WM Western Lines Engineering Report

[wm3798]

During the era I'm modeling, it was pretty typical to slap a coat down over aging concrete to extend the life until the funds were available for a full deck replacement.  The 1952 Chesapeake Bay Bridge had an asphalt deck for years.  My plan is to weather it down, add a whole lot of tar lines and patches, and give it that good ole "deferred maintenance" patina.

Lee

[DKS]

During the era I'm modeling, it was pretty typical to slap a coat down over aging concrete to extend the life until the funds were available for a full deck replacement.

Still common today. Almost every bridge I crossed on my work commute originally had a concrete deck that was at some point covered with asphalt.

[Ian MacMillan]

Still common today. Almost every bridge I crossed on my work commute originally had a concrete deck that was at some point covered with asphalt.

Same thing around here.  You will see a few bridges (built post 2000), that may use a concrete deck and top layer but the majority have an asphalt top coat. NHDOT had the bridges on the NH Route 101 expansion (1995-2000) built with visible concrete decks but under the Recovery Act (2009) repaving they paved the decks over, commenting that the transition from asphalt to concrete and back to asphalt on the bridges was causing the plow blades to wear improperly and also caused damage to the asphalt and expansion joints. Concrete roadways are not something Northern New England has adopted yet. MA Turnpike Authority has started experimenting in sections they are replacing on I-90 and I-84 with concrete lanes and asphalt shoulders.

[davefoxx]

Concrete roadways are not something Northern New England has adopted yet. MA Turnpike Authority has started experimenting in sections they are replacing on I-90 and I-84 with concrete lanes and asphalt shoulders.

I always thought this had something to do with road salt, i.e., that concrete is more susceptible to being damaged from road salt then asphalt.  If true, it would explain why you see more concrete roads down south than up north.

DFF

[C855B]

Yes. The salt (or other anti-icing chemical) leeches through the concrete and attacks the rebar. Then when the rebar rusts enough, it pushes away the concrete and loses adherence, and the road surface crumbles as it's loaded/unloaded by traffic.

I'm a little surprised to hear of all of the "paved over" bridges. Bridges are engineered to a spec which allows for a specific load weight for the road surface. Just paving over with asphalt reduces the allowable vehicular loading, and you end up with a restricted bridge. Fine for you and me in our two-ton cars, but a major annoyance for big rigs and especially cement trucks with their high axle loading.

[Ian MacMillan]

That I did not know. See you learn something new everyday.

How do the northern Midwest states fair with it as I know Wisconsin and Minnesota have some pretty good snows and use concrete.

[C855B]

There is a sealer admixture in the concrete that is supposed to help, but it kinda sorta doesn't. It possibly extends the service life by about 10 years, and then you're still back to chipping off the surface down to the rebar, sandblasting, and pouring new concrete... if you're very lucky. The bridge down the street from our second house (in St. Louis) was concrete deck built in the early '70s, and was demolished and rebuilt last year. Same goes for a very large number of bridges in the STL region - demolish, and re-do.

[wm3798]

Fortunately, my bridge is made from an old vertical blind slat, so it's specially formulated to withstand harsh UV light.  It's a little particular about what glue it likes, but since the vehicles themselves don't move (except for those slippery CMW vehicles with their Hot Wheels like axles) there's very little in the way of weight or live load action to damage the thin layer of spray paint that I used to pave the surface.

I know this is listed as an Engineering Report, but really...  Let's get back to the action...

Lee

[wm3798]

Brought home a couple of ReStore cabinets to solve a storage problem, and set about cleaning the workshop.  I find that projects take less time to complete if I can find the outlet to plug in the soldering pencil.

More news as it happens.

Lee

[wm3798]

Now that I've found my workbench, I've resumed my efforts on the Cumberland Station.  It seems the bigger the project is, the more debris it leaves on the work surface...

Anyhoo, I've found yet another use for those bolster slugs that come with Micro Trains trucks...  You've seen a few of them before:


As a headlight housing on my slug is one of my favorites...

Here's the latest:


As column bases for the platform shelter on the station at Cumberland...  I just have to work out a way to consistently cut the bottoms of the styrene rod I'm using to let them nest in the little holes.  I'm figuring that having these superglued to the platform surface, then the rod glued into these bases, should give me a right sturdy connection.  The platform is also attached to the building there above the first floor windows, so that should reinforce it even better.

I also finished the steps down to the subway...


I used some plastruct railings to keep people from tumbling down the steps, and lined the wall with H&R brick to represent the white glazed subway tiles on the prototype.  I added a wall mounted light fixture in the stairwell to help highlight it.

I also worked on some printed roof shingles to improve the look of the roof.  I sized it a bit small to reach the whole length of the roof, which is just a hair shorter than 11", so I may have to switch to legal size paper to get it right.

Lee

[wm3798]

Well, now that we've been drinking all night at the Hard Hat, it's time to stagger across the street for some sliders...



Lee

[seusscaboose]

1) brilliant on the passenger shed post bases... very nice...  i will steal that. 
2) Stagger for the Slider...  sounds like a country song. 

[Zox]

Wow. That's the first time I've seen one of those White Towers painted up, and with the lighting and the figures it's pretty amazing.

Speaking of amazing, Lee, how do you shoot these up-close photographs? I have the devil's own time convincing my camera to do unreasonable things like, say, actually focusing on the object in the middle of the image...

[wm3798]

Canon S3, Macro or Super Macro setting.

You have to press the button halfway to get it to focus where you want it, then POW!

BTW, got the doors in the mail yesterday or Thursday, and WOW.  So there you have it.  POW and WOW in the same post.  How's that for value?
 

[wazzou]

The depot is looking really good Lee.