EBS, when properly maintained, along with the rest of the braking system, will save a roll-over on that poorly designed roundabout that has caught your unfamiliar driver unaware, there is a significant benefit from EBS.
In the past 25 or so years, vehicle safety technologies and reliability has improved. Its now more than 30 years since the first heavy vehicle electronic engines arrived on the scene, the sceptics all aired their reservations it was the same with ABS, EBS and other technologies. More recently LDW (lane departure warning) ACC (adaptive cruise control) and other technologies have been adopted, many relying on ABS and EBS as a key part of the base package.
Whilst some may not agree, the recent generations of ABS/EBS have been of significant benefit to safety for vehicles. However, an often-discounted fact is that this is all dependent on the foundation braking system, if the foundation braking system isn’t 100 per cent functional don’t expect the ABS/EBS to be the fix all.
Major brake defects continue to be significant at heavy vehicle interceptions/inspections. The National Roller Brake Testing Procedure (https://www.nhvr.gov.au/files/201801-0760-national-roller-brake-testing-procedure.pdf), addressed the history of issues with air suspension and roller brake testing and false negatives. What remains a concern is that many operators do not understand how the braking system basics on a heavy combination vehicle function.
The supply system (red line) to a trailer (or trailers) doesn’t supply air unless the parking brake is released and considerable time it may take to charge the trailer/s (10 minutes plus for an air depleted B-double).
The control signal (blue line) doesn’t provide the air to actuate the trailer brakes, it is the control signal and meters air from the trailer air storage system to activate/operate the brakes. A typical (pre-EBS) road train brake system can take around 1.5 seconds to apply/release the brakes at the last trailer, which is why clear-bore couplings were necessary to meet AVSR (Australian Vehicle Standards Rules) brake response times.
The arrival of combination smart EBS systems (prime mover communicates with trailer/s and vice versa): ADR 38/05 mandated ABS for trailers with an ATM > 4.5 tonnes and vehicle stability function (directional control and rollover function) for all TD category (GTM > 10 tonnes).
Many operators accepted T-EBS because they had to, and some trailer salespersons didn’t help, the education was poor and the risk management and potential benefits of these safety systems were not communicated. One example was a situation where a vehicle combination had 259 roll stability interventions in the previous year, at event #260 the combination rolled-over; the driver had complained about the brakes coming on in corners, but no one had explained (educated) the RSS intervention.
Talk to your EBS system supplier’s technical team to learn what is available and how to get the best from the system. Another benefit of smart EBS systems is the response times for multiple axle groups, with T-EBS within a couple of milliseconds of the prime mover service brake being applied it sends an electronic signal to the trailer groups (this won’t happen if the EBS isn’t connected) and it even applies the brakes if the control line is not connected; the further advantage is that as the brakes on all trailing axle groups are activated almost immediately there is greater brake performance due to the lack of lag in the brake response, less speed sooner.
In November it will be 4 years since ADR 38/05 mandated ABS, directional control and roll stability. A recent article suggested that currently less than 30 per cent of heavy trailers are T-EBS equipped, road transport needs to do better! Axles don’t last forever, so at axle replacement upgrade with wheel sensors and T-EBS.
Industry has little control over potholed roads, poor roundabout design, rest area design and location; but industry can be more embracing of adopting proven safety technologies, supported by appropriate and structured maintenance programs.
A properly maintained brake system with T-EBS is a valuable investment in risk management!