Thread: Slipway material

how is the slipway supported?

is it run on a cement slab or on piers?

cheers

In the boatshed it will be on a concrete floor.

Once outside the door it will go across a 1.5 metre concrete pad (to be laid) and then has to cross 2metres before it hits the bottom of the lake.

I plan on having welded legs and feet to bury in the lakebed to support the slip at 1 metre intervals.

The slip will only support a Hobie Cat so around 250lb or 120kg plus trolley at perhaps 25kg.

I think this is of sufficient strength but as always it's worth getting other, like minded, people's opinion.

I've built a garden railway, using pvc pipe for track. Narrow gauge, and movable track sections which latch together for assembly. Much simpler than bolts. Can easily support 250-lb on each carriage. I usually use it for moving heavy logs, and the locomotive is a work in non-progress. It's still night here, but I can post some pictures tomorrow. My track lengths are about 6 feet, but standard length of 20 feet (~6m) would likely be manageable, including cross ties. For wider gauge, shorter lengths and cross-bracing would be advisable.

Cheers,
Joe

Here are some pictures of my garden railway. I'll post something more comprehensive when I complete the locomotive.

The rails are pvc pipe, 1" nominal IPS. Sections are connected with over-center latches. The slot in the alignment dowel accommodates the bulged end of pop rivets attaching the latch. The extra holes were used in a previous connector design. Newer cross-tie connectors are placed away from the running surface.

Carriages were originally built to hold plastic buckets of dirt for crawl space excavation. I made a couple swivel plates to hold logs. The swivels allow passage along curved track. The carriage wheels were harvested from inline skates from garage sales.

I didn't actually use the railway for these logs, because the distance was too short to justify it. This setup was strictly for photography. I have, however, used it for much larger logs.

A more robust development may use all pvc instead of wood. Some sizes of pvc pipe telescope with one another (for the dowels), and partial pipe fittings could also be used for sleeper attachment.

I see no reason why this scheme couldn't be scaled up for your application. The pipe is certainly strong enough. Lightweight, portable track systems like this are also used for dolly tracks for cinematography. Mobile camera carriers are generally heavier than small boats, especially with one or two camera operators aboard.

Cheers,
Joe

Our Australian sun eats poly pipe left exposed.

Additionally the wave action (we have up to 3" waves on the lake) would most likely knock it around too much.

I like your wheels. How do you keep them on the rails without any flanges?

I was looking at making wheels with a double flange from a large quantity of nylon material I obtained from our State railways. Same material as cutting boards and about 10mm thick.

I'm certainly open to suggestions.

plastic pipe is used in the film industry for dolly track...they run the carrage on either rollerscate or rollerblade wheels.

They way they get them to track is they mount two wheels at 90 deg.. both at 45 deg to vertical.

If you were to run plastic pipe......you would have to go with one of the black plastics.....high preasure black polly pipe might be the go.

OR

HFT electrical conduit

both stand up in the sun pretty well... but the pollypipe comes in continuous lengths so it would be possible to do it with no joins... but you would still have to come up with a streader system and tie it down.

I may just be simpler to go steel..... But I recon channel would be the go..and you just run standard tyres in the channel....on the cement you more or less just bolt it down.....from there you will need to weld spreaders in and support it however.

Having seen the renovation of a local boat ramp..... why not just run cement all the way down past the LAT point...there are a number of ways of doing that.....if it is slab all the way down you only need 1 track.. and that could be channel..and the trailer could remain unmodified and able to run on the road.

cheers

G'day, mates. Still daytime here.

Like soundman says, CPVC pipe or conduit is UV-stabilized, and more resistant to deterioration.

The carriages in the crate are stored with the tops facing you. Just beyond the nearest wheels, are plastic bottle caps attached to the undersides. They provide enough lateral support for guidance. On some mobile camera platforms I've seen, the wheels have a reverse crown, like the inside of a donut. And there are other standard wheels with a V-shaped notch on the rim to ride on angle iron with the open side down, and welded to flat plates. Pairs of wheels also work well, as soundman says.

Dolly tracks usually have folding cross ties, to collapse into side-by-side rails from rectangular to parallelogram to flat.

For your wider gauge, diagonal cross bracing could hold the spreaders in position. And bags of shot could be lowered onto the spreaders for ballast, with lines to floats for retrieval.

This might not be the perfect solution, but it's food for thought.

Cheers,
Joe

We get up to 3' waves on the lake so I can't see the poly pipe surviving too many seasons.

I'll have another think about it and see if any other viable alternatives pop up.

I don't want to use any timber as it only rots away so steel is the obvious material.

I'd looked at using stainless steel but my welding skills aren't up to that.

Black high preasure polly is pretty damn tough stuff.....if you can nail it down well enough it should last plenty good.

cheers

I can "nail down" the first 6-7 metres of the slip then the next 2 are suspended over low a seawall until it hits the lake bed.

I would need to support the 2 metres where it goes over the seawall then work out some way of "nailing it down" to the lake bed.

I thnk I need weight/stength to hold it in place and/or span the gap after the seawall.

Perhaps that why originally they used 90lb rail line.

I'd looked at using stainless steel but my welding skills aren't up to that.

I think the price would scare you more. As one of my steel suppliers recently said to me, "stainless is drug money!!". Dont recon stainless is that bad to weld myself.

As previously stated black high pressure poly is quite tuff. Maybe replace joe greiner's timber cross members with concrete blocks.

The price of stainless doesn't bother me unduly. What it costs it costs. If you want it to last you need to put your hand in your pocket.

I have a problem making the poly pipe stretch over 2 metres without any support where it crosses the sea wall.

Still exercising my mind on this problem.

Word pictures have apparently become inadequate. Can you post a sketch showing a side view of the situation? Preferably with approximate dimensions and slope of the slipway, waterline locations, etc. Bridging the gap might be done with a separate support structure. Building the whole affair based on the shorter requirement isn't the way it's usually done, especially if it doesn't need to be removable.

Cheers,
Joe

Sorry no photos. The slip is 100km away at the weekender.

The slip runs at a pretty constant angle of (approx) 15degrees.

The biggest problem is getting over the seawall and onto the bottom of the lake.

Additionally whatever I put in there must be heavy enough to not try and wash away or move with wave action.

Those two reasons are why I keep go back to steel in my thoughts.

I appreciate the ideas/suggestions so please keep making them.