Page 99 - Dutch Ships in Tropical Waters
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layer of planking well covered without lead\] (NA .., VOC , --, -- ). The Admiralty ships that were sent to Asia in were sheathed and were protected on the vulnerable areas of the hull around the waterline ‘between wind and water’ by lead sheathing (NA .., Oldenbarneveldt ). Case Study -. Sheathing Many techniques have been tried over the centuries to prolong the life of ships’ timbers. The English- man Sir Richard Hawkins described those he knew, writing c. about experience gained on a voy- age which started in (from Markham , p. ). ‘And for that I have seene divers manners of sheathing, for the ignorant I will set them downe which by experience I have found best. In Spain and Portingall, some sheate their shippes with lead; which, besides the cost and waight, although they use the thinnest sheet-lead that I have seen in any place, yet it is not durable, but subject to many casualties. Another manner is used with double plankes, as thicke without as within, after the manner of furring: which is little better then with lead; for, besides his waight it dureth little, because the worms in small time passeth through the one and the other. A third manner of sheathing hath beene used amongst some with fine canvas; wich is of small con- tinuance, and so not to be regarded. The fourth prevention, which is now most accompted of, is to burne the utter planke till it come to be in every place like a cole, and after to pitch it; this is not bad. In China, as I have been informed, they use a certain betane \[probably bitumen\] or varnish, in manner of an artificiall pitch, wherewith they trim the outside of their shippes. It is said to be durable, and of that vertue, as neither worme nor water peirceth it; neither has the sunne power against it. Some have devised a certain pitch, mingled with glasse and other ingredients, beaten into powder, with which if the shippe be pitched, it is said the worme that touched it dyeth; but I have not heard that it hath been usefull. But the most approved of all, now adayes in England, with thin bourdds, halfe inche thicke; the thinner the better; and elm better than oake; for it ryveth not, it endureth better under water, and yeeldeth better to the ships side. The invention of the materialles incorporated betwixt the planke and the sheathing, is that which avayleth; for without it many plankes were not sufficient to hinder the entrance of of this worme; this manner is thus: Before the sheathing board is nayled on, upon the inner side of it they smere it over with tarre halfe a finger thicke and upon the tarre anothe halfe finger of hayre, such as the whitelymers use, and so naylec it on, the nayles not above a spanne distance one from another; the thicker they are driven the better. Some hold opinion that the tarre killeth the worme; others that the worme passing the sheathing, and seaking a way through, the hayre and the tarre so involve him that he is choked therewith; which me thinkes is most probable; this manner of sheathing was invented by my father, and experience has taught it to be the best and of least cost. Almost every ship that left the Netherlands for Asia was sheathed. Only if it was expected that a vessel would make a quick return trip, was the risk sometimes taken to send less protected vessels (see e.g. NA .., VOC , fol. ; , fol. ). The quality of the sheathing the materials in between the layers, and the state of the main planking determined to a large extent the period a vessel could operate in tropical waters before it needed be sheathed again. The triple-layered method of planking described above was found on the wrecks of the VOC ships Mauritius (ID:), , and Batavia (ID:), , and the Anglo-Dutch yacht Avondster (ID:). It has been suggested that, in the case of VOC ships, this construction is an adaptation for the specific conditions encountered in sailing between Europe and Asia, and also within Asia (Parthesius ; Van Duivenvoorden ; Parthesius et al. ). If the sheathing pro- vided good coverage to the submerged hull, and if the materials were of good quality, the time the vessels could sail without maintenance to the hull could increase by several years. The cheaper pinewood served the purpose better than the more expensive oak because the ship- The shipping and logistics in operation
