We’ve now heard from Circa and Avatar‘s owners about the newly installed get-home system. The news is good.
Get-home systems which only work in light winds and smooth water are a negative in our opinion, as they increase drag and complexity without any real benefits. Afterall, if the winds are light you can use the dinghy as a tug, or anchor and fix your problem. So we are happy to report that the get-home system on Avatar looks like it will give a long distance cruising speed of 7.5 knots, with moderate RPM and sound levels. And while the system has only been tested in 20/25 knots of breeze, it appears as if good progress into wind and sea can be made up through 30 knots or more.
Maneuvering at slow speed on the main engine has been reported as minimally impacted, except for in reverse where the tendency to pull to starboard has almost totally been eliminated.
The track in the photo above shows an offshore turn in both directions. Turning to starboard, where the get-home prop is on the outside of the turn, is the tighter of the two. Maneuvering in port under get-home is not as crisp as with main engine, but certainly acceptable.
Finally, performance under power with the main engine does not appear noticeably degraded. Avatar has had a stern extension added, and her gain from this has more than offset the loss from the second prop skeg drag.
Circa did a nice job on the installation, with minimal impact on access to the other systems.
We are impressed with how well this turned out, as retrofits are never easy. Thanks are due to Carol Parker for sharing her photos with us.
Posted by Steve Dashew (April 18, 2012)
April 23rd, 2012 at 7:47 am
Instillation looks clean and neat but what impact does using a different manufacturer for the get home engine than the main propulsion engine have on requirement for spare parts and tools for potential repairs and routine maint.?
April 23rd, 2012 at 12:19 pm
For the HP range we are targeting there is no real option, other than the Yanmar. As a back up engine, the spares inventory would be very limited.
February 6th, 2015 at 2:36 am
Any comment on fuel burn of the get home system? What I am after is if Murphy hits the worst time, midway crossing the ocean, will switching to gethome affect your range calculations/reserve fuel amount?
February 7th, 2015 at 9:27 am
We have not done a calculation based on the get home but the prop efficiency is lower and you have the added drag of the main prop. But slowing down from 230 miles day to 175 would go a long way toward offsetting these losses.
February 8th, 2015 at 11:53 am
Steve, so you think by slowing down enough you could offset the range penalty from lower efficiency of the wing engine? So by doing so you could keep to your original plan, rangewise if not timewise?
February 8th, 2015 at 11:25 pm
Yes, Andy,that is roughly the theory. However, you might want to alter course to a closer destination and deal with the problem to the main drive line.