覆
27
One of the very important problems which has
been studied ia that of the depth and width of the channels which should be provided between Whampoa and
the sea. More or less extensive shoals exist at three
pointe,
sensiv
the First Bars and the Lintin Bar. The first
Λ
two are relatively short, together aggregating seven kilometers. But the Lintin Bar channel will have to be over forty kilometers in length and will be one of the longest in the world. This fact makes it imperative to keep the cost as low as possible because it will be large in any event.
After prolonged study of all the boats in the world se listed in Lloyd's Register and then of all those which were reported sa bavim visited Hong kong fros May 1, 1937 to August 1, it was decided to dredge the channel to a depth of 34 feet at low tide at the ocean end of the Lintin Bar and to increase the depth to 25 feet at the whampoa end.
The second and First Bars should be dredged
to 27 and 28 feet respectively.
Some of you may wonder why these depths are different. You know that the highest and lowest tides each day are later at Canton than at Hong đọng. The average difference was found to be 3 hours and 52 minutes for high tiies, and 5 hours and 18 minutes for low ones. This means that a tidal wave moves up the river.
If a vessel could proceed as fast as the wave moves, it could come up from Hong Kong, keeping always on the crest of the wave. On the other hand, slace the tidal wave never moves down stream, a vigel must start from haupoa before the tide is high at the riret, ecund, and upper end of the Lintin Bars, The channels must consequently
be deeper and deeper as they occur further and further nor th if a vessel is to be given a proper depth of water
at