New mast development for the Laser 2

[Andrew Whapshott]

A new one piece mast has been made for the laser 2, and was tested on my boat in light winds at Datchet last weekend.

It seemed okay, but I am not an expert and would be interested to hear the opinion of someone with more experience..
We've put together a report, if you could pass on your views/advice it would be greatly appreciated  :-) ,   (Attached below) 

(I know a few of you are ex-L2 sailors.. and as a class you play with masts a lot..)

[roland_trim]

How much does a new mast cost?

[Andrew Whapshott]

~£850 I think.       (We were told the new one piece would be sold at the same cost as the original lower section)

Admittedly a new boat could be brought for this.. But I gather there are already 4/5 future buyers.. 

[JimC]

The big advantage of the rig with diamonds is that you don't need shed loads of rig tension to avoid the rig going floppy when the crew gets out on the wire. Bearing in mind your boats are not getting any younger *and* were not designed for the sort of rig tension a spreader rig requires I think you'd be well advised to stick with the diamonds no matter what you do with the tube.

[Will_Lee]

Biggest problem is that it is likely to be much quicker that the two part masts, once they are set up properly.

[Andrew Whapshott]

Thanks; Yes I think the diamonds did have a lot of benefits...  The new mast manufacturer doesn't have any for this section, but we have nudged them to see if they can sort something. 

  Yes the tension will be more.. but they are fairly robust, hopefully!  The first laser 2's did have "normal spreaders" and there are a few still about.

Will; Yes it will be faster..  but it will keep boats going. 

[JimC]

but we have nudged them to see if they can sort something.  

Take
piece of aluminium rod approx 10mm in diameter, length = span of spreaders
drill 2.5mm hole in each end
two pieces of alloy tube about 25mm long, id same as od of rod, about 7mm wall thickness
drill 10mm hole through mast tube
insert alloy rod
slide on the pieces of tube each side so they are flush with the mast section
rivet (not poprivet) the collars on the spreader

When satisfied with dimensions do a bit of machining/tidying up t o make it look more elegant.

Needlepsar used to do exactly this for spreader brackets on lightweight wing masts they made in the 70s.

[Andrew Whapshott]

Ahhh.. Yes!  

  I will suggest this..  Thanks.  

..Not sure why I didn't add it in, I've got a laser 2 mast with that setup.  (It belongs to an older boat that's currently in bits!)    admittedly it does not look very elegant compared to the swept spreaders..  but will keep racing level.   I think the Tasar has something similar..

[Phil Alderson]

There was a very old one peice laser II mast setup exactly like Jim described from one of the very old Uni Laser IIs.

[JimC]

There was a very old one peice laser II mast setup exactly like Jim described from one of the very old Uni Laser IIs.

Here's a lighter but higher budget option from my Bethwaite wing mast.
piece of 13mm id alloy tube through mast, peened over at ends
piece of 13mm od alloy rod about 150mm long through tube and mast.
13mm id *titanium* spreaders socketed on the rod each side
plastic end caps for the diamond wire to go through.

[phil_kirk]

From how the report is written it appears that the location of fittings, halyard lengths and especially trapeeze line attachment points haven't been considered very carefully and the class should have been consulted on these details before holes were drilled.

From the picture the new mast looks like a Super Spar  where as the L3000 mast has proctor spreader fittings. Due to their design these can be articulated to greater angles.

the spreaders should be able to be swept back sufficiently to put an inch of pre bend into the mast (the maximum I think you will need) and long enough to deflect the shrouds outboard by 50-70mm.  There should also be enough adjustment to allow the mast to be raked at least + or - 50mm from the optimum mast to transom distance. 

The ent carries 400 lbs of shroud tension with straight shrouds deflecting spreaders and mast.  I suspect this tension is sufficient for most boats even with trapeezes. I would have thought that a laser 2 hull could take this kind of rig load. With longer spreaders you would expect the spreaders to deflect the shrouds outboard. Idoubt that the sail needs much more than 1/2 -3/4 inch pre bend since the old mast wouldn't have had any induced bend. A bit of bend will flatten the sail in light winds however the spreaders will restrict further lower mast bend in stronger winds.

[JimC]

The other question of course is "have you talked to Bethwaite?" He does seem to maintain a healthy interest in his offspring, and anything he has to say has to be useful input.

[Andrew Whapshott]

Thanks for the feedback, will pass on what you have said to see if we can find a better arrangement..     

I will attempt to get in touch with bethwaite; It would be good to know his views. 

[tim_unerman]

You could always try needle spars as an alternative small spar manufacture might be helpful (http://www.hawkmarineproducts.com/needle.htm)

[Andrew Whapshott]

Job done.. Finally   

We calculated the bend characteristics of the old rig using a collection of broken sections (Odd that only half of them had internal stiffners, so we had all been racing with odd rigs anyway!)   Anyway, handed the task over to Selden who have produced a decent replacement with diamonds, at the right cost and pretty quickly since we approached them.

Should see my boat back afloat post-exams, but it won't lower my cherub commitments! 

(...I wonder if my insurance company remembers me...!)