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Lower Mast Crosstree and TrestleTree Snape

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Good Morning all,


I'm currntly fabricating masts and spars for HMS Liverpool.  First, as I've known from experience over and over, use the given dimensions rether than scaling from a drawing.  The set of plans that I have for the masts and spars are shown on a drawing that was published in Shipwright years ago.  While it is generally 1:96, the tops and crosstrees are not drawn to the same scalle as the masts.  Hence, two crosstree/trestletrees go in the object lesson bin!


Steel defines the following:

"SNAPING, reducing the ends of any piece to a less substance."


The crosstree has what is called a "snape" at each end.  Basically, it is a tapering in the vertical plane with the taper of differnt length at either end of the cross tree.  Lee's does describe these in detail as does Steel.  I've seen many models with the longer taper on the fore side and the shorter on the after end of the cross tree.  However, Steel says the following:


"TRESTLE-TREES are sawed or hewed to their sizes thus. In length, they are one-fourth the length of the top-mast; in depth, half the given diameter of the mast; and in thickness, two-thirds of the depth. The insides are trimmed straight, and out of winding, and the thickness set off parallel thereto. The uppersides line straight and square, and the depth parallel. The undersides are snaped at each end, and the edges chamfered the length of the snape. One end to be once and a half the depth, the other end once the depth only, within the ends, and the snapes are lined to half the depth of the trestle-tree, and rounded to a sweep at the ends; the lower outer edge is chamfered along the whole length, and the inside only to the cross-trees.


The longest snapes to be at the foremost ends of the main trestle-trees, and the after ends of the foremast trestle-trees."


The instruction in the bold text is something that I've not seen before nor described anywhere else.  It also doesn't state and instruction on the mizzen mast.  This detail will not be visible to the casual observer of a model in 1:96.  However, it is very curious.  Have any of you run into this previously?




Tom Ruggiero


Director Nautical Research Guild

Member Ship Model Society of New Jersey (Past President)

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It does seem an odd point to highlight so deliberately. I would have assumed the tapering was simply to reduce unnecessary bulk and windage aloft. But the instructions above are describing a different practice for different crosstrees, suggesting it's not about reducing bulk. I'm trying to come up with a sail handling explanation but why would the configuration differ between fore and Main?

Or it could be about providing support for the tops and it's indicating loads in the tops are expected to verry on the fore and Main but I can't imagine why.

Even more implausible would be it's a measure taken for the sake of swaying loads Into and out of the Main hatch, to reduce the cross section of the crosstrees most likely to be fouled by rigging used in those operations? But the rim of the top would be the part being contacted, not the crosstrees, and I doubt there would be any line chafing on the underside of the tops.




 Niagara USS Constitution 


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