BlueSkyNick
Well-Known Member
Why are sail measurements refered to as I and J for the foresail, P and E for the main, Py and Ey for the mizzen if applicable?
What do the letters stand for?
What do the letters stand for?
Sail dimensions
- Thread starter BlueSkyNick
- Start date
Twister_Ken
Well-Known Member
Sorry not to have called tonight, didn't get back in until 2330.
Apropos sail alegebra, I suspect (but don't know) that it comes from some long forgotten rating rule, when a whole bunch of dimensions were number crunched to come up with a rating for a boat. They probably used the lower letters for the hull measurements, so by the time they got to the rig they were well passed halfway. I seem to remember there's even a letter dimension for the length of a spinny pole.
Apropos sail alegebra, I suspect (but don't know) that it comes from some long forgotten rating rule, when a whole bunch of dimensions were number crunched to come up with a rating for a boat. They probably used the lower letters for the hull measurements, so by the time they got to the rig they were well passed halfway. I seem to remember there's even a letter dimension for the length of a spinny pole.
thomas1
Active Member
Oo shucks big nick i don,t know yet perhaps if I do the zero to hero bit, I will ask for you Tom
BlueSkyNick
Well-Known Member
[ QUOTE ]
didn't get back in until 2330.
[/ QUOTE ]
Me neever - and I lost almost two quid playing crib ! tomorrow will do.
Re dimensions they are shown HERE the spinnaker pole seems to be called SPI !
didn't get back in until 2330.
[/ QUOTE ]
Me neever - and I lost almost two quid playing crib ! tomorrow will do.
Re dimensions they are shown HERE the spinnaker pole seems to be called SPI !
Twister_Ken
Well-Known Member
Howzat allow for an overlapping genoa, then?
BlueSkyNick
Well-Known Member
Dunno - That's part of the reason I asked the question.
tome
Well-Known Member
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Howzat allow for an overlapping genoa, then?
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Greetings from late night Amaya.
Believe that the dimensions are based on horizontals and perpendiculars based on mast being perpendic. This gives plain areas for main and foretriangle and avoids the contours of sails.
The overlap refers to the area beyond the natural triangles, or more or less the mast overlap.
Don't quote me on this - it's my simple understanding.
Howzat allow for an overlapping genoa, then?
[/ QUOTE ]
Greetings from late night Amaya.
Believe that the dimensions are based on horizontals and perpendiculars based on mast being perpendic. This gives plain areas for main and foretriangle and avoids the contours of sails.
The overlap refers to the area beyond the natural triangles, or more or less the mast overlap.
Don't quote me on this - it's my simple understanding.
Lizzie_B
Well-Known Member
Dunno completley, but would guess they are vestiges of old system of rig measurements- the other letters being used on rigs more complicated than the nowadays common Bermudan sloop. For example I and J are to do with foretriangle dimensions, including K being the perpendicular from the forestay through the gooseneck to the deck.
I would suspect other sails occupied other parts of the alphabet. Perhaps a student of sailing rig design could tell us.
Of course they're now are used as a statistical starting point for various handicapping systems such as PHRF
I would suspect other sails occupied other parts of the alphabet. Perhaps a student of sailing rig design could tell us.
Of course they're now are used as a statistical starting point for various handicapping systems such as PHRF
Oldhand
Well-Known Member
IOR rating rule sail measurement designations which have stuck ever since.
Roberto
Well-Known Member
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the spinnaker pole seems to be called SPI !
[/ QUOTE ]
it was actually SPL, like spinnaker pole length, I think one of the few symbols having a connection with the actual name of the dimension
ah there was B like beam too /forums/images/graemlins/smile.gif
the spinnaker pole seems to be called SPI !
[/ QUOTE ]
it was actually SPL, like spinnaker pole length, I think one of the few symbols having a connection with the actual name of the dimension
ah there was B like beam too /forums/images/graemlins/smile.gif
