Eighth time you've been asked this week: how can I build a sliding seat?

Greenheart

Greenheart

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Not many dinghies have sliding seats, as an alternative to the trapeze...International Canoe...Toy...umm...that's it, I think.

I'm mainly interested in the tracks/sliders used to carry the seat, plus the considerable weight of the crewman, letting them shift in a moment across the boat. Do they use costly rails/bearings like mainsheet travellers, or just sliding-door tracks?

Don't ask why I'm wondering! :o
 
Many are simpler than that.
Years ago I had a MiniSail with a bolt on sliding seat, it was a box-section of plywood sliding in a wood frame.
It does not have to slide while your weight is on it.
 
lw395 said:
It does not have to slide while your weight is on it.
Click to expand...

I hadn't thought of that...I was picturing superfast tacks, with the seat's rider unratcheting the seat and zooming downhill towards the leeward sidedeck, spinning around ready to start the other tack...not so sure how he'd avoid horrific facial impact with the boom...:rolleyes:
 
Stainless ball-bearing drawer slides are available if you want 'em, though. My chart table runs on a pair that are rated to 125kg, so I could (just :p) sit on it while extended without it breaking. Nobody ever is going to sit on it, but things people may grab or fall against need to be strong :)

Pete
 
Thanks Pete. Where d'you get 'em from? And what length of rails are available? Were they by any chance megabucks?
 
Dunno the name, I just googled "drawer sliders" and got a site specialising in them :)

They did all different lengths, can't remember what was the maximum. Mine slide out by about 80cm or so, but they may have bigger.

Megabucks? About £60 I think, so certainly not cheap. This was for all-stainless, salt-water-immersible, food-safe (!) - plain galvanised were a lot less.

Pete
 
Thanks for that. Watch this space for the first dinghy ever, to have a slide-out chart-table, doubling as a worktop/divan. :rolleyes:
 
Dan,

the Hornet has a sliding seat too, though I have a feeling some may have converted to trapezes; could be wrong.

Of course the snag with these seats is if you dip to windward and it digs in; next step is a float on the end and you've got a proa !
 
dancrane said:
Not many dinghies have sliding seats, as an alternative to the trapeze...International Canoe...Toy...umm...that's it, I think.

I'm mainly interested in the tracks/sliders used to carry the seat, plus the considerable weight of the crewman, letting them shift in a moment across the boat. Do they use costly rails/bearings like mainsheet travellers, or just sliding-door tracks?

Don't ask why I'm wondering! :o
Click to expand...

I think you need a boat first! :D

Years ago I crewed on a Hornet with a sliding seat. I think the basic idea was that it was easy to slide with no crew weight on it but there was enough friction to effectively lock it into place once there was some weight on it. I don't remember any elaborate bearings, certainly no rollers, just varnished wood sliding in a slot lined with some sort of plastic IIRC.

Trapezes save a lot of weight and allow the crew to adjust his height to cope with varying sea conditions, so they have largely replaced sliding seats.
 
I sailed an Int Canoe for a couple of years (with conspicuous lack of success - I never completed a race without at least one capsize.

The construction is pretty simple, a hollow box of wedge shaped X-section so that if the wind drops you plane along on the sloping underside rather than digging in. The carriage had no fancy bearings as you don't want it sliding inboard while you're perched on the end with your feet 2' from the gunwale. The carriage has a stout metal hoop over the centre which takes a lot of the load, the slide fully extended has its inboard end just over the centre line. A rope attached to each end of the slide passes over the top of the hoop preventing you sliding it right out of the carriage and over the side. When tacking you grab the rope, give a great heave and, as long as the boat is fairly level, it goes right across. You stand on the new weather gunwale and as the boat heels the slide comes up to meet your descending bum.

There is no mechanism to lock the seat in position and the only time it moves on its own is when the mast hits the water.

Boats like the Hornet had much less extreme seats and most are now replaced by trapezes.
 
Hornets again

Hi Dan,

Like DJE, I also crewed a Hornet in the distant days of my youth when they were sliding seat boats, and also helped t rebuild one. DJE's description is spot on - you want the seat to stay in place when uou're actually sitting on it to prevent it sliding down to leeward when the boat heels, then you want it to free up when you take the weight off, so you can slide it across as you tack.

The Hornets I remember had no fancy runners but used wood (mahogany, I believe) running on brown plastic (probably tuffnel (sp?)) as the bearing arrangement. Early seats were more or less a flat plank running in a female "track" and later ones were had grooves built under the fore and aft edges of the plank so they ran on a male "track". The whole construction, seat and "track", was of timber construction, apart from the tuffnell facing on one side of the parts which run against each other. This arrangement seemed to provide just the right amount of friction.

The rope Snowleopard describes was replaced by a length of toe strap webbing, but the seat had positive timber stops to prevent the inboard end going past the centreline of the boat.

All the dinghies that employed sliders were more or less self drainining because capsizing was a regular ocurrence - not a system for a cruising dinghy, and rightly replaced by trapezes / wings for performance dinghies.

Peter
 
These are extremely helpful and detailed replies, many thanks to you. I'm sorely tempted to tell what manner of daftness led me to ask the question, but I don't want to be mocked, so silence must reign. :rolleyes:

I suppose racks/wings fitted to recent skiffs/International Moths have put the sliding seat more-or-less permanently in the history books, although I think their extremity, aboard designs like the Canoe, earn our admiration for their users' handling of them.
 
dancrane said:
I think their extremity, aboard designs like the Canoe, earn our admiration for their users' handling of them.
Click to expand...

I never progressed beyond having my feet on the gunwale, let alone hiking off the end of the seat!

2007corus_morgan_3.jpg
 
Look at rowing boat suppliers, racing rowing boats all have sliding seats - when I rowed 20 years ago these were aluminium extrusions and the seats had wheels and axles. They may have moved on since then.
 
snowleopard said:
I never progressed beyond having my feet on the gunwale, let alone hiking off the end of the seat!

2007corus_morgan_3.jpg
Click to expand...

That's a fabulous picture. Presumably such a position is only tenable in very steady winds? Or is the 'sitter' able to come in very suddenly when there's a lull? At least on the trapeze, one can bend the knees to reduce the righting effect. I expect the Sydney Harbour skiff crews fit sliding seats to their racks, then trapeze of the end of the seat, one on another's shoulders...:rolleyes:
 
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