Checkstays?

IanHB · Post by **IanHB** » 07 Jan 2004, 08:00

Is there a written defination of CHECKSTAYS?
I think I know what they are, but I need to be positive in my interpration before I give out the wrong advice.

If nothing is written then how about this?

CHECKSTAYS (Whiskers, Lower lowers) Stays connected to the mast below the bottom mast band, to control the lowest portion of the mast.
To work in tension only.

Roy Thompson · Post by **Roy Thompson** » 08 Jan 2004, 01:05

I suggest moving this to the Tech area rather than measurements, but anyway...

...Stays connected to the mast below the bottom mast band, to control the lowest portion of the mast....

Since the use of the word 'checkstay' isn't in bold or italics in the IOM class rules (niether F3.4 or F3.3 (b) (10)), I guess that this means that ISAF don't feel the need to specifically define it (in ERS or RRS) and it's 'general' or nautical definition would apply - and to be honest that's something that I haven't got completely clear either - suggestions with diagrams please....!

Apart from that, surely it would be somewhat difficult to have stays completely below the bottom mast band? or am I reading this wrong and they can be fixed above and below or they go to the deck from a point below the lower mast band? From exactly where to where are you thinking of? There is very little space between the lower mast band and the deck, (D1.5 states 60 to 100mm between lower limit mark and deck limit mark) - the stays would need to be very short indeed - would they have an effect? And the height of the checkstay rigging point (ERS definition in ERS F7.4) above heel point (ERS definition = the lowest point on the spar and it's fittings) of 100mm max (as in F3.4) is also somewhat limiting, no? I've looked in a couple of maritime dictionaries but can't find a good definition (or better still a diagram).

More help needed here I feel, but it's a good point - many of us can't define adequately a checkstay, but nevertheless they appear in the class rules more than once and are permitted.

IanHB · Post by **IanHB** » 08 Jan 2004, 04:33

Roy, I am happy if you wan`t to move this subject to the technical area, it was simply as a measurer I needed a definative answer before outlawing an owners boat.

My own understanding of CHECKSTAYS is that they are attached below the lower mast band and connected to the chainplates with some adjustments possible to tighten against the thrust of the main boom to enable the lower portion of the mast to remain straight, or hold the shape and angle as desired by the tuner. They are only allowed in the absence of a mast ram and are only really useful with a deck stepped mast.

I feel we must make an effort to define this as it is about to become a problem with some fitting a second set of stays from just below the spredders and claiming these are checkstays as allowed under F. 5.2(b)(1)

If the rule drafters aggree with my interpretation of what checkstays are then we need to take all my verbal garbage and turn it into a precise and neatly worded DEFINITION.

Lets hear some other comments please.
Good sailing,

Post by **Chairman** » 08 Jan 2004, 10:18

IanHB wrote:My own understanding of CHECKSTAYS is that they are attached below the lower mast band [...] They are only allowed in the absence of a mast ram

Hi Ian

My unofficial opinion is that the mast band is not involved in the location or definition of an IOM checkstay. Yes, checkstays only allowed if there is not a mast ram or mast stay. But I think the class rules tell us what we need to know:

IOM Class Rules wrote:F.3.4 DIMENSIONS
Height of checkstay rigging point above heel point ............................(maximum) 100 mm

IanHB wrote:I feel we must make an effort to define this as it is about to become a problem with some fitting a second set of stays from just below the spredders and claiming these are checkstays as allowed under F. 5.2(b)(1)

It would be difficult to reconcile such stays with F.3.4.

Roy Thompson · Post by **Roy Thompson** » 08 Jan 2004, 15:03

My point exactly Lester, with the limit imposed by F3.4 I don't think we need further definition. Taking into consideration the ERS definitions, I can't really see how they could be made to work - they would be almost horizontal (OK at maybe 30 degrees from horizontal) if fixed to the chainplates from a point up the mast no more than 100mm from the mast heel! It doesn't specifically state however, where the other end of the 'checkstays are fixed - I pressume if they go to, for example, the end of the spreaders, they would be called something else - maybe thats where the confusion comes from and we need to be sure of the general 'nautical' meaning of the word. (Aside, F5.2, 1b only says that they are optionally permitted, no?)
Mast rams generally work only in the forward aft plane if the mast is keel stepped, but also commonly in the athwartships plane for deck stepped masts, and if the checkstays are going to start to be used to control this sideways movement, then I think the current rules have it covered.

IanHB · Post by **IanHB** » 08 Jan 2004, 21:30

Lester, Thank you so much you have solved my challenge.
You have also shown up my stupitity in not reading the rules throughly
enough to see that my question is answered within, DUH!
I shall carry on reading and come back in the technical area with any other dumb questions.

Thanks again to you both,
Ian Hull-Brown.

Roy Thompson · Post by **Roy Thompson** » 08 Jan 2004, 22:53

Ian,
I think this proves the tremendous benefit of this type of forum, and no one should be ashamed to ask what may seem a trivial or 'dumb' question as you put it. That's what we're all here for - to learn together!
Keep up the good work and keep the questions coming!
Roy

Chris · Post by **Chris** » 12 Jan 2004, 01:50

Ian

CHECKSTAYS (Whiskers, Lower lowers) Stays connected to the mast below the bottom mast band, to control the lowest portion of the mast.

Do you mean from below the spreaders?? As I have just put 3 new rigs together I am of the assumption that I can have stays (checkstays?) from just below the spreaders tot he chainplates to prevent the centre of the mast moving.

Is this okay??

Rob Davis · Post by **Rob Davis** » 12 Jan 2004, 03:25

Chris, the IOM rules in F.3.4 say the highest attachment point is 100mm from the heel of the mast. Do your rigs meet this rule? If not, then your checkstays aren't legal.

Roy Thompson · Post by **Roy Thompson** » 12 Jan 2004, 17:33

Rob is right, F3.4 is the critical rule and stays from the spreaders or just below to the chainplates would almost certainly be illegal.

It seems that the type of 'checkstays' allowed by the rules would be useful for a deck stepped mast (without ram as IanHB points out) and where the deck and foredeck etc are at the same level, ie. no well for the mast step etc. so that the distance between the attatchment point on the mast (max 100mm from mast heel) is the greatest distance possible from the chainplates - not sure if thats exactly what is desired, but I guess it would provide the best allround answer to (very)lower mast movement in the absence of a ram using checkstays. (Jan, would it be ok to put your diagram here please?)

IanHB · Post by **IanHB** » 13 Jan 2004, 07:48

Chris, Sorry mate but your recently fitted (Lowers) are NOT legal and will have to be removed for competition within the class.
It was after a discussion I had with Noel B that I realised I was not up to speed with the latest version of the rating rule.
Not to worry I am working on that and will be a total bore with my new found knowledge.
Hope to see you on Saturday at the regatta.

Chris · Post by **Chris** » 13 Jan 2004, 20:43

Ian
Bugger!
Wire cutters going to work - will be legal by Saturday

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