Bridges

[The Hood]

As we are very short on bridges I'm going to try and fill that gap next.  At the minute I'm proposing the following types for immediate attention:
Plate Girder e.g. http://www.newrailwaymodellers.co.uk/images/bridges/large/boughton1.jpg (done)
Truss e.g. http://www.flickr.com/photos/4737carlin/2406455006/in/gallery-tom-swailes-72157622846469784/
Concrete viaduct (elevated way version as well) e.g. http://www.flickr.com/photos/hamishfenton/4471109766/
Wrought Iron arch bridge e.g. http://www.london-traveltips.com/pics/blackfriars-bridge-st-pauls-cathedral.jpg
Wrought iron viaduct (elevated way version as well) e.g. http://adriadavidson.com/blog/wp-content/uploads/2011/01/georges_dock_building.jpg
Wrought iron trestle (see below)
Wooden viaduct e.g. en.wikipedia.org/wiki/Cornwall_Railway_viaducts

I've tried to stick to ones which will look good in simutrans (so no requests for the forth bridge please unless you plan to implement a patch to allow bridges with different images for different tiles along the length like in transport tycoon!).

If you have any thoughts about these, e.g. speeds and weight limits, or any other good designs to try, post here.  I'll also keep updates here as and when they happen.

EDIT: first preview: plate girder railway bridge (only a preview; needs snow, and pillars for longer versions as well as some sensible data).  I've reused most of the brick viaduct sprites for the approaches and the only new images are for the spans themselves; I think it looks OK but I'd be interested to see if others agree.

[jamespetts]

Excellent! Just what we needed. Incidentally, I suggest that you look at some of the bridges in the Experimental version, which define bridge types along with various limits, relative costs, etc., albeit have no graphics - if you want ideas as to bridge types, you could do worse than to look there. (I notice that many of your types fit in more or less with those types in any event).

As to the plate girder bridge, why don't you make two versions - one that can only span one or two tiles (perhaps in a different colour) and one that can be longer, with pillars? You could make the shorter type cheaper per tile: see the various Experimental bridges (without their own graphics) for an idea as to what I mean. In any event, however, that bridge does look lovely.

[The Hood]

To be honest James I'm no civil engineer and I can't quite relate the descriptions in experimental to what they are supposed to look like.  If you could post pictures of what each is supposed to look like that would be good. 

Secondly there is no need I can see for two versions of the bridge with and without pillars; I am planning on making the pillar distance 2 tiles so 1-2 tile bridges wouldn't get pillars anyway.

[jamespetts]

Will try to have a go when I can - am a bit busy to-day having a tea party...

[AP]

EDIT: first preview: plate girder railway bridge

Looks good!

Can I suggest a wrought iron trestle/truss type? It's quite an important early design, and about the only one which could be used for overly tall viaducts. At present we have a vaguely-American wooden trestle, which can be built tall, but that looks a bit odd (and is very slow). With metal truss  bridges, the piers just extend which is how simultrans seems to handle such things (not sure if the taper is possible). For those of us who like hilly maps it'd be rather an improvement.

The classic UK precedents are Belah and Crumlin viaduct (1850s) and Meldon viaduct (1870s). EDIT: Google throws up some less lofty versions of the design e.g. Bennerley.

[The Hood]

Good suggestions AP, I've ammended the first post.  I'll do those all as a single type of iron trestle viaduct.  Any reason why you removed the link to the cornish trestle viaducts?

[AP]

Heh, you're clearly too quick for me.  I removed my Brunel's Cornish viaducts comment it because I saw your perfectly fair remark about the Forth bridge, and thought they might be similarly a bit more complex. Also because they're not that 'flat' - ie they only work if they are sufficiently tall to allow the 'fan', and I wasn't sure Simutrans could handle that. Although now I think about it, the game handles arches okay, so perhaps...

[The Hood]

I would make the fans the same height as the arches currently, with pillars making up the rest - we'll see if it looks good.

[AP]

It would certainly be great to get them in-game - they were both quite distinctive visually and economically - low initial outlay but higher ongoing maintenance costs - hence they were all replaced later on. That's certainly something which could make them useful in-game (as in reality).

[greenling]

The Photos From the Old Bridge be Very Nice.
Thumbs UP!

[jamespetts]

Some pictures for the various bridge types in Experimental without graphics:

1. Short steel girder (will suffice for heavy/light versions - perhaps different colours for each):



2. Light box girder:



3. Normal box girder:



4. Supported Steel Lattice Bridge

This is the same type as AP has identified above

5. Cantilever

This is the forth bridge type that you consider too difficult

6. Suspension bridges (various)

Many, but see, for example:



7. Concrete spanning bridge (various light/heavy, etc.)



8. Concrete supported bridge (various light/heavy, etc.)



We could probably also do with a bridge like this crescent bridge:

[The Hood]

Latest update: snow version and road version complete:



Regarding the above James, most should be possible (although the suspension bridge also falls into the same category as the cantilever - not that it's too difficult to draw but that simutrans doesn't support "long" bridges which aren't made up of repeating 1x1 tiles).  The last two look essentially the same though (just one has intermediate pillars).

[The Hood]

Preview: steel truss bridge.  I'm planning on doing new approach sprites for these.  What do we think about player colours?  Worth it?  Should I do player colours for the plate girder too?

[sdog]

the pak-britain player colours are very well chosed, they look excellent with steel latices.

[jamespetts]

Very nice!

[AP]

I think they're maybe a bit garish in player-colours. Could perhaps just the bottom rails, or top rails, be player coloured, and the rest a battleship grey? (I'd say red-oxide but that maybe a player colour!). I mean, FGW may have purple trains but their bridges are definitely not!

Another suggestion - we need a flat bridge - that is a bridge for rail (and road) to cross water on-the-level. The ideal might be that a swing bridge (or bascule bridge) evolves into a more modern interpretation at some c20th date. A swing bridge needs an island, of course, I can't recall if river traffic works like roads, left and right sides, or not...

Swing Bridge, Norfolk (there's a nice one in Newcastle too, but it's a bit bigger).


I recall being told it's not possible to vary a crossing type with a timeline, but presumably it's done with level crossings - gates become barriers at some point I assume? If so, in pak.128 is a lift bridge like the kingsferry bridge on the isle of sheppy. We could use that as the later one?


The alternative, of course, perfectly realistic, is to have a single flat crossing, which does not allow water craft to pass - that is, a fixed short bridge which deliberately obstructs navigation. Which would force the use of 'better', higher bridges to cross water - the sort of dilemma which faced real engineers and led, for example, the GWR not to build a railway line to Dartmouth (since they'd have needed another Saltash-type bridge) and go to Kingswear instead.

e.g. a bridge like this:

[The Hood]

Timelines are now available for crossings, hence the various barriers in pak128.Britain.  I will ultimately add various crossings like these too.

Re player colours I was probably erring towards having them as they didn't look too bad to me.  I'd be interested on other views though, as I don't ever play the game so I'm never really bothered about player colour issues, but I'm told it's important for multiplayer...

[AP]

Timelines are now available for crossings

Cool. For completeness, perhaps a bascule bridge might be useful too, especiall for the 1750-1830 sort of era. Would work for road and early rail, if designed correctly.

I'm told it's important for multiplayer...

Useful, in that it saves using the magnifying glass tool, not sure about important - not for bridges. Definitely important for vehicles and stations- the things one interacts with. But I think it's important it's tasteful, pak.gb is one of the better-looking paks, and multicoloured bridges could upset the visual cohesion. Same arguement goes for over-all roofs on the big stations - purple railings and lamp posts are subtle, massive purple roofs less so. But that's just my view.

[jamespetts]

I'm not sure that water crossings are a good idea, as they detract from the need to build proper bridges.

[sdog]

most simutrans rivers are in valleys, most of the time one wants to build proper bridges to avoid the climb up again. For the cases where a river is completely on flat terrain, they are very usefull, as a proper bridge would require that climb.

Is there a way in simutrans to define crossings with rivers only for the smaller types? Not for the widest two types of navigable rivers?


on the player colour bridges:
i wouldn't worry too much, most of those player colours look quite similar to rust protecive paints especially the light blue, rust red and green one. If i'm not mistaken, the yellow is also a colour available in 19th century. The purple and bright blue and cyan are a bit off, but players don't have to chose it if they don't like it.

[jamespetts]

Is there a way in simutrans to define crossings with rivers only for the smaller types? Not for the widest two types of navigable rivers?

I suspect, alas, that this cannot be done - otherwise, it would be a useful workaround.

[AP]

I'm not sure that water crossings are a good idea, as they detract from the need to build proper bridges.

Not so sure- I mean, I'm more interested in preserving level track - and thus keeping running speed high - so will always use an embankment and raised viaduct. Unless i'm building track alongside a canal, or terrain has dictated the track must be right at water level (e.g. to match levels elsewhere), when I'll cross it on the flat - which seems entirely reasonable and realistic.

If it's a gameplay worry, we could prohibit lifting bridges on that basis though - the price you pay for the flat crossing being insufficient clearance for navigation?

[jamespetts]

The issue with the crossings is rather more acute with roads than rail, as gradients are lessof an issue.

[AP]

The issue with the crossings is rather more acute with roads than rail, as gradients are lessof an issue.

Not unrealistic, though - it's normal to build a road down a valley, a small bridge over the water, and up the other side (unless you're building the Millau Bridge).

If it's a gameplay concern, presumably including flat rail crossings whilst prohibiting flat road crossings would be considered somewhat unfair? I wonder if we could use speed limits to mitigate? As in, put a 30mph speed limit on all lifting bridges...

[The Hood]

Another option with water/road bridges is to make the water speed = 0, i.e. un-navigable.  This would represent low bridges boats could not fit under.  That said there may be a gameplay concern in multiplayer here if player A is using rivers to transport stuff and player B builds a bridge over the river and blocks it...

[AP]

 

if player A is using rivers to transport stuff and player B builds a bridge over the river and blocks it

Heh, but that goes on anyway. On the pak-gb online game, one of the players used the raise-land tool to block another player's oil tankers. But that game had no moderator/rules - with a decent moderator it wouldn't happen. There are plenty of ways to disrupt other players if you're creative about it... traffic light frequencies, slow buses...

The 0 speed limit is interesting though. Even if the bridge opens, the speed limit through the open span should still be very low.

[AP]

7. Concrete spanning bridge (various light/heavy, etc.)

That's a model!!  Not convinced about the structural proportions of it either, unless there's a concrete downstand beam hidden underneath... just sayin'!

[jamespetts]

One of the main problems with these crossings is that they cost the same as a basic road (etc.), whereas proper bridges cost much more: this causes economic distortions.

[AP]

One of the main problems with these crossings is that they cost the same as a basic road (etc.)

Could that not be fixed globally? Make them the same as a higher-spec road/rail tile instead?

[VS]

Since crossings are selected and built fully automatically, these costs would have to be made transparent. (just saying...)

[sdog]

Player B could as well just bulldoze the river.
It has to be clear in a way, so fair player can avoid it. At last resort, there is always communication in game. I think you shouldn't worry too much, it seems most online players now are very polite and cooperative.

[ӔO]

To be honest James I'm no civil engineer and I can't quite relate the descriptions in experimental to what they are supposed to look like.  If you could post pictures of what each is supposed to look like that would be good. 

Secondly there is no need I can see for two versions of the bridge with and without pillars; I am planning on making the pillar distance 2 tiles so 1-2 tile bridges wouldn't get pillars anyway.

@james, hood

here's a bunch I've accumulated for design reference. I don't quite recall where I've gotten them from.
I've mainly narrowed them down to ones that can be drawn for simutrans, but there are still quite a few parts on some of those bridges that just can't be drawn in because the pillars are a single repeating image. That is, unless height is restricted so you only get one pillar height.
http://dl.dropbox.com/u/17111233/Bridge_Ref.rar

[The Hood]

Thanks for those ideas AEO.  I will try and condense them into styles I think look good in simutrans and idealise them slightly to get round the issues of repeating tiles.  I really do wish we could have multi-tile bridges like in OTTD!

I take it no further opinions on player colour bridges then?  I might try a demo version of the bridges with (a) no player colour (b) subtle player colour highlights (c) all over player colour. 

EDIT:

I've just stumbled upon this again, not sure how I managed to miss it!  Did you ever get any further with any of these parts AEO?  Seeing as there is a lot of good stuff here I'd love to use it, but I think there are some consistency issues that would need resolving e.g. consistency of tracks.  I could try importing these into blender to resolve or cutting and pasting track graphics in gimp.

For blender I would need them as Collada .dae files, and for gimp obviously I'd need the rendered images as pngs.

[AP]

Player B could as well just bulldoze the river.

I always thought that ought to be fixed...

[The Hood]

Using the png files in the previously linked thread I've managed to adapt AEO's tubular bridge in GIMP to use consistent tracks with the rest of the pak.  Here's the result:



I'm hoping to do something similar with the beam bridge too.

Can't find sources for any other bridge parts in there - AEO do you have these?