View single post by Si.
 Posted: Wed Oct 12th, 2016 10:48 pm
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Si.



Joined: Thu Feb 23rd, 2012
Location: London
Posts: 5684
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Hi Michael

I checked out the 2 bridges you mentioned.
BOY ! do they look 'spindley' to my untrained eyes !!
Still standing though.
So obviously well up to the job.

I looked at some truss-bridges a few days back.
These were smallish sized road bridges in Pennsylvania.
The website had many photos & was promoting Pennsylvanian historic bridge preservation.
These bridges are apparently quite widespread in the area.

I learned that around the turn of the century & into the '20s & '30s, steel truss bridges were widely built.
It seems due to falling construction costs & that pre-stressed concrete had not quite become the norm yet.
On-site mobile-riveting equipment had made this possible.
I read that as probably meaning, better, smaller, more portable air-compressors ??

( excuse my vague research, I can get totally drawn in to it, if I'm not careful ! )

Anyhow.
The Pennsylvanian small-road trusses, appeared to be BUILT LIKE TANKS to my eyes.
Way more steel & rivets etc. than those two D&RGW bridges.
By comparison they seemed WELL over-engineered, for 'light' trucks & typical road traffic.

Mmm...

On the bridge kit I have.
If the 'overhead steel' is left out, the bridge appears visually much 'lighter'.
I guess more close to a 'half truss', although a bit high for a true 'half'.
I generally appreciate the 'prototype for everything' scenario, it does help avoid ANXIETY !!

I do like the way the bridge at Pagosa Junction is right next to the Depot !
I had kinda imagineered this for Mysterious Moose Mountain, but thought it might not look 'real'.
The alternative was a 50 foot bridge spanning a HUGE CHASM, Indiana Jones style !! ??
Just keep me away from the 'whimsical' Michael ! ... I have an 'unrealistic' magnetism pulling me toward it !!

:moose:

Si.

Question is
Do I burn my bridges ?
DAMN they're steel
Very non-combustible . . . !



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