Why not bimaran paddle wheeler warships?

[Avimimus]

Paddle-wheels were of limited utility for warships due to vulnerability to enemy fire and taking space from the broadside...

So, in the brief period before screw propulsion becoming dominant why not use a bimarana and simply put the paddles in the centre?

 

[Fluff]

as a warship you want your boilers protected, if your paddle wheel is in the middle, then your engines are on the outside, not a good place, one minor hit and you are literally 'dead in the water'

Likewise you haven't gained space for broadside, as the engines are in the way.

Also I would think paddlewheels were pretty resilient to damage, in terms of losing total efficiency.

That's that sorted....

 

[drejr]

Fulton's Demologos fit this description, and the later Cairo-class ironclads had central paddle wheels. The drawbacks were low speed and steering problems.

More conventional paddle wheelers had a number of virtues - they were fast for the time and had low drafts and convenient places to store large boats.

 

[Tony Williams]

With any twin-hulled ship, the stresses caused by waves can be considerable. Every time the vessel encounters a wave, one hull goes up while the other goes down, subjecting the connecting bridge deck to twisting stresses. These get stronger as the hulls get bigger, and mean that the bridge deck must be very strongly built, or very deep as shown below. This is also not a good configuration for engine location - the hulls are slender.

 

[Apophenia]

Stretching a point, the USS Wolverine (IX-64) and USS Sable (IX-81) training aircraft carriers were both conversions of sidewheel paddle steamers

 

[Yellow Palace]

With any twin-hulled ship, the stresses caused by waves can be considerable. Every time the vessel encounters a wave, one hull goes up while the other goes down, subjecting the connecting bridge deck to twisting stresses. These get stronger as the hulls get bigger, and mean that the bridge deck must be very strongly built, or very deep as shown below. This is also not a good configuration for engine location - the hulls are slender.

Catamaran paddle-steamers use a very different interpretation of the catamaran concept. The hulls are much broader and bluffer than modern high-speed vessels, giving ample space for machinery, and the 'tunnel' is much narrower. Unfortunately the result is a hydrodynamic nightmare - it's been tried, and doesn't work well at all.

 

[DWG]

And paddlewheelers were predominantly riverboats, so most never faced fully developed waves.

 

[Moose]

And paddlewheelers were predominantly riverboats, so most never faced fully developed waves.

Substantial numbers of ocean-going paddlewheel ships were produced in the 19th century, many of those faced heavy sea states. Check out the story of the Great Eastern sometime. Wheels are not a great method of propulsion, but in the early days of steam they had their uses.

 

[DWG]

And paddlewheelers were predominantly riverboats, so most never faced fully developed waves.

Substantial numbers of ocean-going paddlewheel ships were produced in the 19th century, many of those faced heavy sea states. Check out the story of the Great Eastern sometime. Wheels are not a great method of propulsion, but in the early days of steam they had their uses.

Oh, I know the history, but the enduring use of paddlesteamers was on rivers, lakes and coastal waters. All of which reduce the chance of encountering fully developed seas. If someone wanted to produce a catamaran paddlewheeler, then there were plenty of waters in which it wouldn't face severe wave stress.

 

[Yellow Palace]

If someone wanted to produce a catamaran paddlewheeler, then there were plenty of waters in which it wouldn't face severe wave stress.

The one I'm most familiar with was an English Channel steam packet, which definitely isn't light duty. She was unsuccessful, but not for structural reasons.

Paddles kept being used in certain areas because of local characteristics that were unfavourable to the use of screw propellers. Usually, this would be shallow draught (which is why the PS WAVERLEY was built in 1946) or maneuverability - a paddle tug can turn much more tightly than a screw tug by putting one engine ahead and one astern. As soon as screw propellers became technically possible for a particular service, or the service changed to the point where paddles couldn't deliver it, they started seeing adoption.

Interestingly, one thing that paddle steamers would be good for is minesweeping. The Royal Navy ran one of their last paddle tugs over an acoustic range in the 1970s, at a time when they were looking for anything that might give them an edge in mine warfare, and found that it was virtually undetectable by acoustic mines.

 

[Arjen]

The one I'm most familiar with was an English Channel steam packet, which definitely isn't light duty. She was unsuccessful, but not for structural reasons.

PS Castalia. images found here: https://www.gettyimages.nl/illustra...illustration&family=creative&phrase=catamaran

Text from wiki:

Her lack of speed meant that she could not operate in connection with mail trains and she was not a success financially. Only capable of 11 knots (20 km/h), she needed to be able to achieve at least 12 knots (22 km/h) to be as fast as ships then in service on the cross-channel route, and 13 knots (24 km/h) to be able to provide the required service. It had been hoped that Castalia would be able to achieve 14 knots (26 km/h).
[...]
Reaction from passengers who sailed on board Castalia was generally favourable. Castalia was reported to only roll by about 5° to port and starboard in heavy seas, whereas a conventional ship would roll by 15° or more. In identical conditions, Foam was reported to have taken 1 hour 42 minutes for a crossing from Calais to Dover, pitching and rolling heavily, whereas Castalia took three hours, but with little pitching and rolling.

 

[Arjen]

 

[Tony Williams]

Interestingly, one thing that paddle steamers would be good for is minesweeping. The Royal Navy ran one of their last paddle tugs over an acoustic range in the 1970s, at a time when they were looking for anything that might give them an edge in mine warfare, and found that it was virtually undetectable by acoustic mines.

I suspect that modern computer processing of hydrophone returns would be able to detect paddle ships if programmed to do so (not much point at the moment!).

 

[Tony Williams]

Reaction from passengers who sailed on board Castalia was generally favourable. Castalia was reported to only roll by about 5° to port and starboard in heavy seas, whereas a conventional ship would roll by 15° or more. In identical conditions, Foam was reported to have taken 1 hour 42 minutes for a crossing from Calais to Dover, pitching and rolling heavily, whereas Castalia took three hours, but with little pitching and rolling.

This reminds me of the time when the big cross-channel hovercraft were still running. I was returning to Dover on a conventional ferry (normally capable of travelling at only half the speed of the hovercraft) in rough seas, observing a hovercraft trying to overhaul us and failing. The movements of the hovercraft were large and violent, and I remember being grateful that I wasn't on board - I suspect they might have run out of sick bags!

I have always had a soft-spot for multihulls. My only sailing experience, decades ago, was a couple of weekends on a 30' cruising catamaran off the south coast. I recall sailing in a breeze strong enough for monohulls to have a heel angle of up to 45 degrees, while I could leave my coffee cup on a table without spilling a drop...

 

[Yellow Palace]

I have always had a soft-spot for multihulls. My only sailing experience, decades ago, was a couple of weekends on a 30' cruising catamaran off the south coast. I recall sailing in a breeze strong enough for monohulls to have a heel angle of up to 45 degrees, while I could leave my coffee cup on a table without spilling a drop...

The high initial stability of catamarans is great in reasonable conditions, but can turn into a liability for a passenger ship. Since they're very stable, they don't heel much - but when they do get rolling, they have a very short roll period with some odd accelerations that makes them incredibly uncomfortable.

The fundamental problem with CASTALIA, though, was to do with the flow that the paddlewheels created across the hulls. There was a significant transverse element, which robbed power and increased resistance, leading to her performance falling well short of expectations. Ultimately, it's nice to keep the passengers comfortable, but if you can't keep to schedule and/or pay the fuel bills, the ship's a failure.

 

[TsrJoe]

Paddle driven catamaran ... Denny Wavetank Museum archive, Dumbarton

 

[Dilandu]

The main reasons seems to be uncertainty about double-hull configuration reliability (it was not well-researched at this time, and, well, the whole theory of shipbuilding was in infancy), and problems with docking.

 

[MadRat]

Its hard to fathom how any large paddlewheel design would have ever made sense, even on rivers. Those wheels are so much heavier to turn than a shaft and propeller. Even the long oars of the far east would have taken less energy to animate.

 

[Artie Bob]

In river operation, one of the limiting power factors is channel depth, IIRC when I worked on an Ohio river towboat, the minimum channel depth was 8 feet. This really limits the diameter (and power transmission ability) of screws. In real operation. pushing a tow, we were often bottoming the screws (think of porpoising as in current F1 cars). There was a shroud around the blade tips (called a Kort nozzle IIRC) to protect blade tips. Loaded, our tow displaced 20,000 tons, which we moved with two 1600 hp diesels. Before the government dredged and built dams to maintain channel depth the rivers had many really shallow sections. In those circumstances, the paddle wheels served quite well. Yes, my father was an engineer on paddle wheel river boats.

ArtieBob

 

[riggerrob]

Modern SWATH hulls and X-bows reduce pitching in high seas.