Containerships

Gallagher, S. P. and Lanza, R. L. 2007. Detection of nuclear weapons and fissile material abroad cargo containerships. US Patent 7183554 B2. 2007-Feb-27. 

The KLT-40 plant is senally produced and has been operating in nuclear ice-breakers and in the"Sevmorput lighter-containership with an accumulated experience 140 of reactor-years, therefore no R D is needed. 

Modern containerships can carry more than 10,000 containers of twenty feet in length. Container shipping has drastically reduced the cost of moving cargo by sea. 

Containerships can be loaded and unloaded in twenty-four hours or less. Containers are quickly loaded onto trucks or railcars for land transportation. 

Most of the time squat at the bow, 5b, represents the maximum value, especially for full-form ships, such as supertankers. In very narrow channels or canals and for high-speed (fine-form) ships, such as passenger liners and containerships, the maximum squat can occur at the stern 5g. The initial trim of the ship also influences the location of the maximum squat. The ship wUl always experience maximum squat in the same direction as the static trim. If trimmed by the bow (stern), maximum squat will occur at the bow (stern). A ship trimmed by the bow or stern when static will remain that way and will not level out when underway to offset the sinkage at the bow or stern due to squat. 

The most important dimensionless parameter is Fnh, which is a measure of the ship s resistance to motion in shallow water. Most ships have insufficient power to overcome Fnh values greater than 0.6 for tankers and 0.7 for containerships. Most of the empirical equations require that F h be less than 0.7. For all cases, the value of Fnh should satisfy F h < 1, an effective speed barrier and the defining level for the subcritical speed range. The Fnh is defined as... 

Example 1 BAW Post-Panamax containership in unrestricted channel... 

Fig. 26.4. Comparison of BAW s experimental measurements, empirical formulas, and numerical model of bow squat for a Post-Panamax containership in an unrestricted channel (open water).

Fig. 26.7. Laboratory measurement of the effect of head-on passing on bow and stern squat for a PM containership passing a large bulk carrier in the River Elbe. The dark blue curves represent the single runs of the containership the light blue curves the encounters with the large bulk carrier.

Fig. 26.9. Cumulative distribution of the increase in squat for 125 head-on passing encounters of large PPM containerships (HLCL and YM) at the channel of the lower and outer River Elbe.

During the seven-hour transits of the 12 ships from Hamburg to the sea, 125 head-on passing encounters were recorded. Figure 26.9 shows the increase in bow (blue diamond) and stern (red square) squat due to these head-on passing encounters and the corresponding cumulative distribution curve. The increase in squat was about the same at both the bow and stern. For this limited set of large containerships in the River Elbe, the maximum increase in squat was 0.44 m 50% of the cases experienced bow or stern squat less than 0.16 m, while 90% were less than 0.33 m. 

Fig. 26.10. Effect of passing encounter on ship bow and stern squat as a function of ship speed in FHR tow tank for containership and bulk carrier. ...

Fig. 26.11. Laboratory measurements of the effect of overtaking on bow and stern squat for General Cargo (VG3) and Feeder containership (VG4) at the western Kiel Canal. The bow and stern squat values for the VG3 are shown in red, and the VG4 are shown in blue.

Fig. 26.12. Effect of overtaking maneuver on bow and stern sqnat as a function of lateral distance between ship centerlines for a containership and bulk carrier in the FHR tow tank.

The FHR has conducted towing tank experiments with containerships to study ship... 

Pig. 26.15. Influence of drift angle on squat of a containership at constant speed in a rectangular channel of 565-m width with /i = 16 m. Ship test specifications same as Fig. 26.14. ... 

Figure 26.21 illustrates the effect of the presence of a mud layer on the sinkage and trim of a containership for the case in which the initial UKC is sufficiently large so that the interface undulations do not cause any contact between the keel and the mud layer. The sinkage for a ship sailing in a muddy bottom condition is decreased... 

Fig. 26.21. Sinkage (a) fore, (b) aft, (c) and midships, and (d) trim as a function of ship speed for Containership D Lqa = 300 m, B = 40.3 m, h = 13.5 m) sailing above a mud layer of 1.5 m thickness with 15% clearance referenced to mud-water interface (26% to solid bottom). Note the legends are the same for all plots.

Figures 26.4-26.6 showed comparisons of the PIANC empirical formulas with the measured laboratory measurements. These figures also included comparisons with the numerical model predictions for each example. These examples included BAW s PPM containership in an unrestricted channel, FHR s tanker in restricted water, and Tothil s Canadian Laker in a canal. In general, the numerical model matched the measured values from the laboratory measurements very well. Details of the individual examples are given in the following sections.

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