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Working Lift Bridge Diorama


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Looks to me like you know exactly what you are doing.

Those build diagrams for the bridge, dated 23rd December, and wiring circuit for the PSU are excellent.

 

I am looking forward to looking in and seeing your progress, I can tell already its going to be a show piece which I hope the museum will keep available to visitors for a good length of time.

 

carry on the great work.

regards

Ian

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Thank God you didn't take on anything too big for your return to modelling! 😆

Certainly looks like you can handle it; it really looks good so far.  I shall follow with great interest, keep up the excellent work!

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Added 3 mm Masonite sheets for road base, kerbing, and footpath to span plate.

 

cp6Rt6Z.jpg

 

The underside has red and green navigational beacons, plus 8 contacts (shown later). To hide the wires, I decided to carve out trench to route the wires to far side of span where the framework will be. Then the wires can be attached to the framework and routed to the span hut without being too noticeable.

 

fjaiWG7.jpg

 

Then I drew up a template for the framework and started making the span frame. Used 2.5 mm bamboo skewer sticks for doweling wherever I could.

 

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While building the frame a solution anchoring the span cables to the frame came to mind. I used half a fishing swivel attached to a bolt head. Any twisting tensions on the cabling will be neutralized by the swivels.

 

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Then I placed the span on the bridge to get an idea of how the rest of the bridge may present itself.

 

kOfyNt8.jpg

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This is an amazing project. Your planning and execution are impeccable,and you really seem to know your way round the electronics involved. 

Any museum would be proud to host your work. 

 

Matt

This is an amazing project. Your planning and execution are impeccable,and you really seem to know your way round the electronics involved. 

Any museum would be proud to host your work. 

 

Matt

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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.

 

Pr6VBMf.jpg

 

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

 

ZRV2fyJ.jpg

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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.

 

n1sN6lg.jpg

 

The base plan:

 

6UfoEkA.jpg

 

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.

 

o2rt8RA.jpg

 

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.

 

qfufvki.jpg

 

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

 

5wRtZYX.jpg

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Thanks @John_W for thumbs up. And thanks @Gorby for compliment. 

 

 

Photograph of the bridge's bumper rollers.

 

cxEbilY.jpg

 

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

Only used the rollers from the microswitch actuators this time.

 

tTpdzqg.jpg

 

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

 

eqUTPHp.jpg

 

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

Here they are drying on my window sill.

 

z80z2tZ.jpg

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Thank God you didn't take on anything too big for your return to modelling! 😆

Certainly looks like you can handle it; it really looks good so far.  I shall follow with great interest, keep up the excellent work!

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Thank you @JOHN W@Gorby, @Badder, and @Derek A, for thumbs up.

 

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.

 

oRjN655.jpg

 

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

 

6M2f8NC.jpg

 

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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.

 

NyDd7gx.jpg

 

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

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Thanks fellow modellers for thumbs up.

 

to continue:
Since the console interior is to be another diorama, I decided to add a touch of drama by adding Power Status Indicators. Each DC voltage source has two LEDs. Green for all okay; Red for 'blown fuse'. Also cleaned up the terminal strips and made new set of printed numbers (1-60) for them. Then I installed the Power Supply Unit into the console.
 

gqSXtXw.jpg 


At this stage, the console was at the museum. To cut down on double handling, I got the console delivered to my place.

 

mWXPQgp.jpg

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I'm a late comer to this but hugely impressed with what I'm seeing, not a little intrigued too by the idea of the bridge operator going up & down all day. I can't help but wonder why on earth it was done like this? I'll be keeping an eye on this. :)

Steve.

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Thank you fellow modellers for your reactions.

@Sgt.Squarehead, the bridge was built in 1964. Thanks for informing me about the XXX Corps, I had to Google them to find out what you were talking about. That is what I like about this forum, plenty of stuff to learn from.

 

@stevehnz, I am not sure why the bridge operators hut was on the span. Perhaps to be in the centre to see both sides of the passing vessel. Also perhaps to get a birds-eye view once the span is raised (one could see what else was coming around the nearby river bend. Originally, the span had no traffic lights for the vessels and the operator went out onto the balcony to signal the boat to pass under.

 

When I interviewed the current operator, he told me that the hut had an upside down periscope. It was to make sure both vehicle and pedestrian traffic was clear before unlocking the bridge span. Today it has closed circuit television.

 

When the bridge was first built, there was more river traffic happening, especially for hauling logs and earth. The area is primarily used for sugar cane growing, and barges full of sugar cane were towed by a steamer. I know the barges would have no trouble getting under the bridge, but I am still not sure about the steamers used. The tug shown below ought to be able to pass under the bridge (especially on low tide).

 

Px1omWT.png

 

These days it is rare to see the bridge actually used for tall boats. I think the bridge still gets a regular (once a month) exercise in bridge raising - without having a boat to go under it.

 

 

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Thanks @stevehnz, and @Sgt.Squarehead for 'likes'.

 

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.

 

EfO5SWD.jpg

Edited by Getunderit
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1 hour ago, Sgt.Squarehead said:

Following with much interest (but limited understanding).  ;)

I am assuming you are referring to sweat-soldering the washers together. If so, this is what happens.

 

There are two ways that I know about sweat-soldering. One method is to apply a thin coat of solder on the surface of the washers that are intended to touch each other. Then rest the washers on top of each other and apply enough heat for remelting the solder, which in turn welds the washers together. The method I used was simply to put a piece of soldering wire between the washers and heated the whole lot in one go. My thinking was that the one-go method contains flux in the joining part as well as heating the solder once. As you may know, reapplying heat to solder, without flux, gets dry by oxidation (a bit brittle).

 

Hope this helped.

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44 minutes ago, stevehnz said:

We,ve got friends just north of the border we intend to visit in the next few years, I don't reckon it would be too far out of the way to go & see this, & the real thing of course. :)

Steve.

Hi Steve.

Hope the bridge will be finished and working by then :lol:

For the Aussie, 100-150 kilometer (1-1.5 hr) drive is not unusual or seen as too far away. Distance is relative I suppose. I like cycling and do about 300 kms per week. One day a week I ride 100 kms, which is equivalent from Ballina to the Queensland border. Besides that, the Ballina Naval and Maritime Museum has a huge collection of scratch-built vessels, and all sorts of real stuff. For a modeller, it can take a few hours to see it all. So be prepared for a day's outing.

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