2e vehicle guide, or no-one at Mongoose can sail

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Moppy
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2e vehicle guide, or no-one at Mongoose can sail

Postby Moppy » Fri Dec 07, 2018 4:20 am

2E vehicle handbook says sailing craft (unpowered vehicle, wind) can never exceed the wind speed. Yet they frequently do ...

You can wiki it (plenty of literature and speed records to look at), but intuitively, draw a triangle. The two short sides are the boat speed and the wind speed. The long side is the apparent wind created i.e. what you feel from the combination of boat and wind speed. When you get this in the sail, you can use it to exceed the true wind speed.

It's now also possible to sail directly into the wind with a rotating wing sail, but I cannot explain the physics of how that works :-)
G. K. Zhukov
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Re: 2e vehicle guide, or no-one at Mongoose can sail

Postby G. K. Zhukov » Fri Dec 07, 2018 8:38 am

Moppy wrote:
Fri Dec 07, 2018 4:20 am
It's now also possible to sail directly into the wind with a rotating wing sail, but I cannot explain the physics of how that works :-)
Well - it was always possible to sail into the wind by tacking. <== Click link.
Old School
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Re: 2e vehicle guide, or no-one at Mongoose can sail

Postby Old School » Fri Dec 07, 2018 11:56 am

Of course you can tack into the wind, but not directly into the wind. Tacking requires an angle for the keel to push the vessel forwards against the sail.
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Re: 2e vehicle guide, or no-one at Mongoose can sail

Postby msprange » Fri Dec 07, 2018 2:07 pm

The last time I went sailing, I was 16 years old and my boatmate (?) nearly fell overboard on a perfectly calm lake...

We could obviously do a lot of rules governing sailing, but this is Traveller - the amount of times it may come up during a game means it is not worth going into detail in a core book. Maybe we will revisit this in an adventure of other supplement but, for now, we just want players to get on a boat and try not to sink themselves. If your group is anything like mine, you will have your hands full just trying to do that...
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Re: 2e vehicle guide, or no-one at Mongoose can sail

Postby steve98052 » Fri Dec 07, 2018 6:47 pm

I did some sailing as a kid on a three person sailboat, and I could tack slowly, or even go fast if the winds were just right for the too-small lake that had sailboat rental. Neither is all that difficult; my tumbles into the lake were more from horseplay than difficulty with sailing.

My parents had a time-share lease on a big sailboat for a while, and my father was a good sailor. (And my mother was a good sport.) With a few extra hands aboard, he could really get the thing going fast. He probably could have tacked into port, but the V-8 back-up engine was preferred around most Seattle area moorages. They didn't renew the lease because my father has trouble finding people with time to join the crew even for a week, and my mother mostly saw it as a way to get to restaurants with sailboat moorage.

The real sailors in the (extended) family are my wife's aunt and uncle. Last time they sailed away from their home port, they blew past the motorboats that were there to guide them to the docks (an optional service that apparently expected everyone to use), pulled up at a speed that apparently alarmed the guides and the people on the docks, then suddenly slowed to a gentle bump right at the reserved spot. But they're top-tier sailors; he has crewed on America's Cup racers.
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Re: 2e vehicle guide, or no-one at Mongoose can sail

Postby WingedCat » Wed Dec 12, 2018 6:53 am

Maximum sailing speed is at least within the speed band of wind speed, yes? I'd use that as the ruling, even if it''s possible to go a bit beyond wind speed (and not necessarily - in fact, preferably not - only in the direction of the wind).

For instance, if the wind is 30 kmph (Very Slow), you're not going 150 (Medium) under wind power alone.
Moppy
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Re: 2e vehicle guide, or no-one at Mongoose can sail

Postby Moppy » Wed Dec 12, 2018 5:08 pm

WingedCat wrote:
Wed Dec 12, 2018 6:53 am
Maximum sailing speed is at least within the speed band of wind speed, yes? I'd use that as the ruling, even if it''s possible to go a bit beyond wind speed (and not necessarily - in fact, preferably not - only in the direction of the wind).
3x wind speed is possible today at sea. When I was young it was 2x but technology happened.

The physics says there's no theoretical upper limit so it's down to efficiency and new ideas like using a wind-powered rotor to drive wheels. Given how much we don't still know about about turbulence and airflow, who knows what TL 15 has.
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Re: 2e vehicle guide, or no-one at Mongoose can sail

Postby Moppy » Wed Dec 12, 2018 5:10 pm

WingedCat wrote:
Wed Dec 12, 2018 6:53 am
Maximum sailing speed is at least within the speed band of wind speed, yes? I'd use that as the ruling, even if it''s possible to go a bit beyond wind speed (and not necessarily - in fact, preferably not - only in the direction of the wind).
3x wind speed is possible today at sea at speed. In low winds this multiplier can higher. When I was young it was 2x but technology happened.

The physics says there's no theoretical upper limit so it's down to efficiency and new ideas like using a wind-powered rotor to drive wheels. Given how much we don't still know about about turbulence and airflow, who knows what TL 15 has.

edit: https://www.odt.co.nz/sport/yachting/ho ... -yachts-go
"These boats are incredible, the performance you can do in light airs really the amazing thing. In 7, 8, 9, 10 knots of breeze you can be up over 30 knots at times," he said.
There's a limit based on the wind causing waves to "rock the boat" limiting its performance, but I'm supposing that's one of the things TL or alien oceans might change.

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