Stellaprima departs, loaded with an alumina shiploader

Project Summary

A 1,500 t/hr alumina shiploader was delivered to the Alunorte pier in Vila do Conde, Brazil, in February 1996. This shiploader, designed and built by Sade Vigesa, had been erected at the Verolme yard in Angra dos Reis, Brazil. For the ocean transportation, the heavy-lift ship Stellaprima, owned and operated by Jumbo Navigation NV, was contracted. The shiploader, weighing approximately 300 t, was lifted onto the heavy-lift ship using the Verolme gantry crane and was then secured for the voyage using Jumbo's standard slings and turnbuckles. Seafastening took less than 24 hours and on February 6, the Stellaprima departed Angra dos Reis with destination Vila do Conde. The voyage was without incident, with maximum reported roll angles on the order of 4 degrees

Early morning on February 13, the ship arrived at the offloading pier in Vila do Conde. Immediately upon arrival, the lashings were removed and the lifting beams were rigged and installed in place under the lower platform of the shiploader. The following morning, the shiploader was lifted from the ship onto its quay rails, using the Stellaprima's own cranes, which have a combined safe working load of 650 t.

Argonautics Marine Engineering was hired by Sade Vigesa to assist with the transportation engineering and on-site supervision of the loading and offloading operations. As part of the scope, a Finite Element study was done. The 3-dimensional structural model of the shiploader consisted of over 600 beam elements. One of the reasons for making such a detailed model was to accurately determine the weight and center of gravity of the structure, since these were critical for the lifting operation.

Scope of Work

The project scope included:

• Review of all loading/transportation/offloading procedures;

• Independent stability and ship motion analyses;

• Structural analysis of the shiploader subjected to lifting forces;

• Full structural analysis of the shiploader subjected to dynamic loading during transport;

• Designs for internal strengthening and securings of loose parts;

• On-site assistance during loading, internal seafastening and offloading operations.

This successful transportation of the Alumina shiploader was featured in the April 1996 issue of the "Maritime Reporter and Engineering News"...

Project Photographs

At the construction yard, the shiploader was lifted onto the ship using the large 600 t capacity gantry crane.	The shiploader was seafastened by the crew, using a large number of slings and turnbuckles.	A Finite Element structural analysis was perfomed to confirm the feasibility of the lift by the ship cranes.	The shiploader lifted from the ship onto the shore rails, using the two ship cranes and heavy lifting beams.