ikcdab

3 minutes ago, fulton said:

My bridge is similar, but supported by plate girders, the deck is open with just the area between the rails filled in, there is a walkway either side, the main structural baulks supporting the rails would be first, then the decking is just an infill, I walk under this bridge each time I go shopping.

Looks really good. My issue would be intalling the infill in the four foot as i have 3d printed complete track bases. I suppose I could add planking on top of the transoms.

Where is the prototype?

Ian

23 minutes ago, Philou said:

Hi,

 

I'm just doing a bridge deck using baulks (I assume your waybeams) with longitudinal beams under the alignment of the rails with a deck in-between.

 

You might find this link interesting as it shows waybeams and the transoms in detail:

 

https://assets.publishing.service.gov.uk/media/64f098e0a78c5f0010c6f3a0/R122020_201116_Wanstead_Park.pdf

 

Whilst my bridge is nowhere as sophisticated as yours (I doff my hat your way) perhaps you'd like to see my construction method from about page 40 onwards:

 

 

Cheers,

 

Philip

 

I forgot to add that you can have a clear look at the underside of the bridge via Google StreetView.

Hi Philip, thank you thats very helpful.

I am so tempted just to stick down sheets of scribed plasticard and put the track on top and your link shows me that this is an acceptable approach!

Once the track is down i might add some extra walkways either side of the track, we will see.

Thanks again

Ian

Some of you will have seen my layout thread where I am building a steel double track girder Bridge

As you will see, the structure is complete. I also have longitudinal girders which I have made but not in the photos.

I am not sure how best to do the decking. 

The track is laid on waybeams.

In order to keep smooth flowing track, i plan to install the bridge, then add the track afterwards so that i get the nice, sweeping gentle curve I need. If i lay track on each bridge section first then it would be difficult to get the smooth curve i want.

I seem to have two options

1. The easiest.  Lay an overall plasticard deck then lay the track on top of the planking. I can then turn the structure upside down and glue the longitudal girders to the plasticard.

As I said, this much the easiest way, but.. Is it prototypical?  I have looked at loads of pics of waybeam bridges, and they all seem to be different. I have found a few when it looks as if the decking is under the waybeams.

2.  Second option is to lay the waybeams directly onto the cross girders, then glue the longitudinal girders under each waybeam. Then I can cut planking to go either side of the tracks. I suspect (though I don't know) that this is more prototypical but will be harder to accomplish. I. Also don't know what then happens in the four foot. Do I lay planking on top of the transoms?

I really don't know the best way to do this, any comments gratefully received!

1 hour ago, MikuMatt81 said:

 

That GM500 unit looks interesting, so I can hook up my existing GMC-PM2 motor to the GM500, and have it manage polarity switching for me, is that correct?

 

If so id happily buy a bunch of these if meant I could use my existing PM2 motors.

why buy thise when this sort of thing is more flexible, cost effective and easier to use:

https://www.ebay.co.uk/itm/123790409463?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=9hOxI6nZQ-6&sssrc=2047675&ssuid=oMX1GZ5VQyG&var=425275799840&widget_ver=artemis&media=COPY

2 hours ago, MikuMatt81 said:

 

The problem I have is that I already have very basic Gaugemaster GMC-PM2 point motors fitted, which of course  dont support polarity switching. 

 

I could of course easily buy new point motors, but everything is already such a tight fit under my highly compressed layout, (with Dapol signal motors and all sorts of everything in the way of the point motors),  id struggle to even get the old motors out and replaced.

 

If you really feel live frogs are the only way to go, very sadly id have to can the project before it gets started 😢

 

 

If you want decent running and something which looks the part, then live frog IS the only way to go. It is also far simpler.

And dont worry about the point motors - use what you have and just switch the polarity with a miniature relay that can be sited anywhere out of the way. It really is simple to do, the miniature rerlays are very cheap and its very satisfying too.

My railway (see thread in my sig) is housed in a 7.5m x 4.5m shed in the garden.

Providing its lined and fully insulated then there will be no damp problems. In the winter i leave an oil-filled radiator on over night but only in the winter months.

The fully insulated is the most important part. I have 75mm loft roll in all walls and in the roof andf there is thick polythene underneath the exterior cladding.  The shed is raised slightly above the ground so there is air circulation underneath.

I actually built my own shed. It really isn't that difficult  - its simple carpentry. My fully insulated, lined shed with flooring, electrics and lighting cost me around £3500, homebuilt in 2020.

I also wonder why you limit yourself to the PD maximum sizes. You can build a shed whatever size you like if you get planning permission for it.  Its not that expensive and worth doing for something that is a long term investment. You could discuss it with your local planning dept and see what they say.

And a final thought, if you do stick to the PD maximium sizes, you can still have external tracks which in O gauge are very practical.  So a garden railway with the main bits being in your shed.

2 minutes ago, rovex said:

Thanks. I'll make sure I split my orders in future to keep the below the limit, but of course that will put up the postal charges!

 

Which makes me ask again does anyone know a UK equivalent to Shapeways?

There are loads of people who will print 3d files for you...but you need to have the file to print from.

So unless you can persuade someone to give you a .stl file, then you are stuck with shapeways.

Depending on what you are producing, you could use something like fusion 360 and design your own - its not that difficult, depending on what it is you are printing.

16 minutes ago, Enterprisingwestern said:

 

Sitting!!

 

Mike

Haha! Yes of course!

23 minutes ago, Piskey said:

Just what dining tables are meant for!  No curve to your bridge then.

 

That's mighty impressive Ian, so pleased I was able to assist a little. 

 

Peter

Hi Peter, there will be a very gentle curve but not as much as the original!

And so the 3d printer has been working overtime. 

The main girders are 466mm long so clearly far too long for the printer.  I have split them into three sections for printing.  

For the outer ends, I uploaded one end to the printer then just flipped it mirror image to make to other end. My sharp eyed daughter spotted that the 2024 little date plaque also got mirrored so I have some mirror text. Luckily it's all too small to see really. 

Here are one set of girders ready to be joined together.

So this is the bridge I am trying to recreate.  Little Petherick Creek bridge near Padstow.

Made a trip there over Easter and got a lot of detailed pictures

Found out a lot. Seems like the square sections at the top of the pillars are hollow...I have designed them as solid granite or concrete pads.

Oh well, my bridge is "inspired by" rather than an exact copy!

If you do this, all you will be reporting by the led being on is that you have pushed the button. I'm imagine it might be easy for things to get out of sync and for the panel to display the wrong aspect.

You might be better to rig a microswitch to the actual point operating bar. When the point moves, the microswitch is operated and this could trigger a spdt relay to operate one led in one direction and another when the point is lying the other way. If you are using servos on your points then it's easy to rig a microswitch to be triggered when the servo horn rotated. Loads of stuff online about it.

21 minutes ago, MikeB said:

I agree with Jeremy, with one caveat.  If it is a series of identical street lights, for example, one resistor is OK.  If colour light signals, the different colour LEDs have different properties and having individual resistors may help each colour to be of similar intensity.  I'm sure somebody more knowledgeable can explain this in terms of the typical current /resistance of different colour LEDs.

i think that, bearing in mind the "rounding" that goes into choosing resistors from the standard values, the differences are so little that the same resistor fits all for our white/red/green/yellow purposes. For a 12v supply, start with a 1k resistor. You can tweek this as much as you like, but I dont think that it will make much difference to individual colours.

Sat by the lineside by Charlton Bridge Junction waiting for the next train... 

That's quite a wide period,  could be colletts, Hawksworths or mk1s, or a mix! 

It would have varied a lot over the period, you're looking at a brake, a restaurant car then a mix of firsts and thirds.

You might be lucky enough to find some operating notices, otherwise, photos might be the best bet.

11 hours ago, stevel said:

Wow, just discovered this thread and have enjoyed reading through it. I love the railway in the landscape feeling you have captured. Look forward to seeing the progress.

 

Stephen 

2 hours ago, Fishplate said:

 

I've just finished reading through as well👍. Very nice layout.

Thanks to both.  The bridge is coming on well will post details soon

glue blobs

i think you can get transfers - look at the railtec transfer page and search for rivets. Loads come up.

Indent with a sharp point

3d print 

i havent checked, but Lanakshire Models is my go to for buffers.

At Williton on the WSR, the level crossing gates adjacent to the box are worked by hand, not by a gate wheel. Once the gates are across the road, then they are bolted by a lever in the box.

When I first started as a signalman at Williton in 1984, the gates were closed by hand, then locked with a hand lever on the gate. This lever was connected to a long rod that reached back to the hinge post: moving the handle moved the rod that then caused a simple bolthole at the hinge post to rotate to line up to take the bolt that was operated by the lever from the box. I always thought this was a weak mechanism, the rod always seems whippy and if things were worn, then i think the gates could have been opened even when bolted. At some point this mechanism has been replaced with a much neater solution that just locks the catch - the attached pic is fairly self-explanatory.

I presume that the original design was of GWR origin, maybe even B&E as the gate locking dates from the 1870s. 

I also presume that the current mechanism is a more modern BR(W) design?

I cannot now remember when the locking was updated, i guess it was more than 20 years ago. Its a pity as the original was (I presume) a heritage feature that was unceremoniously ripped out and discarded.

Can anyone add any details on GWR or BR(W) manual level crossing gate bolting mechanisms?

I guess this is the old split chassis design. With any problem like this you need to approach it systematically. I would apply power directly to the motor terminals and see if the motor runs. Then work back from there. Its split chassis, so you need to make sure that there is continuity from the wheel treads to the chassis and nothing is bridging the insulation gaps.

I do stir very well between prints as I do think there is some kind of separation of the resin if I let it stand. 

But I don't think resin goes off like that? It isn't an organic compound.

I have recently been printing parts with 4mm scale rivets.  I am finding miniature indentations on the FEP after printing.  I am now thinking that maybe some of the rivets were not supported and ended up floating in the resin. Next print they end up getting compressed by the build plate and indent into the FEP. So filtering resin is my new cause celebre.

20 hours ago, PortLineParker said:

Hi all,

 

Just a quick one; picture a hypothetical section of single track with a 2 platform station along its length. The line passes through the station and a loop is located on the Down side, something like below:

 

If a through train was approaching the station from the left and both lines were clear, would the train still pass into the left hand track to always be on the left hand side or would the through line be set? I was wondering as on the S&D Henstridge was one such station among a few and with trains such as the Pines Express passing through, would they have been given a straight run through or would they have had to slow to negotiate the points at either end of the loop? It sounds silly now I've typed it out but I've been thinking about it for a while and I wonder if anyone knew of any concrete practice or first hand knowledge?

 

Cheers,

 

PLP

Its worth remembering that regular or normal services should only use a properly signalled route. In an emergency then different rules apply, but here I am referring to normal, timetabled services.

For passenger trains, that means that any facing points must be capable of being locked and there should be a signal authorising movement over the points.

If those are not supplied then the answer to your question is yes, the train will always take the left hand route. 

The standard pw hut came with a toolshed that is similar to the one you show. But the ones I have seen do not have windows, so I'm not sure. 

The whole point of these prefabricated buildings was that parts were interchangeable and so all sorts of variations can occur. 

The only thing we can be certain of is that it's a storage shed of some sort.