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MOBILE STOOL SYSTEM, MoSSt. The new generation of bulkcarrier vessels

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[MoSSt]Commercial_sheet_UPM_EN(Innovatech) PDF

Innovative continuous type bulkcarrier´s self-discharging system. The system has no cargo hold loss. The system is fully independent from port terminal and personel, speeding up discharging operations. 

A UPM´s researchers group has developed a new and innovative bulkcarrier ship self-discharging system. The system itself it´s continuous type and uses adapted bucket wheel reclaimers plus conveyor belts placed on the cargo holds of the ship. MoSSt uses a innovative mobile stool system that protects self-discharging gear from cargo during navigation. At the same time the mobile stool system allows full access to the self-discharging gear, in order to guarantee complete cleaning of the cargo hold. That ensures complete independence from port´s terminal at the time that the ship without losing cargo hold capacity compared to a conventional gearless bulkcarrier. This is possible because the self-discharging gear is located on the lower stools present  on any bulkcarrier. This solution skips the cargo hold capacity loss associated to continuous type self-discharging bulkcarriers, having at the same time the independence from port terminals common to continuous type self-discharging bulkcarriers.

Technology Solution

Mobile Stool System, MoSSt, it´s a technical solution for continuous type self-discharging bulkcarriers of new design that uses the lower stools to accommodate the self-discharging gear. The lower stools are present on the cargo holds of conventional bulkcarriers.

For this reason there is no cargo capacity loss in the ship´s cargo holds, comparing it to a conventional gearless bulkcarrier. At the same time have all the advantages on flexibility and port independence from the continuous type self-discharging bulkcarriers.

The system uses new design mobile stools that makes possible for the self-discharging gear easy access every corner of the cargo hold. This technology can be adapted to all bulkcarrier sizes, from Handysize to Cape size, without imposing ship´s hull further conditionings. The innovative system can reduce the time to discharge bulkcarriers, improving ship´s productivity.

‘‘This technical solution is adaptable to all bulkcarrier´s sizes, meaning a new generation of bulkcarriers”


View from a bulkcarrier fitted with Mobile Stool System – MoSSt


Market demands

  • The continuous type self-discharging bulkcarriers, are capable of operate in ports with small infrastructure. On the other side there is a cargo hold loss that occurs with this systems, specially on the gravity type. That means higher freight prices compared to conventional bulkcarriers.
  • The discontinuous type self-discharging bulkcarriers, needs bulldozer stacking in the cargo holds. As a result the these bulkcarriers are not fully independent from port.
  • A new bulkcarrier should have complete independence from port facilities and having at the same time the cargo hold geometry from a conventional bulkcarrier. Having those features together will help to reduce port associated costs and also it will maximize cargo on each trip, increasing productivity.
  • Self-discharging gear shouldn't be in contact with the bulk or weather during navigation and not to condition ship´s hull shape. The self-discharging gear also has to be cost competitive, easy maintenance and minimum power consumption.

‘‘The system joint advantages from continuous type self-discharging gear and have at the same time the cargo capacity from a conventional bulkcarrier’’

Market potential

  • Bulk transport industry
    • Bulkcarrier ships are 20% of merchant ships (abt. 10400 vessels from a total abt.55600) and more than the 40 % of dead weight tonnage (DWT) of world fleet (abt 700 million DWT) [RS Platou, 2013]
    • This type of vessel was the fastest growing type in 2013, with a 6 % growth (abt. 350 vessels)
    • The unitary cost of new contruction bulkcarrier varies from 20M€ to 50 M€. The MoSSt itself will cost abt. 4 to 10 % of ship´s cost.
    • Considering an average construction of 10 continuous type of self discharging bulkcarriers per year, and with an initial anual business share of 10%, it could mean 1 MoSSt ship per year [Lloyd´s list 2010]
  • Minning industry
  • Raw materials storage and stacking 
Competitive advantages

  • The system has all the advantages from continuous self discharging bulkcarrier, but without the inconveniences that those systems carries out with it, such as the cargo hold capacity loss.
  • The system uses the lower stools spaces to house the continuous self discharging gear.
  • The system allows the ship to be fully independent for port facilities.
  • Combined use of stacker and reclaiming continuous system, such as adapted bucked wheels and conveyor belts that reduces reducing technical risks.
  • Mobile lower stool that protects self discharging gear from bulk.
  • Full access to self-discharging gear during navigation and discharge, for maintenance or inspection.


View from a cargo hold fitted with Mobile Stool System - MoSSt


  • A cost competitive, reliable and easy to maintain self-discharging gear, that need minimum power to operate
  • Higher discharging ratios, compared to available market systems, that reduces costs and increases productivity.




  • Researchers group with experts in maritime traffic, port management, ship building and ship ´s maintenance and exploitation.
  • Research and develop of innovative mechanical and automatic systems with market implementation. 

  • Patent pending, Spain [P201430138]
  • International patent request [PCT/ES2015/070074] 
Development stage

  • Concepto
  • Investigación
  • Prototipo-Lab
  • Prototipo Industrial
  • Producción

MoSSt contact

José de Lara Rey; e:jose.delara@upm.es

Sergio Olmos Guío; e: solmos@grupoaid.es

UPM contact

Innovation, Commercialization and Entrepreneurship Area

Centre of Support for Technological Innovation – UPM 

e: innovacion.tecnologica@upm.es

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