Hey Guys,

Thank you so much for the replies, you’ve given me much to think about.

I’m really looking forward to getting on with it now.

Mark, all in (including delivery and VAT) the quote was about £1140.

The next size down - a 10 metre post top column base d 177mm top d 76

was about £200 cheaper, but this only measured 8.8 metres above the inspection hatch cutout so was too short for me

The bottom couple of feet of the mast is probably out of sight, out of the weather and not in the way of anything, yet easily inspected at any time. And a little bit of bulk and/or a couple of kg of extra weight down there is nothing. If the top 10.8 m is OK then there must be a dozen ways of beefing up the bottom 0.2m. Apart from the other normal considerations, the compromised lower 10” of mast needs to be strengthened so that it cannot crush or stretch in circumference. You then need to consider how it will be stepped.

In writing: “Make the step as a socket, and the situation should be better, but I still wouldn't trust it” I do wonder if David T is being a little too conservative. David, would there be anything wrong with inserting a nicely fitted 0.4m (say) internal sleeve, or wooden plug, and then (as you suggest) housing the heel in an outer sleeve or socket? This outer sleeve could possibly even be a metal clamp or series of clamps strong enough to resist stretching or opening up around the circumference. Alternatively, a larger diameter piece of aluminium tube for an external sleeve can be packed to fit – or 3mm aluminium sheet folded into any sectional shape will do if fastened to itself and packed to fit. Whatever, the internal plug or sleeve  must resist crushing, the outer sleeve or housing must resist stretching. The mast step itself, which could be part of the solution, must meet all the other usual requirements. I think that is still being careful and conservative.

Paul, I do feel strongly that if the sail plan is already decided, you should not compromise by shortening the mast. You could, as David suggests, change the sail plan if you think you can’t make the foot of the mast strong enough – but do be generous with your allowance for halyard span at the top of the mast, and paired-downhaul spans between the boom and the deck. Good luck with your split rig, you will like it.

PS here's another thought: make the mast slightly more than 11m so that the bottom 6" is below the hatch cut-out and comprises the full circumference. Then just sleeve or plug the bottom of the mast up to a point, say, 6" or more above the hatch cut-out (the more the better).

As suggested by others, it's probably an insurance thing that has made them reluctant to talk about using the poles as masts.

Doubtless if you looked to buy a simple tapered lighting pole from their suggested supplier, they'd sell you one, no problem.

Just don't mention the word "mast".

With the generous help available on this forum, you can get the spec right for your order.

Hello Paul,

I had a junk rigged Sadler 25 with twin keels, Lliutro, for about 12 years. A great little boat. As far as I remember, the mast was no more than 10.5m overall, a 26ft x 5in dia x 0.128in wall tube with a timber topmast (which wasn't strong enough, I bent it). Your proposed mast tube sounds fine.

However, what aluminium tubes really don't like is being subjected to bursting loads, as the extrusion process makes for less tensile strength circumferentially. Put in a cutout at the heel, and the situation is worse, if you make the mast step in the form of an internal spigot. Make the step as a socket, and the situation should be better, but I still wouldn't trust it. I'd try to find a way of working within 10.8m, by using a wider, lower sailplan if necessary.

Stuart Keevil wrote:

I wonder if it's because they think that they may be liable to being sued if the mast failed and someone was injured or died ... 

Very possibly, I note that they mention their columns are CE stamped.

I don't know but suppose these days everything needs to be TUV-ed (or the equivalent)?

Marwood can only supply what ALC supplies to them, but ALC buys their stock from "an extruder". I'm trying to find out who. Presumably, it must be possible to buy direct to spec, eg without doors cut in*.

Then it's over to someone here to come up with specs ...

I thought it was good to document somewhere, and perhaps update any info on the site, to stop people hassling them/wasting time chasing them to get the same reply.

How much did the people pay?

* Funnily enough, I thought the small (underground) doors the lighting columns had would have been useful for running lighting/radar wires etc up as they came already reinforced.

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Firstly may we apologise for disappointing you, boat masts were an area we had no intension of supplying, we tried to assist one or two people that approached us for assistance.
A board decision was taken that this was outside of our scope and we would carry out no future work in this area.
My only suggestion that could assist you is that you contact an aluminium extruder and purchase tube, ALC do not extrude tube we only purchase C.E. marked lighting columns from an extruder.