Spinnaker boom length

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mauri
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Spinnaker boom length

Inlägg av mauri »

2530 mm according to class rules, measured all out according to conventions (not explicit, I think, in this case)
But: the original Proctor (AKA Selden) serial nr 534012 spinnaker book makes 2530 with the original spinnaker boom ends measured at the center of the cleat cavity, not all out: if measured all out it is (45x2)+2455= 2545, if measured at the center of the cleat where the ropes pass, (37.5x2)+2455=2530 mm.
Now the old endings are obsolete as they absolutely do not allow the opening to the top (safer in removing the boom).
The new endings that allow both directions of use are 15 mm longer. In fact there is one model that is only 45 like the original ones and not 60 mm long, difficult to find.
Now, before seen cut and adapting all the Selden spinnaker booms sold so far (and in particular mine) I'd like to rise again the question on the total length, way to measure and type of endings.
Thanks for the attention
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maja
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Re: Spinnaker boom length

Inlägg av maja »

Read the current Class Rules.

The length shall be measured as per the measuring convension of the World Saling Equipment Rules (ERS), i.e. from one outer end to the other outer end of the boom inclusive end fittings.

There is no guarantee that an old Proctor boom will be according to the current rules, because the measuring convension has been changed during the years. Also, as certification of the spinnakerboom is not mandatory, some of the existing booms may be too long.

See below for the rules. Sorry for the Swedish, but please use the forum translator for better understanding.

Nordiska IFRA Klassregler 2022 för IF-båt page 21 (25)

F.7 Spinnakerbom

F.7.1 CERTIFIERING
(a) Rundhult och beslag ska överensstämma med gällande klassregler
(b) Ingen certifiering behövs

F.7.2 TILLVERKARE
(a) Tillverkare är valfri.

F.7.3 MATERIAL
(a) Rundhultet ska vara av aluminium eller trä. Det får vara eloxerat eller målat.
(b) Beslagen får vara av valfritt material.

As the type of endings are optional, so, when you are exchanging those to a different type , you may find the spar too long to comply with the rules and you will have to cut off a small piece.

F.7.4 UPPBYGGNAD
(a) Fri

F.7.5 BESLAG
(a) Fria.

F.7.6 DIMENSIONER
maximum
(a) Spinnakerbomslängd........................................................................ .... 2530 mm
Marek, IF-båt SWE-829 "Ingela" från Lagunen i Malmö
Medlem i IF-båtförbundet sedan 1985
IF-båtägare sedan 1983
mauri
Inlägg: 11
Blev medlem: 31 jul 2019 15:22
Been liked: 1 time

Re: Spinnaker boom length

Inlägg av mauri »

"There is no guarantee that an old Proctor boom will be according to the current rules, because the measuring convension has been changed during the years"

Thank you Marek for the relevant opinion but this is not exactly my point. What is the actual situation of spinnaker boom length for the actual boat owners? Can someone measure and post his or her spi-boom maker-serial nr-(year when known) and length excluding the end fittings.

A boat has an ideal form, ideal sail, rigging and function, and class rules identify the limits for a fair competition and also, if we want, best practice. So it is the combination of rules and the conventions that follow the boat and not vice-versa.
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