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[Geoff]

What about a very strong eyelet at the balance point on the deck, anchored through to the keel, as this would be less intrusive and prevent strain on the mast structure. Basically hook it on and pull it up. The keel weight should keep the model stable

Cheers

Geoff

[tigertiger]

That would be fairly simple, except that the model will weigh 17-20kg.
Hard on the arms/back mostly.


Some kind of derrick, or something else, is still needed to swing the boat out for launch and back for recovery.

[Colin Bishop]

So what happens if the boat sails off and gets stuck somewhere else and cannot be brought back to the launching site?

Colin

[Umi_Ryuzuki]

Would you be allowed to build, or mount a derrick or plant a post at the site?

[Geoff]

A derrick post can be interlocked with the railings so would be easily removable.

G

[Shipmate60]

Thinking a bit out of the box.
Would it be possible to design a set of steps that could hang on the guardrails.
Or a roof ladder with a cradle sliding on the uprights.
Just a thought.


Bob

[tigertiger]

I could temporarily attach a heavy plastic pipe to the uprights of the guard rail to act as a base for a derrick. Although I have no experience with building derricks. Any design would have to be able to support the weight of 20kg, with a lever effect of at least 500mm.
Any advice on that would be helpful.


The house ladder is also a simple idea. I had considered the rail idea mentioned on the last page, but it was getting a bit complicated. The ladder would be much simpler. I could get around some transport issues by using the ladder as part of the trolley. As the ladder would need to be 3m.

[Shipmate60]

Folding or telescopic ladder?


Bob

[RAAArtyGunner]

Can't draw so KISS, how about a vertical post, max one metre, secured to a handrail upright with say two U-bolts with wing nuts, easy to fix.
Thence a horizontal, long enough to swing out and clear the pathway.
Two slings for boat lowered via a simple block and tackle system, double blocks would handle the load easily and require little effort to operate.
The hard part is aligning the boat for recovery to allow slings to align under and the reverse procedure to raise the boat.

Much same when launching full size with spreader at top to keep slings apart for boat to sail in for recovery.

There is no reason why it can't be built out of timber particularly if metal working is not your forte and be "collapsible" for transportation.

[Umi_Ryuzuki]

I have been and checked, sadly there is no wall.
If I did use a trolley, I would make sure it did not float. The same for any cradle I might make.
The handrail is only at 500mm height, a bit of a lift but do-able. No matter what the solution, I have to lift the boat, or boat plus cradle, over the hand rail.
Getting up the steps with the boat would need the boat to go fore and aft, or lift it above the rails, as the gap between rails is only 1.1m.

The rough layout of the platform is shown in the diagram below.

I think I just created Raartygunner's design... LoL

Take a piece of plywood and drill four holes in it so that you can mount U bolts to the plywood.
Place them at a height that when you put the plywood an u-bolts on the outside of the railing, the
u-bolts pass between  and under the rails. Then drop a piece of bamboo through the u-bolts and tighten them up.
That gives you a vertical support. Better yet, just use disposable zip ties instead of U-bolts.

On the top of your bamboo vertical you can mount a horizontal bamboo pole to hold a pully, and backstay to
That can be tied down at the back of  the post. If an offset mounting bracket is created you can bolt the vertical and
horizontal in a manner that will allow them to fold for transport and storage.

[RAAArtyGunner]

Umi,

Yes, You have it in one.

Well done 

[tigertiger]

Now we are getting somewhere   
I like the idea of a wire stay at the rear. This would be so much stronger than a cantilever.
I don't think I could use zip ties, as I have found that they stretch and creep a lot, and the upright could go a long way off vertical.
A slight variation would be to attach a HD plastic pipe to the guardrail uprights with the U Bolts. The upright pole could then swivel in the tube. This means that the joint at the top of the upright does not need to swivel.
I am not sure what would be stronger/more stable. A swivel at the base end or a swivel joint at the top.

[Colin Bishop]

Just out of interest TT, what is the likely reaction of the authorities to what you are proposing? For example if a policeman discovers you attaching a hoisting mechanism to a public railing?

Colin

[tigertiger]

I have been chased off of public waters before. The general attitude of many security guards (China has mall cops for everything from school gates, to public parks) is that, if there isn't a rule permitting it, it must be prohibited. It only takes one person to say, 'I don't think he should be doing that', for a butt covering exercise to ensue.


However, the water where I sail (the one in question here) is at the back of our property development. Our bank is private property/public area for residents only. No cops. As long as I didn't attach anything permanently, or anything that did damage, I don't envisage any problems.

[John W E]

Hi TT, just out of curiosity how deep is the river that you wish to sail in? Is it too deep to stand in with waders? As I was thinking that maybe you could convert an old rucksack to carry a model on your back and climb down the ladder into the water? problem solved, just requires one ladder and one converted rucksack

john

[tigertiger]

As it is, I could handball the model and climb 1.5 m down 2 big rocks to get down to the waters edge. I do this with my smaller models, and stand on a platform made of cinder blocks about 2ft square for launch.
But the model in question will weigh 17-20kg, and be approx. 1.5 m long with bowsprit, and the model will be approx 1.5m tall from keel to top of mast. Rigging it after launch is not really an option. Handballing I don't fancy.

[grendel]

if there are steps down to the water, can you manufacture a slipway to launch and retrieve the boat, this can then be placed on the steps and provide a ramp to place the boat into and out of the water, alternatively a launch trolley designed to fit on the columns.

[tigertiger]

There are no steps. Generally in China the water's edge is high banked with no access directly to the water. It stops people drowning, washing clothes (yes even in middle class neighborhoods, any free resource is exploited) or car washing. There is also this thing of corralling nature.


What I will do, is go back to the site tomorrow to see what tricks I have missed.

[ChrisF]

A couple of photos would be good.

[Bob K]

A Sikorsky S-64 Skycrane  Helicopter ?    (OK, ideas getting desperate !)   

[RAAArtyGunner]

Now we are getting somewhere   
I like the idea of a wire stay at the rear. This would be so much stronger than a cantilever.
I don't think I could use zip ties, as I have found that they stretch and creep a lot, and the upright could go a long way off vertical.
A slight variation would be to attach a HD plastic pipe to the guardrail uprights with the U Bolts. The upright pole could then swivel in the tube. This means that the joint at the top of the upright does not need to swivel.
I am not sure what would be stronger/more stable. A swivel at the base end or a swivel joint at the top.

If you used a tube, a good idea, and it was slightly loose to suit the "pole', no need for swivel bases etc, just swing it, the vertical pole, to and fro via the horizontal.
Umi's drawing is basically a simplified "crane" which you can refine/alter to suit.

[boneash]

                                   I hope this works!!

[Big Ada]

Umi's plan looks good but you still have to wind the boat up, and that's a lot of weight, I think you may need to gear it for easier winding.

Len.

[John W E]

hi there

Looking at Umi's plan - the only thing that I would be concerned about is - with it being a yacht and on a single lift - with any wind, which there should be, if you are sailing a yacht - once you start to lift the yacht in or out of the water - the wind will begin to blow it all over the place.   That could cause a lot of damage if it is blown in to the wall. 

I have put a rough sketch on of what they had at Ryhope Pumping Station; to lift the boats in and out of the ponds.  Where they had channels, you could supplement them with an aluminium ladder.   I made this sketch while I was eating a beef curry as you will see

Before I forget, I am sure MachineMart have cheap hand winches in for sale.

John

[stringer]

Hi bluebird
As we are taking this problem seriously, as a shop floor tin basher in a very large engineering company, it was not unusual for planning to put a planning sheet onto the shop floor that looks good, but they forgot to run the process.
When the trolley moves down the ladder it has to get pass the platform, but there is the bracket at the back of the trolley that keeps the wheel on the ladder which now looks like it stops the trolley on the edge of the platform, we the shop floor as professional tin bashers know how to get round the problem, but we are returning the planning sheet back to the planners as a problem
Only joking bluebird you need something to hold the ladder off the platform, but I do like your idea the best so far, I bet that Beef curry tasted nice
Geoff