Mast Database

  • 02 Mar 2013 22:13
    Reply # 1231653 on 1204514
    Deleted user
    Mark Thomasson wrote:

    I have been working on the database this w/e. I have:

    - removed all the entries with no mast data.

    - arranged in groups:  Wood solid, Wood hollow, Aluminium, Other.

    - arranged each in order of mast length.

    - moved the most relevant data to the right.

    - changed all into metric


    Mark has now sent the Mast Database. It's an Excel file which can be downloaded  hereMany thanks, Mark. 

    In his email he said, "It's a first draft for comment. I suspect that I may have lost some information, as I found it all too easy to 'cut' then 'paste' instead of  clicking 'insert copied cells', which deletes the line above. As more information is received it can be filled out."

    Mark, could you comment on how you dealt with schooners?

    Members please add your comments below, or email Mark. If anyone wants to help him with this project, ditto.

    NB The database can be downloaded by non-members. Does that worry anyone?

    Last modified: 02 Mar 2013 22:30 | Deleted user
  • 11 Feb 2013 18:36
    Reply # 1205960 on 1204514
    Mark Thomasson wrote:

    One point that had not occured to me when I started is what to do with boats with more than one mast.  My thought is to only look at the main mast. The reasoning being that it may be that at times the main mast has full sail with other(s) with none.  In which case the maximum load would be as a single sail.  The question is this likely to happen?

     

    It certainly happens with a ketch. The mizzen gets reefed first, and the main is doing most of the driving. There were some occasions when full main and no mizzen were used, when I had the wingsail ketch rig on Tystie. The situation is more complex with a schooner. 

    [Webmaster edit: subsequent posts concerning reefing moved to 'Reefing a ketch or schooner' topic, and deleted here. Please reserve this topic for 'mast database' stuff.]
    Last modified: 13 Feb 2013 22:48 | Deleted user
  • 11 Feb 2013 13:32
    Reply # 1204514 on 1174238

    I have been working on the database this w/e. I have:

    - removed all the entries with no mast data.

    - arranged in groups:  Wood solid, Wood hollow, Aluminium, Other.

    - arrange each in order of mast lenght.

    - moved the most relevant data to the right.

    - changed all into metric.

    The last operation taking this most time as it is a mixture of imeprial and metric.

    One point that had not occured to me when I started is what to do with boats with more than one mast.  My thought is to only look at the main mast. The reasoning being that it may be that at times the main mast has full sail with other(s) with none.  In which case the maximum load would be as a single sail.  The question is this likely to happen?

     

    Last modified: 11 Feb 2013 13:33 | Anonymous member
  • 07 Feb 2013 21:05
    Reply # 1201982 on 1174238
    Deleted user
    My quest was to figure out what knowledge was already in the database and see what I can do with it. I haven't queried anybody to get additional data.

    I had already come up with some engineering formulas for calculating stiffness of aluminum tube battens. I made similar calculations with PJR's ash battens as that is a time-tested working "formula"

    I plugged in various scantlings that people had used and reported success, failure, excessive bending, etc, and added data from this database as well. (I was surprised to find complete data for only 19 sails (on fewer boats, with several double-masted rigs), and several of those I had already gotten info from the forums when sizing mine for Flutterby.

    The data looks pretty well behaved. Many boats appear to have spars that are 2~6X as stiff as would be needed, but the point where battens bend or fail seems to be pretty consistent. I've got a formula of sorts comparing stiffness of battens of different lengths, as the needs scale up with length. I've even come up with a formula that would spit out an optimal size for a given batten length that I'm pretty happy with.

    I haven't tried to address breaking strength yet. I may look into that too. (Does anybody with a mechanical engineering background want to review my math?)

    I'm also working on yard strength. I didn't check this out first as I had existing spars I intended to re-use for my yards. On my test hoists and test sails I saw some disturbing bending of my yards, so I'm in the middle of re-considering this. Unfortunately, my yards seem to have numbers matching yards which DID fail. So I'll be looking carefully at this. I've still got some math to do--the PJR yard specs are for tapered yards and my formula treats them as not being cut down, so their strength is probably over-stated a bit.
  • 06 Feb 2013 13:53
    Reply # 1200462 on 1174238

    Have to admit I have been too busy with less improtant things,  hope to make progress soon.

    Mark

  • 05 Feb 2013 14:51
    Reply # 1199344 on 1176832
    Deleted user
    Jonathan Snodgrass wrote:

    Thank you to those who are taking this on. 

    May I make a suggestion from one of the non techy brigade?

    When the fields were first added to the member profile, I did try to add the details for Lexia. 

    However, Lexia is berthed some distance away from home in a place where there is no internet access.  Occasionally I can get access via the mobile phone network and a dongle but this is not reliable.  I tried on a couple of visits to the boat to get access to the web site to see what information was required but was not able to do so. 

    Therefore, on my return home to the computer I decided to print out the information that was required so that I could take the paper with me next time.  However, I found that I couldn't apparently print it out from the profile. 

    I then forgot about it.  There are always much more important things to be done on the boat, including sailing it. 

    As this subject has now resurfaced, would it be possible please for non techys like me to have a proforma on the web site that is readily printable to paper so that I could print it, take to the boat on my next visit, do the measuring and recording and then on return home fill it in on line (which I could do) or, for the really non techy people, send it to someone who would fill it out for them. 

    For those who receive the magazine by e mail then it should presumably be possible to include the proforma to be filled out and returned by e mail.   

    For the really non techy people,would  it then be possible to include the proforma in the printed magazine as an included paper or a tear out with an address for it to be returned to on completion? 

    Could it be a stiff paper 'fold and stick' to display the return address?  Could it be postage paid?  These are just ideas, but they would show that we are serious about trying to garner this information.  It would also show that we are inclusive of those members who are paper only members.

    Some of those ideas above might cost some money, but in terms of meeting the Aims and Objectives of the Association, it might, subject to scrutiny, be money well spent. 

    However, having got so far in this posting, I have come to the conclusion that, like so many things, it deserves a bit of thinking through and preparation.  It might not be something to be rushed into against a deadline for the next issue of the magazine next month.  

    I hope that suggestion may be useful for those who have kindly volunteered to grapple with the mechanics of this potentially very useful database. 

    That would then lead to the question I raised once before, about units of measurement, presumably just Metric or Imperial.  There may still be a debate to be had about using either one system or another or perhaps having columns available for both.  However, it might be necessary to note which is a recorded measurement and which is a conversion.  I presume that for the database to be of most use for comparison purposes it might be most useful to use one system only, and I further presume that the most useful measurement would be in Metric.  However, I am merely raising the question again, not offering opinion or solutions! 

    Mark and Barry - how's it going? No pressure, just wondering.

    Jonathan - Sorry for slow reply. You can print out your profile and thus use it as a form to take to yer boat, take yer measurements, fill it in and take it home = a dongle-less operation. The print button isn't obvious, but if you look at the top right hand side of the profile area, level with where it says 'My profile', it's there - a small picture of a printer, and it works. Click on it and all should be straightforward. If you can't see it you may have to scroll to 'reveal' it - probably depends on which specs you're wearing and/or which screen resolution (wot?) your laptop is set to. So the only people who can't fill this form in are paper-only members - their choice. (Good filler for issue 62 though.)

    I'll stick this advice in the Help section for future ref.
    Last modified: 05 Feb 2013 15:43 | Deleted user
  • 10 Jan 2013 20:15
    Reply # 1176832 on 1174238

    Thank you to those who are taking this on. 

    May I make a suggestion from one of the non techy brigade?

    When the fields were first added to the member profile, I did try to add the details for Lexia. 

    However, Lexia is berthed some distance away from home in a place where there is no internet access.  Occasionally I can get access via the mobile phone network and a dongle but this is not reliable.  I tried on a couple of visits to the boat to get access to the web site to see what information was required but was not able to do so. 

    Therefore, on my return home to the computer I decided to print out the information that was required so that I could take the paper with me next time.  However, I found that I couldn't apparently print it out from the profile. 

    I then forgot about it.  There are always much more important things to be done on the boat, including sailing it. 

    As this subject has now resurfaced, would it be possible please for non techys like me to have a proforma on the web site that is readily printable to paper so that I could print it, take to the boat on my next visit, do the measuring and recording and then on return home fill it in on line (which I could do) or, for the really non techy people, send it to someone who would fill it out for them. 

    For those who receive the magazine by e mail then it should presumably be possible to include the proforma to be filled out and returned by e mail.   

    For the really non techy people,would  it then be possible to include the proforma in the printed magazine as an included paper or a tear out with an address for it to be returned to on completion? 

    Could it be a stiff paper 'fold and stick' to display the return address?  Could it be postage paid?  These are just ideas, but they would show that we are serious about trying to garner this information.  It would also show that we are inclusive of those members who are paper only members.

    Some of those ideas above might cost some money, but in terms of meeting the Aims and Objectives of the Association, it might, subject to scrutiny, be money well spent. 

    However, having got so far in this posting, I have come to the conclusion that, like so many things, it deserves a bit of thinking through and preparation.  It might not be something to be rushed into against a deadline for the next issue of the magazine next month.  

    I hope that suggestion may be useful for those who have kindly volunteered to grapple with the mechanics of this potentially very useful database. 

    That would then lead to the question I raised once before, about units of measurement, presumably just Metric or Imperial.  There may still be a debate to be had about using either one system or another or perhaps having columns available for both.  However, it might be necessary to note which is a recorded measurement and which is a conversion.  I presume that for the database to be of most use for comparison purposes it might be most useful to use one system only, and I further presume that the most useful measurement would be in Metric.  However, I am merely raising the question again, not offering opinion or solutions! 

  • 10 Jan 2013 17:32
    Reply # 1176373 on 1176054
    Barry & Meps / Stellrecht & Schulte wrote:I've got an interest in looking at yard and batten strength/design requirements. I've already figured out battens pretty well, but am just starting to think about yards. (I've noticed that my current yards bend enough to make me worry or wonder)

    PJR covers them well in wood, but most rigs I hear about these days (mine included) use aluminum instead. I'd like to distill what has worked well or badly into a similar recipe for work in aluminum.

    David, would you be willing/able to send me a spreadsheet pulled from the membership database like you described, but with all the yard and batten fields?
    Coming right up.
    Mark and Barry, if you manage to get a significant increase in entries in these cells, I can re-import them into the profile database.
  • 10 Jan 2013 13:44
    Reply # 1176189 on 1174238

    David,

    thanks for the spread sheet.  I will strip away the non relevant info which will be a good starting point.  I will group by type, alumium timber, other.  I think the starting point will be for aluminium masts and see how it goes.

    Mark 

  • 10 Jan 2013 07:28
    Reply # 1176054 on 1174238
    Deleted user
    I've got an interest in looking at yard and batten strength/design requirements. I've already figured out battens pretty well, but am just starting to think about yards. (I've noticed that my current yards bend enough to make me worry or wonder)

    PJR covers them well in wood, but most rigs I hear about these days (mine included) use aluminum instead. I'd like to distill what has worked well or badly into a similar recipe for work in aluminum.

    David, would you be willing/able to send me a spreadsheet pulled from the membership database like you described, but with all the yard and batten fields?
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