Rigging Loads

Rigging Loads - or a tale of scientific progress?

In which your hero tries to work out the starting point for the design of rigs

Those of you not already acquainted with the work of Douglas Phillips-Birt could do worse than visit your nearest second-hand bookshop to rectify the situation. Written some 40 odd years ago, his books have inevitably dated, but still have a remarkably high nugget to dross ratio. For example “Masts are tricky things. It is not for nothing that Lloyd’s, which is ready to specify the scantlings of nearly every other part of a yacht, washes its hands of them altogether and plants the responsibility for their size and shape squarely on the designer’s shoulders; then, as a happy afterthought, advises him to fit lightning conductors. The advice is good; but it leaves the part between the lightning conductor and the step open to various interpretations. The fact that Lloyd’s, with its vast collection of data on wooden yachts, feels like this about masts, suggests that masts are perhaps a little beyond rational analysis.1” As true now as 45 years ago, though it is yachts as a whole which defy complete analysis, not just their masts. The purpose of this article is to explore some of those “various interpretations”. Depending on your viewpoint, it is either a triumph of experience over science, or.....

How to deal with masts, their stays and their fittings? I could just do a piece by piece description of the various fittings, but I think that in doing so you would miss the broader picture which does much to explain why masts and their associated pieces are as they are. So I’m going to follow the logic(?) established earlier by first addressing the engineering aspects of masts and stays. I should at this stage warn you that it is going to take a number of articles to do this, and it may initially seem to consist of digressions followed by sub-digressions before we tackle the more practical aspects. I hope you will bear with me.

Mast Furniture

Mast Furniture   Download a .pdf version

The point of this article is to deal with some of the detailed aspects of mast furniture. A few caveats are in order. Firstly any such list cannot be comprehensive; so if I omit something which has just come to your notice, I apologise in advance. All I can do is offer the benefit of my own experience to date, and what I know of other peoples. And we are all still learning. Secondly, because I am necessarily talking in general terms, it is possible that what I say may not apply to your particular situation. I am not trying to be evasive here, but there are often so many ifs and buts that making a general case can become flaky. Finally, apologies for the laundry-list style of the article. But enough hesitation.