Weathering steel bridges

[eridani]

I've seen lots of information on weathering wooden trestles and lots of information on weathering buildings.

Is there any informaiton available or does anyone have any hints on weathering a steel deck plate bridge?

The photograph I have of the prototype was taken after the line was abandoned and it was all red with rust.

My freelance option is that the line is maintained but it was not a high priority for the railroad

thanks
Robin

[Anonymous]

As a general guide bridges received high priority for maintenance...'cos it cost a fortune if it fell apart.

A sign of a dieing line / very hard times was a bridge in a bad state.

The floor of a deck bridge here (UK) would normally be weathered bitumen... which is (basically) black/brown or brown/black. Sometimes the coating had a weird mid grey/silverish look... this tended to have brown/black lines or patches. Deck coating (usually) spread 6 to 9 inches up the metal sides and fittings. Timber waybeams would be tie colour...'cos they'd be treated the same.

All the rules of weathering track apply... what's happened since it was new? How well has it been maintained? Has anything been renewed/replaced? Has it been cleaned... in this case cleaning means removing leaves and litter which otherwise build up in corners (just like in a garden)... you can get bits of tree, dead fox, dead cat, bits of load fallen from cars (from sand to pallet material... grain could start to grow in the leaf litter) All this should be cleaned out by the MoW because anything rotting will damage the coating, let in water and damage the bridge structure... then the cost rockets.

[We had a double track bridge (rail over road) lifted out by an enormous road crane {this thing was so huge that they dug out the bank on each side on put in concrete plinths for its feet to stand on - the tyres were about 10' diameter - it came all the way from Italy} ... old bridge was cut up and removed, new bridge lifted in... they just had to make the last adjustment and the crane conked out... That was Saturday morning. It took all of Saturday to find the engineer/fitter - who was on holiday in Spain, fly him back to Germany to get his tools then bring him to London. Five minutes in the machine and he came out with a bust O ring about wedding band size. "Here's the problem". So by Sunday tea time they'd located a replacement and had it on the way from Sweden. All this time everything is just standing. One of our British Rail guys wandered out to get fish and chips... as he came back one of the spectators asked him "What's the problem"? "**** bridge doesn't fit"! So next day in the newspaper...

Anyway, back at weathering bridges... you'll get graffitti as well... even on the deck... strange places football fans write things...

You may get waybeams replaced with new coating patching them in. Or just patches in the coating.

In many ways the bitumen coating on a bridge is like the bitumen coating you get on some flat roofs.

In steam days leaves would be removed before they could dry but fire water tubs would be provided as well in many cases so that hot ash or a spark would not start a fire which would ignite the bitumen... suggest you look out for details such as tubs in old photos.


Next post (below) makes a lot of good points. Especially about the paint crew. If I ever get that far I will have signs of a bridge being re-painted - this happens in snatches of time between traffic. repainting involves cleaning, scraping (blasting sometimes), (repairing), priming and several coats of paint... sometimes the graffitti people get in before the work is completed... the work can't be signed off until the whole bridge is clean and new so (if it persists) the RR police get involved... it's amazing how much a K9 looks like it's grinning when it has a lump of pants' cloth in its jaws...

The sides of a steel bridge (inside and out) will weather in all the same ways as a boxcar or gondola... but shouldn't have the dents.

In urban areas there is a huge problem with pigeons roosting under bridges this leaves streaks on the structure and lines of guano on the road or rail below in pairs matching the underside of the beams in the bridge (pairs because they roost both sides of I beams). It is a health hazard... you can also get pigeon mites which bite worse than cat fleas - fortunatley (for me) they prefer females for some reason... we had ladies put off sick because of the evil things.

Have you thought... if you have any cable ducting for phones, signal/point control or whatever or pipework it has to be carried over or under the bridge... look at pics again...

Small (1 gal to 5gal) tubs of maintenance material and tools aren't supposed to be left on bridges but they often are.

Modern era maintenance would often get a portable office and/or a 20' container (or2) parked close by.

Where a road goes under you do sometimes get a dent where a high truck has hit the bridge... but it isn't that big... (a) because the truck loses and (b) because only a small amount of damage can be allowed. You also get scrapes... to the supports as well as to the underside. Bridges are pretty good at removing the load from the top deck of car transporters...

Talking of the supports... If they're brick you get all the weathering associated with buildings... similar for stone and concrete. You get a lot more streaks from water outflow both where it's meant to flow from drains (look for these in pics) and where it seaps and runs. If the air is clean these stains can have moss and ferns growing. You even get small trees starting to grow (they're not supposed to be left to get big). Ivy is frequently a major feature... it's amazing where plants will grow... especially ivy.

Two things associated more with brick retaining walls (than with concrete or stone) are cracks and repairs. Both in bridgework and buildings you can often cracks either following the mortar lines or straight through everything. You can also see new brickwork inserted to repair cracks or just re-pointing to strengthen existing masonry.

The size of cracks in abutments is sometimes surprising. Large areas of masonry can be displaced an inch or so. The critical thing is that the structure settles in a stable position. The engineers often put on various markers to help them monitor the movement of cracks/structures.

While a sidewalk under a bridge may be swept there is often a band of traffic splatter up to 2' up supporting walls on both sides of a road. Under bridges is also a common place for puddles even when there are drain grids.

Manholes (for sewers/drains/telecoms) don't usually come under bridges... but are often close to the approach... also telecom location boxes.

Street lights are often fixed to the bridge support instead of on poles... if the bridge is long they may be on 24/7

There are of course all sorts of road signs associated with bridges - especailly height limit warnings and red/white or yellow /black stripes on both supports and bridge beams. (And people still hit them).

Has this answered the question? [8D]

Going back to the start the reason for bridge maintenance being high priority isn't just that a bridge out shuts the line but it may also shut whatever it is crossing/crossed by with compensation costs. Also a wreck at a bridge is almost always a bad wreck.

Have fun!

[ARTHILL]

My only hint is to paint the bridge its base color. When dry,mist dark from below. When dry mist red from above. Then dry brush what ever special rust needs your eye calls for. Unless you are an artist, go easy on everything. It is easier to add a little than to discover you had too much. That said, I leave most of my bridges looking like the paint crew was there just this year.

[Anonymous]

Check website

modeltrainsweathered.com

look under structures, then CV Plate Bridge. It is great.
Hope this helps.

[eridani]

QUOTE: Originally posted by HERSHCHLOE

Check website

modeltrainsweathered.com

look under structures, then CV Plate Bridge. It is great.
Hope this helps.

I checked the site and found lots of neat stuff about freight cars, especially the underside which will help with my rolling stock. But can't seem to find a structure link. Do you have the exact URL?

thanks

[Anonymous]

To find the bridge pix ,go to the bottom of the home page. There is a section on structures, click on structures and the next page will be various structure projects. The one you want is labeled CV Plate Girder Bridge. Thats about all the help I know how to give on finding it. good luck.

[Anonymous]

the structure page is in the forum

heres the direct link

http://www.modeltrainsweathered.com/forum/viewtopic.php?t=547

[Anonymous]

Good link... I've got a question though... one bridge pier has a 1904 plaque the other 1906... did they take two years to put the bridge in?
As the image downloaded it looked like one pier that had been widened from single to double track... now that could have two dates on it... but facing piers?

I was thinking last night... overbridges are pretty much the most common place everybody really gets a look at railroads... driving or walking the thing is big and up in front of you... so most RR (most of the time) made them look good... even if it was only a coat of black or grey paint... on the outside at least. Some painted their name on them... others used them to get revenue through advertising.. billboards (where access available) or painted on (direct or on placard boards)... the inside of the bridge didn't always look so smart... so you have all sorts of possibilities.

Try this site... http://www.chicagoswitching.com/chicagoswitching/v4/articles/picturedisplay.asp?photograph=../../$library/River_West/tb_cpr_elston_09012005_01.jpg

On masonry... I was parked up right next to a big bridge pier this morning... at least six different brick colours, three colours of pointing, one of the patches had a different bonding pattern to the rest. If you have a large area of brick that you want to make less plain/boring take a wander round... it's surprising how much variation is in (or can be in) just one wall that's been there and been repaired many times over many years.

have fun!

[dehusman]

The pictures I saw the piers were both 1904.

Most bridges I am familiar with are not that rusted, especially in service.

Dave H.

[jecorbett]

The deck bridges I have driven under lately all seem to have spotty rust where the paint failed. The rust spots are almost black. Only very recent rust is orange. Older rust is dark brown or black. To simulate that effect, I paint the rust spots randomly with burnt umber. For the larger rust spots I might put in a few dabs of grimy black. Then using a fine tipped brush and well thinned rusty orange paint (I use Anita's Cinnamon, available at Hobby Lobby), and paint fine streaks of rust straight down from the larger spots to simulate rainwater streaking down the sides of the structure. If these streaks go on too heavy, I let them dry slightly and wash it out with a wet brush. I just want a faint film of rust streaks. The last step is to give it a wash of alcohol/India ink.

[eridani]

Thanks every one for the advice.
The comments on level of maintenance has helped me decide how far to go.
There was some interesting maintenance on the portion of the line that was not abandoned. A large wooden trestle bridge was repaired and the worst wooden bents were replaced by concrete piers and part of the trestle floor reinforced with a steel beam. (I have actually walked along that trestle. Could not reach the rusty deck because the area was closed to the public)

I am scratch building the trestle and using the N Scale Atlas beam and a mixture of Kato and Atlas piers for the piers along with the wood.

For the deck bridge I am using the Kato deck bridge and I will do weathering consistent with consistent but low budget maintenance.

thanks

Robin

[eridani]

Thanks to everyone who helped me with this topic late last year.

I have now completed my project weathering this "neglected" bridge.





Details of how I did it in my blog at

http://robinrowland.com/wns/index.html

[Anonymous]

Someone stole the river! [:O]

Seriously... it looks good [:)][:)]

It's really nice when someone comes back with the results fo our answers! [8D][8D][8D]

[jfugate]

Jack Burgess, of Yosemite Valley fame, when looking at my Coalbank Slough bridge model, gave me a quick rundown on railroad bridge rust and how it works. Jack works for the county inspectors office in CA, so he is well trained in what inspectors look for rust-wise to determine if a bridge is safe.

If the bridge has a fairly uniform coat of medium rust all over it, then that's a "protective" layer of rust and actually acts like paint to prevent further "active rust" from forming. However, if the bridge has lots of large, rough, dark rust pockets, then it has "active rust" and it is eating away at the metal and could start compromising the bridge's structural integrity.

Only model "active rust" if you have a bridge on a branch line that the inspector will condemn the next time he sees it. Jack told me my Coalbank Slough bridge is on the edge of being condemned, given the way it's weathered. [swg]


(click to enlarge)

[davekelly]

eridani and Joe,

Excellent work on both y'all's bridges!! I'm always getting inspired to "go for the next level" when I see pics posted here. Don't know if I'll ever reach it, but it sure is fun to try!

Dave

[ARTHILL]

NICE

[Anonymous]

Love them bridges. Great work guys!

[Anonymous]

QUOTE: Originally posted by jfugate
Jack told me my Coalbank Slough bridge is on the edge of being condemned, given the way it's weathered. [swg]


(click to enlarge)

If the line is to stay open how about adding detail to show work starting to put a new bridge in?
Some people always want more don't they?[}:)]
What locos are they please? Is the second one an Atlas RS11? They look strangely clean for SP...?
Thanks for your ongoing help to all of us.[:)]

[jfugate]

QUOTE: Originally posted by David Foster

QUOTE: Originally posted by jfugate

(click to enlarge)

What locos are they please? Is the second one an Atlas RS11? They look strangely clean for SP...?
Thanks for your ongoing help to all of us.[:)]

David:

The locos are (from front to back):

Athearn GP60 in speed lettering, freshly painted
Athearn SD9, with weathered and faded paint
Kato SD40, weathered and somewhat grungy (hard to tell since it's mostly out of the photo)

The speed lettered loco belongs to my friend Mark Brown, and is a bit out of place on my 1980s SP since speed lettering wasn't first applied to SP locos until 1992. But I like the photo, so I looked the other way at the visiting speed lettered unit, considering it to be a bit of a "back to the future" shot. At the end of the session, Mark took his GP60 home, and that was the last time we saw it on the 1980s Siskiyou Line. [swg]

[jeffrey-wimberly]

I paint the bridge grey to start with, then mist it with light soot coating followed by a light rust spot here and there.

[Anonymous]

SD9? [:O] I was MILES out! [:I][:I]
How about the bridge crew scene? [}:)]