A self-propelled modular transporter or sometimes self-propelled modular trailer (SPMT) is a platform heavy hauler with a large array of wheels which is an upgraded version of a hydraulic modular trailer. SPMTs are used for transporting massive objects, such as large bridge sections, oil refining equipment, cranes, motors, spacecraft and other objects that are too big or heavy for

truck A truck or lorry is a motor vehicle designed to transport freight, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construct ...

s. Ballast tractors can however provide traction and braking for the SPMTs on inclines and descents. SPMTs are used in many industry sectors worldwide such as the construction and oil industries, in the shipyard and offshore industry, for road transportation, on plant construction sites and even for moving

oil platforms An oil platform (also called an oil rig, offshore platform, oil production platform, etc.) is a large structure with facilities to extract and process petroleum and natural gas that lie in rock formations beneath the seabed. Many oil platforms wi ...

. They have begun to be used to replace bridge spans in the

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and more recently

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Specifications

A typical SPMT has a grid of computer-controlled axles, usually 2 axles across and 4–8 axles along.https://www.scheuerle.com/fileadmin/data_all/files/Self-Propelled_Transporters_EN.pdf When two (or more) axles are placed in series, this is called an axle line. All axles are individually controllable, in order to evenly distribute weight and to steer accurately. Each axle can swivel through 270°, with some manufacturers offering up to a full 360° of motion. The axles are coordinated by the control system to allow the SPMT to turn, move sideways or even rotate in place. Some SPMTs allow the axles to telescope independently of each other so that the load can be kept flat and evenly distributed while moving over uneven terrain. Each axle can also contain a hydrostatic drive unit. A hydraulic power pack can be attached to the SPMT to provide power for steering, suspension and drive functions. This power pack is driven by an internal combustion engine. A single power pack can drive a string of SPMTs. As SPMTs often carry the world's heaviest loads on wheeled vehicles, they are very slow, often moving at under while fully loaded. Some SPMTs are controlled by a worker with a hand-held control panel, while others have a driver cabin. Multiple SPMTs can be linked (lengthwise and side-by-side) to transport massive building-sized objects. The linked SPMTs can be controlled from a single control panel.

History

The first modular self-propelled trailers were built in the 1970s. In the early 1980s, heavy haulage company Mammoet refined the concept into the form seen today. They set the width of the modules at 2.44 m, so the modules would fit on an ISO

container A container is any receptacle or enclosure for holding a product used in storage, packaging, and transportation, including shipping. Things kept inside of a container are protected on several sides by being inside of its structure. The term ...

flatrack. They also added 360° steering. They commissioned Scheuerle to develop and build the first units. Deliveries started in 1983. The two companies defined the standard units: a 4-axle SPMT, a 6-axle SPMT and a hydraulic power pack. Over the years, new types of modules were added to this system to accommodate a range of payloads. In 2016 ESTA (the European Association of Abnormal Load Transport and Mobile Cranes) published the first SPMT

best practice A best practice is a method or technique that has been generally accepted as superior to alternatives because it tends to produce superior results. Best practices are used to achieve quality as an alternative to mandatory standards. Best practice ...

guide to help address the problem of trailers occasionally tipping over, which happened even when the operating rules and stability calculations had been precisely followed. Some shipbuilding companies have started to use SPMT instead of

gantry crane A gantry crane is a Crane (machine), crane built atop a wikt:gantry, gantry, which is a structure used to straddle an object or workspace. They can range from enormous "full" gantry cranes, capable of lifting some of the heaviest loads in the wor ...

s for carrying ship sections. This has reduced the cost of transporting huge loads by millions of dollars. Scheuerle Mammoet Stoof 1988 Red Dog

In 2022 Mammoet and Scheuerle developed and employed world's first electric SPMT. This was done with the help of an Electric power pack unit (EPPU) which replaced the gas powered PPU. The ESPMTs help to reduce

carbon footprint A carbon footprint (or greenhouse gas footprint) is a calculated value or index that makes it possible to compare the total amount of greenhouse gases that an activity, product, company or country Greenhouse gas emissions, adds to the atmospher ...

of the companies and also the haulage industry. These electric modules are safer and quieter when compared with the diesel modules, which can benefit operations which are held in mines and energy plants. ESTA has plans to develop European Trailer Operator's License (ETOL) for SPMT operators, this idea is backed by top company operating in heavy haulage sector like Goldhofer and Tii Group. There will be training and practice to obtain this specific license which the SPMT operators have to complete before handling these heavy machines on public roads, but this will improve the safety standards of the industry.

Achievements

Executing the salvage operation of the sunken ferry MV ''Sewol'' in the East China Sea in 2017, the company ALE used SPMTs equivalent to a 600-axle line and a load weight of , exceeding two world records. In December 2022

Shell plc Shell plc is a British Multinational corporation, multinational petroleum, oil and natural gas, gas company, headquartered in London, England. Shell is a public limited company with a primary listing on the London Stock Exchange (LSE) and second ...

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based oil company ordered decommission of their 20,300ton FPSO Curlew ship when it reached the end of its operational life. This operation was assigned to AF Offshore Decom, a decommissioning specialist company based in

Oslo Oslo ( or ; ) is the capital and most populous city of Norway. It constitutes both a county and a municipality. The municipality of Oslo had a population of in 2022, while the city's greater urban area had a population of 1,064,235 in 2022 ...

which partnered with Mammoet of

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to load-in and set-down the structure in

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

with the help of 748 SPMT axle line. This claimed to break two world records, one for the heaviest SPMT movement and another for most SPMT axle lines used for transportation. In February 2023 Sinotrans Heavy-Lift a

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

based heavy transport company moved a hotel building 500 meters in

Sanya Sanya; Chinese postal romanization, also spelled Samah is the southernmost city on Hainan Island, and one of the four prefecture-level cities of Hainan, Hainan Province in Southeast China, South China. According to the Sixth National Populati ...

Hainan Hainan is an island provinces of China, province and the southernmost province of China. It consists of the eponymous Hainan Island and various smaller islands in the South China Sea under the province's administration. The name literally mean ...

using 254 axle lines of Scheuerle SPMT with the help of 15 power packs. This was claimed to be the world's heaviest building transportation ever. The building in the subject was almost 300ft long, 115 ft wide, 65 ft high and weighed 7,500 tons. The relocation was done to comply with the environmental regulations of the state. In December 2023 China Shipping Vastwin Project Logistic a China based logistics company a subsidiary of China based multinational company COSCO Shipping moved five number of buildings at the Ningxia Saishang Jiangnan Museum located in

Ningxia Ningxia, officially the Ningxia Hui Autonomous Region, is an autonomous region in Northwestern China. Formerly a province, Ningxia was incorporated into Gansu in 1954 but was later separated from Gansu in 1958 and reconstituted as an autonomous ...

based in

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. The relocation was done to adhere with the environmental regulations. The buildings in subject were 11,450 tonnes in total of five with the main building weighing 10,000 tonnes, 43 mtr high, 36.9 mtr long and 31.5 mtr wide which was moved on 300 lines of SPMT and ten powerpacks. This resulted in breaking three records of most heights, heaviest building transportation over the longest distance.

Notable manufacturers

* Enerpac * Faymonville *
Italcarrelli
* Mammoet
Greiner Heavy Engineering

Tracta
* Transporter Industry International ** Nicolas
Seyiton

Operators

* Denzai(www.denzai-j.com) * ALE * Mammoet *

Alstom Alstom SA () is a French multinational rolling stock manufacturer which operates worldwide in rail transport markets. It is active in the fields of passenger transportation, signaling, and locomotives, producing high-speed, suburban, regional ...

* Sarens * Lampson International * CLP Group * Omega Morgan
Nordic Crane (Sweden,Norway & Denmark)
* Allelys

References