Portable, tilted ship's mast

For our upcoming production of the Tempest, I'm looking at incorporating sails from a "shipwreck" as a surface for some silhouette/shadow play. Of course I want my mast tilted (because angles). This will also be the show that we take to competition, so the mast needs to be portable.

I'm submitting this to the Hive Mind for thoughts about:
-construction of the mast itself
-best way to weight/stabilize the mast at the base

I'm attaching an initial sketch (first draft, no scale considerations here)
-The thing in the middle (a busted hull as Prospero's cell) may get cut or moved to reveal more screen real estate)
-The two "sails" may be angled (i.e. not one straight line across the stage) though not curved as it looks in the drawing
-dimensions of the overall sail area are TBD based on what we can safely accomplish, but would like a shadow playing area of 15'h x 20' w - so looking at a pretty tall mast.

High School Theatre, so standard limitations in terms of material availability and experience apply.
Thanks for you time!

i built a mast out of 1x2s was a foot in diameter and had plywood disks. have to run the 1x2s through a table saw to get the angle on the so they fit together to from the circumference
around the plywood disks

a little math here 360 degrees in a circle, the number of 1x2s that make up the circumference times by 2 and divide that into 360 and that is the angle to set the table saw and trim both side of the 1x2s

Would it be possible to make a lightweight mast and then use your "stays" as actual support for the mast? From the sketch it looks like you're running sail cloth on either side as a backdrop anyway. We did Pirates of Penzance and rigged the mast on our ship similar to a real one in that the main stays took the job of holding the mast true, the bottom was just footed in the wagon. If you could find a way to brace the base of the mast and then have points on either side strong enough to hold it's weight it would stand up. Granted, that's assuming the material you use for the mast isn't that heavy and you fun afoul of making something that could potentially fall over and do some damage, hence the need for a lightweight mast.

In the sketch I see 2 triangle with a common side, leaning in slightly. (a triangle book) That's a stable arrangement so long as they don't 'open' into a straight line. 5 long poles joined with bolts or hinges and you have something rigid, that packs pretty tight. They will be long, unless you also use something extendable, like tent or tarp poles with nesting pieces.

One can also make folding rigid posts with hinges. One hinge is normal and stays put. A loose-pin one on the opposite side keeps the pole from folding. A bit wobbly, but quite strong. Best on something at least 2", but you would likely want more anyway.

Sandbags in your rocks wouldn't hurt.

Consider Sonotube for the mast.

RickR said:

Sandbags in your rocks wouldn't hurt.

Click to expand...

There's a sentence I don't think I've ever heard before...

Could look at a fiberglass telescoping mast like these: https://www.mgs4u.com/fiberglass-push-up-mast.htm#telescoping
Might need a little help on appearance, but definitely portable, and probably re-usable for future projects.

If it needs to be wider, a couple different carpet tubes can be assembled to resemble a taper.

Thanks, all! Plenty of good ideas to explore. Mostly gratified no one has said, "Are you insane, can't be done!" But that's not really in theatre vocabulary, is it?

For my own reference - small boats can use a "Gunter" rig - a sliding, extendable yard on the mast to rig a triangular sail. "with spars short enough to stow entirely inside the boat."

http://duckworksmagazine.com/05/vintage/sbj/2/index.htm

Yes there are many creative sailing rigs. Keep digging and you'll see some surprising things.

Sent from my SM-G900V using Tapatalk

Interesting, as I am sailing this week. My 29' mast has one bolt on the base. It is the stay wires that attach to the boat, counterweighed with a 600lb keel.

Thinking this through if you were were trying to make plain hollywood flats free standing you would need about 100 or 120 deg (top view) like opening a book. However you actually want sail material.

Take your mast and connect a boom at the bottom using right angle steel plates forming a ridgid 90 angle using 4 bolts 3/8. 2 on mast 2 on boom. This will let you remove one bolt on boom and fold it up to move. Run your cable across the angle and attach a sail. Make your second sail in a similar fashion (different size like you drew) Attach the masts to form an inside corner. Keep in mind it is the base plate that maks it solid.
Experiment -Take your drawing cut the sails out of card board fold at the mast "hing" stand it up.
Unistrut web site has all sorts of connectors. And 2x4's fit inside carpet tubes

Ashley, your proper use of sailing terms alone makes you pretty stellar in my book right now.

(And yes, we do say "it can't be done" around here but it usually applies to DIY flying or pyro).

Is this going to be seen fully in the round or only from the front (proscenium vs. 3/4, in the round etc.)? If it's only seen from the front, then you aren't limited by the necessity of a fully round mast. Construction-wise, imagine creating your 16' (plus or minus) mast in two pieces- build 2 8' pieces as boxed beams of 1x4 (ripped down to 3" wide) and 1x6 (ripped down to 5" wide) leaving space for a 2x4 to fit inside (not too snug). Add an 8' 2x4 bolted halfway inside one of them (bolted so you can remove it completely for transport if necessary), and you have a 16' beam with a fair amount of strength. Add 1/2" plywood to the front of both cut at a slight taper to suggest additional height, and faux paint a bit of shadow/highlight on the edges to create the illusion of roundness. If you need an actual rounded construction, consider starting with the same boxed beams, then adding rounded plywood ribs (either 180 or 270 degrees worth, depending on your sightlines) every few feet and then attaching sonotube or ripped 1x2s as suggested above. Here's an example of a design I created for a children's production of The Little Mermaid (straight play) a while back: https://photos.google.com/album/AF1.../AF1QipNwqcCfsfELRTneCRTxzJ37WB-smD0YDPbJdrGH
We used sonotube for the mast around a wooden spine, and used the angled hull to support the base of the mast.

As far as support for your situation goes, we'll start with the base of the mast itself. It could be as simple as a 24" square piece of plywood with some added wooden blocks or steel angle iron for the mast to bolt onto. However, I think you'd have a much easier time if you build yourself a raised platform that the mast can slide into, and that you can weight down with stage weights or sandbags. It wouldn't need to be much more than 12" or 18" high, and maybe 3' in diameter (could be square, round, or a non-regular shape if you want to imagine it as part of the hull). Now, to support the top of the mast and your shadow screens- normally for a perfectly vertical mast you'd need 3 guy wires. But because angles, I would suggest 4. 2 going upstage and 2 to your rocks downstage that will also hold the screens.

You can use aircraft cable or rope, provided you make sure to choose rope that has a decent working load (I wouldn't use anything less than 500lbs minimum, probably more because overkill isn't a terrible thing). Add some eye bolts to the top of your mast (maybe even give yourself a spar up there so all four lines aren't going to the same place. If you do, just run a 2x4 through the top section of the mast and make sure it's securely screwed/glued/bolted into place). Then, to make your life easier for setup and takedown, add a shackle/quicklink and a pulley to each eyebolt, so your lines can be tensioned and tied off from stage level and you don't have to get up on a ladder to adjust anything. Make it a 2-line pulley for your downstage 2 lines and you'll also have a way to pull up and tension your screens (and you could even have them come down and go up during the show for dramatic effect, if you wish).

Ideally, your guy lines would go to positions that could be securely attached to the floor/ground/architecture. However, if you're going to be taking this to other people's spaces I know that may not be the case. Adding weight to your floor points, as long as it's enough, should be fine to keep your whole structure secure. Definitely err on the side of more weight than you think you need. A 16' mast is a heck of a lever. Good luck!

lots of great ideas, thank you!

And yes, this is for a proscenium space (and give the shadow set up we really must keep all audience to the front, no one to the sides at all). Big spaces, too, so we can definitely get away with some paint magic.

I'm going to add my 2 cents. First - great concept and fine sketch and kudos for doing Shakespeare in a HS. (I see a role for some sail ripplers in the storm scenes.)

I believe charged with building this for school tour, I would focus my primary effort on the mast and base and the (moment) connection required to make that work. Base will have to extend under cantilever and be weighted. Then do the anchors for the lines - the rocks - as free standing and without rigid connection requiring alignment or attachment to the floor or building at all. Set up mast. Attach lines to rocks and push till taut. Doesn't care if you have to widen the angle between a little or narrow it a little for the space. Consider options for weights. If you could use "tanks" and water, can be easy to fill and empty via hose and valves, and lighter to load on and off truck and generally transport. Might be worth retractable casters so they could be filled and emptied outside.

Just some random thoughts on alternatives, but as I grow older I like prefer more tolerance in construction and other things, and a line and snap hook is quite tolerant.

BillConnerFASTC said:

Then do the anchors for the lines - the rocks - as free standing and without rigid connection requiring alignment or attachment to the floor or building at all. Set up mast. Attach lines to rocks and push till taut. Doesn't care if you have to widen the angle between a little or narrow it a little for the space.

Click to expand...

hmm... this also offer some fun options for "play" as the set is being put together during the opening scene, working it into the action. And yes, line and snap hooks are an attractive option for when we have to depend on teens in a high-stress situation.

And thank you for the compliments. I'll keep the thread updated as we progress.

Just about a year, year and a half ago I built a mast for the ship in "The Flying Dutchman" we simply cut 13° angles on each edge of 10 1x4's. lay them on a flat surface with the "outsides" facing up, _/\__/\__/\__/\__ <--something like that . Use a regular old t-50 hand powered staple gun and staple across the seams all the way down the length of each seam. 2 hours and three cases of staples later... Sandwich each end of the 1x4 's between a couple short pieces of scrap. Use the scrap like handles to flip the whole assembly over. lay in a ton of glue on all the seams. Roll it up like sushi. staple across the seam where the final two edges meet. Let it sit for two days. Knock off the excess glue sand the ridges a bit, viola'! 20' mast.

Or SonaTube as np18358 suggested. You will need to sand it down and coat it with something to kill the seam.