Manhattan Bridge Speed Limit

[Harry]

Are the speed limits for the South side (Broadway Line) and North side (6 Av Line) of the Manhattan Bridge the same?

 

I usually cross the bridge on the , and the R160s outpace the R68s ( by as much as 5-10 miles per hour it seems like. Sometimes it feels like the 160s leave the 68s in the dust. I figured the R160s are newer, faster, and that would be the reason unless there's a speed limit difference that I don't know about.

[MattTrain]

I've never seen a train let it be R68/A or R160A/B go faster than 25 miles per hour running on the Manhattan Bridge. I believe the speed limit is the same for both sides of the bridge.

[SmallParkShuttle]

I think its the same speed on both sides. When your on a 68 , they pace about the same. Also, I've had times where the gets to the grade timers and the ( or catches up. I think its just the R160s make the uphill trip child's play. It is fun though to race up the bridge on all that power!

[Harry]

Like today for example, my train felt like it was racing across the bridge while the R68 on the 6th Av side was lugging across. This has happened many times too.

 

I'm also thinking it could be some operators can handle the timers better than others.

[INDman]

Like today for example, my train felt like it was racing across the bridge while the R68 on the 6th Av side was lugging across. This has happened many times too.

 

I'm also thinking it could be some operators can handle the timers better than others.

 

Both sides should be the same speed, about 25 MPH. The Manhattan Bridge and the Williamsburg Bridge are not places where you want a T/O operating too fast. Because of the design of the Manhattan Bridge, the train cause alot of wear and tear on it. At least it's faster then then old El trains over the Brooklyn Bridge, they could not go faster then 15 MPH.

[SubwayGuy]

Same speed restriction on both sides.

 

To be honest I've never paid much attention to it, but R160's may move faster over the bridge because those cars seem to hold their acceleration much better than older equipment, which aids them climbing the grade of the bridge. I'd need to look at the R160 HP/weight ratio again to be sure, but based on two trains leaving a station on level track at the exact same time, 1 R160 and 1 R68/A, the R160 will be moving faster after 10 seconds, so that makes me inclined to think that's true about holding acceleration while climbing the bridge also.

 

On the downgrade, obviously the brakes and operator comfort with the timers would dictate the speed not the motors, so what I'm saying only applies to climbing the bridge.

[INDman]

R160s also accelerate faster, somthing like 3.1 MPH per second. The R68s are very slow at getting up to speed.

[Harry]

R160s also accelerate faster, somthing like 3.1 MPH per second. The R68s are very slow at getting up to speed.

 

Exactly what I thought. New, faster, with the same speed limit on both sides of the bridge. Hey I'm not complaining. :tup:

[PATCOman]

To compare, I think the speed limit for PATCO on the Ben Franklin Bridge is 40 MPH.

[Nature]

Hmm accualy i think the (M2) Lines on the Williamsburg Bridge they go way faster then on the manhattan bridge.

[SmallParkShuttle]

To compare, I think the speed limit for PATCO on the Ben Franklin Bridge is 40 MPH.

 

Hey, wrong forum! :mad: (just kidding!)

[Eric B]

I rode that for the first time a few years ago, and noted the quicker speed, and wondered why our bridges couldn't take that speed. Could be the equipment.

[Fan Railer]

R160s also accelerate faster, somthing like 3.1 MPH per second. The R68s are very slow at getting up to speed.

 

no. the R160's have the same acceleration rates as the old cars (2.5 mphps).

they just manage to hold that acceleration longer with the new AC traction systems, so it seems like they are accelerating faster.

[Y2Julio]

 

I rode that for the first time a few years ago, and noted the quicker speed, and wondered why our bridges couldn't take that speed. Could be the equipment.

The Manhattan Bridge wasn't really designed properly for train usage.

[Amtrak7]

I rode that for the first time a few years ago, and noted the quicker speed, and wondered why our bridges couldn't take that speed. Could be the equipment.

 

PATCO uses ATO automatic operations whenever there is no precipitation. The cars date to 1968 and 1980.

[fordhamkid7721]

I rode that for the first time a few years ago, and noted the quicker speed, and wondered why our bridges couldn't take that speed. Could be the equipment.

 

I blame the bridges lol...seeing as trains are way heavier than cars and trucks, the trains going too fast would cause the bridge to sway too much and that's not good. Plus going slower helps to balance stress on the bridge supports which is vital after years of neglect and deterioration.

[Y2Julio]

I blame the bridges lol...seeing as trains are way heavier than cars and trucks, the trains going too fast would cause the bridge to sway too much and that's not good. Plus going slower helps to balance stress on the bridge supports which is vital after years of neglect and deterioration.

It's not an issue of weight but rather weight distribution.

[SmallParkShuttle]

It's not an issue of weight but rather weight distribution.

 

Yeah, the Manhattan bridge is a perfect example of poor bridge design. Since the Manhattan is a suspension bridge, it has much more flexibility. With the tracks at the extreme egdes of the deck, the deck twists a lot when a train runs over the bridge, which is not good for the steel deck when it happens hundreds of times a day. The proper design would have had the tracks in the middle (like the Williamsburg or the Brooklyn - look for older pictures) so that the bridge doesn't twist as much under the load.

 

However, I believe that the speed restriction is due to the very steep grades of the bridge itself and the complex trackwork that follows after each portal - the turn to Canal St. and the Chrystie St connection on the west and the crazy Flatbush Ave Extension interlocking/tunnels.

[KTrainExp]

The proper design would have had the tracks in the middle (like the Williamsburg or the Brooklyn - look for older pictures) so that the bridge doesn't twist as much under the load.

 

The Williamsburg Bridge also has bad speed limits as well though.

[INDman]

The Williamsburg Bridge also has bad speed limits as well though.

 

Yes but that has little to do with the bridge its self and more to do with the collision that took place there in 1995.

[SmallParkShuttle]

The Williamsburg Bridge also has bad speed limits as well though.

 

That part I was referring to the structural aspect of the bridge, not the speed limits. The design governs the service life of the bridge. If the trains run slow or fast over it, it will have just about the same structural effect on the bridge, which for the Manhattan was localized failure of some members way before their life expectancy time.

[checkmatechamp13]

That part I was referring to the structural aspect of the bridge, not the speed limits. The design governs the service life of the bridge. If the trains run slow or fast over it, it will have just about the same structural effect on the bridge, which for the Manhattan was localized failure of some members way before their life expectancy time.

 

But if the train goes too fast, the sudden weight on one side of the bridge might be enough to snap a weak structural support, if the weight shifts suddenly to the side that the train is on.

[SmallParkShuttle]

But if the train goes too fast, the sudden weight on one side of the bridge might be enough to snap a weak structural support, if the weight shifts suddenly to the side that the train is on.

 

If we're talking about weight shifts, a train going 25mph will not cause a significantly slower weight shift than a train going 35mph; enough to cause a major change on structural behavior. Steel is a pretty strong material. The issue that might cause concern is impact loading from the wheels hitting the rail joints, which will happen at a more rapid rate and be more intense with increasing speed.

 

If there is concern of a support failing due to any kind of train loads, trains won't be running over the bridge, like they didn't do on the south side for over a decade.

 

The Manhattan bridge has some serious uphill and downhill grades that if a train were not to check its speed, can lose control and cause catastrophe at any of the sharp curves waiting at any portal at the ends of the bridge. Realize there's no timers on the uphill stretches? Speed is not a structural issue.

[Kingsbridge Bus]

My R68 actually beat an R160 across the bridge & was going about 5 mph faster

[bstar1]

My R68 actually beat an R160 across the bridge & was going about 5 mph faster

 

That R160 was probably slowing down, because they usually leave R68s in the dust.