Sea Sled Performance: Qualitative Analysis

I was referring to the difficulties of getting relevant numbers related to the movements of the hull. First you have to collect mainly accelerometer (and if possible gyro) data from 3 directions, then comes the analyzing. Today every smartphone has an impressive set of sensors for all kinds of physical signals, but it takes an additional app to make the info available to the carrier.

My absolute favourite toy now is an app from the Aachen uni, called "phyphox" (free and no ads, thanks guys!!). It makes all this info accessible and open for analysis. I recently initiated a "crowd data collection" pilot project; I asked friends and neighbours to use the app to collect acceleration data when they take the family's small boat to the mainland in various conditions (run the app for a representative part of the trip while you put it flat on your seat). This is now accumulating to a data-bank of useful info for further hull development. Looking forward to add the info from m/v "Serenity" to it.....

 

Walabot is another one John may find interesting for the bread work.

phyphox sounds interesting, but how it would be useful without loads, winds, currents is above my paygrade...plan to read up

 

Air lubrication: Only big bubbles do the trick https://www.sciencedaily.com/releases/2016/09/160902125334.htm


Food for thought

 

And an early thread discussion. With numbers.

Monohedron vs. Warped bottom https://www.boatdesign.net/threads/monohedron-vs-warped-bottom.1642/

 

Lots of info on this one:
1925 Hickman Sea Sled Sedan https://bringatrailer.com/listing/1925-hickman-sea-sled-sedan/

 

Hang on now! I just reread @baeckmo 's comment about the tank testing being done with the model in a slight bow-down trim. Had they ever seen a planing boat before? Imagine dragging a deep-V monohedron through the water with a few degrees negative trim. Imagine what the performance numbers would look like. If there's any planing form at all that would perform well with negative trim, I've yet to hear of it.

 

Naaah, that refers to the static trim. The models are free to trim, towing force is applied along the prop shaft direction. This test mimics the hull response to varying longitudinal loading conditions, and is a standard procedure. Look at the graphs, there you can see the plot of trim versus Fn; reread......!

 

The old neck-top computer's calculations often are the best arbiter of ride quality, however occasionally you will find people who insist their terrible boat rides OK, but that could be an internal software problem in their neck-top.

 

Very amusing @Mr Efficiency

 

GM recently bought into Pure Watercraft Boats to pursue electric propulsion.
They put one in a 90 year old Sea Sled!
Imbedded video.
https://www.cnbc.com/2021/11/22/gm-takes-a-stake-in-electric-boating-start-up-pure-watercraft.html
This one shows more planing but just near the beginning:

 

Holy cow! That's pretty cool. I'm trying to see what I can learn from the wake.

 

That sea sled video is very impressive, and the intentions of GM are very honourable.
They note in the video that cars have catalytic converters, but no outboard motors do - I guess because they are too big?
I am wondering what is going to happen at 'crunch time', to all these big centre console fishing boats with 2, 3 or even 4 huge outboards on the transom - what does their future look like?
All of the big manufacturers are building them, and they must be selling well - even at around US$ 500,000 - 1 million.
But they are going to become very tame if they have to have electric motors.
Or will this type of craft simply fade away?

 

Good question. I don't know that there will be a crunch time. Only rich people have those boats, and rich people don't pay for things, that's what poor people are for.

 

The sea sled is actually the perfect boat for this. There's no planing resistance hump to speak of, so if the boat is underpowered, it still can make some reasonable speed. If they'd used a typical deep v monohedron, it might not have been able to plane, and that would look bad.

 

The video is crap, but the Sea Sled footage is interesting.

Hey, congratulations to you Barbados Boy!
Independence is going to look good on you.

BB