OT: Bridge overpass doles out the butt kickings

[Speedy]

That bridge is very, very well marked with lights flashing whenever a high truck approaches. Not all bridges even have the accurate height, sometimes being more than a half foot lower than marked. Many bridges have only two or three inches of clearance beyond the standard 13' 6" so even a pothole can bounce you into it. Speaking from experience.

[Robert M]

Speedy,

And yet morons continue to hit the bridge with their trucks. Pathetic.

Robert

[mrlynn]

Storrow Drive in Boston has similar problems (trucks are supposed to stay off, but. . .).

You'd think it would be easy enough to put up stoplights, triggered by height sensors in well in advance of the bridge.

Notice the train crossing in one of the clips. I'm surprised that those impacts don't compromised the integrity of the tracks—or the bridge itself.

/Mr Lynn

[JoeH]

mrlynn wrote:
Storrow Drive in Boston has similar problems (trucks are supposed to stay off, but. . .).

You'd think it would be easy enough to put up stoplights, triggered by height sensors in well in advance of the bridge.

Notice the train crossing in one of the clips. I'm surprised that those impacts don't compromised the integrity of the tracks—or the bridge itself.

/Mr Lynn

The page on the bridge provided by pRICE cUBE, http://11foot8.com/, mentions the following:

So frequently do trucks crash into the 11-foot-8 clearance trestle, that the railroad company installed a crash beam in front of it. This massive steel I-beam bears the brunt of the impact, protecting the structure that supports this fairly busy railroad track. Believe it or not - they already had to replace the beam once!

[freeradical]

They could you know, raise the bridge a little. There has to be another way around the bridge, so why not shut that road down for awhile and get the job done?

[mrlynn]

freeradical wrote:
They could you know, raise the bridge a little. There has to be another way around the bridge, so why not shut that road down for awhile and get the job done?

Probably easier to lower the road than to raise the bridge. Hard to re-grade the railroad tracks.

/Mr Lynn

[M A V I C]

deckeda wrote:
There's one in TN, can't remember where, off of I-24 that has a warning bar hung by chains and a sign that says, "IF YOU HIT THIS BAR YOU WILL HIT THAT BRIDGE."

Seems easier to build something like that than a bumper bar that takes the brunt of the hit.

Speedy wrote:
That bridge is very, very well marked with lights flashing whenever a high truck approaches. Not all bridges even have the accurate height, sometimes being more than a half foot lower than marked. Many bridges have only two or three inches of clearance beyond the standard 13' 6" so even a pothole can bounce you into it. Speaking from experience.

I have to wonder though, when was the last time they measured it? The pavement isn't flat and as a pretty good grade to it. I wonder if it's 11' 8" in the middle? I also wonder if repaving it has brought the road surface up higher so it's no longer 11' 8".

[ArtP]

mrlynn wrote:
[quote=freeradical]
They could you know, raise the bridge a little. There has to be another way around the bridge, so why not shut that road down for awhile and get the job done?

Probably easier to lower the road than to raise the bridge. Hard to re-grade the railroad tracks.

/Mr Lynn
From the FAQ: http://11foot8.com/faq.html

Can't the road be lowered?

That would be prohibitively expensive because a sewer main runs just a few feet below the road bed. That sewer main also dates back about a hundred years and, again, at the time there were no real standards for minimum clearance for railroad underpasses.

Also found this interesting...

Could they install a low-clearance bar?

A low clearance bar is a bar suspended by chains ahead of the bridge. Overheight vehicles hit that bar first and the noise alerts the driver to to the problem. I understand that this approach has been successful in other places, but it's not practical here. There are many overheight trucks that have to be able to drive right up to the bridge and turn onto Peabody St. in order to deliver supplies to several restaurants. Making Peabody St inaccessible from Gregson St would make the restaurant owners and the delivery drivers very unhappy.

I guess the Sign on a Chain Pre- Warning thing is impractical because of that Street right before the Bridge has a lot of right turn truck traffic.

[Catzilla]

The faster you go the smaller you get!

[M A V I C]

ArtP wrote:
I guess the Sign on a Chain Pre- Warning thing is impractical because of that Street right before the Bridge has a lot of right turn truck traffic.

So put it after the turn? That would still give them a lot more warning.