New boom for 41' mast furling AWB (on a budget) - do we panic?!

[[70521]]

Might find your premium goes up unexpectedly if they perceive you are an increased risk. Particularly of losing the mast etc.

Even if there was a repair, I'd be informing the insurance company what work had been done.

I've always found insurance companies both fair and efficient, provided you keep them up to speed with issues.

If the boat has an issue with the boom, perhaps a mast inspection is in order. BUT I come from a safety engineering background and prefer to, in the words of Mr Spock, 'live long and prosper'.

 

[geem]

Even if there was a repair, I'd be informing the insurance company what work had been done.

I've always found insurance companies both fair and efficient, provided you keep them up to speed with issues.

If the boat has an issue with the boom, perhaps a mast inspection is in order. BUT I come from a safety engineering background and prefer to, in the words of Mr Spock, 'live long and prosper'.

Well that's the difference. I am engineer so just get on with it

 

[Boathook]

I'm sure that it can be repaired. The boom vang might not slide but a 'plate' could be used to cover the hole and pop riveted in place and the vang on top. With the main sheet could it be moved a bit so one end is in between the two holes ? Either way, clean the existing corrosion and 'paint' to give it protection.
If you riviet stainless fittings back on I have used plastic milk bottles to provide protection between materials. This was recommended to me by a rigger years ago; and as it is behind a fitting the sun shouldn't affect it.

 

[Poecheng]

I don't know your set up but if your main is loose-footed, in respect of the mainsheet blocks could you put a dyneema loop around the boom and a fitting on the top of the boom simply to stop the loops sliding forwards (or backwards) and hang your blocks from the loop. Would that force not be on the entire tubular structure (pulling down from the top of the boom) and spread around the structure rather than trying to pull the bottom of the boom out. I am not an engineer!
You might be able to put a reinforcing saddle on top of the boom and do the same in respect of the vang.
I am assuming you are not in-mast reefing.

Apologies - just re-read and you have in mast !

 

[Daydream believer]

If I were fitting plates to take the vang I would want it to be fitted to the side of the boom & be "Z" shaped so the 2 pieces met in the middle under the boom. A hole through them to take a shackle. The pop rivets would be in shear not in straight pull out.

 

[dankilb]

Our plate is two foot long. It has a double row of 6mm rivets. 24 on each side of the boom. I would wrap the plate around the sides or the boom as well. You want it strong. That way you could get a row of 12 rivets where your green marks are and another row along the sides of the boom. If you have time, get the plate anodised before you fit it

If I were fitting plates to take the vang I would want it to be fitted to the side of the boom & be "Z" shaped so the 2 pieces met in the middle under the boom. A hole through them to take a shackle. The pop rivets would be in shear not in straight pull out.

Agreed. I think my original idea for a plate was a bit minimal. No reason it couldn't wrap further around/up the sides of the boom.

It needs to include a beefy bracket to take the pneumatic rodkicker we'll be fitting.

 

[dankilb]

So the track is the second (and perhaps more confounding) issue. Before I realised I couldn't source a car to fit - it was more positive about the prospect of repairing the corrosion on the bottom of the boom.

This is the track:

Let's assume a car isn't available. I have searched for a month or so - inc. overseas - and no joy. So the next suggestion from Ronstan's UK dealer was to bolt their track on top. It would add another inch & half to the height - no problem there:

However, there really isn't much meat to take the 6mm fasteners (btw for some reason there's a stainless bar bolted under the track at the boom end - it is not that thick anywhere else - just 3mm):

I can do helicoils, nutserts, rivets etc. - but not sure any of those would help with this.

Note - ignore those screws (for the random bar). The track is definitely part of the extrusion and so any removal would be very destructive (and quite likely impossible!).

 

[Boathook]

@dankilb re post 27. Presumably the new track has bolts every 200mm or so so they should hold the track in place. If concerned about the end being weak a bracket could be fabricated to rivet in place and help spread the load on the last fastener.

 

[dankilb]

This was the original car, btw. I'm confident it was original as the boom ends definitely haven't been off and that's the only way to remove it:

It clearly isn't the right (modern) design for a furling outhaul, as the block and line end need to be fixed together (and pulling at angles on the one padeye). The car also seems very small compared to current versions that meet our spec. Obscure corners of the internet suggest a design load of 4000lb, which would actually be fine. But our experience has been that it doesn't run nicely even with no load. The wheels are worn. They are helpfully riveted on to make replacement tricky.

The main issue finding a current replacement to fit is the very wide 'track'/gauge of the (thin) wheels. They need to be >20mm apart to clear the top of the 'X' shape of the track:

For comparison, Ronstan helpfully measured theirs at 17mm.

 

[Thistle]

Wasn't there someone on these forums offering to make up smallish parts in stainless? I wonder if they could run up a new car for you to fit the existing track (along with spares of any parts you think might wear out)? Probably no harm in asking.

 

[dankilb]

@dankilb re post 27. Presumably the new track has bolts every 200mm or so so they should hold the track in place. If concerned about the end being weak a bracket could be fabricated to rivet in place and help spread the load on the last fastener.

True - given that plenty of fasteners are involved and there are a couple of spots in the 'X' extrusion where each fastener should grab at least a few full threads I should think it will hold.

Wasn't there someone on these forums offering to make up smallish parts in stainless? I wonder if they could run up a new car for you to fit the existing track (along with spares of any parts you think might wear out)? Probably no harm in asking.

True. I think that's Pete (@PCUK). I'm just not that confident in (my part in) engineering a working replacement. I had a similar experience with the mainsheet traveller track (a whopping 55mm wide and completely idiosyncratic). The wheels on that were attached with (very seized!) fasteners and I was able to cobble together a prototype replacement with acetal wheels I machined to fit. It was only ever a proof of concept, but I just couldn't get it to run nicely. I concluded that wheels/bearings/moving parts are just a bit beyond my engineering knowledge/ability. Of course, if someone was confident they could make a replacement that would be up for the load and would run smooth - I'd happily defer and pay up. I'd just worry that specifying something and getting someone to make it could end up as good money (and time) after bad...

Even if there was a repair, I'd be informing the insurance company what work had been done.

I do get the 'is it insurable?' question. But we've had to DIY re-engineer so many critical things on this boat that I have to take it on good faith that any insurance company would take our evidence (e.g. photos) of things being DIY'd sensibly, conventionally and to spec. We're with GJW and I do keep a document updated for them with evidence of our various fixes specifically for the issues identified by the survey ('corrosion on boom' wasn't one of them - but I'm sure somewhere it says 'check all rigging components and replace as required').

In short, I'm happy that a beefy DIY repair - if that's the route we choose - would be in keeping with the rest of the refit and we haven't had the means to get anything else professionally inspected or signed-off.

I was hoping for at least one reply to my email requests for a quote on the new boom today, just for initial reference - but unfortunately no such luck!

 

[[70521]]

I was hoping for at least one reply to my email requests for a quote on the new boom today, just for initial reference - but unfortunately no such luck!

We all know that the maritime industry works in multiples of spring tides.

I once presented a company who were dragging their feet with a gantt chart and pointed at their very small part then suggested that if they did not get a move on I'd be charging them for my considerable delay costs. They got the message.

 

[fredrussell]

Repair it, not an issue

Agreed, easy job for a competent welder.

 

[Concerto]

I agree that a repair for the missing section in the track is repairable, the X track is another problem that is not simple to fix. Having two major problems on a boom still makes me say replace, not repair. One final point. If you were buying a boat with a repaired boom, how would you feel? I certainly would and would use it as a reason to reduce the price.

 

[dankilb]

I agree that a repair for the missing section in the track is repairable, the X track is another problem that is not simple to fix. Having two major problems on a boom still makes me say replace, not repair. One final point. If you were buying a boat with a repaired boom, how would you feel? I certainly would and would use it as a reason to reduce the price.

Fair point(s). I wouldn’t countenance repair or modification that wasn’t fit for purpose erring on the side of overkill - but there’s a fine line here between swerving the considerable cost of replacement and creating some sort of ‘frankenboom’.

The repair cost is already >£1k realistically for the Ronstan track/car and the bits to make it work. For this I potentially think you’d get a nice solution - the car isn’t specifically designed for outhaul but with the line terminating on the middle pin and returning to a block standing off the aft pin (perhaps aided by a conical spring) I reckon you’d have a nicely balanced and strong outhaul setup:

 

[dankilb]

Of the new boom replacement options, Selden and Sparcraft both offer their booms with a wheeled car running inside a groove.

Selden’s has ‘side’ wheel(s) - apparently they added a second (vertical) axle recently in the same orientation/configuration as B3:

Sparcraft’s is a simple car with only horizontal (axle/track) wheels:


ZSpars sell a (25mm) track car on torlon bearings:

Therefore, quite a different range of setups - in addition/comparison to the Ronstan DIY option.

 

[awol]

My vang also pulled out leaving a gaping hole - so I swapped the ends over, the hole is still there but the vang has good metal. Have you looked at IYE cars?

 

[dankilb]

My vang also pulled out leaving a gaping hole - so I swapped the ends over, the hole is still there but the vang has good metal. Have you looked at IYE cars?

Very good point - must admit I hadn’t thought of switching the ends. Annoyingly, the degraded areas under the bales are right in the middle - but of course the vang could have a new location with solid material.

I have looked at IYE cars. Annoyingly theirs - and others (Pfeiffer) - are genuine X tracks where the bearings/wheels run at 45 degrees. Ours is more a X-beam with the bearings running horizontally on a ‘T’ section at the top.

However, on the topic of tee-style tracks - one option hiding in plain sight could be a Barton 32mm tee-track car. They don’t do a furling main version (with block and eye together) but I wonder if I could tap/bolt an eye where the pin stop goes in this model:


I’ve got an old Barton genoa car I can try next time I’m on the boat. It still feels a bit of a bodge (a slider stop car not really meant for the job) but would be a cheap fix for the track issue.

 

[dankilb]

Btw found a euro price online for the equivalent Selden boom setup for furling at €4k exc.

Eyewatering but not quite approaching the 5 figures I’d feared.

 

[doug748]

As I think Boathook has suggested, shape a long plate to fit neatly inside that extrusion, knock it up the spar and rivet in place. Easy, neat, stronger than new.

For the track, repair and modify the original car, it's lasted this long, it will be ok. If you don't have the tools a workshop will fit bolt on wheels for a price. Total cost 100 quid or so. I think you would have to be minted to consider a new boom.

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