Bowman 26, mast step problem

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Ephraim

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Bowman26 has the mast deck stepped on a substantial s/s plate, secured to cabin roof in way of main bulkhead. The bulkhead has a doorway right underneath the mast!! There is a hardwood beam across the doorway to support the weight, but over the years this has slowly succumbed to the pressure of the mast step & is now flat, instead of arched upwards. This has consequences not just for the head lining, but rigging tension, mast security and so on. It is not going to completely collapse in the short term, but will need some serious rectification this winter.
I have had some thoughts on repair, but would appreciate the collective wisdom available here, before I jump in & destroy something! Perhaps someone also has a Bowman26 & experience of this problem.
Look forward to your help.
Regards
Mac
 
Common problem. Broadly two ways of fixing it. One is to put a compression post in, second is to beef up the coachroof and/or bulkhead. Either way you will have to jack the roof up to where it should be at least temporarily. Problem with the compression post is that it will probably come down the middle of the doorway which is probably why it does not have one. The second and probably only practical method requires the fabrication of a stiffer beam and maybe reinforcing the bulkhead down to the keel around the doorway. Beams can be wood or metal depending on how much space you have and your skills in fabrication. If you are not comfortable with working it out for yourself or can't find somebody who has done the same thing successfully may be worth seeking professional advice.
 
Ephraim said:
Bowman26 has the mast deck stepped on a substantial s/s plate, secured to cabin roof in way of main bulkhead. The bulkhead has a doorway right underneath the mast!! There is a hardwood beam across the doorway to support the weight, but over the years this has slowly succumbed to the pressure of the mast step & is now flat, instead of arched upwards. This has consequences not just for the head lining, but rigging tension, mast security and so on. It is not going to completely collapse in the short term, but will need some serious rectification this winter.
I have had some thoughts on repair, but would appreciate the collective wisdom available here, before I jump in & destroy something! Perhaps someone also has a Bowman26 & experience of this problem.
Look forward to your help.
Regards
Mac
Click to expand...

You could try the hurley 22 owners association as this is where some of the bowman 26 owners lurk.
I would jack the deck up back up to where it should be and replace the beam. Instead of using a timber beam you could try having a s/s beam made up in its place. However whatever you do this needs to be tied in to the bulkhead (I assume there is some kind of pillar reinforcement on the bulkhead) You should slack off your standing rigging before jacking the deck back up.
 
Thanks for the ideas guys, much as I thought. While I was all for going at it & jacking the beam up & then inserting a steel plate reinforcement, my compatriot has urged caution & we are getting a shipwright in for a quote. I will also have a visit to the Hurley O/A & see if they have any further thoughts.
Appreciate the advice.
Cheers
Mac
 
Mast support

Hi,
I owned one of these lovely boats for some years. A previous owner had beefed up the thickness of the s/s plate which seemed to have cured the problem more or less - though I was always cautious abiout over-tightening the rigging!

The surveyor Tony Staton-Bevan knows these boats and the problem - I have always found him helpful and it might be worth seeking his opinion. Even if it costs a bit it might be worth it.....

Incidentally - I changed 'Many Waters' (originally 'Uisgeachan Lionmhor')for a larger Ian Anderson design, the Sovereign 32, for some extended cruising upon retirement. That phase is now over and I would dearly love to get Many Waters back again for more local channel use. Anyone know where she might be?

Please let us know what remedial route you go down and how it resolves.
 
Strengthening beam

Hello Mac, as a Hurley member I can vouch for our technical site on which there is considerable info. I personally fitted an Iroko anti compression post to a Hurley Felicity a couple of years ago and as has been said you need to slacken off the standing rigging first before jacking anything up and do the actual jacking very slowly a bit a day not all in one go. My own boat does not have any compression problems and our former Vice Chairman, Nick Vass who is a marine surveyor says that if there is no compression now there probably wont be in the future.

Anyway if I had to do my own although I am a woodworking joiner I would have a stainless steel beam made with the right amount of pre bend in it and also as others have said this needs to be supported by uprights which go down to keel level and of course in a doorway this is not so bad as there could be one either side. Stainless steel would be a thinner material and still have the tensile strength whereas laminated timber might look good but would need to be thicker thereby reducing the headroom. Those are just my thoughts, there are quite a few around on this issue.
Cheers
Kevin
 
Hi Kevin, Thanks for that, I have got a quote from a shipwright to insert a s/s plate as suggested so will go from there.
I agree that the Hurley website is a fund of info & no mistake, my only minor comment is that in Ian Andersons Biog there is absolutely no mention of his involvement in the design & birth of the Bowman 26, the immediate forerunner of the Hurley 27!
Thanks again for all the help & advice.
Mac
 
Mast Support

Just a few comments which may make sense in your dealings with the shipwright.
If the existing beam across the archway/doorway has flattened on top that is surprising. It might indicate loss of material by rot. Or do you think prolonged pressure has bent the member from arched to straight?
while of course stainless steel is stronger than wood it is the height or thickness of the cross member that gives the strength. Unfortunately it is this same height/depth thickness that will reduce your head height for the door way.
You might consider a beam across the top of the cabin from the base of the mast. The wider it is the less stress on the middle of the under beam.
The strength of the member can also be improved by reducing the span. So a doorway narrow at the top may be acceptable and will give much better support.
As said the vertical supports need to be looked at carefully. They need to transmit the loads to a strong part of the boat. The keel yes but actually much of the load will be to the chain plates so transfering the load to the hull in a direction as near vertical as possible would also be good. Just draw a cross section of the hull mast and chain plates and you will see that in heeling the mast presses down while the stays and chainplate via the hull have to react against that mast pressure.
Good luck olewill
 
Hi Olewill, Thanks for that, the compression has bent the beam from curved to straight, so it is a case of jacking it up, with the mast removed, fabricating a 6mm flat plate with a curved profile to match the original & bolting it through so as to maintain the original curve. The vertical supports for the beam are fine, and apart from removing some material from the ford side of the existing beam, to make room for the new steel plate, there is nothing difficult about the job. Removal of say 6mm of wood is preferable to re-manufacturing the existing GRP headlining to accomodate any increase in thickness of the beam.
Thanks again
Mac
 
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