Designing a new tabernacle
At the end of last season we thought we should take the mast down and check all the fixtures, fittings and rope work, to our surprise as we raised the mast the tabernacle (mast support) fell apart. We have had a lucky escape, had this happened while at sea, who knows what might have happened.
The photos show the splits that developed and it is clear that this happened for two reasons:
- The tabernacle was made in Aluminium to match the mast foot, however we had plate of Stainless Steel on the roof to spread the load and believe this has attributed to oxidisation and galvanic corrosion due to dissimilar metals
- The tabernacle was machined from solid and as you are probably aware this material does not bend freely. When the foot of the mast is in place the bolts that secure the two parts together have been over tightened and bending the Aluminium and encouraging the fractures at these week points where the screws go through
We have designed a new Stainless steel tabernacle for Vandini this has a slightly larger base plate to spread the load on the coach roof, and have added angle plates to anchor the pulleys with a view to bring all our control lines from the mast aft to the cockpit, this we plagerised from Don’s boat Malibu who already has a similar mechanism.
Opposite is the intended design I have created on our works software design package to pass to the metal fabricators. When this has been made and installed I will include another photo of the finished product.
Doug Baynton, Commodore