A dump truck carries loose material such as soil, sand, aggregates and rubble, and unloads it by tipping its body. On a building project it is the link between the excavator and the disposal site, or between the quarry and the working platform. Few machines on site move as much material, and few are involved in as many traffic incidents.
This guide explains the main types of dump truck, how the tipping mechanism works, where the trucks fit into the construction process, and the safety and site-management issues that come with them, particularly in Singapore’s dense urban sites where trucks share space with workers, neighbours and public roads.
What a dump truck is
The term covers any truck with an open body, or box, that can be raised by hydraulic rams to discharge its load. The body is hinged at the rear, and when the rams extend, it tilts so the material slides out under gravity. Some bodies have a tailgate that opens as the body rises; others are designed to eject material over a sloped rear edge.
In Singapore and much of the Commonwealth, the road-going version is often called a tipper truck or tipper lorry. Off-road machines used inside quarries, large earthworks and reclamation sites are usually called dumpers or haul trucks.
Main types of dump truck
Road-going tipper trucks
These are built on a standard truck chassis and are registered for road use. They carry excavated material out of building sites and bring in fill, sand and aggregates. Because they travel on public roads, they must meet road traffic requirements, including load limits and securing or covering loads so material does not fall onto the road.
Rigid dump trucks
Rigid off-road trucks have a single chassis and are designed for very heavy loads on well-maintained haul roads, mainly in quarries and large earthworks. They are rarely seen on urban building sites.
Articulated dump trucks
Articulated trucks have a pivoting joint between the cab and the body, and usually all-wheel drive. The articulation keeps all wheels in contact with uneven ground and gives good traction on soft or rough haul roads. They are used on large earthworks and infrastructure jobs where roads are temporary and conditions change with the weather.
Site dumpers
Small site dumpers, with a skip in front of the driver, move material short distances around a site. They are compact and useful, but have a poor record for overturning and for striking pedestrians because the skip blocks the driver’s forward view.
How the dump truck fits into the earthworks cycle
On a basement project, the trucks set the pace of excavation. An excavator or wheel loader fills each truck in a few passes; the truck leaves, crosses a wheel-washing bay and joins public roads to a disposal site; the next truck moves into position. If trucks do not arrive steadily, the excavator stands idle; if too many arrive, they queue on the street.
Planning this cycle covers more than logistics. Trucks need a stable, well-drained access route and a loading area that does not surcharge the excavation edges or the retaining walls beyond what the temporary works design allows. In a braced basement, the position of the loading point relative to the walls and struts is a design decision, which is why we discuss it in our article on deep excavation shoring.
Bringing material in
Trucks also deliver fill and granular material for working platforms, sub-base and backfill. Tipping material in heaps that are then spread and compacted in layers is standard practice. Uncontrolled tipping of large heaps on a slab, a podium or near an excavation edge can overload the structure or the ground.
Site safety
Vehicle movements are among the leading causes of serious and fatal injuries at Singapore workplaces, and the WSH Council issues regular advisories on vehicle-related fatalities. The legal duties come from the Workplace Safety and Health Act and its regulations, supported by the WSH Council’s guidelines on workplace traffic safety management and on safe loading and unloading of vehicles.
Traffic management
- Plan routes that separate pedestrians from vehicles, with clearly marked walkways and crossing points.
- Use one-way loops where possible to reduce reversing.
- Fit and maintain reversing alarms, mirrors and cameras, and use trained ground guides where reversing near people is unavoidable.
- Control access at the site gate, where trucks cross footpaths and enter public roads.
- Allow only trained, licensed drivers to operate vehicles on site.
Tipping hazards
Raising a body full of material moves the centre of gravity high and to the rear. Tipping on a slope, on soft ground, or with material stuck in one side of the body can overturn the truck. The truck should tip on firm, level ground, with the driver checking the area behind and above. Overhead power lines are a particular hazard because a raised body can reach them.
Work under a raised body is dangerous: maintenance should only be done with the body propped on a proper mechanical support, never relying on the hydraulic rams alone.
Edges and excavations
Trucks tipping into an excavation or over an embankment need stop blocks or a substantial bund to prevent the wheels going over the edge, and the edge itself must be strong enough to carry the wheel loads. The temporary works design should define where trucks may approach.
Environmental controls on Singapore sites
Dump trucks carry mud onto public roads unless wheels are washed before leaving the site. Singapore construction sites are required to implement earth control measures under PUB’s requirements to prevent silt-laden water and soil from entering public drains, and wheel-washing facilities at site exits are a standard part of those measures. Loads should be covered to prevent spillage and dust. Truck movements near homes also fall within NEA’s construction noise controls, which can restrict working hours.
These requirements affect the site layout. A wheel-washing bay, a holding area for trucks and a safe exit onto the road all take space, and on tight urban plots they compete with the space needed for cranes, materials and the excavation itself.
Planning truck movements well
The best-run sites treat truck logistics as part of the construction method. The number of trucks, the timing of deliveries and disposal, the access route, the loading point and the ground conditions are all planned together. Where trucks need to drive over a new slab or a basement roof, or stand near a retaining wall, the loads should be checked by an engineer. Our guide to construction safety discusses how these site hazards fit into a wider safety plan, and our consultancy can review plant loads on structures and temporary works.
Frequently asked questions
What is the difference between a dump truck and a tipper truck?
The terms overlap: a tipper truck usually means a road-going truck with a tipping body, while dump truck can refer to both road tippers and larger off-road rigid or articulated haul trucks used on quarries and big earthworks.
What is an articulated dump truck?
It is an off-road truck with a pivoting joint between the cab and the body and usually all-wheel drive, which keeps the wheels in contact with uneven ground and gives traction on soft temporary haul roads.
Why do dump trucks overturn when tipping?
Raising a full body lifts the centre of gravity high and to the rear, so tipping on a slope or soft ground, or with material stuck to one side of the body, can make the truck unstable and roll over.
Why must trucks wash their wheels before leaving a site?
Wheel washing prevents mud and silt being carried onto public roads and into drains, and is part of the earth control measures that Singapore construction sites are required to implement.
Can a dump truck stand next to a basement excavation?
Only where the temporary works design allows for the surcharge, because the weight of a loaded truck near the edge adds pressure to the retaining wall and soil that the design must account for.
Related reading
- Construction Hoist: How Rack-and-Pinion Lifts Work
- Boom Lift Guide: Telescopic, Articulating and Safe Use
- Scissor Lift Explained: How It Works and Safe Use on Site
- Forklift Safety on Construction Sites: A Clear Guide
Need surcharge, ramps or plant loading checked on your excavation? Talk to our consultancy or get in touch.
