Lift-span Bridge

[Peter HausamannParticipant @peterhausamann71795]

Posted by Jeff Dayman on 08/01/2018 18:29:37:

Hi Peter, you are doing a great job on the bridge model project and are moving right along. Thanks for sharing the pics too. JD

Thanks Jeff Dayman.

At the moment, I am posting photos at piecemeal rate until the progress catches up to where I am at. Then things will slow down. I came to this forum late in the project.

[Peter HausamannParticipant @peterhausamann71795]

I found some springy shim metal and cut out eight contact plates. Installed the contacts, LED navigational lights, and wiring.

The wires are routed to where the frame vertical beams are, so to guide the wires to the span hut.

I filled the trench work with wood putty (after I checked for electrical continuity). Then sanded and painted the span with white acrylic undercoat.

[Peter HausamannParticipant @peterhausamann71795]

Luckily I came across a few photographs of Wardell Bridge via a Company that uses drones for aerial photography. Form these photos I was able to draw a plan for the span hut.

The base plan:

[Peter HausamannParticipant @peterhausamann71795]

Used 3 mm MDF board for hut and gangways, and matchsticks for rail posts.

The extra board you see is the hut floor. I am going to used its edge for gluing the hut walls to.

The rectangular hole is where the wiring will come up from under the span.

 

 

You can see the cable anchoring points have been inserted. I used microswitch actuator arms (the roller type) for bumper rollers. These ones are for longitudinal movements of the span. They are to stop the span from getting caught onto the towers when the span raises and lowers. On one corner is also an opto-couple used for triggering the vessel traffic lights from red to green once the span reaches its upper limit.

 

 

Edited By Peter Hausamann on 10/01/2018 09:38:46

[Peter HausamannParticipant @peterhausamann71795]

The wires got routed to the hut. Glued the wires against the framework for concealment.

 

[Peter HausamannParticipant @peterhausamann71795]

Photograph of the bridge's bumper rollers.

Built another set of four bumper rollers but for lateral movement this time.

Only used the rollers from the microswitch actuators this time.

Added the vessel traffic lights to the centre of the span.

There are several containers on the balconies. These are made from block timber and painted.

Here they are drying on my window sill.

[Peter HausamannParticipant @peterhausamann71795]

Used 3 mm MDF board, 2 mm clear Perspex, and white card to build the hut walls. I was surprised how well the Perspex can give that glass window effect (slight reflection and parallax error). The four tabs at top of walls is for positioning the roof.

Added split bamboo skewers for railings, and fly screen for mesh. Started to paint the span with a home mixed, Bridge Grey oil enamel.

Found some washers that fit over the LED nav; lights. Now they look more like beacons.
Added railings for the road and footpath. Gave that a paint. Will paint road later.

To be honest, at this point of model making I felt really good on how the span turned out.

[I.M. OUTAHEREParticipant @i-m-outahere]

Peter that looks fantastic ! It's amazing how a coat of paint can bring a model to life !

Ian.

[Neil WyattModerator @neilwyatt]

That last photo is knockout.

[Peter HausamannParticipant @peterhausamann71795]

Thanks Ian and Neil for supporting comments.

Added blown fuse indicators for the DC voltages. Also replaced terminal numbers with new printed ones.

[Peter HausamannParticipant @peterhausamann71795]

Doweling the framework

Unbelievably, there is over 11 metres of framing put into the towers.

Edited By Peter Hausamann on 15/01/2018 20:20:29

Edited By Peter Hausamann on 15/01/2018 20:20:45

[Peter HausamannParticipant @peterhausamann71795]

The pulley wheels I wanted were too expensive (to buy ten of them). So I came up with an alternative by solder-sweating different sized washers together.
My first attempt had too much solder, but got it right after that.

[SillyOldDufferModerator @sillyoldduffer]

Most impressive Peter. Have you thought that your construction photos could be part of the museum display? The original bridge is interesting, your model bridge will be interesting and so is how you made it.

Dave

[Peter HausamannParticipant @peterhausamann71795]

Posted by SillyOldDuffer on 16/01/2018 20:35:34:

Most impressive Peter. Have you thought that your construction photos could be part of the museum display? The original bridge is interesting, your model bridge will be interesting and so is how you made it.

Dave

Thanks Dave for response. I don't think there will be any call or room for that at the display. There will be a background painting to this display as well (no wall space for pictures). Besides, not many modellers, who are interested in such things, are amongst the visitors to the museum.

I am recording my design drawings, construction notes, troubleshooting and repair notes for a ring binder (Operating and Service Manual) as I go along. All photos are being stored on a memory stick. It will be stored in the museum library. However, any person can become a museum member ($2 annual fee) and have access to its extensive library, including the Bridge Manual (when completed).

[Peter HausamannParticipant @peterhausamann71795]

Designing and constructing the pulley wheel brackets.

[Peter HausamannParticipant @peterhausamann71795]

The towers are not actually in place in these photographs. They are just positioned to see how it will look, and how close the span bumpers would get to the towers.

The towers have to be installed at the same time as the road surface.

[Peter HausamannParticipant @peterhausamann71795]

Added gangway and paint to the towers.

[Peter HausamannParticipant @peterhausamann71795]

Created traffic lights with large 5 mm LEDs (easier to see from a behind point of view). They turned out over scale, but I am sure the Ballina Museum can live with it.

[Martin WParticipant @martinw]

The more you build the more impressive this project becomes. Looking forward to seeing it in its completed form and perhaps a video of it working. Great stuff.

Martin W

[Peter HausamannParticipant @peterhausamann71795]

Thanks Martin W, I sure hope it all works out okay.

I discovered before installing the towers that once they are in, the span cannot be removed for repairs. There won't be enough room to pass above the pulley wheels. So I cut off the lateral bumper rollers (the hidden side) and replaced them with removable ones.

[Peter HausamannParticipant @peterhausamann71795]

Prepared road base. Installed the necessary span and traffic lights wiring along bridge girders. Assembled road, towers and traffic lights in one go.

[Peter HausamannParticipant @peterhausamann71795]

Took me a few days to add all the matchstick posts and split bamboo skewer railings.

[Peter HausamannParticipant @peterhausamann71795]

Tilted display table on edge to ease the working on the wiring harness. Wires from bridge got terminated and then harnessed to where the Control Box will be.

[I.M. OUTAHEREParticipant @i-m-outahere]

Took me a few days to add all the matchstick posts and split bamboo skewer railings.

I would have taken months to do this and still probably still never got it right !

Ian.

[Peter HausamannParticipant @peterhausamann71795]

Posted by XD 351 on 25/01/2018 05:46:48:

Took me a few days to add all the matchstick posts and split bamboo skewer railings.

I would have taken months to do this and still probably still never got it right !

Ian.

Ha ha ha. Thanks Ian for compliment.

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