Streak: Anything less than 15.5 feet is a bozo-no-no at any place .... and you still have to figure sag and voltage into that minimum number (which can only go up).....Driveways that regulary see commercial trucks will push that figure to 16'
...and nobody wants to pay to raise a pole line, especially the people that built the original pole line before all the other spaghetti was added on. (In Colorado, we've seen some major fails with crossings and parallel lines (impedance) in recent history. Service and income requirements should NOT be making safety be an afterthought ...the same also has requirements for clearing the lines above the bottom wires.
mudchicken The telephone and fiber people are by far the most reckless/clueless of the bunch....
The telephone and fiber people are by far the most reckless/clueless of the bunch....
How true. Live near ATT office. It has added so much copper and fiber to the travelers along the street that now all the cables are lower than the US 13 feet 6 inch clearances. Someone noted that to an ATT crew which crew ignored . Well a restaurant driveway had a TT delivery enter with a big snag. Fortunately no cable breaks. Took months to get a taller 7200 volt pole and to raise power lines, then TV cable, and finally the telephone lines. Have a concrete truck coming this fall and will have to check to see if it will clear the possible snag in front of house.
Our local electric company has placed all wire crossing CSX with guy wires on the poles that cross CSX so the poles will not lean toward the the tracks causing the power lines to sag toward tracks.
Common carrier freight railroads have a 24'-6" target height for catenary electrification. Less than that and you are insulating bridges (lotsa fun with reinforced concrete) and having adverse induction issues. 23'-0" is only protecting people (switchmen) on top of cars for the most part. Model Law from 1958 set the height originally at 22'-6" (railroads adding another 6" as "cushion" for surfacing)....Almost immediately, the states in the eastern 1/3 of the country started whittling that down because of their already older bad clearances and the fact that any major modification to the existing bridge or structure would require the target law height to be met (which would require major $$$ to accomplish and end the structure's "grandfathered-in " status.
Outside of catenary, the heights for wirelines above the track is set by NESC based on potential/voltage of the wireline and won't be less than 27' above the track.
There are still too many rubber-tired engineers (structural, civil, electrical) that have not woken up to the fact that there are hard and fast rules to be followed. (See AREMA Ch 28 [Compilation of state laws) and C1, plus NESC)... It is not OK to guess and blunder around railroads and clearances, but they continue to do so. The telephone and fiber people are by far the most reckless/clueless of the bunch....
And as stated many times on this forum, State DOTs frequently are not qualified to railroad with not a single qualified railroader on staff. These yo-yo's start playing with design criteria rules and it starts getting messy. Scary.
Back in the 1980s (?) TVA proposed to install electrification on both the SOU (NS) and the CSX lines between Cincinnatiti and ATL. TVA would even supply the electric motors that would be used by both SOU and CSX. RRs were requiring TN DOT to put several new and replacement bridges of the named routes and yards. Cannot remember exact height but 23 feet above top of rail comes to mind. That may have been due to electrifications then were only though to be 12.5 Kv or maybe 25 Kv. As well now 141 RE rail stand taller than what was installed then.
Believe TN DOT finally got that reduced but am not sure???
Perry Babin adkrr64 The problem with such devices, according to NYS DOT, is that this is a relatively high speed (55 MPH), four lane road. They are concerned that a truck striking such devices at speed could potentially cause them to become dislodged and airborne, striking another vehicle or bicyclist who were in the wrong place at the wrong time. The barriers that I'm referring to are lengths of 1/4" chain hanging vertically. They can't become dislodged. It's simply there to give an audible warning that there is a problem and much better than striking the bridge or a solid beam. It's like the one below but it's all chain.
The problem with such devices, according to NYS DOT, is that this is a relatively high speed (55 MPH), four lane road. They are concerned that a truck striking such devices at speed could potentially cause them to become dislodged and airborne, striking another vehicle or bicyclist who were in the wrong place at the wrong time.
When drivers are 'in the zone'! Nothing deters them. NOTHING!
Never too old to have a happy childhood!
Tell-tale
adkrr64 The problem with such devices, according to NYS DOT, is that this is a relatively high speed (55 MPH), four lane road. They are concerned that a truck striking such devices at speed could potentially cause them to become dislodged and airborne, striking another vehicle or bicyclist who were in the wrong place at the wrong time.
Drivers entering the Parkway eastbound have to drive under this sign:
Not to mention that the bridge kind of stands out, with a wide fluorescent orange band across it:
Westbound:
As they say, the signs are there...
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
In all fairness, there are drivers out there who are aware of clearance restrictions. Many years back at a different job, we received a call from a driver asking for an alternate route since she knew of an overpass that wouldn't clear her truck on the regular route. I was able to provide one for her that worked.
"portal frame" = Sacrificial Beam .... and those don't always work. Determined stupidity can be a scary thing.
Eisenhower/Johnson tunnel on Interstate 70 on the continental divide has all the advanced warning in the world (including stop lights) and it still has the scars from some pretty big fails.
Perry BabinIt would seem like they would use hanging chain barriers like in drive throughs (banks, McDonalds...) to warn drivers well before the bridges.
mudchickenTelltales and electric eye sensors won't stop them all.
The other is the height sensors reasonably far out on the approaches, the first of them deployed in advance of the turns that should be taken to alternate routes with clearance, that detect sequential approach of an overheight vehicle and sound the loud alarms, strobes, police alerts, etc. that let even the dumbest driver understand that They Will Not Fit. That includes no-turn light-up signs and camera observation, which gives advance warning to local enforcement should a driver just keep going wrong.
What I was saying is that, if there is no effective alternate 'truck route', provide a bypass that doesn't involve significant reverse moves by vehicles that can't turn around to let them cross the railroad at controlled grade. That moves the 'high-centering' transitions sufficiently away from the track foul zone that even long combinations would be stuck with the head or tail end well off the tracks... some of the earthwork expense might be avoided by using an otherwise-suboptimally-safe extreme skew crossing to achieve the necessary control height in the approach and departure grading.
Tell tales and electric eye sensors won't stop them all.
It would seem like they would use hanging chain barriers like in drive throughs (banks, McDonalds...) to warn drivers well before the bridges.
BaltACDI am surprised that the GPS vendors haven't made 'Clearance Notifications' where necessary a part of their Commercial Grade offerings, in as much as it is MOSTLY commercial vehicles that fall afoul of height restrictions.
I'm sure vendors of Commercial Grade GPS have already done this. The inventigations of trucks that have struck the bridge almost always reveal they were using consumer/ free phone GPS apps.
tree68 Overmod The only 'solution' that preserves strict grade separation is to raise the road approaches, on post and beam is there is inadequate room or time to make a properly-settled and graded embankment for the approaches, and provide an appropriate clearance span and protection rails/fences. Of course anything like this ought to be built not to stack clearances, but stack clearances plus catenary electrification -- and that should be the rule for any improvement, infrastructure project, wireline or cable crossing, etc. (in the absence of coherent adoption of hybrid dual-mode-lite). In this case, it's the highway that has the clearance problem. The clearance is shown as 10' 6", although it's actually 11' 9". Getting to a 14' clearance would involve raising the railroad bridge ~3'... Overmod At least in theory, the problem might be addressed by constructing a protected grade crossing only for traffic that doesn't clear the bridge... There are alternate routes in place. The problem is overheight (for that road) vehicles that ignore the numerous warnings and drivers blindly following their GPS. There are even overheight sensors coupled with warning systems. The bridge in question is here: 43.09066 -76.19340
Overmod The only 'solution' that preserves strict grade separation is to raise the road approaches, on post and beam is there is inadequate room or time to make a properly-settled and graded embankment for the approaches, and provide an appropriate clearance span and protection rails/fences. Of course anything like this ought to be built not to stack clearances, but stack clearances plus catenary electrification -- and that should be the rule for any improvement, infrastructure project, wireline or cable crossing, etc. (in the absence of coherent adoption of hybrid dual-mode-lite).
In this case, it's the highway that has the clearance problem. The clearance is shown as 10' 6", although it's actually 11' 9". Getting to a 14' clearance would involve raising the railroad bridge ~3'...
Overmod At least in theory, the problem might be addressed by constructing a protected grade crossing only for traffic that doesn't clear the bridge...
There are alternate routes in place. The problem is overheight (for that road) vehicles that ignore the numerous warnings and drivers blindly following their GPS. There are even overheight sensors coupled with warning systems.
The bridge in question is here: 43.09066 -76.19340
I am surprised that the GPS vendors haven't made 'Clearance Notifications' where necessary a part of their Commercial Grade offerings, in as much as it is MOSTLY commercial vehicles that fall afoul of height restrictions.
OvermodThe only 'solution' that preserves strict grade separation is to raise the road approaches, on post and beam is there is inadequate room or time to make a properly-settled and graded embankment for the approaches, and provide an appropriate clearance span and protection rails/fences. Of course anything like this ought to be built not to stack clearances, but stack clearances plus catenary electrification -- and that should be the rule for any improvement, infrastructure project, wireline or cable crossing, etc. (in the absence of coherent adoption of hybrid dual-mode-lite).
OvermodAt least in theory, the problem might be addressed by constructing a protected grade crossing only for traffic that doesn't clear the bridge...
tree68Can't lower the road - it's all but floating now as it's built alongside Onondaga Lake and on a former canal bed. Raising the bridge will involve raising a lot of railroad, which will have practical limits as there are crossings nearby and the line joins the CSX Chicago Line not far away.
Of course anything like this ought to be built not to stack clearances, but stack clearances plus catenary electrification -- and that should be the rule for any improvement, infrastructure project, wireline or cable crossing, etc. (in the absence of coherent adoption of hybrid dual-mode-lite).
At least in theory, the problem might be addressed by constructing a protected grade crossing only for traffic that doesn't clear the bridge -- perhaps one with mandatory protected access as in the UK. That might be especially appropriate if the route is an important connector and there are no reasonable alternate routes nearby. Has anyone done a traffic count of high vehicles, or a survey of how many vehicles per day would use the crossing if it were not restricted height?
I have seen projects both in Louisiana and California that use active trash pumping to remove stormwater or flood egress from a depressed-clearance crossing "pit". The cost to install and maintain such a thing would be no more than an equivalent sewer lift station, and arguably with the provision of sufficient sealed vaults very few events would require active pumping to keep the road open.
I remember nominal clearance for 'domestic' doublestacks (stacked 8'6") as being 23 feet.
But that's static clearance, and a train is anything but static when it gets to the neighborhood of an overhead clearance. Ride excursions and side-to-side roll can both cause 'incidence'. The folks who came up with the Union Pacific Arrowedge found out something else about vertical clearances and aerodynamic lift... but then again, actual engineers should have known better.
Ah, yes. The infamous Parkway bridge in Liverpool, NY, comes to mind.
Can't lower the road - it's all but floating now as it's built alongside Onondaga Lake and on a former canal bed.
Raising the bridge will involve raising a lot of railroad, which will have practical limits as there are crossings nearby and the line joins the CSX Chicago Line not far away.
After a recent spate of over-height collisions with the bridge, there is talk of actually bringing money to the table. It is estimated the cost will be well into the millions.
Is it possible that track maintenance like tamping could have changed the heght of the rails?
Minimum vertical clearance in Maryland is 22'-0" by statute (COMAR 09.12.91.04 - last changed 2/14/86) Lateral vs. Vertical clearances may be getting confused here.
If the original design was agreed to at 23 feet, I hope the highway bubbas have to pay for the undercutter to get things back to the agreed-to height. That inch and a half may be enough to stop a high load from getting anywhere out of port and destroys all the recent efforts to expand clearances on the east coast. I suspect that the 23 feet distance was more of a system rule with 6" of cushion built into into it going back to the 1958 model laws.
The scandal may be that the engineer or contractor "blew it" during construction and thought that it was no big deal. Either raising the bridge or lowering the track has big con$equence$ when you add in the approach run-offs. The State of Delaware had a bigger cluster-fluff with their 415 freeway over CR/NS about a dozen years ago at Newcastle/Bear. (in that case the bridge deck was raised and the highway approaches were run-off several thousand feet. Not cheap.)
Not uncommon for highway engineers to get caught guessing at horizontal and vertical clearances. If a distance was agreed-to before construction, stick to it!
(The surveyor in me starts asking questions in terms of asking what caught the error?, was there any recent track surfacing playing into this?, was this engineers acting badly and designing down to the absolute mininimum distance without any cushion, datum shifts and so on...? So much for keeping the attorneys underemployed.)
Cutting corners just bit somebody.
Perry: there is more at play here than just the height of a railcar. Non-railroaders shoot themselves in the foot over this constantly. It's not only bridges, wireline utilities are even worse.... and they never seem to learn
What's the likely resolution?
Does there need to be a resolution? Aren't the highest rail loads just over 20ft for a double-stack in a wellcar?
In Baltimore a replacement bridge for US 1 that crosses over the West end of the CSX Mt. Clare Yard is now reported to only clear the top of rail by 22 feet 10 1/5 inches instead of 23 feet.
https://www.wbaltv.com/article/halethorpe-bridge-too-short-residents-fed-up/43978706
I thought I had read somewhere that new and newly rebuilt bridges were required to have 25 feet of clearance over the top of the rail. When the I-70 bridges over CSX's Frederick Branch were rebuilt - visually the new bridges appeared to be at least four feet higher than the bridges they replaced.
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