Traditional Steam Launch Propeller

[PeteThePen1]

Dear Steamboating Friends

I have become involved in a discussion about 'weed free' propellers for steam launches. I am not sure if weed clogging is an issue for folk in other countries, but here in the UK it can be a major issue.
Our discussion has led us to the thought that Victorian engineers put a great deal of effort and thought into their products and it could well be that the traditional 'slim' propeller already has the weed beating characteristics we want.

When I had Frances Ann I never found weed to be a problem. I had a Beckmann Boatshop 18" X 28" traditional prop on Frances Ann and got as far as making a tracing of one of the blades, but never got around to doing other measurements before she had to be sold. The tracing shows that the blade is not actually that slim but only appears so because of the twist. I know that many of you have either the Beckmann version or perhaps original Victorian versions so I was wondering if anybody has done detailed measurements? Of course the ideal would be a 3D laser scan renderd as a STEP file or similar which would allow very detailed examination of the prop's parameters. Having worked hard (obsessively according to the family) to update my 3D drawing skills this winter I am now getting to understand how useful such skills could be especially in this discussion.

Hope those of you in the Northern Hemisphere are coping with the extreme wintry conditions we seem to be having this year.

Regards

Pete

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Frances Ann.jpg (175.32 KiB) Viewed 7677 times

[Kelly Anderson]

All I have to offer are my anecdotal observations, and one weed beating hack.

On my first boat Reciproca, the propellor swung in open water behind the rudders, and without any structures nearby to offer resistance, her prop was a magnet for every weed in the neighborhood. I was impressed to learn that the load on the engine stayed exactly the same from swinging a ball of weeds as it was driving the boat forward. In weed infested waters, the engine RPM remained exactly the same as the boat slowed more and more to a complete stop. Repeated reversing of the engine had little effect in ejecting the weeds, again I believe that was due to the lack of stationary structures near the prop to add resistance to the weed ball's rotation. I would have to lie prone on the rear deck, and pull the weeds off by hand, often dealing with a ball the diameter of the prop.

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My current boat Vividus, is of conventional design, similar to your photos, and has an Elliott Bay propeller. From the start, she has had much less trouble from weeds, and ejecting them by going full astern is pretty effective. I believe that this is due to the dead wood, skeg, and rudder, all of which provide resistance to hitchhiking weeds freely rotating with the propeller.

The final few weeds that she would be stuck with are effectively dealt with be a hack I learned from Mike Condax. By adding a double edged weed cutter to the stern bearing housing, which takes care of any weeds trying to wrap around the shaft, I virtually never see a weed on my propellor anymore. The source for my blade? An old steak knife.

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[RNoe]

Kelly:
I like that weed-cutting solution! Simplicity at work.
I am now inspired to add a similar weed cutter to my boats' prop.
Thanks for sharing.
RussN

[Lopez Mike]

My present 'elephant ear" prop is also a magnet for weeds. On my previous hull I was able (after shutting down the throttle and steam valves as well as opening the condensate drains!!!) to reach the prop by hand and with the aid of an old butcher knife, clear the mess.

My new hull places the prop further under the fan tail and I have been working on weed removers of various degrees of dreadfulness. Dangerous to even have in the boat.

I just bought a traditional low blade area prop and it has a fair amount of sweep on each blade. Maybe this will make it a bit more self cleaning. Hope springs eternal!

Mike

[barts]

Otter's prop can usually be cleared by reversing... I did have to go overboard in Clear Lake, CA in the early 90s to clear the propeller from a giant ball of hydrilla - a really invasive weed.
I've only had Rainbow in the water back in 2017 (before moving, pandemic, etc), but the only thing that gave the prop trouble was reinforced crab pot lines which were basically cut-proof. Combine small floats and choppy water, and crab pots can be hard to spot, esp. sitting in the stern. Being a double ender, Rainbow's prop is can be seen from the boat, at least.

[Lopez Mike]

My most effective tool for weeds has been an ordinary linolium knife attached to a suitable handle. Perhaps a meter or so of plastic pipe.

https://www.ebay.com/itm/256256231621?c ... gIIcfD_BwE

Keeping it very sharp is a good thing.

As to crab pots, If they have no identifying numbers or names, I try to find time to pull them up. I either remove the trap door or cut a hole in them for the animals to escape and cut the line. Problem solved.

The whole subject is quite out of control in my area. Traps are set in narrow channels and, all too often, abandoned. They continue to trap hapless creatures indefinitely.

It is just a matter of time before some boater is disabled on a lee shore. Then the lawyers will get rich.

Mike

[barts]

My most effective tool for weeds has been an ordinary linolium knife attached to a suitable handle. Perhaps a meter or so of plastic pipe.

Pole arms for steamboats! I'd need one a bit longer to reach the prop, perhaps with a wood (enough to float) handle and serrated stainless blade...
Maybe one of these, plastic removed, riveted onto an ash handle w/ ferrules. Sheath would still work for safe storage in the lazarrette.

https://www.homedepot.com/p/Milwaukee-1 ... 90#overlay

[Lopez Mike]

Yeow! What a toad sticker. I guess one would be prepared for pirates as well as weeds.

Mike

[TahoeSteam]

On the Sandin we used to have to pull weeds off the prop every time we left the dock. Eurasian milfoil was the bane of our existence. We used one of these 3-tined gardening tools to rip and pull the stuff off the prop.

https://www.homedepot.com/p/DeWit-52-in ... /324255240

[Peter H]

I also bought one of those 3 tined tools but got a plastic one to lessin the damage to the hull.