Reflections on boat tent design

Moored on the bank of the River Forres on Loch Ness, with calm weather and well sheltered, almost any boat tent would have done the job. Which was lucky as the tent took a bit of battering on previous nights with gale force gusts buffeting the boat and bending the fibreglass poles causing them to split.

Look carefully on the left hand side you'll see a blue rope that I've used to cross-brace the pole. Out of sight the poles are wrapped with gaffer tape.

I've written before about making this tent and how it performed. After a second season of using the tent I've been thinking about a different design.

First, I should admit that I suspect many, if not all of the problems, could be resolved by using better quality materials – I didn't have much confidence in my ability to turn out a competent tent, so I had used cheap fabric and poles by way of experiment. The fabric is uncoated nylon: this stretches when wet contributing to the bagginess of the tent. The poles were at the very edge of their limit for bending, and perhaps with more diligent searching I could have found more flexible poles. I have some spare poles and I can probably get another season out of the tent before I have to make any major decisions or spend any money.

But, in the way that it goes, I've been mulling over possibilities for a new boat tent for a while. And when I read that Anders is planning to build a tent for his Walkabout, I thought he might find it useful if I shared my thoughts.

My concerns about my current tent:

  • The tent is only supported by the poles, and these are bendy. This means that when it's buffeted by the wind the poles can be deformed, weakened and split. (One night it was so windy I got dressed so I would be ready when the tent blew off the boat!)
  • The ridge can't be held taut, so it doesn't shed water well and the tent sags in the middle. I've cured this to some extent by adding a ridge pole. Designer John Welsford suggested adding two poles to form an X between the two existing poles; I didn't get round to this – the ridge pole was a quick fix. I'm sure this would help, but it does mean more poles to carry and put together.
  • Most conventional tunnel tents and many dome tents have guy ropes to resist wind from the side – this isn't possible with a boat. Angling the poles so the slope of the tent is more streamlined might help, this would also reduce the stress on the poles – it would however reduce interior space making sitting on the side benches difficult.

This Navigator moored 50 yards downstream has a much more substantial tent. I'm not sure whether the frame is wood or aluminium, but there's much less space in the Walkabout to stow bulky poles.


This stretched Walkabout has a sprayhood. I'd actually thought of using a sprayhood as the basis of a tent before seeing this. Though if it was to be usable as a tent, it would be too large to be used as a sprayhood while sailing.

I wonder whether something like this might work, hinged like a normal sprayhood. Aluminium tubing would provide a strong framework, and with the right fabric it should be possible for the canvas to be good and taut.
This tent would be stowed folded down around the coaming; while this would create bit of windage, it would be quick to erect and wouldn't need storage space in the boat.
 
The traditional solution would be a boom tent, here I've sketched an oar lashed to the boom and the mizzen to create a solid ridge pole. I'd tie the tent below the boom, to prevent any water from the sail coming into the tent.
I'm inclined toward the sprayhood tent, but won't be making a decision for a while. Any suggestions, do let me know!

 

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About Osbert Lancaster

Creating ripples to foster sustainability. Seeking solace & clarity on the sea by sail & oar.

11 comments

  1. Hey good post Osbert
    I would be very interested to talk to he owner of moody blue about his tent plans and design. Is there any chance you know who hat is and whether they might be prepared to email with me?
    Cheers
    Steve
    http://Www.arwensmeanderings.blogspot.com

  2. I tried to make a boom tent for my Navigator. I found that unless the boom is set incredibly high the slope of the tent end up being extremely flat that you end up having no headroom except in the center of the boat. There wasn’t even enough headroom to sit on the seats in the cockpit.

    I ended up with a tent similar to yours, except it extend from mast to mast and therefore the top can be pulled tight.

    https://plus.google.com/u/0/photos/101488109748928583216/albums/5852131875256676097/5852135853893590930?sort=1&pid=5852135853893590930&oid=101488109748928583216

    I got round the problem of the poles having to bend to much by simply putting a kink into the metal tube that joins two tent poles together. (Approximating a curve with a set of straight lines)

    When we got hit by a storm we had problems with the tent collapsing to the side. Luckily the boat could swing into wind and survives with a few cracked poles. and we carried spares.

    • Osbert Lancaster

      Good point about the headroom in the boom-hung tent. I did have some thoughts about some kind of spreaders, but it would then be difficult to keep the sides taut. I forgot to mention this when writing the post – too late at night!

      Like you tent, but it looks like it would flap around a lot in a side wind? Can’t always moor head to wind – e.g. on pontoon or river bank.

  3. Some nice ideas there Osbert, I really like the sprayhood version, unfortunately it does not work on my boat since I have the coaming forward of the main mast. Will keep thinking until it gets warm enough to actually start building it, will keep you updated.

    /Anders

  4. Osbert Lancaster

    For those interested in more discussion on boat tent design, see this thread on Wooden Boat forum:
    http://forum.woodenboat.com/showthread.php?166273-Sprayhood-tent-hoops-from-ply

  5. Pingback: Re-thinking the boat tent | Forthsailoar

  6. frank

    plastic electrical conduit !!!
    it is tough and resilient and straightens out for stowing
    you can choose the diameter to fit the bend
    put extra poles if tent flexes – wont take up much extra space
    avoid plywood ! – half the grain (and hence weight and bulk!) goes crossways to load and does nothing for strength. it is also , I would think, be more brittle and rigid and hence unreliable. strikes me that compared to other options it is more work for an uncertain result.
    I had willow hoops in my tent – put two in each pocket – tapered tips overlapped in centre. worked ok but now dry (and brittle?)
    am also considering bent tube “corners” cut from junked chairs to slip into straight tubes ….

    hope this helps

    frank

  7. pete e

    I am building a SCAMP by John Welsford and in the thinking stage of a tent design. I noticed the short comings of fiber glass poles. I have some of those on a land tent. The poles are bent to the maxi mine for the tent. They would not take the bend necessary for the boat. I have a piece of plastic pipe used for hot water that is called PEX It is red in color. I find that it takes the bend with out breaking or crimping. It is 1/2″ or 12mm The only downsize is that it retains some memory. Storage in a boat has to be thought of. My thinking at this point is to have the hoop cut at the midpoint and a dowel glued in one half to join to the other half. This I think will solve the storage problem.( polycarbonate tubing might be the answer according to Yerdon) I will have check that out, PEX tubing is inexpensive compared to fiber glass poles.

    I will be watching the wooden boat forum

    finding answers

    Pete

  8. Dr. Tim

    I plan to use bamboo for the 2 ends of cockpit by heating and bending slowly to make a permanent bend of conestoga canopy… Have bamboo ridge pole with split bamboo ribs and few split runners…The canvus will roll up on 2 bamboo poles and can be tied in any position…This is a permanent canopy that rolls up and doesn’t interfere with sails… Just wondering how much will the frame interfere with sailing??

    • Osbert Lancaster

      Hmm. In such a small boat it’s difficult to see how the permanent frame won’t interfere with the sailing. It will be in the way of the mainsheet, and will be in the way of your body as you move in the boat, and when you get in and out.

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