In short: Side dump versus rear dump is decided by where material can land safely on site, not by which way the body tips. A side dump discharges beside the deck without the tractor moving; a rear dump reverses into a tip bay and tips out of the back. That constraint drives cycle time, fleet size and fuel use.
The choice is not really about which direction the body tips. It is about where the material can land safely on your site — and that single constraint decides your cycle time, your fleet size and often your fuel bill. A side dump discharges beside the deck. A rear dump discharges out of the back. Everything else follows from there.
How each one actually discharges
Rear dump. The trailer reverses into the tip position, the body lifts and the load slides out behind the trailer. It is the default on construction and aggregate work because reversing into a known tip bay is a routine the driver already knows. The catch is that the space behind the trailer has to be clear and level, and the trailer has to be able to reverse into it — which is not always possible on a bench, a narrow fill or a one-way site road.
Side dump. The load goes down beside the trailer. On a mining bench, a road embankment or a stockpile edge, that means the trailer pulls alongside the tip line and discharges without any reversing manoeuvre. The trade-off is that you need usable, level ground on the discharge side, and the tipping forces work across the frame rather than along it.
What your site decides
| Site condition | Better fit |
|---|---|
| Clear, level space behind the tip bay, room to reverse | Rear dump |
| Bench, embankment or one-way road with no reversing room | Side dump |
| Tight stockpile where a tractor cannot straighten up | Side dump |
| Soft ground that will not take a loaded trailer beside the tip | Rear dump, tipped from a prepared pad |
| Wet or sticky clay that hangs in a box | U-shape body, or side dump with a clean-plate profile |
| Rock and overburden at 80–100 t per trip | Four-axle U-shape rear dump |
What the load does to the frame
This is where the specification matters, and where a cheap trailer shows up first.
Our 3-axle side dump runs a Q345 high-tensile I-beam on automatic submerged arc welding, with an 18 mm x 140 mm top flange, a 14 mm middle flange and a 20 mm x 140 mm bottom flange at a 500 mm section height. That flange set is sized for the twisting load a side tip puts into the frame. The body is 1,600 mm high in 6 mm plate over an 8 mm checked floor, on three 13 t axle sets with 10-leaf 90 x 13 mm springs.
The 3-axle rear dump carries 25–35 CBM on a Q345 I-beam with a 12 mm x 140 mm upper flange, an 8 mm web and a 12 mm x 140 mm lower flange, again at 500 mm section height, with a 6 mm checked floor and 1,600 mm side walls. A rear tip loads the frame in bending and pushes along its length, which is why the geometry differs from the side dump.
For rock and overburden, the 4-axle U-shape rear dump trailer goes heavier: a Q345B main beam with a 16 mm upper plate, a 10 mm web and an 18 mm lower plate, rated 80–100 t, with a genuine HYVA hydraulic lifting system and a U-shape body that releases sticky material instead of holding it.
Cycle time, safety and cost
- Cycle time. A side dump removes the reversing manoeuvre, which on a short haul can be a measurable share of each cycle. On a long haul with a proper tip bay, a rear dump is faster.
- Stability. Tipping sideways needs level ground across the width of the trailer. Tipping rearward needs level ground along its length and clear space behind.
- Tare and payload. A side dump body is typically shorter and heavier for the same tonnage; a rear dump gives you more volume per tonne of tare.
- Common equipment. All three models share the same 28 t two-speed landing gear, WABCO RE6 relay valve with T30/30 spring brake chambers and 40 L air tanks, optional ABS and an electric tarpaulin as standard.
Which one to order
- Construction spoil, sand and gravel, standard tip bay → rear dump.
- Mining bench, embankment, narrow or one-way site roads → side dump.
- Rock, ore and overburden at 80–100 t → four-axle U-shape rear dump.
- Wet or sticky material that hangs up → U-shape body, or a rear dump with a clean-plate profile.
Send us the material, its density, the haul road profile and whether the trailer can reverse into the tip position. We will confirm the body size and the tipping system rather than quote a standard build. Start from the side dump range or the rear dump range, or tell us about your site.
FAQ
Can a side dump tip on a slope?
It needs level ground across its width on the discharge side. If your tip point is on a slope, a rear dump from a prepared pad is usually the safer answer.
Which one handles wet clay better?
Neither box likes it, but a U-shape body releases sticky material more cleanly than a flat-sided box. Tell us the material and we will size the body accordingly.
How many axles should a dump trailer have?
Three axles covers most 30 t work. Four axles is the answer when you are moving rock at 80–100 t per trip and want the load spread across more tyres.
Is an electric tarpaulin included?
Yes. All three of the models above ship with an electric tarpaulin as standard equipment.
What is the lead time?
About 15 days for one set. Ten sets or more run about 30–35 days depending on the model, confirmed before production starts.
Key facts
- A side dump discharges beside the deck; a rear dump discharges out of the back.
- Rear dump needs clear, level space behind the trailer to reverse into.
- Side dump suits stockpiles beside the haul road where the tractor stays put.
- U-shape rear dump bodies reduce residue with sticky or wet material.
