Environmentally Sound Submersible Backhoe
Type:
Presented during:
WODCON XIX: "Dredging makes the World a better place" - 2010, Beijing, China
Authors:
Takanobu Kumagai
Abstract: Underwater work at offshore construction sites has often been carried out by divers. Recently, marine construction sites in Japan have been shifting from shallow depths near the coastline to deeper depths far offshore. The severe working conditions due to this deeper marine work have increased the burden for divers.
From the above back ground, several types of the underwater construction machinery have been developed to improve working efficiency and safety aspects.
An underwater excavator named “Yellow Magic” was developed by enhancing a land side excavator, which is used for a lot of construction purposes. The specialty of the “Yellow Magic” is that the driving source for the hydraulic pump was changed from a mechanical engine to an electrical motor. The “Yellow Magic” is able to operate by just connecting the electrical cables with which it is equipped to the support ship without a hydraulic hose. Hydraulic oil in the hydraulic system uses a fatty acid ester which is biodegradable and therefore makes less of an impact on the environment compared with the adoption of mineral oils.
As mentioned above, the design of “Yellow Magic” series can operate by remote control at the support ship.
Until now, the “Yellow Magic” series of machines has been used for various construction works, i.e. trimming of a rubble bed, submarine buried cable, submarine rock excavation, clean up of a discharge channel, creation of a submarine forest etc.
The efficiency of the work capacity is about 5 to 8 times better when compared with any manpower involvement in past projects such as that required for the trimming of a rubble bed for caisson mound work.
This paper introduces the mechanical characteristics, attachments and a real application of the “Yellow Magic”.
Keywords: Versatile Underwater Backhoe mechanization of the underwater construction increased efficiency of construction work electro-hydraulic motor various types of attachments