Modular Trailer (HMT)
Also known as: HMT · Hydraulic Modular Trailer · Modular trailer · Modular axle lines · Axle lines · Bouzhi · Boji · Moduler dorse
A modular trailer is built from axle lines that are coupled end to end and side by side. Hydraulic suspension keeps the load level, and the capacity grows with every axle line — up to hundreds of tonnes.
Names in other languages
- English
- Modular Trailer (HMT)
- Türkçe
- Modüler Dorse
- فارسی
- بوژی (تریلر مدولار)
- Русский
- Модульный прицеп (HMT)
- 简体中文
- 模块挂车（HMT）
- العربية
- مقطورة معيارية (HMT)
Specifications
Typical figures — they vary by manufacturer and by country rules on weights and sizes.
| Internal width | 3,000 mm |
|---|---|
| Deck height | 900–1,500 mm |
| Capacity per axle line | 30,000–45,000 kg |
| Loading method | Top · Rear |
Typical cargo
Transformers, heavy machinery, refinery and plant parts (reactors, columns, vessels), bridge beams, and other very heavy indivisible loads.
In plain words
Each module has several axle lines with hydraulic suspension. The modules are bolted together lengthwise and, for very heavy or wide loads, also side by side. The hydraulic system shares the weight evenly over all axles and lifts or lowers the deck (often by about ±300 mm), so the load stays level on slopes and road camber. All axles steer, which helps on tight corners. One or more heavy tractor units pull or push the trailer, and the combination can include goosenecks, beams, or bridge decks for special loads.
Moves on public roads need special permits from every authority on the route. A route survey checks bridges, tunnels, power lines, road signs, and roundabouts; sometimes signs or barriers must be removed and put back. Escort vehicles, and often the police, go with the convoy, and many moves happen at night when traffic is low. The weight allowed per axle line on public roads is usually much lower than the trailer's technical capacity and is set in the permit.
Advantages
- Capacity can be built up to hundreds of tonnes by adding axle lines.
- Hydraulic suspension keeps the load level and spreads the weight evenly.
- All-axle steering for tight corners.
Limits
- Needs special permits, a route survey, and escorts — planning can take weeks.
- Very slow travel, often only at night.
- High cost for equipment, tractors, and crew.
Example from real shipping
A power company moves a 180-tonne transformer from a port to a substation 60 km away. The heavy-haul team couples 14 axle lines, plans the route with a survey, and gets permits for two nights of travel. With a pulling and a pushing tractor and police escort, the convoy drives at walking speed over the critical bridges.
Related terms
- SPMTAn SPMT is a modular platform with its own engine and drive. It needs no tractor unit, is steered by remote control, and can move extremely heavy loads over short distances.
- Low-loader (Lowbed)A low-loader is a trailer with a very low deck, so tall and heavy machines can be carried without going over the height limit. Many have ramps so vehicles can drive on.
- OOGOOG cargo is cargo that sticks out beyond the normal outside size of a container — too high, too wide, or too long. It usually travels on a flat rack, open top, or platform.
- Road vehicle typesA side-by-side comparison of the trucks and trailers used in road freight: load space, payload, volume, pallet places, loading method, and typical cargo.
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Request a QuoteThis glossary is general information, not legal or customs advice. Rules, fees, and practice can differ by carrier, port, and country.