Anchor Geekdom
- Thread starter Panope
- Start date
Panope
Super Anarchist
- Thread starter
- #182
Here is the Excel undergoing my "Decreasing Scope" test.
I have already executed this test with the Manson Supreme, Spade, and Genuine Bruce. All did very well but the Manson reined supreme for this test. As you may recall from video #24, the Manson somehow held the boat at 3000 RPM with a scope of only 1.3 to 1.
The Excel takes second place. It held 2750 RPM with a scope of 1.5 to 1. The Excel got an unlucky break at the 1:35 minute mark of the test when the boat drifted about 15 or 20 degrees out of alignment with the anchor. This caused a small pivoting of the anchor that may have worked against it's final outcome.
The Bruce comes in third as it also held the boat at 1.5 to 1. (video #25) However, it got a lucky break when I cut the power just as it was releasing at 1.7 to 1 scope.
The Spade held 2500 RPM at 1.7 to 1 scope. (video #24, second half).
The reality is that there are no "losers" here. All these scopes are ridiculously short and in no way represent any sort of normal anchoring.
Steve
Video #32 Excel Reducing Scope:
I have already executed this test with the Manson Supreme, Spade, and Genuine Bruce. All did very well but the Manson reined supreme for this test. As you may recall from video #24, the Manson somehow held the boat at 3000 RPM with a scope of only 1.3 to 1.
The Excel takes second place. It held 2750 RPM with a scope of 1.5 to 1. The Excel got an unlucky break at the 1:35 minute mark of the test when the boat drifted about 15 or 20 degrees out of alignment with the anchor. This caused a small pivoting of the anchor that may have worked against it's final outcome.
The Bruce comes in third as it also held the boat at 1.5 to 1. (video #25) However, it got a lucky break when I cut the power just as it was releasing at 1.7 to 1 scope.
The Spade held 2500 RPM at 1.7 to 1 scope. (video #24, second half).
The reality is that there are no "losers" here. All these scopes are ridiculously short and in no way represent any sort of normal anchoring.
Steve
Video #32 Excel Reducing Scope:
kimbottles
Super Anarchist
Steve, I will be in Seattle Tuesday, do you want me to pick up iStream's anchor for testing?
(Then you don't have to go to Seattle, just Bainbridge.)
Kim
Max Rockatansky
holy fuckfarts!
- 3,600
- 853
for what it's worth,
I have a 45 lb Manson Supreme on a 1992 Catana 40S boat about 16,5K lb weight.
I set at 7:1 unless it's not possible to do so. 110' chain, so I'm almost always set at all chain in the shallow northern GOM anchorages with sandy-mud bottoms.
Instances:
-In a very protected area (Little Sabine, Pensacola, FL) a wind shear reversal occurred at estimated 50kt and the boat swung round hard, anchor held
-At this recent Dauphin Island race, when caught in the anchorage by the (NWS measured) 60kt downburst, set the Manson at short scope 3:1? in emergency, anchor held, in fact had to pay chain quickly to attempt to avoid another boat who had come adrift (the drifting boat had a claw anchor)
-In anchorage north side of Ship Island MS, a squall came through at estimated 50kt. The fetch was protected from waves but boat did undergo full wind force, anchor held
-Anchored at The Horseshoe, Horn Island MS, thunderstorms came through with north fetch, boat held through estimated 30-40kt gusts, 4' Mississippi Sound chop.
I'm sold on Manson Supreme.
I have a 45 lb Manson Supreme on a 1992 Catana 40S boat about 16,5K lb weight.
I set at 7:1 unless it's not possible to do so. 110' chain, so I'm almost always set at all chain in the shallow northern GOM anchorages with sandy-mud bottoms.
Instances:
-In a very protected area (Little Sabine, Pensacola, FL) a wind shear reversal occurred at estimated 50kt and the boat swung round hard, anchor held
-At this recent Dauphin Island race, when caught in the anchorage by the (NWS measured) 60kt downburst, set the Manson at short scope 3:1? in emergency, anchor held, in fact had to pay chain quickly to attempt to avoid another boat who had come adrift (the drifting boat had a claw anchor)
-In anchorage north side of Ship Island MS, a squall came through at estimated 50kt. The fetch was protected from waves but boat did undergo full wind force, anchor held
-Anchored at The Horseshoe, Horn Island MS, thunderstorms came through with north fetch, boat held through estimated 30-40kt gusts, 4' Mississippi Sound chop.
I'm sold on Manson Supreme.
Panope
Super Anarchist
- Thread starter
- #186
Istream, Last week my name was drawn in the Cruisers Forum December giveaway (sponsored by MANTUS). The prize was 1/2 off anything on their website (up to $200). A 45 lb. Galvanized Mantus should be arriving at my house any day now.
I really appreciate your offer, but with a 45 pounder on the way I think your anchor will not be needed (if I remember correctly, your Mantus is 85 lbs).
Steve
I really appreciate your offer, but with a 45 pounder on the way I think your anchor will not be needed (if I remember correctly, your Mantus is 85 lbs).
Steve
Norse Horse
Super Anarchist
DXL shank angle seems to be lower than the other angles in the last video
Norse Horse
Super Anarchist
Here is the Super Max, looks like nice sharp edges to set. http://maxmarineproducts.com/supermax-anchors/
Max Rockatansky
holy fuckfarts!
- 3,600
- 853
that supermax looks even shittier than the claw, which was (not) holding a boat which hit mine. No thanx
Panope
Super Anarchist
- Thread starter
- #192
Things are picking up in my anchor testing world:
I have recovered from a bought with pneumonia.
DDW came through and sent a very cool, digital load cell tester. Thank you. Tomorrow I will conduct a dockside, bollard pull test of Panope's pulling force in forward and reverse at various RPM.
I now own a 45 lb. Mantus anchor. The anchor arrived in a very thin package, dissembled. The workmanship of the anchor is good. This backyard engineer sees a sound structure although it is noticeably less robust than the Manson or Excel. Two of the supplied bolts were a bit too short (in my opinion) and one of the nuts was defective. A quick stop at the hardware store solved both those issues. Test coming soon. Stay tuned.
Steve
I have recovered from a bought with pneumonia.
DDW came through and sent a very cool, digital load cell tester. Thank you. Tomorrow I will conduct a dockside, bollard pull test of Panope's pulling force in forward and reverse at various RPM.
I now own a 45 lb. Mantus anchor. The anchor arrived in a very thin package, dissembled. The workmanship of the anchor is good. This backyard engineer sees a sound structure although it is noticeably less robust than the Manson or Excel. Two of the supplied bolts were a bit too short (in my opinion) and one of the nuts was defective. A quick stop at the hardware store solved both those issues. Test coming soon. Stay tuned.
Steve
IStream
Super Anarchist
- 10,730
- 2,932
Steve,
You'll find that the nooks and crannies around the bolts on the Mantus will trap mud very effectively and, once dry, it won't let go willingly without mechanical removal. It's good practice to wash it down promptly after retrieval while the mud is still wet and can be ablated. It's also tough to get the open roll bar ends clean from on deck. They can occasionally catch mud and will then trap a column of seawater below the weep holes shown in your photo. I always give the bar ends a quick look and clear them if necessary after returning from a cruise. If you're a sharpshooter with your washdown sprayer, you can hit them while the anchor dangles from your roller before fully retrieving it.
You'll find that the nooks and crannies around the bolts on the Mantus will trap mud very effectively and, once dry, it won't let go willingly without mechanical removal. It's good practice to wash it down promptly after retrieval while the mud is still wet and can be ablated. It's also tough to get the open roll bar ends clean from on deck. They can occasionally catch mud and will then trap a column of seawater below the weep holes shown in your photo. I always give the bar ends a quick look and clear them if necessary after returning from a cruise. If you're a sharpshooter with your washdown sprayer, you can hit them while the anchor dangles from your roller before fully retrieving it.
Panope
Super Anarchist
- Thread starter
- #195
Engine thrust tested.
Panope has a Yanmar 3JH3E, 40 HP engine. The propeller is a fixed, 18 inch diameter X 10.5 inch pitch. The gear reduction box has a ratio of 2.61 in forward gear and a ratio of 3.16 in reverse.
The boat makes 3 times more thrust in forward as it does in reverse at the same ENGINE rpm. I believe that much of this discrepancy is due to the propeller being much less efficient in reverse. Another factor is the higher gear reduction ratio of the reverse gear compared to forward.
Here is a table showing the results:
And here is the video:
https://www.youtube.com/watch?v=kb0OZNyGjMg&feature=youtu.be
Panope has a Yanmar 3JH3E, 40 HP engine. The propeller is a fixed, 18 inch diameter X 10.5 inch pitch. The gear reduction box has a ratio of 2.61 in forward gear and a ratio of 3.16 in reverse.
The boat makes 3 times more thrust in forward as it does in reverse at the same ENGINE rpm. I believe that much of this discrepancy is due to the propeller being much less efficient in reverse. Another factor is the higher gear reduction ratio of the reverse gear compared to forward.
Here is a table showing the results:
And here is the video:
https://www.youtube.com/watch?v=kb0OZNyGjMg&feature=youtu.be
Norse Horse
Super Anarchist
Wonder why it spiked at 910 with full throttle, the largest increase in the H.P. range ? That's the start of a good rooster tail you got going astern there.
IStream
Super Anarchist
- 10,730
- 2,932
Steve,
I wonder if the stretch in the line between the boat and the load cell affected the accuracy of the measurements, particularly at high RPM. Also, not that it matters for the purposes of anchor testing, but have you checked the accuracy of your tach? I have a 4JH3 with the same panel and have found that my tach reads high, especially at higher RPM. I have a handheld reflective tachometer you're welcome to borrow if you wish.
I wonder if the stretch in the line between the boat and the load cell affected the accuracy of the measurements, particularly at high RPM. Also, not that it matters for the purposes of anchor testing, but have you checked the accuracy of your tach? I have a 4JH3 with the same panel and have found that my tach reads high, especially at higher RPM. I have a handheld reflective tachometer you're welcome to borrow if you wish.
Alex W
Super Anarchist
Glad to hear that you are feeling better!
This test has forward and reverse bollard pull tests of a lot of props, including a standard 3 blade prop that should be similar to yours:
http://flexofold.com/upload_dir/docs/Test_YachtingMonthly_low.pdf
They only show about a 40% decrease in reverse compared to forward (265kg vs 163kg), where you are seeing a 67% decrease. I wonder what accounts for such variability? Their boat is obviously very different (it is a fin+spade modern cruiser).
They are using a smaller Yanmar engine, but with the same gearbox as yours.
This test has forward and reverse bollard pull tests of a lot of props, including a standard 3 blade prop that should be similar to yours:
http://flexofold.com/upload_dir/docs/Test_YachtingMonthly_low.pdf
They only show about a 40% decrease in reverse compared to forward (265kg vs 163kg), where you are seeing a 67% decrease. I wonder what accounts for such variability? Their boat is obviously very different (it is a fin+spade modern cruiser).
They are using a smaller Yanmar engine, but with the same gearbox as yours.
Panope
Super Anarchist
- Thread starter
- #199
Norse, I skipped the 3250 rpm reading and went strait to max power. It was a remarkable amount of water movement.Wonder why it spiked at 910 with full throttle, the largest increase in the H.P. range ? That's the start of a good rooster tail you got going astern there.
Note: When this boat is free to move through the water (not tied to a dock), the engine will turn 3800 rpm.
Steve
Panope
Super Anarchist
- Thread starter
- #200
IStream Line stretch should not affect the results except to dampen "surges". I did my best to record the "average" of this variable.
I have not tested my tach. Thanks for the offer but I think I can borrow a handheld tach locally. I'll post results when available.
Steve