Among multiple level of upgradation in BS6, one of the revolutions we are seeing in BS6 regime is the introduction of new GCW (Gross Combination Weight) of tractor trailers. Technically a two-axle horse coupled with a three-axle trailer used to provide a GCW of 40.2 tons before the introduction of Increased Axle Load (IAL) norms in July-2018. However, post IAL same vehicle became a 45.5 Ton GCW tractor trailer which is commonly known as a 46 Ton vehicle.

Off late, trailer manufacturers and OEMs have come up with interesting innovations related to 3 axle trailers which has allowed the same two-axle tractor & three-axle trailer combination vehicles to achieve multiple GCWs. What that means is with a 6-wheeler horse, & 12-wheeler trailer we can have GCWs in following categories:

• 45.5 Ton
• 50 Ton
• 51 Ton
• 52 Ton
• 53 Ton
• 54 Ton
• 55 Ton

There are four laws related to axle rating by CMVR which allows above combinations-

• A three-axle trailer in case have all the axles placed within 3 meters spacing (known as tridem axle) qualifies a rating of 27 tons.
• A three-axle trailer with tridem spacing beyond 3 meters results into one independent axle with rating of 11.5 ton and a set of two axles within a tandem spacing of 1.8 meters qualifies for a rating of 21 ton. Overall GVW of the trailer qualifies for 32.5 tons in such case.
• A three-axle trailer with all the axles spaced wider than 1.8 meters gets independent rating of 11.5 ton each. Such trailer naturally qualifies for GVW of 34.5 tons.
• If any of the independent axle of 11.5 ton has pneumatic suspension mechanism, IAL norms permit 1 ton of extra load on such axles. In that case the independent pneumatic axle qualifies a tonnage rating of 12.5 ton.

Below is the pictorial representation of how exactly with a 4x2 two axle tractor & multiple type of trailers, the OEMs are able to offer 7 different GCWs-

Advantage of 4x2 higher GCW configurations-

Newly configured 4x2 higher GCW tractor trailer has multiple advantages over a traditional 4X2 46 tonner and 6X4 55 tonner:

• GCW advantage:50T, 51T, 52T, 53T, 54T & 55T GCWs.
• Payload advantage:Approx. payload with side wall trailer- ~36T on 50T, ~37T on 51T, ~38T on 52T, ~39T on 53T, ~40T on 54T, ~41T on 55T (Please note: 55T 4x2 has higher payload than 55T 6x4).
• Tyre advantage:Saving on 4 tyres.
• Mileage advantage:4x2 offers higher mileage than 6x4.
• Lower maintenance expense advantage:Single differential tractor of 4x2 configuration needs lower differential oil than double differential tractor of 6x4 configuration.
• Lift axle advantage:Few of the trailers comes with pneumatic lift axles as option. Lift axle offers the benefit of longer tyre life, higher kmpl & better maneuverability in case return movement is either empty or underload.

Stay tuned for more exciting tools