Part 1 of this article was originally published in edition 31 of Port Technology International. It is available for download at https://220.127.116.11 under journal archives.
Abstract for Parts 1 and 2
The bridge grab ship-unloaders with different trolley travelling forms are mainly divided into two types: the self-travelling trolley type and the rope pulling type.
Part 1 analysed the advantages and disadvantages in practice for two types and introduced four different designs of the rope pulling type:
A) Two rope (hoisting and closing) with one trolley design,
B) Conventional rope scheme with main and auxiliary trolley design,
C) Four ropes with planetary winches design, and
D) Four ropes with the electrical synchronisation design.
Part 2 of this article will continue comparing the advantages and disadvantages of the four different designs of rope pulling type grab ship-unloaders mentioned above and come to the conclusion of which one is the best and most reliable form for ship-unloaders with the capacity from 1,000t/h to 3,000t/h.
Different designs of bridge grab shipunloaders continued
Steel wire rope
(The diameter of rope is estimated under the sme operation conditions. For example, the lifting load is 35t.)
a) The diameter is 31.5mm for hoisting and closing. It is 28mm for trolley travelling
b) The diameter is 31.5mm for hoisting and closing. It is 42.5mm for trolley travelling
c) The diameter is 42.5mm for hoisting, closing and trolley travelling
d) The diameter is 42.5mm for hoisting, closing and trolley travelling
Steel wire rope diameter (d) and sheave diameter (D)
The sheave diameter in the grab is limited by the structure …..
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