How to measure mast height ?

[Superstrath]

Fatal Flaw, Nigel

[ QUOTE ]
I still like the shadow method ....

[/ QUOTE ]

My stick-and-eye method is contrived to be used in places where there are no shadows. Equador in March or September, for instance, or anywhere at night, or here.

You would also fail in high latitudes where the shadow is probably longer than the tape measure. /forums/images/graemlins/grin.gif

 

[Colvic Watson]

Re: Fatal Flaw, Nigel

Why do you keep confusing things with this damn tape measure? The science of mast measurement has come a long way since the dark days of "the tape measure"

 

[StugeronSteve]

Re: well if you want to nit pick

Many years ago, when the kids were little, we took them to hear a story teller. The women droned on, for what seemed like hours, about these woodland characters, until she came out with this immortal line:

"Oooh, look who's up in the tree, it's Sammy squirrel and he's chomping on his nuts." Never before had I known just how much it could hurt trying not to laugh.

 

[KREW2]

I don't know how to tell the exact height of your mast, but its age will give you a clue, cut it in half and count the rings

 

[Como]

But you need to know its height to know where the half way point is to cut it.

 

[snowleopard]

set all sail and go out sailing on a bank holiday. As the masthead touches the water, wallk out to the end with your tape measure.

 

[jonjo]

Re: If you only have a 6\" ruler

Near the summer solstice the midday altitude of the sun barely changes day to day so this is your opportunity to calculate your mast height. Just before the solstice start heading south until at midday the end of the shadow of your mast just touches the aft end of your deck. Somewhere down by Gibraltar or Madeira will suffice for this.

After noting your latitude by GPS on June the 21st move another 60 miles due south then at midday on the 22nd measure, with that 6" ruler, how far the end of the mast shadow on deck is from the transom.

Hand over all the raw data to an 18 year old about to sit A Level Maths and give a hint that the solution involves trigonometry and simultaneous equations.

 

[peterb]

[ QUOTE ]
How about measure the luff of your mains'l then add the length from the foot to the deck?

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But is the question about mast height or air draught? Should you take in to account the height of the mast step above the waterline? And what about the VHF aerial? It's unlikely that the bird will be sitting on top of that.

Still, Fireball did suggest that the bird might rise after being shot. I reckon that if I were hit by an airgun pellet from below I would "rise up" by about the length of my VHF aerial!

 

[Phoenix of Hamble]

Dont forget when climbing the mast, that it gets 10' longer for every 10 years you get older... so do it before you hit 70.....

 

[Lakesailor]

Frighten the ship's cat so it runs to the top of the mast.
Call the Fire brigade to come and rescue it.
Listen to the radio in the Fire Engine cab so that when they call in and tell the control "We've got a cat stuck up a 55 foot mast" you've got the answer.

 

[Gunfleet]

Rubbish. You just swing a compass from each end and join up where the arcs cross.

 

[richardabeattie]

Re: Starling shites yer answer, innit.....

Buy a pair of mast climbing boots (the ones with the aluminium magnet inserts) from Nauticalia and walk up the mast pushing a road measuring wheel. The only tricky bit is turning round at the top before you walk down. For saftey you will however need to double knot the laces.

 

[BrendanS]

Chimney sweepers brush. Push up and attach rods until brush is level with top of mast. Then mark of bottom of mast on rod. Take down and measure rod length

 

[fireball]

Re: Starling shites yer answer, innit.....

Them mast climbing boots are quite expensive though ... and no good on a wooden mast.

if your unfortunate enough not to live in a seagul or starling area then I suppose (if you can't get someone else to climb the mast with a dog to drop) an alternative method could be to shoot your windvane ... time the gap between firing the shot (only use an airrifle here ...) and the windvane departing company with the mast ... if your quick you can also time the windvanes fall to the deck - don't forget to keep it for next year - I believe the calcuation would be the same as the seagull but multiplying by a factor of 43/56^2

 

[fireball]

Just how do you propose getting the brush inside the mast?! and anyway everyone knows that there is usually a compression strut at the spreaders ...

 

[BrendanS]

Re: Starling shites yer answer, innit.....

Wooden mast? Easy - tree climbing spurs and belt, lumberjack style. Stick spurs in, flip belt up (it's attached to waist and goes around the mast), take strain on belt, then lift one leg and kick spur in, lift other leg and kick spur in. Repeat

 

[BrendanS]

/forums/images/graemlins/grin.gif I knew someone would go for that option.

Outside the mast dear boy, outside

 

[fireball]

But ... old man ... the chimney sweep brush poles are BENDY!! ... you wouldn't get to the top of the mast ... well - not on your boat anyway! /forums/images/graemlins/tongue.gif

 

[BrendanS]

So you just get a ladder and strap the rod every 3 feet or so up the mast. Simple innit! Young whippersnappers just have no idea of how to bodge properly

 

[jfkal]

Leica Disto. Aim shoot read http://www.ybw.com/forums/images/icons/lightbulb.gif
lightbulb /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif