Should we be considering adopting the Selden Sunbeam mast?

[Neil Andrew]

When carbon was discussed at the 2019 AGM the Itchenor trial was inconclusive. Manufacture and delivery of the demonstrator mast for Fleury had been late so it had been used significantly less than intended. The mast does not feature jumpers, and it was reported at the time that it is a strict ex-factory one-design mast for which nothing can be changed, e.g. positions of kitty pole eye, gooseneck and kicking strap.

Since then there have been several developments.

Notwithstanding the limited trial, the carbon mast was approved for use at Itchenor and has been fitted to more boats.

Although the 2020 season was curtailed by the pandemic – most significantly Cowes Classics and Cowes Week, which would have provided invaluable open-water demonstrations, were cancelled – many more boat-hours use have been accumulated in Chichester Harbour.

It has been suggested that an authorised mast supplier such as Mylor Rigging would be permitted to attach fittings supplied loose. If this is true, could it include fitting jumpers if Falmouth owners are especially keen to retain this rig adjustment feature?

Is it the time to launch a formal re-examination of carbon before the 2021 AGM?

• This topic was modified 8 months ago by Neil Andrew.
• This topic was modified 1 week, 3 days ago by Neil Andrew.

[Paul Pullen]

With two glass boats coming down both of which having carbon masts we will be able to see them in action.

[David Owens]

We will be managing and sailing Misty as much as possible once she arrives, but given our J80 commitments there will be plenty of opportunities for existing Sunbeam sailors to try the glass boat and carbon rig. Roger Wickens is really keen for this to happen. Contact me or Mandy once we know more about the easing of lockdown and we can make the necessary arrangements on behalf of Roger. Give it a go.

[Gilly Fox]

The debate around carbon masts has a number of aspects to it and there appears to me to be some risk that the discussions will lose clarity unless the area of discussion is kept clear. For me, the distinct aspects are:

1. Mast configuration (jumpers, spreader angle (in-line vs. swept-back), spreader height, runners)
2. Mast construction material
3. Mast cost and availability (aluminium vs. carbon)
4. Sail area distribution (this has to be included as all carbon trials to date have been with large mainsail/small jib)
5. On-the-water mast rake adjustment
6. The rules of the Solent Sunbeams and the strategic desire to re-align the class rules of the two fleets

I am not recommending separate forums for each aspect (that would surely be tortuous) but would hope that we, as a group, can avoid wide statements that mix up the aspects.

I note that this carbon rig forum has not had any entries for some time outside Dave Owen’s post regarding the availability of Misty for sailors to try. As a starting point, therefore, I thought it would be useful to copy here the text below that provides a summary of the Falmouth meeting discussion on carbon masts that took place in May-19. It was agreed by all at that meeting that the Falmouth fleet’s view regarding carbon masts should be shared with the Solent fleet at that time, so the text below was drafted in the form of a letter to the Itchenor fleet. I’m not sure why it was never sent.

Best, Gill
————————————————————————————
Dear …….

As you know, members of the Falmouth fleet were invited to a meeting to discuss the proposals for carbon masts on Tuesday (14 May). The meeting promoted some good discussion and one or two possible actions. As it was informal, no minutes were taken. However, we agreed to let the Solent fleet know the general sentiment in Falmouth regarding the carbon rig proposals and provide a summary of any outcomes from our discussions. To ensure accuracy, I have circulated the text below to the Falmouth fleet prior to sending it to you.

For a number of different reasons presented at the meeting, a high proportion of the Falmouth fleet is resistant to a rule change that will allow carbon fibre masts. For the minority that are more amenable, their reasons relate to inevitability of the change over time. Except for the availability issue of carbon vs. aluminium masts, within the meeting there were no advocates for carbon masts as being advantageous to the class.

The removal of jumpers from the carbon masts and the lowering of the spreaders by 200mm were seen by the group as fundamental changes to the rig design. There is strong resistance to these being proposed and introduced at the same time as the change in mast structural material. The reasoning is that it will be impossible to establish the reason behind any performance difference that the new mast and rig configuration might be perceived to bring. Trialling a re-designed rig in this way was felt to be less likely to provide objective results for the stated aim of ensuring minimal performance difference between old and new.

In terms of fleet dynamics, Falmouth has two spare aluminium masts and has enjoyed a comparatively low rate of mast failures over the last 20 years. Should this continue, we ought to be able to support a strong racing fleet for the next few years without difficulty or revision to the rigs. It was recognised that the Solent Sunbeams are facing a more urgent issue with the sourcing of masts. As previously agreed at our Spring meeting, we are happy for a boat using a trial carbon rig to compete equally in our 95th celebration championships. However, this was on the basis that we believe the Solent fleet is already committed to building the trial rig and that we may all learn from seeing it and sailing against it. The group was keen to point out that the inclusion does not imply a tacit agreement to the Solent fleet’s carbon rig proposals.

The Falmouth meeting provided an opportunity to (once again) discuss the problem of sourcing aluminium masts for Sunbeams. One notable solution is that apparently employed by the Sigma 33 fleet. Faced with the same dilemma, their Class Association had extrusion dies made for the Sigma mast section and then purchased and stored multiple mast lengths from an aluminium extrusion company. We understand that this was successfully implemented some time ago and wish to examine the approach further. It also appears that an investigation into the availability of new aluminium masts hasn’t been undertaken by the Falmouth fleet for some time, so it was agreed to revisit this to ensure no opportunities have arisen.

I should mention that the group appreciated the collaboration the Solent fleet is extending on this issue and expressed a continuing desire to ensure that the two fleets do not diverge further in terms of materials or configuration. We are all looking forward to some good racing at the 95th celebrations in September and the opportunity to talk through the issue in person.
———————————————————————————————————————–

[Andy Stevenson]

Thanks to Gilly for the helpful precis of the issues at hand which need consideration. I will admit to mixed views about the carbon rig. On the one hand we have seen two glass boats with the rig sailing in Falmouth Week and the Championships (albeit Misty changed to inline spreaders for last weekend) and the results achieved clearly show that in the Falmouth configuration inline spreaders are faster downwind. The relative performance difference between aluminium and carbon is more difficult to determine as Tiffany was last in both series and Misty clearly improved with the swap to inline spreaders (plus Roger W sailed a blinder). I am inclined to the view that it merely proves that the crew clearly is the overriding factor.

The configuration points Gill raises are valid and it is these factors which essentially define what a Falmouth Sunbeam is, so any change has to be weighed carefully and balance maintaining the character of the Falmouth Sunbeam against the desire to unify and assimilate the two fleets, insofar as that is possible.

The main drivers that I have heard articulated for the adoption of a carbon rig is availability & cost plus a vague desire to have a one design mast. As I understand it the cost differential is significant with a carbon rig being about 2/3rds the cost of aluminium. One other thing to consider is the quality of the aluminium available this has deteriorated as the proportion on recycled aluminium in the extrusions has increased, so there is a durability issue to consider. We could also throw into the mix the fact that aluminium smelting and production has a very high energy consumption and aluminium ore is a scarce resource. Looking forward are aluminium masts sustainable? If not then we need to look at alternatives and carbon is an obvious choice as it an abundant material, also carbon masts are also more easily repaired than aluminium.

I said at the start I have mixed feelings about carbon. I think it is inevitable in the medium to long term but I would share Gilly’s view that we do not know how the rig will perform in a wooden boat in the standard Falmouth configuration. So of Gilly’s 6 points I think the following are the ones that we may not know enough about to make a fully informed view:

1. Mast configuration (jumpers, spreader angle (in-line vs. swept-back), spreader height, runners)
4. Sail area distribution (this has to be included as all carbon trials to date have been with large mainsail/small jib)
5. On-the-water mast rake adjustment

For me these are where the discussion and debate should be focused.

Finally, having spent the summer trying everything possible to get Mayfly’s current John mast to work I have concluded I am fogging the proverbial dead horse, so I will be changing the rig this winter. I am exploring options but will not commit to anything until a decision is reached on the carbon issue.

Hope this is of some use.

Andy

[Author]

Posts