Thailand longtail type propulsion pro/con?

[black_sails]

Originally Posted by Alan Mighty

Sounds in part like the not-fully realised dreams of:

Well.. the boats ARE fast and work just fine in thailand. The paper was to figure out why they seemed to work so well under varying conditions there, racing or slower speed fishing.

[SailingHarmonie]

Originally Posted by black_sails

Well.. the boats ARE fast and work just fine in thailand. The paper was to figure out why they seemed to work so well under varying conditions there, racing or slower speed fishing.

If you want to fish by trolling (which is usually what "slow speed fishing" means) a long tail would be the WORST possible choice. It would be the perfect way to go chopping off lines and hooked fish. You can't leave the helm in gear for a SECOND to tend lines or deal with a hooked fish.

But... whatever you think best.

And of course longtails can race each other. That would be fun. But do you really think they can compete in a drag race with a similar HP outboard? At a fraction of the weight? But they can be cobbled together cheap, so if cheap is your priority, have at it.

If you really think that a long tail is the best choice for a recreational CRUISING boat, you are (with all due respect) nuts. There is no way to rig an autopilot, you have to have an experienced person at the helm every second the boat is underway, and in any kind of sea state they get to be a real issue. If you want to race across a calm estuary for an hour (which is how they are used in Thailand, BTW), then fine, but that's not cruising.

Have you ACTUALLY driven one? They can be damn exhausting. Very loud and heavy vibration on the tiller, with no way to take a break for a piss. Driving them is a bit of a skill. You can not hand the tiller to a guest along for the ride and say, "GO that way."

All drives are compromises, longtails can be cheap. That's a plus. There are lots of better ways to do all of the other things that you think they are good at.

Maybe you came here expecting everybody to tell you what a great idea they are...

But, it's your money.

[skipperpete]

I repowered a 40’ long Australian yacht that had a long tail with a 30 hp Diesel engine. The original perkins 4-108 drank raw water in Indonesia and the long tail was apparently the only option at the time. It wasn’t a steerable longtail but it pivoted in the vertical plane and had guy wires to keep it centered the owner liked it so much he did 2 trips to Bali from Singapore and finally up the straits of Malacca for his shiny new Yanmar to be installed.
There’s some peculiar ( to me) increase in efficiency with surface piercing propellers but it only seems to work well with high speed vessels like fast patrol boats...... and Thai cargo and racing boats[emoji848]

[valhalla360]

Ironically, just got back from the Floating Market in Bangkok a 1/2 hr ago.

The big ones aren't really suitable to displacement cruising boats. A 200hp automotive engine is overkill to reach displacement speeds...and they are crazy noisy.

They use them out on rough water so the angle isn't that big of a deal.

Probably the biggest issue is they are a workout to operate. It's a full body exercise to turn a 300lb V6 with a 15ft drive leg.

For smaller boats, they do use what appear to be air cooled lawnmower versions. If you spend a lot of time in really shallow water, a small one on the dingy could be an option.

[s/v Jedi]

Better yet, when you swing the prop out above, you get vertical takeoff as well, great for close quarters work

[mako]

I like it for when the pirates in the Strait of Malacca come after you. I can see fingers and heads getting chopped off. Even in the marina. Wonder what one would do when you accidentally swing it onto a nice Zodiac. Yep, far superior to a boring outboard.

[MicHughV]

here you go..

https://www.wildfowlmag.com/editoria...g-boats/280865

[Baronkrak]

Precursor?

https://www.youtube.com/watch?v=d0X6L9L8cC8

[capn_billl]

There are a couple of reasons Longtails are popular in Southeast Asia, and the same reasons they are popular no where else.

Shallow draft.

Highly maneuverable,

Cheap where things like a gear train, or packing glands are prohibitively expansive.

And attach easily to the canoe stern pangas that are the popular boat design.

Why they aren't popular in the rest of the world.

Large dangerous prop in densely populated marinas.

Heavy engine, and long prop shaft is difficult to steer or to go straight.

Unnecessary when lower outdrives, or I/O drives are available, and an outboard is cheaply available in every size from 2 HP, to 2000HP.

With fiberglass boats transoms are a thing.

Even an inboard with a rudder is steerable enough.

Longtails were a solution to a part of the world that was rowing, or sculling just before engine technology was brought to their part of the world.

The long tail became culture, and tradition nearly a century after the rest of the world moved on.

[SailingHarmonie]

Years ago I captained a charter in Thailand through the Moorings. We had a problem with our dinghy outboard. If I remember correctly the carb float got stuck, and flooded the engine. With the rudimentary tool kit they give you, I took it apart and fixed it.

At the end of the week, I was doing the end of charter debrief with the site manager, and explained to him what had happened, and he might want to have his mechanics keep an eye on it. He offered me a job on the spot. "Nobody here knows ANYTHING about outboards!"

[black_sails]

Originally Posted by SailingHarmonie

If you want to fish by trolling (which is usually what "slow speed fishing" means) a long tail would be the WORST possible choice. It would be the perfect way to go chopping off lines and

Perhaps I misspoke. They use them as a low cost propulsion method to get to fishing areas, do their fishing, then go home. They just dont stick huge engines on those. The thai people even use their boat design and longtails on the ocean a bit at least to from Koh Chang to Koh Mak and Koh Kood, and those boats will be built with higher side walls and such for the waves. Apparently the propulsion method still works fine cuz they use it even there. But I haven't interviewed someone doing those routes.

Originally Posted by SailingHarmonie

And of course longtails can race each other. That would be fun. But do you really think they can compete in a drag race with a similar HP outboard? At a fraction of the weight?

Dunno, if I build one and have similar engine HP and boat weight do you want to put some cash on the table to see? I'd just think it would be physics and i'm not sure the longtail propulsion systems weigh radically more than an outboard for the power (especially modified like those putting out 500hp) and i'm not sure the props esp in semi-cavitating mode are any less efficient than what outboards would be running in the 40-70 knot or higher range. Some of those videos look definitely faster than 70 knots.



The boats themself when running higher power are a combination of a light wood and a fiberglass. The power to weight ratio seems to make them mindbendingly fast - watch the videos of the truly fast ones. I'm sure you could build lighter out of carbon fiber at 10x the cost just like an outboard with 500hp would have 10x the cost.


I just find them FASCINATING for how much they do at what cost, for a DIY homebrew solution in a country without a lot of money. I think the implied question of 'how cheap' is the wrong attitude, my question will always be what is my budget and how much boat and propulsion can I get for that money? $15,000 USD sounds like it'll get you a 28 foot longtail boat with over 300hp. I'll happily race that boat against whatever you can pick up for $15,000 and we'll race for pinks. :P

Originally Posted by SailingHarmonie

Maybe you came here expecting everybody to tell you what a great idea they are...

But, it's your money.

Not really, I expected to hear the pros and cons from people with more boating experience than me. I expect to have OR BUILD a boat in the next 7 years future in the under $50k range with propulsion and I want to have as much boat as I can for the money. Probably a catamaran built myself out of wood. (not a longtail) Even with an outboard i'd be expecting to be 100% in control of the boat at all times - I didn't suggest this was my long range passagemaking cross-ocean solution. It's something i'd like to use for fishing, and fun, if I just wanted slow i'd be a pontoon boat but i'd like to build long slender wave piercing hulls and actually get some speed out of it - maybe 25-35 knots. I'm gazing at longtail propulsion because we've got lots of shallow areas in the lakes, lots of weeded areas that foul up propellers, and minnesota lakes are generally much more calm than big waves. Though taking the boat on the great lakes in calmer weather would be kind of interesting.


I value EVERYONES experience and insight because I DONT HAVE MUCH YET and i'm wanting to build this smaller cheaper project, before I do anything fancier, bigger, or more expensive. I need this cheaper catamaran to get more time in the wheelhouse before I ever consider building a bigger project.


And I wouldn't rule out a longtail type propulsion on a bigger project - it's just that I can't know until I know from experience what the ups and downs of this design will be. I know I don't want to spend $15k on just a 125-150hp outboard for a ~30 to 35 foot catamaran i'd like to build, and i'm not sure how much power i'll need but I know how sluggish the 40hp I had in a small fishing boat was. So yeah, the design has me all curious!

[SailingHarmonie]

Originally Posted by black_sails

Perhaps I misspoke. They use them as a low cost propulsion method to get to fishing areas, do their fishing, then go home. They just dont stick huge engines on those. The thai people even use their boat design and longtails on the ocean a bit at least to from Koh Chang to Koh Mak and Koh Kood, and those boats will be built with higher side walls and such for the waves. Apparently the propulsion method still works fine cuz they use it even there. But I haven't interviewed someone doing those routes.





Dunno, if I build one and have similar engine HP and boat weight do you want to put some cash on the table to see? I'd just think it would be physics and i'm not sure the longtail propulsion systems weigh radically more than an outboard for the power (especially modified like those putting out 500hp) and i'm not sure the props esp in semi-cavitating mode are any less efficient than what outboards would be running in the 40-70 knot or higher range. Some of those videos look definitely faster than 70 knots.



The boats themself when running higher power are a combination of a light wood and a fiberglass. The power to weight ratio seems to make them mindbendingly fast - watch the videos of the truly fast ones. I'm sure you could build lighter out of carbon fiber at 10x the cost just like an outboard with 500hp would have 10x the cost.


I just find them FASCINATING for how much they do at what cost, for a DIY homebrew solution in a country without a lot of money. I think the implied question of 'how cheap' is the wrong attitude, my question will always be what is my budget and how much boat and propulsion can I get for that money? $15,000 USD sounds like it'll get you a 28 foot longtail boat with over 300hp. I'll happily race that boat against whatever you can pick up for $15,000 and we'll race for pinks. :P







Not really, I expected to hear the pros and cons from people with more boating experience than me. I expect to have OR BUILD a boat in the next 7 years future in the under $50k range with propulsion and I want to have as much boat as I can for the money. Probably a catamaran built myself out of wood. (not a longtail) Even with an outboard i'd be expecting to be 100% in control of the boat at all times - I didn't suggest this was my long range passagemaking cross-ocean solution. It's something i'd like to use for fishing, and fun, if I just wanted slow i'd be a pontoon boat but i'd like to build long slender wave piercing hulls and actually get some speed out of it - maybe 25-35 knots. I'm gazing at longtail propulsion because we've got lots of shallow areas in the lakes, lots of weeded areas that foul up propellers, and minnesota lakes are generally much more calm than big waves. Though taking the boat on the great lakes in calmer weather would be kind of interesting.


I value EVERYONES experience and insight because I DONT HAVE MUCH YET and i'm wanting to build this smaller cheaper project, before I do anything fancier, bigger, or more expensive. I need this cheaper catamaran to get more time in the wheelhouse before I ever consider building a bigger project.


And I wouldn't rule out a longtail type propulsion on a bigger project - it's just that I can't know until I know from experience what the ups and downs of this design will be. I know I don't want to spend $15k on just a 125-150hp outboard for a ~30 to 35 foot catamaran i'd like to build, and i'm not sure how much power i'll need but I know how sluggish the 40hp I had in a small fishing boat was. So yeah, the design has me all curious!

You have decided. You want one. SO do it. What anybody else says does not matter. What do you want from here?

[StuM]

Originally Posted by black_sails

i'm far more considering these for where room and space is not an issue like in a large lake or the ocean. Where the outboards of equivalent power cost 10x as much. I'm wondering if there's downsides I don't know about in that use practically, or if it's more "people just think its ugly" which is often a way of saying unfamiliar.

With the prop so far astern, it's going to be spending a lot of time either buried deep or out of the water in any sort of real waves.

Fine for inland waterways, but offshore?

[Alan Mighty]

Originally Posted by capn_billl

Longtails were a solution to a part of the world that was rowing, or sculling just before engine technology was brought to their part of the world.

So true!

Levavasseur in France was probably the first company that built a longtail. That was right at the start of the 20th century (around 1905-06). The Levavasseur-designed vessel, called Antoinette, was one of the first gasoline-engine powered planing hulls. Antoinette was a short stubby hull with an inboard 50 hp petrol engine. A very long prop shaft. Prop shafts those days had to be supported, so Antoinette had a hinged aft appendage with a bushing, just before the prop, which supported the shaft. See attached clip from Scientific American of 1907.

Before the internal combustion engine, a few attempts were made at small steam engines for small boats, all to avoid rowing or sculling.

Silas Harthan (1838-1919) was one of two or three people who came up with what could be called outboard-mounted (and hence detachable from the boat) steam engines. We know Harthan's design well because it's covered by a US patent: US 366662 (filed 1886, granted 1887). See attached Harthan graphic.

American Motor Company apparently manufactured a gasoline-fuelled outboard, with a variable pitch propeller, in 1896. Several were made and sold. No evidence of a patent application. Perhaps because it was seen not as an invention but as a simple modification of Harthan's design.

Cameron Waterman's Porto, mating a gasoline-fuelled motorcycle engine to a prop always gets a mention because in the subsequent advertising and marketing, Waterman (1878-1955) used the terms "outboard" and "outboard motor". See the attached graphic from Waterman's US patent (US851389; filed 1905, granted 1907). Waterman manufactured and sold Waterman Portos for a decade or more. Portos were the leading outboard (detachable engine-prop combination) until just before WW1.

Ole Evinrude's spouse, Bess Cary, was perhaps the next significant person to pick up Capn_Billl's point. Cary wrote the advertising copy for Evinrude and her adverts read: "Don't row! Throw the oars away! Use an Evinrude motor!". Ole Evinrude's story and design are reasonably well known, so I'll only touch on a few points: Evinrude (1866-1934) started working with internal combustion engines in 1905, focusing on replacing dinkum horse power (Ole was the son of a farmer). He and a partner successfully designed a small petrol engine, with the US govt as one of the principal buyers of the donk. The partnership ended and Ole Evinrude and his bookkeeper (Bess Cary) spent most of 1909 trying to work out how to avoid rowing by adding a prop to his petrol engine. His 11th attempt passed the critical eye of Cary, leading to US patent 1,001,260 (filed 1910, granted 1911). See the attached Evinrude graphic. Evinrude established a partnership in 1911 with Chris Meyer. Ole sold his half of Evinrude Motor Company to Meyer in 1914. EMC merged with others to become Outboard Motor Company (OMC) about 1929.

As for longtails, I'll mention two applications.

1. We were cruising Indonesia and after being battered by a nasty squall or three, we chose a uninhabited bay on a small island (and largely uninhabited island) to anchor and rest. On the second or third day, a vessel about the size of our dinghy showed up, run by an Indonesian maritime official. He checked our papers and asked if we wouldn't mind moving and anchoring off his office, in one of the only two kampung on the island, just so he could keep his eye on us.

What powered his vessel? The equivalent of a petrol-fuelled brushcutter, with a two-blade prop. Easier (and lighter) to detach and remount than my outboard.

2. In the marina that's been our home base for a decade or more now, there's a Catalina owned by an engineer. He took a electric-powered brushcutter with a prop, connected to ship's DC power, and built a mount for it. Mounted almost vertically at the transom in use, but easily swung out of the way or detached to be used at the bow. It's use: it's a detachable stern thruster (or a bow thruster). Takes all the fuss out of docking/undocking (singlehanded when mounted at the stern). Why aren't there more of them?

[valhalla360]

Originally Posted by StuM

With the prop so far astern, it's going to be spending a lot of time either buried deep or out of the water in any sort of real waves.

Fine for inland waterways, but offshore?

The whole drivetrain pivots, so the only time it's out of the water is if the helmsman lifts the prop out.

Likewise, no reason for it to be particularly deep.