Ruddershaft cracked...

[ProjectManaia]

The shaft joins to the upper shaft part and tiller (one part) with a bolt and nut.
The end of the tiller is connected to the bar joining it with the other tiller. From the bar lones are run to the wheel with a chain bit on the wheel itself

The marine growth is not in the crack. Around it yes.... need to clean more often it seems

[ProjectManaia]

I will add a picture of the upper part of the shaft later today when back to the boat and returned to internet island... but it should be in several videos (f.ex. sailing sea nomad - expedition sailboat afloat) i remember standing back there for a talk....

[UpOnStands]

While we wait for photos.
Does any of you have experience with this type of rudder? small diameter (4"?) stock running the full length of the blade with a large dia head pintle - not sure what to call it.

[ProjectManaia]

Originally Posted by UpOnStands

While we wait for photos.
Does any of you have experience with this type of rudder? small diameter (4"?) stock running the full length of the blade with a large dia head pintle - not sure what to call it.

Sorry it took longer, internet in the mergui islands....
But here we go
The upper big bold holds the two pieces of the shaft together, the loswer smalle bolt is holding the "washer" in place, which again holds the tiller above the deck and stops the whole constuction from dropping lower...

[UpOnStands]

Originally Posted by ProjectManaia

Attachment 144914

Wow, the design and build of this boat is a real puzzle maker.
So its only the lower small bolt you have to remove to drop the rudder?
Can't you turn the rudder, cut the head off and pull it out from the threaded side? may have to cut it. Of course, you will have to support the rudder to prevent jamming.



Judging from the size and position of the crack shown and the tear in the metal up the neck of rudder I would not risk the boat on any trip other than across the harbor.
Any other comments/advice from the community?

[ProjectManaia]

As far as i remember the shaft goes through the rudder blad and is welded to the blade inside as well.
Since i see another shaft (?) Inside the crack i hope it is fine.
Cutting is not an option, next place to weld aluminium is 3 days sail from here....

[atoll]

Originally Posted by ProjectManaia

As far as i remember the shaft goes through the rudder blad and is welded to the blade inside as well.
Since i see another shaft (?) Inside the crack i hope it is fine.
Cutting is not an option, next place to weld aluminium is 3 days sail from here....

what you describe sounds like a normal engineering solution for the rudder blade construction in aluminium, if the tolerances on the inner shaft and outer tube are fairly tight,a short weld should be sufficient to prevent shear when the rudder turns on your return trip using the rudder.

at this time of year winds should be offshore for your return trip to ranong so very little swell.

even if you do lose the rudder the catamaran should happily sail with 1 rudder,and a bit of sail trim,in close quarters you can use your engines to steer.

you could also make a steering oar and mount it on the stern mid way between the two hulls with lines forward and either side to support the lower section in the event that you lose both rudders.

don't sweat it!
it is only a coastal trip in moderate winds at this time of year,plenty of anchovie boats out there as well if you needed a tow as well

[ProjectManaia]

Originally Posted by atoll

what you describe sounds like a normal engineering solution for the rudder blade construction in aluminium, if the tolerances on the inner shaft and outer tube are fairly tight,a short weld should be sufficient to prevent shear when the rudder turns on your return trip using the rudder.

at this time of year winds should be offshore for your return trip to ranong so very little swell.

even if you do lose the rudder the catamaran should happily sail with 1 rudder,and a bit of sail trim,in close quarters you can use your engines to steer.

you could also make a steering oar and mount it on the stern mid way between the two hulls with lines forward and either side to support the lower section in the event that you lose both rudders.

don't sweat it!
it is only a coastal trip in moderate winds at this time of year,plenty of anchovie boats out there as well if you needed a tow as well

Thank you for this answer, was hoping for a comforting comment at some stage 😊
There sure is plenty of fishing boats along the way.
Steering with engines wont be the big option since one is seized and the working one has the cracked rudder behind it... troublesome combination.
But sailing is the preferred option anyways, hoping we can catch the wind before it turns....

[UpOnStands]

Good luck with the trip then.

[atoll]

Originally Posted by ProjectManaia

Thank you for this answer, was hoping for a comforting comment at some stage 😊
There sure is plenty of fishing boats along the way.
Steering with engines wont be the big option since one is seized and the working one has the cracked rudder behind it... troublesome combination.
But sailing is the preferred option anyways, hoping we can catch the wind before it turns....

yes you would definitly want to move before the monsoon turns to onshore in the next month or so.

assuming you have a working outboard on your dinghy,this could be used,with the dinghy tied outboard of the hull with the siezed engine, for getting up the river and onto the dock.

it is probably worth constructing an emergency rudder in case of loss of all steering.

this is easily done with 2 planks,a few bolts ,a board,and a tiller arm.

sandwich the rudder board and the tiller arm between the 2 planks at the correct lenth,so the board is below the surface and the tiller arm ~2ft above cross beam level when hung off the cross beam.

through bolt,then drill some holes for your lines to attach at cross beam level and at the water line level.

then lash the plank to the cross beam,mid ships so it can turn 30 deg each way.
then make a bridal by running lines from both bows under the bridge deck to the lower attachment point,as well as a line from each hull next to the cross beam.

this should support your emergency rudder and prevent it from moving side to side when in use.

use headsails only if the wind is aft of the beam,and the faster you go the better the steering board will work

[atoll]

Originally Posted by atoll

yes you would definitly want to move before the monsoon turns to onshore in the next month or so.

assuming you have a working outboard on your dinghy,this could be used,with the dinghy tied outboard of the hull with the siezed engine, for getting up the river and onto the dock.

it is probably worth constructing an emergency rudder in case of loss of all steering.

this is easily done with 2 planks,a few bolts ,a board,and a tiller arm.

sandwich the rudder board and the tiller arm between the 2 planks at the correct lenth,so the board is below the surface and the tiller arm ~2ft above cross beam level when hung off the cross beam.

through bolt,then drill some holes for your lines to attach at cross beam level and at the water line level.

then lash the plank to the cross beam,mid ships so it can turn 30 deg each way.
then make a bridal by running lines from both bows under the bridge deck to the lower attachment point,as well as a line from each hull next to the cross beam.

this should support your emergency rudder and prevent it from moving side to side when in use.

use headsails only if the wind is aft of the beam,and the faster you go the better the steering board will work

jpg of a steering oar,similar to my description