You're viewing a single thread.
Any engineers happen to know (I'm curious) how stable a design like this is?
This is Crib trestle bridge of the Columbia & Nehalem Valley Railroad at the McBride Creek, circa 1905. A source: https://www.vintag.es/2017/10/vintage-photographs-of-incredible.html
Which says:
Early timber bridges had their drawbacks. Untreated lumber only lasted about 20 years and locomotives could easily cause the wood to catch fire. Collapses - rare today - were a regular occurrence on logging railroads and there are numerous accounts of train crews that regularly hopped off their slow moving locomotive as it approached a high, untrustworthy trestle, allowing it to cross before they would then run across the bridge and jump back on.
But that's about log bridges generally, not this one. Here's an unhelpful wiki page: https://en.wikipedia.org/wiki/Crib_bridge
So, you're telling me that conductors would ghost ride their own train as a safety precaution? What a wild time!
I can only imagine the instances where the track dipped downhill a little after a bridge, picking up unsuspected speed, and leaving the crew frantically sprinting after the caboose.
Or that one bad day, when it's late into your shift, and you're feeling kind of sick and tired, and just don't have it in you to jog after your train over the upteinth bridge tonight, so you decide to risk it, relax a little, and ride it out. But then your luck also runs out, and you fall down the ravine in a burning metal cage only to then drown in the river, like some big budget action shot in a 1926 silent-film.
There's an engineering saying: "Any idiot can build a bridge that holds a load. An engineer can build a bridge that barely carries a load." It looks like they overbuilt the bridge to compensate for lack of solid engineering.
Not an engineer at all, but I gotta say the random logs going up sideways from the river to support the construction make me nervous.
There's always bits leftover, even if you follow the instructions.
Assuming they are either nailed down in few places or at least has some slits or something similar, they should be pretty stable. That is until the logs themselves are in good condition.