How to work out if a plant trailer will carry your machine

Most people shop for a plant trailer by deck size. They measure the machine, find a tray that looks big enough, and hand over a deposit. Then they load up on a Monday morning and find out the trailer is rated for less than the machine weighs, fuelled and fitted with a bucket. Deck size was never the problem. Weight was.

Start with the machine, not the trailer.

What your machine actually weighs

The number on the spec sheet is a starting point, not the number you tow with. Operating weight is the base figure manufacturers quote, and it usually assumes an empty machine with no attachments.

Add to that:

• The bucket or attachment currently fitted, not the smallest one available
• A full tank of fuel, not whatever’s left on Friday
• Anything riding in the tray with the machine: chains, timber, a generator, spare buckets

A mini excavator, Bobcat, skid steer or Posi-Track can pick up several hundred kilograms once you account for all of that. Weigh the machine as it actually sits on site, not as it appears in the brochure.

The sum that matters

Once you know what the machine weighs, the trailer’s payload is the number to check against it.

Payload is ATM minus tare.

• ATM (Aggregate Trailer Mass) is the maximum the trailer is rated to carry, including its own weight.
• Tare is what the trailer weighs empty. It’s stamped on the compliance plate, fixed to the trailer itself.

Take the ATM, subtract the tare, and that’s your payload: the maximum weight the trailer can legally and safely carry. Compare that number to what your machine weighs, fully fuelled and fitted out. If the machine is heavier than the payload, the trailer isn’t the right one, no matter how well the deck fits.

Do this sum before you buy, not after you’ve loaded up.

3.5T or 4.5T: picking your payload capacity

Wrangler’s plant trailer comes in two ATM capacities: 3.5T and 4.5T.

The difference isn’t the deck. Both sit at 14 ft × 6.5 ft. The difference is how much weight the trailer is built and rated to carry once you’ve worked out your payload sum above.

If your machine, loaded and fuelled, sits comfortably under a 3.5T ATM once tare is accounted for, that’s your trailer. If it’s closer to the top end, or you’re regularly swapping attachments and adding weight, the 4.5T gives you the margin. Run your own numbers against each capacity’s tare and payload rather than guessing which one “looks right” for your machine.

If what you’re moving is lighter or wheeled rather than tracked, a flat top trailer may suit better than a plant trailer built around tracked machinery. Our flatbed trailer range covers that case.

Loading and unloading without the drama

Every Wrangler plant trailer runs 1500 mm ramps matched to its capacity, wide and long enough for the machines they’re built to carry.

Tracked machines sit low. That means less clearance and a longer run-up than most people expect before the tracks bite properly onto the ramp. Rush the run-up, or set the ramps at too steep an angle, and you get a machine that stalls halfway up, slides sideways, or worse, tips.

A bad ramp setup doesn’t punish you in the yard. It punishes you on a slope, at 6am, when the ground’s wet and there’s nobody around to help. Get the trailer parked level, extend the ramps fully, and take the run-up slow. That’s the whole trick.

Keeping it there

Getting the machine on is only half the job. It needs to stay exactly where you put it for the whole trip.

Wrangler’s plant trailer has 10 tie-down points, positioned so the machine sits correctly relative to the axles rather than hanging off one end. Weight distributed evenly over the axles tows straighter and brakes more predictably than weight bunched at the front or back.

For tracked plant, chain over strap. Straps can work loose against steel tracks in a way chain won’t, and the last thing you want is movement mid-trip that you can’t see from the cab.

Don’t forget your tow vehicle

The trailer is only one side of the equation. Your tow vehicle has its own limits, and they need checking against the loaded trailer, not the empty one.

Two figures matter: the vehicle’s rated towing capacity, and its ball weight limit. Both are set by the vehicle manufacturer and shouldn’t be treated as flexible. Check them against what the trailer weighs once your machine, fuel and attachments are loaded on, not the trailer’s tare weight alone.

The compliance plates on both the trailer and the tow vehicle carry the figures you need. When in doubt, that’s where to look, not a rule of thumb from someone at the servo.

Built to work. Ready when you are.

Wrangler’s plant trailer range is built in Bullsbrook, hot-dip galvanised as standard, and fitted with 12-inch hubs and electric brakes with handbrake for the loads it’s rated to carry. It’s a standard, work-ready range: if your job calls for something outside that, it’s worth a conversation rather than a custom build.

Pickup from Perth or delivered Australia-wide.

Work out your machine’s weight, run the payload sum, and check it against the 3.5T and 4.5T plant trailer specs before you buy. That’s the method that keeps you off the side of the road.