of 7,500 kg, and the loads will have to be equalized.
The lift axles can be raised when trailers are empty or lightly loaded, and when vehicles are reversing.
While the four- and five-axle trailers will also require on-board scales, these can range from electronic systems to simple pressure gauges and accompanying charts that can convert the pressures into weights.
Extensive tests have been conducted on the five-axle designs, which became a focus after a series of computer simulations.
“I’ve got four gigabytes of data files on my computer at home,” said the National Research Council’s John Billing, referring to the extent of the tests. In real terms, that means the designs have been put through a wide variety of turns and situations to prove they aren’t prone to flipping, off tracking outside their lanes, or losing control if the self-steering axles twist for no reason at all.
When the latter situation occurred, “the axle went right over; the driver steered right ahead,” he said, noting that it didn’t affect the control of the vehicle even though tires, axles and other components were put under additional stress. “And the tires certainly weren’t serviceable for re-capping.
The test results are being used to determine how much the self-steering axles should actually turn.
“Stiffening up the steer brought the back end in significantly,” Billing said, of designs that included the axles at the rear of the tridems.
“And a 2S/2M (ABS system with two sensors and modulators) would significantly reduce the effect of a brake-induced steer,” he added. “The ABS all around seems like a very good idea for this configuration.”
The video that showcases the tests could be shown during an installment of the World’s Worst Drivers television show. “The speeds here are far above what a driver would normally take a turn like this at,” he said. High-speed off-tracking tests involved 0.2g turns, reaching 100 km/h on a curve with a tight 393-metre radius.
While the rear wheel could strike a curb in such a turn, causing a rollover, these speeds aren’t reached in urban environments where curbs can be found in the first place, he said. (At excessive speeds, drivers also tend to cut inside the turn.) “Drivers of this class of vehicle are sensitive to rollovers.”
If both steer axles are located ahead of a tridem, the one in the lead will need to turn at a sharper angle.
But as Ontario moves to introduce the new rules, there are some loose ends that still have to be addressed. While the self-steering axle at the rear of a configuration with a shorter wheelbase must lock in place at high speeds, the specific speeds have yet to be identified, although rules for C-dollies suggest that they may need to lock in place at 60 km/h, and unlock at 50 km/h.
Once the new configurations are introduced, previous designs will begin to fade out of existence.
“For example, starting in 2006, all one-to-three axle non-dump semi-trailers must meet SPIF standards or operate at a reduced weight,” Madill said. Rigid lift axles will initially lose 3,000 kg of their allowable gross weight, but the penalty will grow to 4,500 kg by 2010.
After that, trailer owners will have to go to a shop certified to apply a National Safety Mark, and convert their trailers to SPIF configurations. The other choice is to operate at a reduced weight or retire the equipment. “There’s virtually no grandfathering involved here,” Madill said.
Dump semi-trailers must now be SPIF designs or face 4,500 or 9,000 kg in gross weight reductions, with the older models grandfathered to 2011, although permits will allow them to be used beyond that date until the units are 15 years old. (Hoppers can be about 20 years old.) At the end of the period, single lift axles are reduced by 4,500 kg, and double lifts lose 9,000 kg.
New four- and five-axle trailers will need to meet SPIF requirements by Jan. 1, 2006, or face gross reductions of 4,500 and 6,000 kg based on the number of liftable axles. Like the dump trailers, these will be grandfathered for 2016, and can operate under special permits for 15 years, with tankers allowed to live 20 years.
Once the reforms are completed, more than 95 per cent of the tractor-trailer combinations in Ontario are expected to meet the SPIF standards.