New self propelled modular transporter from Hydrospex

06 March 2009

Tjerko Jurgens, Hydrospex managing director

Tjerko Jurgens, Hydrospex managing director

A new self propelled modular trailer (SPMT) system offers advantages over competitors, according to its manufacturer, Netherlands-based Hydrospex. Tjerko Jurgens, Hydrospex managing director, demonstrated the new high capacity system to Alex Dahm.

Hydrospex in the Netherlands has further expanded its hydraulic heavy equipment range with the announcement of a new self propelled modular trailer (SPMT).

Aside from two major differences, the Hydrospex HSPMT750 has similar functionality to other SPMT systems on the market. Setting it apart, however, are a couple of major differences, according to its creator, Tjerko Jurgens, Hydrospex managing director. These are its slim design and its lower access height, which make it more user-friendly and it offers better accessibility in confined spaces, Jurgens says.

Entering the SPMT market is a big step for Hydrospex, says Jurgens. "We are going to enter a market that is quite new for us. It is a captive market controlled by three major players and Chinese manufacturers are waiting at the border with their alternatives."

The Hydrospex SPMT is a three axle modular system available in two versions: HSPMT750, which has all axles driven; and the un-propelled HMT750. HSPMT and HMT trailers can be combined into a six axle trailer using one power pack. The combined trailer offers a 150 tonne payload.

More payload is available. The standard control system can operate up to six modules (18 lines) with, adjacent, another six modules, creating a transport platform about 20 x 5 m. Payload capability is then 900 metric tonnes.

Gross capacity is 25 tonnes per line. If you build the trailers together - a six liner - it will be 6 m long. Capacity would be about 120 tonnes. But if you take a 120 tonne object it is always longer than 6 m so you always have enough capacity, Jurgens explains.

Different requirement

Unlike some, the Hydrospex SPMT is incompatible with systems from other manufacturers. "The reason for the different manufacturers making SPMTs that could work together was that 10 years ago Mammoet and Sarens, for example, each had a number of lines of SPMT and they would get together to do big jobs because their systems were compatible. Now, they have grown so much they do not need each other so much any more."

What Jurgens found his potential customers wanted was different from that offered by an SPMT design that would be interchangeable with others. Existing SPMTs have features that are not used enough, Jurgens says, "Are there any features - to get a better price - that we don't need?" Rough terrain capability is one. "My clients are ones that always drive indoors or always on good paved roads," Jurgens explains. The new SPMT is more for moving things around a plant than for carrying large and heavy loads by road.

The potential customers "told me that the price is more important than the high axle load, than the road running capacity or driving at 15 mph - these are things they don't need." It makes the design both easier and more complicated. "First of all, to build a trailer that is only half the height of an existing SPMT requires more than a little bit of engineering."


In its lowest position the 650 mm deck height is lower than any other self propelled trailer on the market today, Jurgens claims. Deck height fully raised is 1,000 mm. A deck height of 1.2 m is typical for existing SPMTs, Jurgens says.

"Standard SPMT tyres are 835 mm diameter so there is the first conflict - they are never going to do it. So we had to find a tyre that is about 450 mm diameter. We have managed to develop it with a fork truck tyre. It is a solid tyre and to create suspension for differences in terrain, we have used a cradle design with an accumulator. We developed everything ourselves."

The Hydrospex SPMT is designed to fit in standard sea containers. Its weight is low enough (6 tonnes) to allow four modules (12 lines) to be stacked in a 20 foot container. Its overall width of 2,300 mm is designed for optimum manoeuvrability, Jurgens says.

On the control side, the trailers are operated by the Intellidrive wireless control system that uses the same technology as the Intellilift system that Hydrospex developed for telescopic hydraulic gantries. One person can operate the Hydrospex SPMT and there is no difficult-to-configure software; just connect, select and drive, Jurgens says.

"We did a lot of engineering work in the control system. You can switch it on and go. They have electronics on that can detect what the configuration is. You plug in the cables and it works out how many lines are connected and where and you just have a joystick like a Nintendo and you can drive with it. Driving a fork lift truck is more complicated than driving my SPMT."

The HSPMT requires a diesel power pack. Two types are available: 33 kW with a capacity of three trailers; and 7.5 kW, also for up to three trailers but just used for towing. The Hydrospex power pack is 600 mm tall and, depending on the trailer configuration, up to four power packs can be connected together.

The power packs fit on the front or rear side of a unit. To avoid collision with curbs or other obstructions the power pack can be tilted up to 10 degrees. A feature of the modular design is to allow easy through-linking of the power pack's hydraulic hoses.

Delivering the goods

"We hope that on the first of April [2009] we can start the mass production of these trailers. Our building should be ready for the manufacturing. We have purchased the manufacturing machinery necessary to build it - the robotic welding machines, the CNC lathes, etc. Our objective is to produce one trailer a week and our forecast for 2009 is that we are going to supply something like 150 lines. We would be very happy if we can sell this number of lines."

The SPMT will be built in three-line units and the only option will be the colour. "It will be completely standard and very cheap. We are going to offer it at between 50 and 60% of the competition price. It is low but there are also things it cannot do. But, to get you started, for a six liner with power pack I can help you for about 250,000 Euros," Jurgens explains.

"Our expectation is that the minimum configuration is six lines, so that means I need to find 20 customers in that area. My customer is going to be the crane or transport company that employs 25 to 40 people, has already got hydraulic gantries, plus a small crane, perhaps, and doesn't want to call a big renter to rent a trailer from them. I am not looking for people who will order 300 lines."

Technical specification

Hydrospex modular trailer type HSPMT750

Payload: 750 kN per trailer

Weight: 6,000 kg

Speed (unloaded): 5 km/h

Speed (loaded): 2 km/h

Steering range: -45° to +45°

Lifting range: 638 to 1,000 mm (362 mm stroke)

Maximum number of trailers: two rows of six trailers

Power: 33 kW per power pack (propelled)

7.5 kW per power pack (towed)

For a large view of the detailed drawing follow this link (

Latest News
CSCEC-built spiral tunnel officially recognised as world’s longest
A spiral tunnel in China, built by Chinese construction giant China State Construction (CSCEC), has been recognised as the world’s longest
Consortium wins €302m deal to build Swiss railway plant
A consortium led by Swiss construction company CSC Costruzioni has won a contract worth €302 million (US$327 million) to build a new railway plant in Switzerland
Epiroc to acquire French attachments manufacturer
Swedish OEM continues massive attachments expansion following Stanley acquisition