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How to Specify a Dump Truck Body: Duty, Cylinder Position, Tailgate and Sub-frame

A dump body works harder than almost any other cargo body. It is loaded by excavators and wheel loaders, carries dense material such as sand, gravel and rubble, and lifts the whole load every time it unloads. A body that is specified too light cracks or bends. One that is specified too heavy wastes payload on every trip. Qingdao Hailong Machinery Group builds dump bodies in light-duty and heavy-duty versions with several cylinder, tailgate and structure options. This guide explains each decision and what it means in daily use.

1. Light duty or heavy duty

Start with the cargo and how it is loaded, not with the truck.

• Light-duty bodies suit lighter or finer material, such as soil, sand and agricultural loads, loaded from a modest height.
• Heavy-duty bodies suit dense or sharp material, such as crushed stone, quarry rock and demolition waste, and loading by large excavators where impact on the floor is high.

The duty class sets the floor and side plate thickness, the cross members and the reinforcement. Tell us the material, its typical lump size and how it is loaded, and our engineers will size the structure.

2. Front-top or middle-top cylinder

Hailong offers dump bodies with the lifting cylinder mounted at the front of the body or in the middle, under the body.

The right choice depends on payload, body length, chassis layout and how steeply the body must tip to empty your material cleanly. Wet clay and sticky material need a higher tipping angle than dry gravel.

3. Tailgate opening

The rear door decides how the load leaves the body. Hailong dump bodies can be built with left, right or lower rear-door opening.

• Lower opening is common for bulk material that should pour out across the full width.
• Left or right side-hinged opening lets the door swing clear, which helps with large lumps and demolition waste that could jam a lower-hinged door.

Think about the site as well: spreading material on a road, tipping into a hopper and dumping on a pile all favor different opening styles.

4. Side structure

Hailong offers vertical rib and reinforced side structures. Ribs stiffen the side panels against bulging under a full load and against impact from the bucket. Heavy-duty work usually calls for more reinforcement on the sides and along the top rail, where loaders tend to hit.

5. Sub-frame

A sub-frame sits between the body and the truck chassis. It spreads the load, especially during tipping, when the hinge point and cylinder mount carry high forces. Sub-frame options should match the chassis model, its frame width and the body maker's mounting guidelines. Send us the chassis model and drawings so the sub-frame and mounting points fit first time.

6. Corrosion protection

Dump bodies are scratched by every load and often stand outside in wet weather. At Hailong, steel cargo bodies are fully e-coated and finished with high-temperature baking paint. E-coating reaches seams, corners and the inside of profiles, where corrosion usually starts.

Checklist: what to send for a quotation

1. Truck chassis model, wheelbase and the space available behind the cab
2. Material carried, its density and lump size, and how it is loaded
3. Target payload and body volume, or internal dimensions
4. Light-duty or heavy-duty preference, if known
5. Cylinder position and required tipping angle, if specified
6. Tailgate opening style
7. Quantity, destination market and any local dimension or marking rules
8. Drawings or a sample, if available

Hailong can build by drawing, by sample or to a target specification, and our engineers review the structure before quoting. Read how to choose a truck cargo body, steel vs aluminum cargo bodies and how truck cargo bodies are made.

About Hailong Group

Hailong Group was founded in 1955 and is certified to IATF 16949, ISO 9001, ISO 14001 and ISO 45001. Truck body production is based in the group's Bei'an Intelligent Manufacturing Park, with a capacity of about 30,000 cargo body sets a year.