Originally Posted by goboatingnow
Ferro = bluewater you're having a laugh mate. The impact resistance of ferro is appalling. Dave.
No mate, it's theory vs. observation. I know about the impact resistance figures and they don't look good. That's the theory. But I've also seen the damage caused to a ferro vessel by hammering against rocks over a four day blow. That's the observation.
The entire starboard bow section was severely damaged but the boat did not sink. Anything other than metal or ferro-cement would have been holed and gone to the bottom in the first few hours or quicker.
The secret for its survival was the way it was holed and the way it leaked - and that is why I said "and maybe ferro".
What happened is that the impact crushed the hull
as the theory predicted but it didn't create a big clean hole for the water
to rush in. Instead, all the cement compound bits and pieces were largely contained within the ferro structure, and the water
seeped in rather than rushed in.
And the inflow was therefore easily kept up with by the bilge
pumps. Further, because the inflow was moderated, the crew managed to stuff the wound with towels and other objects such that the inflow was virtually abated.
When conditions eased, they were able to motor
off the rocks and to the yard, where the repairs
were made. I observed these repairs
and have posted about them elsewhere on this forum. I was amazed by the simplicity and cheapness with which the repairs were made, and it was then that I first considered getting a ferro myself.
Another tale of interest... I spoke to a fellow club member
just yesterday as it happens who once owned a sistership to mine, and he told of how he picked it up for a mere $14K. It had shortly prior been sold
in Adelaide to a Sydneysider for $85K and a delivery skipper
was taking it around the coast.
Seems he anchored inadvisedly outside Port Phillip Bay and went aground on rocks. Same story - it remained afloat with the same sort of seepage wound.
company wrote it off and the $14K bid won it for this bloke. He simply patched it with a beach sand mix, then set sail into Melbourne to fix it properly. The ferro parts
looked brand new, like it was stainless, and only needed straightening. Simple, cheap
and logical and it wasn't long before he again had an $85K boat.
For a great boatbuilding material, it's had some terrible press. And the desk engineers with their 'impact resistance' figures don't help; like the weatherman, they should try looking out the window.