Modern Hi Tech Viking Ship Development Class

[gonzo]

Thank you Gonzo. I am aware that the volume increase faster. I thought that was an advantage because you can ad more grunts, but I see that the resistance increases faster too. By surface area do you mean floor or deck area? I think I understand.

Also the sides of the boat.

 

[Johan Strydom]

Have you come across Bantry Bay gigs and Atlantic Challenge International? They are 38', 3 mast, 10 oared boats that compete in sailing/rowing/seamanship contests including passage racing.
I know its not quite what you are thinking about but they are probably the closest thing that exists. I have often thought I would love to do a longer multi day passage race in them, and have also spend many hours wondering about what a modern day equivalent could be like.

Atlantic Challenge International https://www.atlanticchallenge.org/

Atlantic Challenge Great Britain https://atlanticchallengegb.org/

Thank you for the links, beautiful boats. My thinking is still vague. It looks like I have to think of this size boat.

http://www.balta.fr/tangara/p3.jpg

https://api.europeana.eu/thumbnail/...ediaLib/588/media-588070/large.jpg&type=IMAGE

 

[gonzo]

The first has no provision for oars. The second is a typical coastal boat. Neither fulfills your SOR.

 

[Rumars]

Thank you Gonzo. I am aware that the volume increase faster. I thought that was an advantage because you can ad more grunts, but I see that the resistance increases faster too. By surface area do you mean floor or deck area? I think I understand.

In simple words, the boat weight (and resistance) increases faster than you can add horsepower. It's a problem that can be solved by lighter and stronger materials only up to a point, afterwards the hp/kg ratio diminishes and the boat gets progressively slower. That's why olympic rowing boats look that way, it's the minimal amount of boat necessary to float the rowers in calm conditions. You can build a viking design in carbon foam and it will weigh less and be potentially faster then the wood original, but that's all. And this still does not adress all the other factors like behavior a sea, etc.

 

[clmanges]

I thought of a rowing system where the seat stays stationary, but the rowlocks move. the rowlocks can be on a bar so that they all move at the same speed. If a pulley system is used the direction of the rowlock movement can be reversed. this will allow the rower to face fore ward. The oars will stay at 90 degrees to the hull throughout the stroke.

I can't think of a way to make this work. The oarlock has to be attached immovably (fore/aft) to the hull in order to serve as a fulcrum to transmit the oar's motive force to the boat.

 

[bajansailor]

Clmanges, have a look at the brilliant Ro-cat - instead of a sliding seat they have a fixed seat with sliding outriggers controlled by the rower's feet.
description of the ROCAT rowing catamaran http://www.rocat.org.uk/boat/description.htm

You can download a video of the Ro-cat underway here -
ROCAT - downloads gallery http://www.rocat.org.uk/galleries/downloads.htm

 

[Johan Strydom]

Clmanges, have a look at the brilliant Ro-cat - instead of a sliding seat they have a fixed seat with sliding outriggers controlled by the rower's feet.
description of the ROCAT rowing catamaran http://www.rocat.org.uk/boat/description.htm

You can download a video of the Ro-cat underway here -
ROCAT - downloads gallery http://www.rocat.org.uk/galleries/downloads.htm

View attachment 164596

Thank you very much for this. It is wonderful to see that my thinking can be a reality, I wonder when they thought of that. Dudley Dix said it was done long ago. I took it one step further. Maybe I should share that with them.

 

[sharpii2]

Viking ships had sails and keels for a reason. The keel allowed at least rudimentary upwind sailing. And, of course, the sail was large enough to propel the ship.

I don't think they were really galleys, but sailing ships with oars. The oars were likely for getting on and off the beach, and for getting up creeks and rivers when there was little or no wind.

Suppose you stipulate five requirements for these boats

1.) they can not have an engine or an electric motor for propulsion.
2.) they must embark from a beach, then land on a beach.
3.) they must be monohulls.
4.) they must be able to cross at least 3,000 kilometers of open sea.
5.) the crew must be able to set up and take down the mast(s) with no outside help, even while on quiet water.

If I were to speculate what these boats might look like, I would expect to see something with a flat bottom and a well rounded bilge, with maybe a deep fore foot, a deep detachable rudder, a Beam of around 8 ft, and a length of maybe 60 ft. There would probably be a crew of 20 or less.

It would have at least two masts, maybe three, and would probably carry lug or sprit-peak sails.

This being a race, there will be an automatic incentive to make the boat as long as practical. Longer length means less power to get the same speed. Very useful for very limited power, mechanical (oars), and limited sail.

 

[Johan Strydom]

I can't think of a way to make this work. The oarlock has to be attached immovably (fore/aft) to the hull in order to serve as a fulcrum to transmit the oar's motive force to the boat.

It had been done.

 

[Johan Strydom]

In simple words, the boat weight (and resistance) increases faster than you can add horsepower. It's a problem that can be solved by lighter and stronger materials only up to a point, afterwards the hp/kg ratio diminishes and the boat gets progressively slower. That's why olympic rowing boats look that way, it's the minimal amount of boat necessary to float the rowers in calm conditions. You can build a viking design in carbon foam and it will weigh less and be potentially faster then the wood original, but that's all. And this still does not adress all the other factors like behavior a sea, etc.

Thank you for making it very clear. The design of the hull would be totally open for optimizing. The above water part can shaped to minimize wind resistance. The power available can be more effectively used. The options may be to accept additional power sources, wind or even power, or limit the distance. Average time for a marathon is 4 h. The distance can be based on that. What is the maximum size boat that human power can still be significant. It is clear that a racing 8 size boat will be hard to beat, if speed is the only requirement, though a cat might be better option at sea.

 

[Tiny Turnip]

 

[Tiny Turnip]

The Boat https://www.rannochadventure.com/roxy/the-boat

Technical Specifications
No. of Rowing Positions
Eight
No. of Berths
Eight
Length Overall
38 ft 8" / 11.8 m
Load Waterline Length
37 ft 3" / 11.36 m
Beam (canoe body)
5 ft 9" / 1.74 m
Load Waterline Breadth
5 ft 2" / 1.58 m
Hull Draught
1 ft 1" / 0.34 m
Displacement (loaded)
2,250 kg
Overall Height (keel to cabin roof of canoe body)
5 ft 6" / 1.68 m
Construction
Carbon & Fibreglass

edited to add video and spec.

 

[Johan Strydom]

Yes Viking longships was primarily designed for sailing. Adding a keel will ad resistance, when relying on human power. I will use dagger boards, that can also be used when needed to prevent leeway. A motor might be needed for safety. Beaching is an interesting angle I have not considered before. The keel serves then as a skid, and to protect the hull. Well worth considering. 3. Why do you insist on monohulls? With the Polynesian double canoe, the stability problem is solved. For human propulsion the hull shape should be as rounded as possible to reduce surface area. For sailing you need more hull stability. I am thinking of using removable, inflatable outrigger(s).

Thank you. I enjoyed that. Good video. Looks like they are really moving. I do not think it will last long at see. Thank for sharing.

 

[Johan Strydom]

The Boat https://www.rannochadventure.com/roxy/the-boat

edited to add video and spec.

WOW. Thank you Tiny Turnip. 8 berths ! This will keep me busy for a while. All these boats seem to have similar LOA. Racing 8, Dragon boat, whale boat, Bantry Bay Gigs, Femboring. 36'- 39' So I should think of 40' LOA max.? beam 6'

 

[hoytedow]

With bilge keels you reduce draft and it can sit levelish on the strand at low tide.