Page 66 - Practical Design Ships and Floating Structures

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TABLE 4
MAIN DIMENSIONS OF THE PROTOTYPE AND RENOVATION
I renovation
Type of barge prototype
Length overall 75.00111 79.00m
Length on waterline 73.50111 77.50111
Breadth 16.00111 16.00m
Depth 4.50111 4.50m
Draught 3.80111 3.50m

The model test was carried out by three kinds of stem. The results are demonstrated in figure 3.
Some conclusions can be drawn from the test:
1) Comparing with the prototype, in the full scale, the resistance of the simply cutting stem reduce 15%
at speed lOkm/h.
2) The resistance of the tunnel cutting stem reduces 19.3% at speed lOkm/h comparing with prototype.
3) In order to ensure the freeboard on the sea area route, the deadweight for the tunnel cutting stem
barge has to reduce 130t. Under this condition, the resistance can be reduced 26.9% at lOkm/h.
Considering the resistance and the cost for the rebuilding, the simply cutting stem was selected as the
renovated barge's bodylines. The structure and other performance were designed based on the direct
calculation or related regulations. The rebuilding barge was suitable for coasting line. The structure and
the general arrangement are shown in figure 4.

Resistance of full scale
j 12000
I
- 10000
2 8000 +simply cutting
v stern
aJ
6000 -tunnel cutting
stern
u
Y)
'z 4000 +prototype
2
2000
0 -
6 8 10 12 14
Speed (km/h)
Figure 3: Test result

5 CONCLUSIONS
The pushing fiame for the sea is reliable. It is convenience for the tug and barge to connect or separate.
The frame makes the tug and barge linked rigidity as whole in the transverse direction while can roll in
the longitudinal direction, which can ensure the safety of the fleet when navigating on the sea.

The current speed range measured in the test is from 3km/h to 13km/h. It is difficult for hybrid fleet to
navigate counter-current flow in high flow speed. In order to navigate safely all the year, the design
speed should be higher than 14km/h. But too high design speed is not suitable from economic point of