New system for dredging on the surface.


2014 → 2014

Background/Principal objective

Dredging works are common techniques that are carried out in the maintenance and restoration of beaches.  This work consists of cleaning the seabed of the area affected by possible debris deposited by the wind and the waves, so that the screened and selected remains also help to reconstruct the sandy area.

The starting situation that led to this development is the dredging of a beach with a surface draft of 3.5 to 4 metres and a bathymetric profile with a sudden initial step.

Currently, there are systems in which the machine motor is dismantled and installed on a floating pontoon, making it possible to work at a greater depth to solve this problem that arises when the draft in the work area exceeds the depth of the backhoe motor.

In this case, the main advance proposed is the development of a metallic, auxiliary, external and removable structure that improves the performance of a dredge-type backhoe since it avoids the use of a pontoon when working at deeper levels. The designed structure elevates the machine motor 2 metres so that it can access the necessary depth without having to disassemble the motor during the work, significantly improving the dredging performance over the previous situation, using the pontoon.


The prototype responds to the initial design criteria of quick and easy assembly, being formed by rolled steel profiles of the HEB series for the horizontal and vertical bars and IPN for the diagonal bars. However, the size is determined by the structural analysis, welding the joints.

The Horcas Coloradas beach, located in Melilla, was chosen to implement the prototype for the dredging work.  This area has a draft of around 3.5 and 4 metres and a bathymetric profile with a sudden initial step.

Therefore, taking into account the particular conditions in terms of wind, waves and other forces, a structural analysis of the prototype was carried out, with notable results in terms of the efforts involved, the deformations produced and the overall stability of the machine for normal working conditions.

Later, the implementation and commissioning of the prototype takes place according to the following phases:

  • After carrying out the pre-assembly of the prototype in the workshop, the structure is assembled and welded according to the design guidelines.
  • Once the welding and assembly of the structure is finished, the structure is hoisted and installed on the backhoe using a self-propelled mobile crane.
  • After placing the developed solution on the machine, the motor is installed on the structure with the corresponding installation and wiring between the motor and the backhoe.
  • Finally, the dredging work is carried out successfully, using the new system implemented on the machine under the described depth conditions.


The innovative character of this Project has been accredited by an External Entity, through its certification as an R&D Project according to standard UNE 166.001.