In the list of the ships, vessels and craft of the Dutch India Company made in 1683 there is constantly referred to the problems at the yard at Onrust due to lacking enough (qualified) ship-carpenters. The result was that ships had to wait to long before they could be repaired. The effect was that ships only could be used at calm fairways or even had to be broken up far for their time.
In their report to the Central Committee in The Netherlands Cornelis Speelman and counsellors dated 31 December 1683 gave more details. There was a serious lacking of ship-carpenters in the service of the company. At Onrust there were in 1673 130-140 ship-carpenters and 60-70 at Batavia, nowadays there were totally just 105, among them many sick. There arrived also much less than acquired to replace the 55-60 which were to return to the Netherlands. Onrust was fitted out to be able to careen 3 large ships at the same time, smaller were repaired/fitted out at the island Kuyper. Available were 3 ships of 660 last, 1 of 550 last, 14 of 500 last, 12 of 350 last, 1 of 320, 4 of 300 last, 22 of 230-30 last, fluyts: 3 of 350 last, 2 of 400 last, 31 of 250-80 last, 12 hookers of 70-50 last, of which 5 served at Ceylon, totally 113 ships and vessels of which 25 had to be repaired before able to service and if this wasn’t done within a short time they would be rotten! Of these 113 ships 31 were outward or homeward bound. According to the yard master Harmens Lodewijcks the short duration of life was due to the building of new ships on such a scale that the quality of the used timber was disregarded. In the past the ships served 20-25 years, nowadays 8-12 years. Timber of a worse quality infected that of good quality and attracted insects. Constantly tarring couldn’t anticipate this sort of problems. Fluyts were handsome and handy but due to the curves sawing not with a long duration of life. The last two years were the heavy Dutch timbers of very worse quality, the kiaten of djati wood coming of Java was of a much better quality. If there come enough ship-carpenters from the Netherlands, it wasn’t necessary to sent boats from the Netherlands, but instead built those of djati wood in the Indies. Masts although requiring a lot of space during the transport coming from the Netherlands were of a much better quality than the ones from the tropics.
Source
J. van Goor. Generale Missiven van Gouverneurs-Generaal en Raden aan Heren XVII der Verenigde Oostindische Compagnie. Deel IV: 1675-1685. The Hague, 1971, p. 644-645.
