The Shipworm Eating Seattle’s Waterfront

The filling in of the tide flats and the creation of waterways, through which the fresh waters of the Duwamish River will flow directly along the main water front, will prove an incalculable saving to the wharf owners, for little or no trouble will then result from the destructive teredo, which thrives only in salt water. It is conservatively estimated that fully half a million dollars have been spent by wharf owners and by the railroads having trestles along the water front of this city within the past eight years for repairs alone, which are continually necessary, and new wharves appear in place of the old ones about every two or three years. Toward the head of the bay, where the influence of the fresh water from the Duwamish River is felt, the life of the piles is much longer than those farther north, and especially in the wharves in North Seattle. Piles in the bay on the tide flats have been known to last for six years, but those in the North End have to be replaced at least every two years. The Oregon Improvement Company has gone to great expense in putting in copper-covered piles as a protection against the teredo, but it is necessary to put in new fender piles on the bunkers every year. It has been demonstrated that an unprotected pile will be totally honeycombed in five months, and when protected by several compounds and solutions used for such purposes it will last at best but four years, but a wharf over three years old is not considered safe.

When it is considered that the wharves along the water front have a total first cost of from $50,000 to $100,000, and that it is absolutely necessary to rebuild at least every three years, the burden to the owners can easily be understood. To better illustrate the ravages of the teredo, a few instances of the wharves which have broken down within the past three years and that have required rebuilding will be given. The list, as near as can be ascertained, is as follows:

Wharves That Have Collapsed. McNaught dock, foot of Pine Street, collapsed two years ago, carrying warehouse and sheds into the bay. Fish wharf, adjoining the same dock, went down on the same day. Baker’s wharf, large warehouse and sheds, went into the bay two years ago. On this dock was a cargo of Christmas goods from Japan, and the total loss was very large in consequence, for everything was destroyed. Wharf at the foot of Seneca Street fell down one night without warning, the work of the teredo having been much swifter than usual and the structure being supposed to be good for at least another year. Oregon Improvement Company’s wharf, below the bunkers, tumbled in a few weeks ago without warning. Manning’s wharf, foot of Vine Street, fell in three years ago. Harrington Smith’s wharf was threatened with collapse a few weeks ago and part of it did fall in the bay, but repairs were speedily effected and the whole structure was saved from total destruction. Stimson’s wharf, foot of Depot Street, went down [three years] ago. Hall’s wharf, adjoining Manning’s wharf, tumbled in three years ago. The wharf owned by the Mechanic’s Mill Company went down two years ago. Part of the Oregon Improvement Company’s trestle between Colman’s wharf and Manning’s dock is now in need of repairs, part of it being very shaky and unsafe. The Seattle Dry Dock and Ship Building Company’s wharf went into the bay less than a year ago. And all of the wharves north of Schwabacher’s have tumbled down within the past three years.

Cannot Figure on Mr. Teredo. Some years the teredo is more active than others, and it brings on erratic results; the wharf owner can tell nothing about him, and must ascertain as best he can just how far he has progressed without taking up a pile and examining it. Sometimes a wharf will appear to be good and strong, and there will be no indication of weakness, but the strain of a vessel at its fastenings will sometimes pull a whole structure into the bay without a moment’s notice.

At best the building of wharves is an expensive enterprise. A well-known pile-driving contractor has given the following estimate for building an ordinary dock, the piling being in no manner whatever protected from the teredo, each pile to be forty feet long: [dimensions omitted in OCR]; price per pile, 12 cents per lineal foot, or $5,445 per acre. Protected piles, or piles that have been put through a solution, will cost about twice as much.

With so many grave difficulties to contend with, it is not at all surprising that those interested in shipping should look favorably on any proposition that would relieve them of so great a tax, and most of them have concluded that the south canal scheme will have the wholesome effect desired.

Increased Water Frontage. Without considering the immense wharfage area that would be available along the eighty miles of shore line on Lake Washington, where teredos are unknown, by the building of the canal, it is interesting to know the area of wharfage that will be available when the flats have been filled in and the waterways excavated. The lineal feet of frontage on the waterways through the flats and along the made harbor line will be approximately as follows: East waterway, 10,600; West waterway, 5,400; Canal waterway, 9,300; total fresh-water frontage, 25,300; salt-water frontage on harbor line, about 49,900; total of all frontage, 75,200.

In other words, this would give a frontage of nearly thirteen miles, all of which would be to a great degree protected by the fresh water from the teredo. The frontage on the east and west waterways will be divided into slips at an angle of 45 degrees with the shore line, and available wharfage front thereby very materially increased. The canal waterway being but 200 feet wide, [vessels] can lie alongside. All this frontage will be pure fresh water, and the wharves will not be subject to the depredations of the teredo. Small vessels can also lie alongside in the Duwamish River as far up as Braun’s brewery. All the frontage will be somewhat curtailed eventually by bridges to carry streets across the inter-ways. On the lake the eighty miles of frontage will permit innumerable wharves of any length to be erected.

The east waterway when completed between the bulkheads will project the fresh water of the Duwamish River along the lines of the existing wharves, and will thus mitigate the depredations of the teredo so as to prolong the life of the wharves to three or four times their present life. The beneficial effects of this admixture of fresh water from a river with the salt waters of the Sound is strikingly illustrated at New Whatcom, where the Nooksack River [protects the] water front, as shown in the report of United States engineers.

Prohibitive Insurance Rates. [Unless the flats are] completely filled in, it will be impossible for business of whatever character to attempt to put up buildings. The high rates would be practically prohibitory. [If lots] to be sold in cities and [buildings] by private individuals erected on the land thus made, the property could not be insured at a reasonable premium, for the risk would be very great. Where the foundation of the buildings on the flats is on piles, the tendency to increase the rate of insurance is also great, and if the district was closely built up the rates would be made prohibitive by all conservative insurance companies. The filling in of the flats, from an insurance standpoint alone, would be in itself a great benefit to Seattle.