K
13
12
an alternative to the 51. In the same report, M. de Rijke suggested, as improvement of the river below Upper Gough, the cutting of an entirely new channel from this point to the Yang-tsze. Whatever may be the engineering aspect of this proposal, it was abandoned as impracticable, in consequence of the opposition which was anticipated from the Chinese authorities, to the removal of the mouth of the river from the neighbourhood of Woosung, where forts had been constructed and custom-houses established, and also on the ground that, by the adoption of the project, Woosung, itself a treaty port and important native town, would have been cut off from the sea.
Messrs. Franzius and Bates' Report.
52. In 1902 a German engineer, M. Ludwig Franzius, in conjunction with an American engineer, Mr. Lindon W. Bates, submitted a general report on the river, and put forward, as an alternative to M. de Rijke's scheme, a proposal for the development of the Ship Channel as the main navigation track to Shanghai. One of the principal contentions in this report was that the Ship Channel could be improved and maintained at much less cost than the Junk Channel.
VI-FINAL SCHEME OF IMPROVEMENTS.
53. As already stated (paragraph 26), it was not until 1905 that it was definitely decided to improve the river, and that M. de Rijke was appointed engineer-in-chief An entirely to design and carry out the necessary works as recommended by him." new survey was proceeded with, it being found, in some reaches, that great changes had occurred.
54. M. de Rijke was not requested to submit a general plan of the works to be constructed prior to the same being commenced, nor was an estimate of their cost prepared, the improvements being carried out generally on the lines laid down in his 1898 report, no modifications of any magnitude or importance being considered, by reason of such changes in the river as had taken place in the meantime.
Commencement of Works.
55. The works were commenced early in 1907, those portions which appeared at the moment to require priority in attention being first taken in hand, the most important being the training works at Woosung and those at the lower end of Gough Island.
The latter were necessary for the maintenance of Ship Channel and the depth of water over the Inner Bar as then existing, until the time arrived for opening the Junk Channel for navigation. Other subsidiary works for confining or enlarging the channel were also designed at Pheasant Point, Pootung Point, and the Chinese city at Shanghai, as well as many small protective works to the banks at threatened places.
"Normal Lines.”
56. From the upper limit of the river near Kiangnan Arsenal to the Yang-tsze "normal lines" were laid down by M. de Rijke, the width between the same being based on that of the stream in Black Point Reach, which was considered to be the best naturally maintained portion of the river below Shanghai. M. de Rijke's proposals included the cutting back or bringing forward of the low-water margin to confine the stream as far as practicable within the "normal lines." These lines have been adopted by the Whangpoo Conservancy Board, and all structures such as wharves erected in the river, have rightly to be carried out in conformity with the
same.
VIL DESCRIPTION OF WORKS ALREADY MENTIONED.
57. The works referred to in this section are shown upon the accompanying drawings Nos. 1 and 2, those coloured green are entirely or almost entirely completed, those coloured red are further proposals considered essential by M. de Rijke but not yet commenced.
58. It should here be mentioned that in the following description the term 'parallel work" is applied to any structures lying longitudinally with the axis of
* Not reproduced.
"is used for any structure at a right angle the stream, whilst the expression "erib to the river bank. A "erib work" is a combination of a length of "parallel work" with one or more "cribs."
59. Generally speaking, the whole of the training works have been carried out on the Dutch system of mattresses loaded and protected with rubble stone. The various
zinkstuks," forms of fascine work comprising
gabbioni," "laag work," referred
to in the following paragraphs are described in detail in the appendix to this report.*
60. We propose, in the first instance, to describe the works mentioned above and coloured green, being those which are already either completed or well in progress.
Woosung Fort Jetty.
61. The works at Woosung consist of a training pier known as "Fort Jetty," commencing at the shore lines on the left bank of the river and projecting for a length of about 4,500 feet towards the Yang-tsze, on a curve of 75,000 feet radius. The object of this work is to confine the tidal flow over the site of the outer bar, and to cause the currents to have a true lead into and out of the Whangpoo. At the inner end of the jetty a small "work harbour" has been formed for the accommodation of craft engaged in connection with the improvement works. The jetty has also been extended up the river on the "normal line" a short distance above the "work harbour," where it is connected with the shoro, at its upper end, A considerable area has been reclaimed at the root of the by a strong crib. "Fort Jetty," between the latter and the original shore-line northward of the "work harbour" by means of dredgings from the Junk Channel deposited there.
62. Both the jetty and the walls of the "work harbour" and sea dyke are built upon "zinkstuk" mattresses. The upper part of the jetty is composed of a stone covering, finished with a protective coating of 5-ton concrete blocks. Six rows of piles are driven longitudinally on the line of the jetty which serve to keep in place the stone covering and the concrete blocks.
63. The "work harbour" is still being dredged, but the deposit of silt within the enclosure is so rapid that the contractors are experiencing difficulty in providing the required depth of 6 feet at low-water ordinary spring tide simultaneously over the on the entire area of the basin. The shore-line up-stream of the "work harbour" concave, or Woosung, side is protected as far as the new railway bund, by Chinese pile and timber work having a stone apron.
64. The whole of foregoing works, which were practically complete at the commencement of this year, were carried out under a lump-sum contract by the East Asiatic Dredging Company, the price being 1,997,798 Shanghai taels. To this sum must be added 23,326 Shanghai taels for extra works, making the total cost 2,021,124 Shanghai taels.
Training Works at Gough Island.
65. The works at Gough Island, especially those at the upper end, constitute the most important feature of the improvements which have been carried out on the Whangpoo. The main object of these works was the closing of the Ship Channel and the radical improvement of the Junk Channel by concentrating the whole energy of the tidal movement in the latter.
Low Gough Works.
66. To effect these objects a parallel work of training-bank has been formed at the northern end of the island, on a foundation of "zinkstuks," stretching towards the Yang-tsze for a distance of 5,400 feet. Extending up-stream from the mainland near Pheasant Point, a second parallel work has been constructed, also formed mostly of "zinkstuks" and joined to the shore by a crib. The opening between the ends of these two main parallel banks is 1,400 feet in width, and whilst these works are of assistance in directing the tidal flow into Junk Channel, the considerable width of the opening between the ends of the banks permits, for such time as is desirable, of the easy ingress and egress of tidal water into what is now a cul-de-sac, formerly the site of the old Ship Channel, which under existing conditions will in course of time naturally silt up,
[2958 hA--1]
* Not printed.
F
400