THE PRICE OF POOR DESIGN

  • 21 Feb 2024 18:17
    Reply # 13318872 on 13306875

    These are screenshots from a video taken during a visit to Rudolf van der Brug at his home near Stavoren in the Netherlands last summer. Rudolf made both the mast and retaining sleeve of carbon fibre. The aluminium lower section has to be lifted out to let his 8m boat pass under a low bridge over the approach to his private mooring.

    4 files
    Last modified: 22 Feb 2024 11:05 | Anonymous member
  • 21 Feb 2024 14:26
    Reply # 13318634 on 13318022
    Anonymous wrote:

    Thank you, Gavin. I've been hoping to see a photo of Robin Blaine's hinge design. Those heavy machined components are beyond the abilities of a backyard bodger such as myself, so I'll probably end up with something very like Richard Brooksby's version.

    I was aware of Richard's disability; it's a great pity it has put an end to his wonderfully detailed, useful blog entries, for which I'd like to thank him. I hope he continues to enjoy looking after and sailing in Tammy Norie.

    My first boat ‘Fever’  which I converted in 1988 had an identical Needlespar Mast with the same hinge/sleeve tube. I used Needlespar again for a mast for ‘Miranda’, in 2012, this time a tapered mast which fitted into a deck socket tube. 

    I have just checked Google and they are still in business. 

    Paul McKay

  • 20 Feb 2024 13:21
    Reply # 13318022 on 13306875

    Thank you, Gavin. I've been hoping to see a photo of Robin Blaine's hinge design. Those heavy machined components are beyond the abilities of a backyard bodger such as myself, so I'll probably end up with something very like Richard Brooksby's version.

    I was aware of Richard's disability; it's a great pity it has put an end to his wonderfully detailed, useful blog entries, for which I'd like to thank him. I hope he continues to enjoy looking after and sailing in Tammy Norie.

  • 19 Feb 2024 16:53
    Reply # 13317705 on 13306886
    Anonymous wrote:
    Anonymous wrote:

    I hope folks will find this cautionary tale interesting.

    I continue to enjoy sailing with the Junk rig and being part of this great association.

    As Annie says I cant imagine having a boat with any other rig. 

    Bad luck, Alex.

    If you're interested in the idea of a hinged mast - as am I - have a look at Richard Brooksby's blog https://tammynorie@wordpress.com, which you should find useful.

    Although his blog posts mysteriously came to an abrupt end a few years ago, Brooksby's inventive ideas on his Coromandel trailer sailer are worth studying.

    Richard has been suffering from Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) for several years, which is the reason why there are no further instalments of his blog, as this appalling condition leaves him almost unable to physically function normally. The horrible irony of this is that Richard is a highly intelligent and previously super-active person who was making a considerable contribution to the JRA prior to being hit by ME (for which there is no known treatment and currently no known cause). Concerning the mast issue, the hinged masts on Tammy Norrie and several other boats in the 80s and 90s were supplied by Robin Blain who I believe sourced them from Needlespar in Fareham; I myself have a Coromandel ('Yellow Rock') with one. The key elements of the design are that, instead of a tabernacle, the mast is keel-stepped but has a custom-made hinge about a metre above the coachroof, effectively dividing the mast into two sections joining at the hinge. That hinge is a solid billet of aluminium forming a plug in the top of the lower part of the mast, machined with with a slot about 5cm deep and 5cm wide across the diameter of the mast with an offset hole for a removable bolt or rod that passes through a matching solid billet forming a plug in the base of the upper part of the mast, machined with a thick matching 'tab'  projecting from its base that fits into the slot below when the two elements of the mast are vertically in line, the rod passing through both to receive the offset hinge pin. A 2-metre 'sleeve' of mast tube with an internal diameter matching the external diameter of the mast itself then slides down over the hinge and beyond to form a secure reinforcement to maintain the lower and upper sections of the mast in line with each other. The whole mast is then effectively a single, keel-stepped unit with the 'bury' extending from the coach roof down to the step on the internal floor below. Obviously, this provides a much better-supported mechanical unit than a deck/coachroof-mounted tabernacle. I am unaware of any instance where the mast so supported failed anywhere near the joint or below the deck/coachroof. See photos attached. Notably, the mast can be lowered only towards the aft end of the boat because of the offset pin. Once lowered in a straight line, the hinge pin is then withdrawn, allowing the main part of the mast to be disconnected from the lower section and then laid along the centre of the yacht without significant projection at either end. In the photo you can see that the sleeve is fitted with a bevelled extension at the top end to allow the parrels to pass down the lower section of the mast, obviating the need to remove the sail bundle from the mast if you wish to leave the rig undisturbed.
    5 files
  • 29 Jan 2024 04:05
    Reply # 13307109 on 13306875

    Thanks Asmat,

    I will check it out although now my mast base is buried Iwill no longer be using the hinge method but will just guide the foot to the partners and lower it in. In the world of masts mine is tiddler and I shouldn’t have any problems

    Cheers

  • 28 Jan 2024 11:13
    Reply # 13306886 on 13306875
    Anonymous wrote:

    I hope folks will find this cautionary tale interesting.

    I continue to enjoy sailing with the Junk rig and being part of this great association.

    As Annie says I cant imagine having a boat with any other rig. 

    Bad luck, Alex.

    If you're interested in the idea of a hinged mast - as am I - have a look at Richard Brooksby's blog https://tammynorie@wordpress.com, which you should find useful.

    Although his blog posts mysteriously came to an abrupt end a few years ago, Brooksby's inventive ideas on his Coromandel trailer sailer are worth studying.

  • 28 Jan 2024 04:39
    Message # 13306875

    I hope folks will find this cautionary tale interesting.

    I continue to enjoy sailing with the Junk rig and being part of this great association.

    As Annie says I cant imagine having a boat with any other rig. 

    6 files
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

                                                              Site contents © the Junk Rig Association and/or individual authors

Powered by Wild Apricot Membership Software