A matching pair of new Sloanebuilt “Stag” trailers is the right solution for Gunlake Quarries.
There are several options when you’ve got to move bulk aggregate from A to B. Traditional end-over tippers in B-double configuration are one solution, another alternative being the use of rigid trucks together with four-axled, five-axled or even six-axled dog trailers.
As we’ve seen recently in TrailerTorque, there’s also increasing interest currently taking place for the adoption of 8×4 or even 10×4 rigid tippers. Add the further alternatives of side tippers and belly dumpers and it soon becomes obvious there easily is more than one way to get the job done.
One option we haven’t yet mentioned is that of the B-double Stag trailer combination, where the three-axled B-trailer runs with an overall body length of 6,300 mm, in direct contrast with the lead trailer that has a body length of 10,355 mm.
Although not a regular sight on Australian roads, the B-double Stag trailer design does have specific benefits, especially where access space for tipping and delivery is limited.
Sloanebuilt Trailers of Smeaton Grange, in Sydney’s west, recently delivered a matching pair of B-double Stag trailers to Southern Highland’s operator Gunlake Quarries. These immaculate aluminium tri-axled trailer sets were required for a specific regular daily transfer of hard rock aggregate and concrete products from the company’s quarry near Marulan, NSW, to its concrete plants at Silverwater, Glendenning, near Smeaton Grange, and Narellan.
As Trevor Dennis, general manager of Gunlake Quarries at Marulan explained:
“A 6×4 rigid truck with a quad dog trailer is usually the better option for general deliveries. The disadvantage is that the bodies for some get a little long and can restrict movement on roads and in suburbs where the trees are close alongside the carriageway.
“Our depot at Smeaton Grange is also tight on access space. That’s where the advantage of the Stag trailer design provides benefits,” said Trevor.
On entering the site the driver travels over the grid with both trailers and then reverses back, jackknifing the B-trailer and tipping the contents of the lead trailer over the drawbar of the B-trailer into the grid.
The driver then heads forwards again, straightening the combination before reversing back to tip the B-trailer over the grid. The shorter body length of the B-trailer, at 6,300 mm, takes up much less space when jackknifed, compared to a conventional quad dog or semi-tipper. Even going to a five-axle dog doesn’t give enough room for access at that particular site. At other sites, where there is sufficient space to drive straight over in one direction, these concerns do not apply.
Belly dumpers are not too much use for the concrete plant, and, like side tippers, they are good for some sites but are too specific.
The Stag trailers have a payload of 45.5 tonnes, with a gross of 68.5 tonnes when running under PBS approval and NHVAS permit, together with satellite tracking. In their current position prior to receiving individual PBS approval, the Stag units are running at a gross weight of 65.5 tonnes.
EBS (Electronic Braking Systems) by WABCO to ADR38/03 requirements are fitted throughout the B-double combinations, together with roll stability control. These features enable Gunlake Quarries to take advantage of the full suite of options available, such as on-board weighing, lift axles and deck-height levelling to match variations in loading dock heights.
The all-aluminium bodies feature 5 mm single-piece sidewalls in bright plate, a 6.35 mm thick front wall with a 10 mm thick extruded top band, and a 5 mm thick rear tailgate finished flush to the outside with a rubber seal. Hella LED lighting systems are fitted throughout.
Hyva FE-Series hoists are fitted to both trailers, the lead trailer being rated at 55 tonnes capacity and the rear rated at 32 tonnes capacity. Ball-race turntables and landing legs are by Holland Hitch.
The suspension system throughout uses the Hendrickson Intraax low-line design with HXL7 wheel ends that feature a 1.2 million km warranty, using parallel bearings, chromed Hendrickson caps, aluminium hubs, centrifuge drums and digital hubometer. The leading axle on each trailer is retractable, using the control available through the EBS control system, which also facilitates the onboard weighing system. The axle weights are displayed on dials mounted in the dashboard that match the original equipment gauges and bezels used by Kenworth.
As you look closely through the trailer design it’s easy to pick the small design details for which Sloanebuilt is renowned.
Couplings are colour coded to simplify connections, there are well-positioned ancillary lights to assist the operator when reversing or tipping, and the trailer is also fitted with a jackknife alarm to prevent trailer damage. Neat mounting brackets also secure items such as brooms, keeping them handy but stowed under the tipper body.
Both trailers are fitted with an automated roll-over tarp system called Slide-A-Panel, developed and supplied by Georges Canvas Auto-Tarp of Smeaton Grange.
The Slide-A-Panel tarp system has been designed with over 15 years of experience designing, installing and repairing retractable tarping systems.
The main feature of the system is that the tarp is made up from individual tarp sections. This feature allows for tarp repairs to take place without the need to remove the entire system from the truck body, plus removing all bows and bow ends.
Each roll-over tarp panel is easily identifiable by a specific bar code, linked back to the initial trailer build order, and can be reordered direct from Georges Canvas prior to the vehicle arriving for repair.
This benefit has seen downtime that would result from a system removal, repair and reinstall of six to eight hours reduced to a one-hour service. Trailer operators can now choose to carry spare tarp panels, bows and plastic bow ends for their own repairs.