Propeller saga ends at last
08 December 2021
• Hayling Island
by Martin Whitfield
Sorry for the slight gap in transmission, but I was waiting for discussions on the propeller's blade coming off to conclude before the next update.
Well, now all has been resolved and I have had the maintenance charge refunded for the overhaul of the propeller during the big refit in the winter of 2019-20.
Although it is impossible to find out exactly what went wrong, there are a few indications of what have been the cause. Firstly, from the first use of the serviced propeller there was a very distinct "clunk" each time gear was engaged (forward or reverse). The engineer who installed the engine and drive (a very experienced Beta engine dealer) thought this might have been the new SigmaDrive coupling, of which he had limited knowledge. I thought it might "bed in" through use, but it didn't. There was also significant noise from the transmission - more so than when the same propeller was fitted to the old Bukh 36.
Since the failed propeller has been replaced, both these issues have disappeared. There is no "clunk" when gear is engaged and the running is altogether smoother and quieter. Presumably, this is how they should be with a SigmaDrive.
I am sure that this is not a general issue with the Autoprop as the system on Topaz Rival was better before the new engine (Beta 35) and serviced propeller were installed. It is always very difficult to be definitive on exactly where mechanical noises come from on boats, but all I know is that they are now significantly reduced.
Given the above and the fact that eventually a blade fell off the propeller after less than two seasons' use would lead me to suggest that something was not quite right in the factory rebuild.
Not surprisingly, Bruntons have not been willing to point to a cause directly, but have been helpful in trying to resolve the issue. I was offered a much reduced (nearly half-price) replacement, but there did not seem much point in having a very expensive propeller sitting in a locker unused. So we have finally agreed on the service refund which I think is an acceptable compromise for all the hassle but realising that we are talking about a 22-year-old propeller (purchased in 1999).
It was not possible to test the new Darglow Featherstream (in the picture) on the short journey from Lymington to Hayling Island. So I am looking forward to the new season to see if it has a positive effect on going in reverse (ie in anything like a predictable direction). Let's hope so!
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