PDA

View Full Version : How do you get 80 ft of mast under a 65 ft bridge?


AB_Monterey
04-17-2012, 02:24 PM
http://www.wimp.com/mastbridge/

:eek:

BEAUTIFUL boat.

SIKSUKR
04-17-2012, 04:02 PM
Thats unbelievable and very creative.Wow!

NoBozo
04-17-2012, 05:24 PM
This is how you do it. The BAGS have water in them. Once you go under the bridges..you dump the water and the boat goes upright again. BRILLIANT. :) NB

Winnipesaukee Divers
04-17-2012, 07:26 PM
Where is the 65' bridge on Winnipesaukee? How does this apply to the lake?

SAMIAM
04-18-2012, 07:42 AM
Pretty cool.......might work on some of our bridges.

lawn psycho
04-18-2012, 07:58 AM
Nice! That's one of the times you don't get a do over if your geometry is off:D

camp guy
04-18-2012, 08:32 AM
Seeing is believing (I guess), but let's remember that bridge clearances are given at high water, and mast lengths are measured end to end. This having been said, the mast sets into the boat maybe about 6 ft below the deck (leaving 74 feet over the deck, and, if the boat passed under the 65 ft bridge at low tide (say, maybe 5 ft tide), then the clearance would be 70 ft, so the boat and mast would have to make it under with 74 ft over the water. Still, a very clever bit of boatmanship.

Maybe some of the math whizzes can calculate the angle of healing necessarty to clear the bridge.

brk-lnt
04-18-2012, 09:06 AM
Maybe some of the math whizzes can calculate the angle of healing necessarty to clear the bridge.

Assuming the bridge clearance really is 65ft, and the mast is 80ft end to end, with the base being roughly at water level (since it goes through the top of the boat and down into the hull) you'd need a list angle approximately 35.7 degrees.

pm203
04-18-2012, 10:24 AM
Who would have figured.

Grant
04-18-2012, 11:48 AM
Where is the 65' bridge on Winnipesaukee? How does this apply to the lake?

Troublemaker. :D

AB_Monterey
04-18-2012, 12:35 PM
Where is the 65' bridge on Winnipesaukee? How does this apply to the lake?

http://www.youtube.com/watch?v=C6cxNR9ML8k

no-engine
04-18-2012, 04:06 PM
There are other threads and posts that really don't fully apply to lake. !!!

The other side of coin is: been in that situation during a transit of Inland Waterway. Quite interesting!

Does not matter if boat designer measures mast end to end, as long as proper calculations are made at water level, and I've seen on many specs for a mast height above water!

RailroadJoe
04-18-2012, 05:57 PM
What is the clearance for the Rt 3 bridge at the Weirs? Can a sailboat get through there with no trouble?

NoBozo
04-18-2012, 06:12 PM
What is the clearance for the Rt 3 bridge at the Weirs? Can a sailboat get through there with no trouble?

An obscure note on the Bizer chart says the clearence is 21 feet. NB

NoBozo
04-18-2012, 06:21 PM
Those skippers that "Do The Waterway" with sailboats know Exactly how high their masts are from the Waterline. The key is waterline to top of mast.....including masthead instruments.. (Wind speed and relative wind direction... radio antenas...etc) :) NB

no-engine
04-18-2012, 07:57 PM
Those skippers that "Do The Waterway" with sailboats know Exactly how high their masts are from the Waterline. The key is waterline to top of mast.....including masthead instruments.. (Wind speed and relative wind direction... radio antenas...etc) :) NB

For sure, as I was crew, we knew well that measurement!

I think I had read somewhere of clearance 20-25'. Thanks

Some sailboats have an easy method to hinge the mast at deck fitting, in order to get under obstructions.

MAXUM
04-21-2012, 02:27 PM
I can't imagine that suspending that much weight off the mast is a terribly good idea. Imagine that boat hitting a good sized wake while in a balancing like that?

NoBozo
04-21-2012, 07:14 PM
I can't imagine that suspending that much weight off the mast is a terribly good idea. Imagine that boat hitting a good sized wake while in a balancing like that?

Not a problem at all. Sailboats sail day after day..week after week ....At Sea.."heeled"... (NOT Keeled) over like that under the Press of SAIL. The masts are "Stayed"..held up by their shrouds ..steel cables designed to spread the load on the mast.

Fore and aft "pitching" of the boat in seas, (waves) combined with lateral heeling under wind load from the sails is much more stressful to the MAST than going under a bridge with ballast bags over the side.

BTW: Looking at the waterway charts there are various bridges and obstacles that skippers will become aware of. Bigger boats usually "Go Outside" for sections of the waterway that have ...ISSUES. The other ISSUE for bigger boats in the waterway is "Draft" of the boat. The waterway is not all that deep in places...deeper draft...another reason to "Go Outside".

It all depends on how fast you need to get there..(Fla). OUTSIDE is the fastest way...for those inclined.....and experienced with offshore... :D NB

AB_Monterey
04-24-2012, 01:46 PM
Rather than start a new topic.

Adventures at the launch....

Sometimes, bad ideas are contagious.

http://www.bitoffun.com/video_vault/boat-launch-fun.htm

Steveo
04-25-2012, 11:46 AM
Rather than start a new topic.

Adventures at the launch....

Sometimes, bad ideas are contagious.

http://www.bitoffun.com/video_vault/boat-launch-fun.htm

Too funny!!!

AB_Monterey
04-25-2012, 05:37 PM
I kept saying, "No, they're not..." and they just kept on coming. :laugh:

Winnipesaukee Divers
04-26-2012, 06:36 AM
A few years back, I was at the Selectmen's meeting in Wolfeboro. I was there on WCYC business, but they were discussing the upcoming Smith River bridge renovations. Someone poised the question about raising the bridge to make better use of Back Bay. After a brief discussion one of the Selectmen said, "We don't need to raise the bridge, we'll just dig the channel deeper". To which the state engineer responded, "Why didn't we think of that..." and the audience clapped with approval of such a simple solution to the problem.

I rolled my eyes back in my head and thought "if this is what I have to work with... I might as well go home now.

Pineedles
04-26-2012, 07:36 AM
That is too funny!:laugh:

RailroadJoe
04-26-2012, 07:46 AM
Sure, the deeper the channel the bigger the submarine.

no-engine
05-05-2012, 11:27 AM
A few years back, I was at the Selectmen's meeting in Wolfeboro. I was there on WCYC business, but they were discussing the upcoming Smith River bridge renovations. Someone poised the question about raising the bridge to make better use of Back Bay. After a brief discussion one of the Selectmen said, "We don't need to raise the bridge, we'll just dig the channel deeper". To which the state engineer responded, "Why didn't we think of that..." and the audience clapped with approval of such a simple solution to the problem.

I rolled my eyes back in my head and thought "if this is what I have to work with... I might as well go home now.


Seriously? State engineer's answer joking or truly serious?
I know we all have minimal confidence in many State Officials.

RailroadJoe
05-05-2012, 01:42 PM
Who is the smartest? The state engineer or the audience for clapping with approval.

no-engine
05-05-2012, 02:18 PM
Well, the answer should be neither. All should leave.

If one has traveled to FL, we observe bridges over canals; the approach roads are built up and then down, just to allow clearance for certain boats.
The roads are often only a little above the water level. Forget the rise an fall of tides!
How about Tappan Zee Bridge over Hudson River, or Annapolis Bay Bridge, which rises to allow ocean going vessels under and then returns to ground level.
There's a few covered bridges here in NH which are designed with approaches and bridge higher then surrounding lands.