Lattice Girder Deck Truss Bridge - Kit bashing

[zr2498]

4 hours ago, Vecchio said:

Inspired by your work I just ordered myself a bridge kit from Central Valley Model Works. Postage is quite a bit, but I think it's worth it. 

Great stuff. So which one have you opted for? Will it be a build as provided, or a kit bash?

[Enterprisingwestern]

4 hours ago, Vecchio said:

Inspired by your work I just ordered myself a bridge kit from Central Valley Model Works. Postage is quite a bit, but I think it's worth it. 

 

5 minutes ago, zr2498 said:

Great stuff. So which one have you opted for? Will it be a build as provided, or a kit bash?

 

Well, that's two of us, maybe you should be on commission!

 

Mike.

[Vecchio]

Commission is a good idea... Even more important is to share delivery....🙄 

 

Ii is going to be a kit bash - The bridge I have in mind is this one. The model I have ordered is the 150ft. HO scale Truss Bridge Kit

 

Will be a slow build. Many other things to do (like work...) and being ill every 4 weeks doesn't help.

[zr2498]

1 hour ago, Vecchio said:

Commission is a good idea... Even more important is to share delivery....🙄 

 

Ii is going to be a kit bash - The bridge I have in mind is this one. The model I have ordered is the 150ft. HO scale Truss Bridge Kit

 

Will be a slow build. Many other things to do (like work...) and being ill every 4 weeks doesn't help.

Thanks for the link. Looking forward to seeing how you approach the construction of the swing bridge, especially as it will be rotating. 

[zr2498]

For future reference, I came across some information about spacing of chairs on waybeams.

 

 

 

Wishing I had found this earlier. My waybeams are a tad wider than the scale width. This was needed to able to fit the width of 2 trimmed L1 chairs pushed together, and a wider check rail gap (for OO gauge).

I should however have 6 chairs per way beam length, rather than 7 as installed. I had scaled off poor photos but I guess it looks OK. 

 

Next is the installation of the check (guard) rails. The chairs were lined up, the gap checked with a check gauge and fixed with Butanone. The weights are needed to keep the rail and chair sitting square to the sleeper.

 

 

This was followed by finishing off the transom bolts. On the outside of the waybeams, a combination of flat washer and nut are used to tension up the bolts. These are represented by components from 'Grandt Line'

 

 

 

Two tracks completed over the waybeam portion.

 

 

The tracks will be set at 45mm between centres. The remaining parts of the tracks on the bridge assembly will consist of standard cross timbering, but with the same L1 bridge chairs to fit guard rails which will extend beyond the length of the bridge.

 

[Off Tackle]

Found this thread as I'm currently building a very small plate girder bridge with rails carried on longitudinal timbers/waybeams. This is an amazing build with museum quality level of detail and execution, very inspirational. 

 

Can't thank you enough for posting the waybeam diagram, answers a bunch of questions I've been trying to find answers to, and the clear details of your waybeam sections is really helpful too. Can I ask how deep your waybeam timbers are, and what you've made them from? I've made some up at a scale foot deep, based on eyeballing rough measurements from a photo of timbers taken off a bridge by Network Rail, but it's basically just a guesstimate.  

[zr2498]

8 minutes ago, Off Tackle said:

Found this thread as I'm currently building a very small plate girder bridge with rails carried on longitudinal timbers/waybeams. This is an amazing build with museum quality level of detail and execution, very inspirational. 

 

Can't thank you enough for posting the waybeam diagram, answers a bunch of questions I've been trying to find answers to, and the clear details of your waybeam sections is really helpful too. Can I ask how deep your waybeam timbers are, and what you've made them from? I've made some up at a scale foot deep, based on eyeballing rough measurements from a photo of timbers taken off a bridge by Network Rail, but it's basically just a guesstimate.  

 

Hello

Pleased to help. I have basically done the same as you, i.e. scaled off photos combined with looking at wood materials available.

This is what I ended up with.

The waybeam / baulk timbers are made up from the 7 X 3.2 mm strip wood 44mm and 48mm length, and the transoms from 3 X 3mm, 8.5mm length to give the required track gauge with check rails included.

The timbers are 7mm wide to accomodate the 2 X L1 trimmed chairs to take running rails and check / guard rails

 

Supplier https://www.hobbies.co.uk

 

 

 

I will end up with 3.2mm (thicker than web site value) + 0.5mm = 3.7mm (about 10 scale inches deep) as there is a strip of styrene under the track base plates. As modelled 'plating' and wooden walkways will sit alongside the waybeams the total depth will be disguised to some extent. 

Hope this helps

David

[zr2498]

Deck design detail: The plan is to have a plated deck with a walkway added on one side, and some service pipework on the other.

It's been a struggle to find any plated deck details for a bridge from photographs.

Fortunately, when the bridge for Tony Wright's Little Bytham M & GNR line was constructed, some construction drawings became available.

I will use this as the basis of the design, but the variation will be that the wooden way beams are attached to the steel rail bearer beams, with plating sections in between.

Below are parts of the M & GNR drawings

 

 

 

Before setting out the splice plates for the plate sections, the two sets of rails needed to be accurately located with the 45mm set between centres.

A pair of 'Proses' gauges were used but in a non-standard way. This would set the distance between the outside of the the 2 outer way beams. Works out at 67.25mm

 

 

Set up on the deck plate sheet (45mm between centres)

 

 

At this stage, with the rail sets centred on the styrene sheet, the position for the electrical connections were marked and 2mm holes drilled 0.5mm outside the running rails. This was done at both ends to build in a degree of redundancy.

 

 

The sheet was matched to that on the bridge and the matching holes drilled

 

 

Check of rail position

 

 

A small job done before the rail sets could be fixed.

The brass transom bolts were primed with grey enamel.

 

 

The layout of the walkway and the cross timbering (+ ballast retention timber) was set up

 

 

 

First, the walkway framework was constructed

 

A jig (3 timbers width), used to set the framework width

 

 

Some additional plates added to supprt the timbers

 

 

 

Next, the parts needed for the splicing of the deck plates. Back to some kit bashing with the CVMW double track bridge kit.

Parts from the two frets as below were used.

 

 

These parts used for the wider splice plates

 

 

And modification to the narrow strips by trimming and removing the profile on the back (via scraping with scalpel)

 

 

Parts prepared, ready for cutting to required lengths

 

 

To make the painting and weathering of the deck plates easier, the rail assemblies were attached temporarily to the styrene with tape. This would allow fixing of the splice plates, and removal of the rail assemblies prior to painting.

 

 

Splice plates fixed

 

 

A small addition to the deck plate is the access hatch for access to the walkways underneath.

Made up with another part from the same fret, plus some styrene strip and 0.5mm diameter brass for the lifting handle.

 

 

 

A few more details will be added before painting the deck

 

 

 

Edited December 17, 2022 by zr2498
Photo added

[zr2498]

Further detail for the deck plating.

The longitudinal edges of each plate, (adjacent to the waybeams) will be supported on narrow girders which also fix the waybeam position on rail bearers.

Here is a diagram to show a typical arrangement, albeit my waybeams will sit much more pround of the deck plate and also sit on longitudinal rail bearers rather than cross beams as shown below.

 

 

This will be represented as narrow splice plates along the edges

Preparation - some more kit bashing

 

Half section girders from the CVMW pack are used

First cut one side off

 

 

Then trim and thin to leave a flat

 

 

A row of plate with rivets are cut to make strips of the same width (via the chopper)

 

 

Ready to install. Each piece cut to length to fit between the transverse splicing plates

 

 

Installed

 

 

Next, is preparation of the walkway timbers

C & L sleeper timbering cut to length, holes formed to represent fixing to steel frame, and stained with Colron wood dye

 

 

 

 

To get good alignment of the rails next to those which will be installed on the future stone arches either side, I have adopted to use the Modeltech Protrack Rail Aligners. Not quite as the instructions, as the outer sleeper position is level with the edge of the deck plate. Only one rail is aligned to prevent 'over constraining' the system.

These were firmly fixed with a combination of Butanone and then superglue (Hot)

 

 

 

Next will be some service piping

[zr2498]

A couple of jobs before the piping.

To get the correct height for the wooden ballast retainers, a few strips added for a 0.75mm uplift

 

 

And to get a level for fixing the cross timbering, black 2mm styrene blocks added which is the same thickness as the rail aligners

 

 

The holes for wires will be drilled through the underneath

 

And another little detail. Although not modelled, it is assumed that there is a slight intentional bow to the plates to aid water drainage. Drain covers will be added later but some preparation first.

 

 

Sitting on 0.5mm styrene strip

 

 

Piping will be used from the Cornerstone kit

 

 

Lengths of pipe are cut via the Albion alloys jig, and then squared off on the DSPIAE sander

 

 

 

Pipe supports are made up from the kit (reduced in size), and added to kit bashed plates from the CVMW double track truss bridge kit

 

 

 

A temporary placement of the deck onto the bridge

 

 

 

 

A pause in case some detail is missed but I guess this is ready for painting!

 

 

Edited January 3, 2023 by zr2498

[simon b]

Outstanding work, cant wait to see the finished result. 

[zr2498]

There was some detail missing!

On mounting the deck to the bridge assembly, it was clear that the outer edges (adjacent to the fence), needed to match the deck splice plates.

Pieces made up as before and cut with the chopper

 

 

Added to the outer edges bridge deck

 

 

 

The track sections which were temporarily attached to the deck plate (removed before painting), allowed access to additional splice plates to be added to the deck plates between the pairs of way beams.

 

 

 

Ready for painting 🙂

 

 

[zr2498]

Painting:

The first job is to darken the white styrene with black acylic primer (brush painted). This will better match the black styrene prior to light airbrushing primer coats over the whole area of the deck

 

 

Drain covers added

 

 

Holes for M2 screws added to corners of the deck. This will enable temporary fixing until the adjoining tracks on the planned stone arches are ready.

 

 

The nickel silver etches for the deck fences will have an etch primer airbrushed prior to the acrylics.

Ideally this can have the coats of paint applied to both sides without handling them.

Jigs (fence holders), have been constructed to enable this.

 

 

 

 

 

 

 

[zr2498]

Fence painting - first coat is an etch primer

All parts were sprayed with a Pheonix Precision grey etch primer using the ‘Ian Rathbone’ mix of:

2 parts thinner (PQ2) + 1 part cellulose thinner + 1 part paint primer (PQ31A)

 

 

24 hours drying time

 

 

Then two coats of paint with the usual mix (same as the lattice framework)

 

 

For the deck painting, the strips where the rail assemblies will be glued were masked off

 

 

Acrylic primer (Panzer Grey) was first applied

 

 

Then two light coats of the usual mix + a little modulation done by light air brushing with acrylic black and then the usual mix with a little grey green added

 

 

While that was drying the service pipes were painted. Acyrilic grey primer to start, and then two coats of a cream colour (Lifecolor UA 706)

 

 

Back to the deck. Testors dullcote was sprayed over the acrylic paint prior to start of weathering.

 

The area between the way beams was darkened via a spray of Lifecolor Roof Dirt and the whole deck area darked by a very light spray of Lifecolor Weathered Black

 

 

The task of 'pin' washing with Enamel Track Wash around, and on all the splice plates was done.

This was followed by the 'sponge' technique for adding just a few area of rust chipping  (mig Old Rust)

 

 

 

Just to make sure that the weathering so far would be in keeping with that done on the lattice framework, the deck was put in place

 

 

 

 

Still more washes and then pigments needed, BUT caution as it would be too easy to over-weather. Weathering and fixing of the fences will be a challenge.

 

 

Edited January 13, 2023 by zr2498

[zr2498]

Now, to the weathering and fixing of the the deck fences

First, all the surfaces were treated to Track Wash via the rigger brush, with surplus taken off with the flat brush

 

 

The top surface of the fences on the prototype shows some pale discolouration

 

 

This was replicated with a neutral wash (heavily diluted with thinners)

 

 

And more general dirt and smoke added by a spray with Lifecolor Weathered Black

 

 

Time to marry the fences to the lattice girder assembly. As the fences basically clipped over ledges of the deck, the final fix could be done with  medium setting superglue. And then the extra plates were fixed as below.

 

 

Looking again at Findhorn Viaduct photographs the fence appear to be heavily rusted

 

 

Perhaps a little too much for my liking so I will reduce the rusting but still give the overall impression.

 

Pigments - starting with Burnt Umber,  then Army Green and a little Track Rust for colour variation

 

 

So, fences basically weathered, although some finishing touches may be done when the track deck is added

 

 

 

Next will be painting of the rails but have not yet decided on enamels or acrylics for that

[zr2498]

Back to the track.

My first track painting and weathering, so did a bit of research to get the best method to deal with tracks having so many chairs and the full length guard rails.

Decided to use enamels as possibly a little more robust, and also paint by hand rather then air brushing so as to maintain the character and colour of the wooden sleepers. I used a mix of Railmatch paints, one part Dark Rust (405) to two parts Frame Dirt (402), and enough thinners to enable good flow and coverage.

 

 

The Humbrol brushes mostly 0, and with touch up using 00 were perfect for this. Quite a lengthy task!

The paint was removed from the running rails with the edge of a ply sleeper. The guard rails will be left painted.

 

 

 

Whilst the paint was drying, some brass chairs were narrowed by filing. These will be soldered as pairs on to pretinned sleepers which will be installed at the extreme ends of each track.

 

 

 

[zr2498]

This is the range of washes and pigments to weather the deck

 

 

First the plates between the rails as they cannot be accessed once glued down

 

 

Rail section glued to the deck (no going back now!)

 

 

Cross timbering added at the ends of the deck. The DCC Concepts pre-tinned sleepers were fixed to the deck by epoxy

 

 

Brass chairs were soldered to the end sleepers and the other cross timbering chairs fixed with Butanone.

Rails were cut to length with a small over hang. This will have lift out capability.

 

 

 

Electrical connections made

 

 

End of rails painted and some more weathering of the deck. Guess it's looking rather grubby! I guess that's the idea.

 

 

 

Not the best lighting for the last couple of photos. Need to take some more in natural / better light.

Not much remaining to get to the finish 🙂

Not sure how to make the end 'black' fibre glass sleepers match the wooden timbers.

Service pipes to weather and fit, and perhaps some ballast to add at the ends?

Just past the 4,000 components 

 

 

 

[zr2498]

Service pipes

I wanted to get something similar to that seen on the Latchford viaduct

 

 

A couple of washes as below, and then dark Umber and Black Smoke pigments

 

 

The end (fibre glass) sleepers were scuffed, and then painted with Railmatch 'Sleeper Grime' enamel.

Some temporary loose ballast was added at one end to see the effect of the boundary between the plated deck, and the ballasted track which will be laid on the stone arches either side.

 

 

So basically finished, as the ballasting / cess and the final fix of the service pipes need the stone arches in place .

It's been a long journey (too long), with over 4,000 components and many hours. However, much learnt, and it will be a centre piece on the layout.

A few photos of the end result

 

 

 

 

 

 

 

 

[k22009]

Magnificent